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  • Life and Medical Sciences  (1,207)
  • Inorganic Chemistry  (668)
  • Industrial Chemistry
  • 1985-1989  (1,875)
  • 1950-1954
  • 1986  (1,875)
Collection
Keywords
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  • 1985-1989  (1,875)
  • 1950-1954
Year
  • 1
    Electronic Resource
    Electronic Resource
    Editorial (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 1-1 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060102
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  • 2
    Electronic Resource
    Electronic Resource
    A new model of reticulopodial motility and shape: Evidence for a microtubule-based motor and an actin skeleton (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 2-14 
    Details
    ISSN: 0886-1544
    Keywords: Allogromia ; reticulopods ; cytoskeleton ; microtubules ; actin ; saltatory transport ; cell shape ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cytoskeletal inhibitors were used as probes to test the involvement of microtubules and actin microfilaments in the development, motility, and shape maintenance of the pseudopodial networks (i e, reticulopodia) of the foraminifers Allogromia sp strain NF and Allogromia laticcllaris. Agents that disassemble cytoplasmic microtubules (cold, colchicine, and nocodazole) arrest all movement but have variable effects on reticulopodial shape. Electron microscopy reveals a granulofibrillar matrix but few, if any, microtubules in these motility-arrested reticulopods. Allogromiids treated with cytochalasin B or D lose substrate adhesion and undergo dramatic changes in shape and motile behavior, highlighted by the coalescence of reticulopodial cytoplasm into irregularly shaped bodies with chaotic motility. Serial semithick sections of such preparations, viewed by high-voltage electron microscopy, document a striking rearrangement of microtubules within these cytochalasin-induced bodies. All aspects of cytochalasin-altered motility are completely inhibited by colchicine. Actin is present in reticulopodia, as determined by staining with rhodamine-phalloidin; this staining is not observed in cytochalasin-treated organisms. These data provide compelling evidence that microtubules are required for reticulopodial motility. An actin-based cytoskeleton is thought to play a role in maintaining shape, mediating pseudopod/substrate adhesion, and coordinating the various microtubule-dependent processes.
    Additional Material: 7 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060103
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  • 3
    Electronic Resource
    Electronic Resource
    Towards a new classification of intracellular particle movements based on quantitative analyses (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 128-135 
    Details
    ISSN: 0886-1544
    Keywords: motion analysis ; axonal transport ; cytoplasmic transport ; Brownian motion ; AVEC-DIC microscopy ; saltatory particle motion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: A survey study of organelle movements in a variety of cell types of plant and animal origin was made with the aid of video-enhanced contrast, differential interference contrast (AVEC-DIC) microscopy followed by fine analysis of the motile behavior of the individual organelles. We found that there exists besides Brownian motion a wide spectrum of active motions in cells, i.e. motion that is directionally biased through the expenditure of metabolic energy. The types of active motion seen range from a continuous motion (sometimes appearing as streaming) in plant cells and neurons to various types of less ordered and less well directed motion. We did not see any clear-cut qualitative difference between plant and animal cells or between systems presumed to be actin- and microtubule-based. A preliminary classification of the types of active motion is presented. The ongoing research activities, which aim at a more precise definition of the different types of motion by a set of quantitative parameters, are described, and the progress made so far is reported.
    Additional Material: 3 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060210
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  • 4
    Electronic Resource
    Electronic Resource
    Intracellular particle motions (cytoplasmic streaming) in staminal hairs of Setcreasea purpurea: Effect of azide and low temperature (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 305-313 
    Details
    ISSN: 0886-1544
    Keywords: cytoplasmic streaming ; Setcreasea purpurea ; intracellular particle movements ; intercellular transport ; azide ; low temperature ; calcium ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Cytoplasmic streaming and its response to azide and low temperature were examined by using high-resolution video-enhanced light microscopy in Setcreasea purpurea staminal hair cells of immature flowers. Particles and organelles examined moved along well-defined pathways, in repeated and unequal saltatory steps, at different rates and sometimes against the main direction of flow (bidirectionally) in both transvacuolar strand and peripheral cytoplasm. Particle movements were reversibly inhibited with azide. Low temperatures caused transvacuolar strands to shift or break. This cytoplasm accumulated in areas outside of the vacuole where spherosomes continued to saltate, but not along well-defined pathways. In the peripheral cytoplasm, however, the spherosomes continued to move normally, amyloplasts became swollen, and they plus the other organelles (except spherosomes) were stationary. Normal particle movements were obtained when chilled cells were rewarmed to 27°C for ca 15 min.
    Additional Material: 8 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970060307
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  • 5
    Electronic Resource
    Electronic Resource
    Naturally occurring tubulin-containing paracrystals in Allogromia: Immunocytochemical identification and functional significance (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 363-375 
    Details
    ISSN: 0886-1544
    Keywords: Allogromia ; cytoplasmic transport ; microtubules ; reticulopod withdrawal ; tubulin-containing paracrystal ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Bundles of microtubules (MTs) are readily visualized in vivo by videomicroscopy in highly flattened reticulopodia of the foraminiferan protozoan Allogromia sp. strain NF. In this report we use videomicroscopy, immunocytochemistry, and high-voltage electron microscopy to characterize the dynamic changes that occur in this extensive MT cytoskeleton, and in the associated cytoplasmic transport, during induced withdrawal and subsequent reextension of reticulopodia. Within seconds after application of the withdrawal stimulus (seawater substitute made hypertonic with MgCl2) intracellular bidirectional transport along linear MT-containing fibrils ceases and is replaced by an inward, constant-velocity flow of cytoplasm along the fibrils. As withdrawal continues, most fibrils become wavy and coalesce to form phase-dense pools. These wavy fibrils and phase-dense pools contain a paracrystalline material and few if any MTs. Same-section correlative immunofluorescence and high-voltage electron microscopy reveal that the paracrystalline material contains tubulin. During recovery linear fibrils (MTs) rapidly extend from the phase-dense pools (paracrystals), which concurrently shrink in size, thus reestablishing normal network morphology and motility. We conclude that the MT cytoskeleton in Allogromia reticulopodia is transfonned during withdrawal into a tubulin-containing paracrystal, which serves as a temporary reservoir of MT protein and an initiation site for MT regrowth.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970060403
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  • 6
    Electronic Resource
    Electronic Resource
    Structure and composition of the cytoskeleton of nucleated erythrocytes: III. Organization of the cytoskeleton of Bufo marinus erythrocytes as revealed by freeze-dried platinum-carbon replicas and immunofluorescence microscopy (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 376-388 
    Details
    ISSN: 0886-1544
    Keywords: marginal band ; spectrin ; vimentin ; surface-associated cytoskeleton ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Platinum-carbon (Pt-C) replicas of freeze-dried erythrocyte cytoskeletons of the toad, Bufo marinus, were prepared using a modified Balzers 300 system. Examination in stereo of replicas of the microtubule-containing marginal band revealed filaments projecting from the microtubule walls to form links between adjacent microtubules. These cross-bridging proteins may bundle the microtubules into the configuration of the marginal band (MB) and may also serve to stabilize the structure. The MB appears to have linkages to components of the surface-associated cytoskeleton (SAC). The SAC forms a continuous matrix that spreads across the upper and lower surfaces of the cell adjacent to the plasma membrane and extends around the outer perimeter of the MB. Thus, the SAC encapsulates the MB and the central nucleus. After lysis, the elements of the cytoskeleton remain in a configuration similar to that found in the whole cell. Spectrin (fodrin) and actin were identified by immunofluorescence in the region of the SAC. When labeled with antibodies specific for vimentin and synemin, a network of intermediate filaments can be detected in the region between the nucleus and the MB. These vimentin filaments are also enclosed within the SAC and appear in Pt-C replicas to emerge from the area of the nuclear envelope. As the filaments extend toward the periphery of the cell, they form attachments to the SAC. Attachments of intermediate filaments to both the nucleus and the SAC thus appear to anchor the nucleus in its central position within the cytoskeleton.
    Additional Material: 11 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060404
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  • 7
    Electronic Resource
    Electronic Resource
    Masthead (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060501
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  • 8
    Electronic Resource
    Electronic Resource
    Kinetochore microtubules in crane-fly spermatocytes: Untreated, 2°C-treated and 6°C-grown spindles (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 428-438 
    Details
    ISSN: 0886-1544
    Keywords: kinetochores ; spindle apparatus ; anaphase ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We investigated the involvement of kinetochore microtubules (kMTs) in mediating chromosome-to-pole connections in crane-fly (Nephrotoma suturalis and Nephrotoma ferruginea) spermatocytes. Two experimental treatments were used to yield spindles with reduced numbers of nonkinetochore microtubules (nkMTs). Short-term (10-15 min) exposure of spermatocytes to 2°C caused depolymerization of the majority of nkMTs, resulting in a kMT:(kMT + nkMT) ratio of 0.76. Long-term (24h) exposure to 2°C followed by recovery at 6°C resulted in a kMT:(kMT + nkMT) ratio of 0.55, the spindle having more nkMTs than a 2°C-treated spindle but fewer than an untreated spindle, in which the kMT:(kMT + nkMT) ratio was 0.27. The numbers and lengths of kMTs in 6°C-grown spindles were similar to those in untreated cells, suggesting that the overall inhibition of MT assembly at 6°C apparently did not affect the mechanism by which kMTs are formed. We observed most kMTs of early anaphase spindles to be long (〉3 μm), and many extended to the polar regions of the spindle. Thus, the crane-fly spindle appears not to be as atypical as it was previously suggested to be.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970060408
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  • 9
    Electronic Resource
    Electronic Resource
    Effects of taxol on microtubule arrays in cultured higher plant cells (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 469-478 
    Details
    ISSN: 0886-1544
    Keywords: plant microtubules ; mitosis ; cytokinesis ; plant cell culture ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Treatment with 10 μm taxol disrupted mitotic and cytoplasmic arrays of microtubules (MT) in cultured cells of two higher plants, Vicia hajastana (vetch) and Zinnia elegans. When treated for 1, 24, and 48 h, cells in both cultures showed similar effects. After 1 h, multipolar arrays of MT were noted in prophase, large aster-like arrays of MT appeared in metaphase, and extra MT shared poles with otherwise normal-appearing metaphase and anaphase configurations. After 24 and 48 h, some phragmoplasts were multipartite or misplaced. In interphase cells, micronuclei and multinucleate cells were evidence of irregular mitosis and cytokinesis. Cytoplasmic MT in elongated cells were oriented parallel to, instead of at right angles to the long axis of the cell. Some interphase cells lost asymmetry while maintaining organized arrays of MT. Taxol appears to disrupt mitotic and cytoplasmic arrays of MT, seemingly overriding the mechanism(s) regulating MT polymerization and orientation.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970060505
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  • 10
    Electronic Resource
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    A protein of 175,000 daltons associated with striated rootlets in ciliated epithelia, as revealed by a monoclonal antibody (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 56-67 
    Details
    ISSN: 0886-1544
    Keywords: basal body ; centrosome ; ciliated epithelium ; ciliary rootlet ; cortex of metozoan ciliated cells ; monoclonal antibody ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Basal bodies from laying quail oviduct were semipurified and used as immunogen to produce monoclonal antibodies. On 38 clones obtained and among those staining the apical pole of the ciliated cell, CC-310 was chosen because it labeled the apical region with a punctated aspect, suggesting a staining of basal bodies or of basal body-associated structures; the basal pole was also labeled.The ultrastructural localization performed by the immunogold technique showed that the labeling was mainly associated with the striated rootlets. The basal feet, the side of the basal bodies, and the basal poles of the demembranated cells were also decorated. The identification of the antigen performed by immunoblots of deciliated cortices revealed two proteins of 175,000 and 40,000, whereas immunoblots of basal bodies showed only the 175,000-mw protein. The possibility of these two proteins sharing the same epitope, located at both poles of the cell, is discussed.Immunofluorescence ascertained that CC-310 decorated the striated rootlets in ciliated epithelia from other species: mussel, frog, and human tissue. Finally, when tested on cultured cell lines, CC-310 labeled the centrosome and its associated rootlets on PtK2 during interphase. During mitosis the poles of the mitotic spindle were stained without any apparent rootlet-like structure.
    Additional Material: 8 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060108
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  • 11
    Electronic Resource
    Electronic Resource
    Masthead (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060201
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  • 12
    Electronic Resource
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    The origin of flagella-autogenous or symbiontic? (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 96-98 
    Details
    ISSN: 0886-1544
    Keywords: microtubules ; evolution ; eukaryotes ; phagotrophy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Earlier hypotheses of the origin of flagella appear untenable in the light of recent evidence on the ancestry of eukaryotes. It is suggested that microtubules and flagella evolved early in eukaryote evolution to enhance phagotrophy.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060205
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  • 13
    Electronic Resource
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    Dynamic aspects of the contractile system in Physarum Plasmodium: II. Contractility of triton cell models in accordance with the contraction and relaxation phases of the plasmodia (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 448-457 
    Details
    ISSN: 0886-1544
    Keywords: cytoplasmic fibril ; birefringence ; microfilament ; contraction-relaxation cycle ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The contractility of Physarum plasmodium was investigated using cell models that were prepared by treating thin-spread plasmodia with ice-cold 0.2% Triton X-100. Cell models obtained from the anterior regions of the thin-spread plasmodia in the contraction phase retained many birefringent cytoplasmic fibrils. The fibrils vigorously contracted on addition of ATP, inducing simultaneous contraction of the whole cell models. In contrast, cell models prepared from the anterior regions in the relaxation phase scarcely contained the birefringent fibrils and exhibited only weak contractility on addition of ATP. The posterior regions of the thinspread plasmodia, which were composed of ramified plasmodial strands, always retained many fibrils when treated with the Triton solution and showed intensive contraction on addition of ATP.SDS-polyacrylamide gel electrophoresis showed that the model was enriched for actin and myosin. About 40% of the actin was extracted from the plasmodium by the Triton treatment, while scarcely any myosin was extracted.Fragmin, a F-actin-fragmenting factor, caused the birefringent fibrils to diminish in the presence of Ca2+, but more than 30 minutes was required for their complete disappearance. The birefringent fibrils weakened by 30-minute fragmin treatment disappeared immediately on addition of ATP or AMP-PNP.
    Additional Material: 9 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970060503
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  • 14
    Electronic Resource
    Electronic Resource
    Masthead (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060301
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  • 15
    Electronic Resource
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    Polarized microtubule gliding and particle saltations produced by soluble factors from sea urchin eggs and embryos (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 537-548 
    Details
    ISSN: 0886-1544
    Keywords: microtubules ; sea urchins ; kinesin ; mitosis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In this report, we describe an in vitro system for analyzing microtubule-based movements in supernatants of sea urchin egg and embryo homogenates. Using video enhanced DIC microscopy, we have observed bidirectional saltatory particle movements on native taxol-stabilized microtubules assembled in low speed supernatants of Lytechinus egg homogenates, and gliding of these microtubules across a glass surface. A high speed supernatant of soluble proteins, depleted of organelles, microtubules, and their associated proteins supports the gliding of exogenous microtubules and translocation of polystyrene beads along these microtubules. The direction of microtubule gliding has been determined directly by observation of the gliding of flagellar axonemes in which the (+) and (-) ends could be distinguished by biased polar growth of microtubules off the ends. Microtubule gliding is toward the (-) end of the microtubule, is ATP sensitive, and inhibited only by high concentrations of vanadate. These characteristics suggest that the transport complex responsible for microtubule gliding in S2 is kinesin-like. The implications of these molecular interactions for mitosis and other motile events are discussed.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970060602
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  • 16
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    Decoration of microtubules by fluorescently labeled microtubule-associated protein 2 (MAP2) does not interfere with their spatial organization and progress through mitosis in living fibroblasts (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 570-579 
    Details
    ISSN: 0886-1544
    Keywords: microinjection ; mitosis ; microtubule-associated proteins ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Microtubule-associated protein 2 (MAP2) derivatized with iodoacetamidotetramethylrhodamine or with iodoacetamidofluorescein binds to microtubules after injection into living interphase cells [Scherson et al, 1984]. The binding of derivatized MAP2 stabilized microtubules in vitro; it was therefore important to check if the binding of MAP2 in vivo perturbed the dynamics and organization of the microtubule network. We have addressed these questions by studying the effect of the injection of derivatized MAP2 on mitosis in PtK 1 cells and on the recovery of the microtubule network from low temperature incubation in interphase cells. We found that the presence of derivatized MAP2 did not change the duration of any mitotic stage and that the injected cell normally completed mitosis. We subsequently showed that the injected MAP2 bound to the microtubules within 5 minutes after injection and remained bound throughout the course of mitosis. The reorganization of the microtubule network upon cooling and rewarming was studied in the cytoplasm of human foreskin fibroblasts (356 cells). During the recovery, the distribution of the fluorescent MAP2 in living cells was identical with the microtubule pattern visualized by immunofluorescence in lysed and fixed cells.In these experiments, the fluorescent MAP2 bound to microtubules can be considered as a nonperturbing reporter of the microtubule network. This result is discussed in terms of the role of MAPs in the dynamics and organization of microtubules in living cells.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970060605
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  • 17
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    Slow pulsatile movements of Schwann cells in vitro: A time-lapse cinemicrographic study (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 595-603 
    Details
    ISSN: 0886-1544
    Keywords: tissue culture ; Swann cell ; pulsatile movement ; time-lapse cinemicrography ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Slow pulsatile movements of Schwann cells in vitro were studied quantitatively by using time-lapse cinemicrography. Schwann cells from peripheral nerves of 3-day-old rats were cultured in serum-free medium. Most Schwann cells showed intermittent episodes of pulsatile movement; each episode consisted of one or several contractile pulses. About half of the episodes consisted of a single pulse, and episodes with more than four pulses were rare. The average episode of activity lasted 2.6 min, while the average duration of a single pulse was 1.5 min. The mean quiescent interval between episodes of activity was 3.7 min. Some cells showed no pulsatile activity. Active cells averaged 6.6 episodes/h. The fraction of time which a Schwann cell spent in pulsatile activity varied widely, with an average of 28%. Behavior of Schwann cells in HEPES-buffered Hanks saline was generally similar to that in the complete medium. Raising K+ to 40 mM or Ca++ to 10 mM did not markedly affect the time course of the pulsatile motility, although the contractions were more vigorous in the high Ca++. Pulsatile movement was reversibly inhibited by cytochalasin B and appeared to be potentiated by drugs that disrupt microtubules.
    Additional Material: 5 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970060608
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  • 18
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    Antigenic interrelationship between the 40-kilodalton cytokeratin polypeptide and desmoplakins (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 628-639 
    Details
    ISSN: 0886-1544
    Keywords: monoclonal antibody ; cytokeratins ; desmoplakins ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We describe here antigenic cross-reactivity between the human 40-kilodalton cytokeratin polypeptide [Moll et al] and components of bovine desmosomal plaque, namely desmoplakins I and II. This relationship was revealed by an antibody (KM 4.62), raised against cytoskeletal preparation of cultured human breast adenocarcinoma cells (MCF-7) and selected by immunoblotting and immunofluorescent labeling. In cultured human cells that contain the 40-kD cytokeratin, antibody KM 4.62 labeled arrays of filaments throughout the cytoplasm. This antibody labeled the basal layer of nonkeratinizing squamous epithelia as well as various simple (normal and malignant) epithelia and epithelial elements of the thymus. In liver tissue, labeling was obtained only in bile ducts and canaliculi but not in the hepatocytes.In bovine cells and tissues, on the other hand, immunofluorescent labeling with antibody KM 4.62 was strictly confined to desmosomes. This was verified by double immunolabeling with both antibody KM 4.62 and specific cytokeratin or desmosomal antibodies. Immunoblotting analysis indicated that the former antibody reacts specifically with the high molecular weight components of the bovine desmosomal plaque, namely desmoplakins I and II. These immunochemical results suggest that bovine desmoplakins share same structural relationship with the human acidic, 40-kD cytokeratin.
    Additional Material: 7 Ill.
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    URL: http://dx.doi.org/10.1002/cm.970060611
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  • 19
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    Erratum (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 674-678 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060615
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  • 20
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    Characterization of alpha-actinin from Acanthamoeba (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 649-661 
    Details
    ISSN: 0886-1544
    Keywords: actin ; gelation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Characterization of a protein from Acanthamoeba that was originally called gelation protein [T.D. Pollard, J. Biol. Chem. 256:7666-7670, 1981] has shown that it resembles the actin filament cross-linking protein, alpha-actinin, found in other cells. It comprises about 1.5% of the total amoeba protein and can be purified by chromatography with a yield of 13%. The native protein has a molecular weight of 180,000 and consists of two polypeptides of 90,000 Da. The Stokes' radius is 8.5 nm, the intrinsic viscosity is 0.35 dl/dm, and the extinction coefficient at 280 nm is 1.8 × 105M-1·cm-1. Electron micrographs of shadowed specimens show that the molecule is a rod 48 nm long and 7 nm wide with globular domains at both ends and in the middle of the shaft. On gel electrophoresis in sodium dodecylsulfate the pure protein can run as bands with apparent molecular weights of 60,000, 90,000, 95,000, or 134,000 depending on the method of sample preparation. Rabbit antibodies to electrophoretically purified Acanthamoeba alpha-actinin polypeptides react with all of these electrophoretic variants in samples of purified protein and cell extracts. By indirect fluorescent antibody staining of fixed amoebas, alpha-actinin is distributed throughout the cytoplasmic matrix and concentrated in the hyaline cytoplasm of the cortex. The protein cross-links actin filaments in the presence and absence of Ca++. It inhibits slightly the time course of the spontaneous polymerization of actin monomers but has no effect on the critical concentration for actin polymerization even though it increases the apparent rate of elongation to a small extent. Like some other cross-linking proteins, amoeba alpha-actinin inhibits the actin-activated ATPase of muscle myosin subfragment-1. Although Acanthamoeba alpha-actinin resembles the alpha-actinin from other cells in shape and ability to cross-link actin filaments, antibodies to amoeba and smooth muscle alpha-actinins do not cross react and there are substantial differences in the amino acid compositions and molecular dimensions.
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    Incorporation and turnover of labeled exogenous tubulin in the mitotic spindles of Chaetopterus oocytes and HeLa cells (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 114-121 
    Details
    ISSN: 0886-1544
    Keywords: mitosis ; microtubules ; tubulin incorporation ; assembly polarity ; Chaetopterus ; HeLa cells ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The incorporation of tubulin into mitotic spindles in situ was studied by incubating permeabilized mitotic cells in solutions containing [3H]GTP-labeled or dichlorotriazinylamino fluorescein (DTAF)-labeled tubulin. Metaphase HeLa cells or spindle-containing “minicells” from Chaetopterus oocytes were lysed in a microtubule-assembly buffer plus 0.5% Nonidet P-40, 1 mg/ml 120,000g supernatant mammalian brain tubulin, and [3H]GTP. After different periods of incubation, mitotic spindles were isolated in 2 M-glycerol-containing assembly buffer and separated from unbound counts by centrifugation through a 4 M-glycerol cushion; 3H counts per mg protein increase linearly for 8-12 min and then reach a plateau or steady state in both Chaetopterus oocytes and HeLa cells. Addition of 4 mM CaCl2 blocks or reverses incorporation. Little or no [3H]GTP is incorporated if exogenous tubulin or lysed cells are omitted from the assembly mixture.To measure the loss rate of [3H]GTP-tubulin from mitotic spindles, cells were incubated in tubulin plus [3H]GTP for 30 min, and a 20-fold excess of cold GTP (2 mM) was added. Samples were removed after incubation for different periods, and spindles were isolated as described above and counted for 3H content. [3H]GTP is lost from spindles at a rate of about 16%/min until a new steady state is reached in about 8 min. These results are consistent with an incorporation and turnover of [3H]GTP-tubulin in spindle microtubules of these lysed-cell models.The location of this newly incorporated tubulin in the spindle was investigated by incorporating fluorescent DTAF-tubulin into mitotic spindles of these lysed cell types. A short pulse (2-5 min) appears to label microtubules (MTs) near metaphase chromosomes and longer exposures label the entire spindle.The rates of incorporation and turnover that we see by [3H]GTP and fluorescent tubulin incorporation in situ are faster than those observed with brain MTs at steady state in vitro but are in the range of the rates of spindle fiber formation in prophase, and spindle MT reassembly after cooling.
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    URL: http://dx.doi.org/10.1002/cm.970060208
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    Calcium-modulated contractile proteins associated with the eucaryotic centrosome (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 193-197 
    Details
    ISSN: 0886-1544
    Keywords: centrosome-associated proteins ; calcium-binding proteins ; flagellar apparatus ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Affinity-purified antibodies that recognize the 20,000-dalton molecular weight (20 kd) striated flagellar root protein of Tetraselmis striata have been used to identify antigenic homologs in other eucaryotic organisms of diverse evolutionary origins. Among the green algae, Tetraselmis and Chlamydomonas, and their colorless relative, Polytomella, the 20-kd homologs appear associated with basal bodies. This occurs most prominnently in the form of flagellar roots of both striated and microtubule subtended types. Among cultured mammalian cells (PtK2 and primary mouse macrophage cell lines), flagellar root protein homologs appear as basal feet, pericentriolar fibrils, and pericentriolar satellites. Mammalian sperm cells also show flagellar root protein homologs associated with their basal bodies. We envisage a functional role for these fibrous calcium-sensitive contractile proteins in altering the orientation of centrioles or basal bodies with their associated MTOCs by responding to topological calcium fluxes.
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    URL: http://dx.doi.org/10.1002/cm.970060218
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    A model for the molecular basis of filament contractility and sliding as demonstrated by helix models (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 229-236 
    Details
    ISSN: 0886-1544
    Keywords: α-helix ; filament motility ; filament contractility ; filament sliding ; microtubules ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The twisting behavior of α helices has hardly been considered hitherto with regard to the function of proteins. The well-known electrostatic repulsion between the highly charged side chains, which depends on their interaction with ions, is absolutely connected with torsional rotations of the helix as long as its hydrogen bonds hold. This means a direct transformation of chemical into mechanical energy. However, the stability of a twisted single α helix with charged side chains is low in an aqueous environment. It may easily ball up to form a globular molecule with nonhelical regions of the polypeptide chain. This corresponds to a primitive contraction that obviously occurs with spasminlike proteins that contain strongly twisted filaments as Salisbury [J. Submicrosc. Cytol. 15:105-110, 1983] has shown. Steps that increase the stability and rigidity of α helical filaments are (1) the formation of coiled-coils, (2) self-intertwining (“telephone cord phenomenon”) or intertwining with other coiled-coils as shown with the intermediate filaments, and (3) association with cytoskeletal elements (microfilaments, protofilaments of microtubules) that contain globular subunits. These coarser elements are rotated by winding and unwinding of the smaller helical molecules and thus transmit the torsion produced in the α helices to the microscopic level by the sliding (screwing) motion and the shearing effect that is connected with the waves of a rotating helix. Particles are transported if connected to the helical side arms. Since the displacement of the side arms seems to occur along the single protofilaments of a microtubule, a rotation of these protofiiaments is suggested. The bidirectional transport of particles along single microtubules may be explained by the association of left- and right-handed helices with the protofilaments. According to the models, parallel and antiparallel sliding of neurofilaments and neurotubules is suggested.
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    URL: http://dx.doi.org/10.1002/cm.970060223
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    Rearrangement of tubulin, actin, and myosin in cultured ventricular cardiomyocytes of the adult rat (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 291-304 
    Details
    ISSN: 0886-1544
    Keywords: cytoskeleton ; microtubule ; microfilament ; adult ; culture ; cardiac ; myocyte ; immunofluorescence ; antibodies ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Antitubulin, phalloidin. and antimyosin were used to study the distribution of microtubules, microfilaments, and myofibrils in cultured adult cardiomyocytes. These cells undergo a stereotypic sequence of morphological change in which myotypic features are lost and then reconstructed during a period of polymorphic growth. Microtubules, though rearranged during these events in culture, are always present in an organized network. Myosin and actin structures, on the other hand, initially degenerate. This initial degeneration is reversed when a cell attaches to the culture substratum. Upon attachment, new microtubules are laid down as a cortical network adjacent to the sarcolemma and, subsequently, as a network in the basal part of the cell. Actin and then myosin filament bundles appear next, in a pattern corresponding to the pattern of the microtubules. Finally, striated myofibrils are formed, first in the central part of the cell, and subsequently in the outgrowing processes of the cell, A mechanism is suggested by which the eventual polymorphic shape of a cell is related to the shape of its initial area of contact with the culture substratum. Finally, a model of myofibrillogenesis is proposed in which microtubules participate in the insertion of myosin among previously formed actin filament bundles to produce myofibrils.
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    Computer simulation of bend propagation by axoplasmic microtubules (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 347-353 
    Details
    ISSN: 0886-1544
    Keywords: axoplasmic transport ; flagella ; microtubule ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The generation of bending waves by microtubules in squid nerve axoplasm has been modelled using appropriately modified versions of computer programs developed previously for simulation of flagellar bending waves. The results confirm that a constant longitudinal force directed along the axis of the microtubule is sufficient to cause the generation of regular oscillations and propagated bending waves when the forward gliding movement of the microtubule is obstructed. No control mechanism is required to modulate the active force-generating system. In order to obtain bending waves similar to those observed experimentally, it was necessary to use a model for the force-generating system in which the active force decreases with increasing sliding velocity. If the elastic bending resistance of axoplasmic microtubules is similar to that of microtubules in sperm terminal filaments, the longitudinal force per unit length generated by the axoplasmic microtubules must be of the same order of magnitude as the force generated by dynein arms along the doublet microtubules of eukaryotic flagella.
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    URL: http://dx.doi.org/10.1002/cm.970060311
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    Influence of translocation track on the motion of intra-axonally transported organelles in human nerve (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 339-346 
    Details
    ISSN: 0886-1544
    Keywords: axonal transport ; human nerve ; video-enhancement ; digital image processing ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The mechanism by which organelles are transported bidirectionally in axoplasm is still unknown; however, evidence of a key role for microtubules in many nonmammalian models has been established. We have observed common or shared tracks within the axoplasm of human nerves along which multiple organelles of varying size and shape are bidirectionally transported. Organelles traveling anterogradely and retrogradely were visualized by video-enhanced differential interference contrast optics and analyzed with the aid of computer-image-processing techniques.Speeds of translocating organelles were determined at eight to 16 translocation points along a path or “track.” Each translocation speed was plotted against its corresponding position on the track to develop a “speed/position diagram.” Regardless of mean organelle speed or direction of motion, organelles sharing a common track exhibited similar patterns of “speeding up” and “slowing down” relative to position along the track. Speed position data for organelles translocating the local axonal region of a common track showed no unique patterns (not different from a uniform distribution, p 〈 0.05). The unique speed/position patterns exhibited by common tracks were not necessarily related to the patterns of other tracks in the immediate vicinity (distance between tracks of 〈 0.50 μm). These findings suggest that (1) there are “common tracks” shared by organelles moving retrogradely and anterogradely; (2) both the organelles and the “track” associated with its translocation play a role in the resultant motion of that organelle; (3) the influence exerted by a common track on the motion of an organelle results in a pattern of speed changes related to position along the track.
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    URL: http://dx.doi.org/10.1002/cm.970060310
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    Masthead (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060401
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    Independence of centriole formation and initiation of DNA synthesis in Chinese hamster ovary cells (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 355-362 
    Details
    ISSN: 0886-1544
    Keywords: centriole ; DNA synthesis ; cell cycle ; Chinese hamster ovary cells ; taxol ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The relationship between centriole formation and DNA synthesis was investigated by examining the effect of taxol on the centriole cycle and the initiation of DNA synthesis in synchronized cells. The centriole cycle was monitored by electron microscopy of whole-mount preparations [Kuriyama and Borisy, J. Cell Biol., 1981, 91:814-821]. A short daughter centriole appeared in perpendicular orientation to each parent during late G1 or early S and elongated slowly during S to G2. Addition of 5-20 μg/ml taxol to a synchronous population of cells in S phase did not inhibit centriole elongation; rather, elongation was accelerated. In contrast, when taxol was added to M phase or early G1 cells, centriole duplication was completely inhibited. The taxol block was reversible since nucleation and elongation of centrioles resumed as soon as the drug was removed. Cells exposed to taxol progressed through the cell cycle and became blocked in mitosis, as indicated by an increase in the mitotic index, but eventually the mitotic arrest was overcome, resulting in formation of multinucleated cells. A peak in mitotic index was seen in the following generation, indicating that chromosomes duplicated in the presence of taxol. Incorporation of 3H-thymidine followed by autoradiography confirmed that DNA synthesis was initiated in the presence of taxol even though formation of daughter centrioles was inhibited. It seems, therefore, that centriole duplication is not a prerequisite for entry into S phase. Since DNA synthesis has already been demonstrated not to be necessary for centriole duplication, these two events, normally coordinated in time, appear to be independent of each other.
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    Relationship between intermediate filaments and microfilaments in cultured fibroblasts: Evidence for common foci during cell spreading (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 406-418 
    Details
    ISSN: 0886-1544
    Keywords: Intermediate filaments ; microfilaments fibroblast cell spreading ; focal center ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Spreading and fully spread chick embryo fibroblasts (CEF) were examined by double-label fluorescence microscopy using the actin-specific probe rhodamine-phalloidin and an antibody directed against CEF intermediate filaments (IF). During midspreading, a striking relationship became discernible: statistical analysis showed that approximately half of the cell population exhibited one or more phase-dense, phalloidin-binding nodules that appeared to act as foci from which IF diverged. Coincidence between actin-containing structures and IF was not limited to these centers; IF could also frequently be seen running in close parallel arrays with stress fibers.Ultrastructural analysis confirmed the presence of non-membrane-bound out-pocketings along the length of stress fibers from which 10-nm IF diverged. These structures varied in size and shape, and displayed a dense, fine fibrillar appearance. IF and microfilaments (MF) were distinguished by size and by decoration of MF with myosin subfragment-1. Other IF-MF interactions were seen in cells of all stages: IF were observed to loop through stress fibers, most frequently at the cell margins. In colchicine-treated cells, IF became redistributed into cables that often ran parallel and appeared to merge with stress fibers. Cytochalasin D-treated CEF exhibited loose aggregates of actin-containing material that appeared to be associated with IF.These results suggest the possibility of an interaction between actin-containing structures and IF, particularly during cell spreading in cultured fibroblasts.
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    Dynamic aspects of the contractile system in Physarum Plasmodium: I. Changes in spatial organization of the cytoplasmic fibrils according to the contraction-relaxation cycle (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 439-447 
    Details
    ISSN: 0886-1544
    Keywords: dynamics of actomyosin fibril ; microfilament bundle ; NBD-phallacidin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Dynamic changes in the spatial organizations of cytoplasmic fibrils (microfilament bundles) related to the contraction-relaxation cycle in thin-spread plasmodia of Physarum polycephalum were investigated by fluorescence microscopy, where NBD-phallacidin was used to stain the fibrils, combined with polarizing light microscopy.The fibrillar organization in the anterior region, which consists of a fanlike spreading plasmodial sheet, strikingly changed according to the phase of the cycle. In the early stage of the contraction, as the endoplasm began to stream backward, the fibrils developed into a number of slender and flabby fibrils emanating from the inside of the cell membrane and the nodes. They became thicker and more straightforward fibrils running parallel to each other at the middle stage, and finally formed a thick framework consisting of a “polygonal network” near the tip of the migrating front and a “parallel array” in the inner part. In the relaxation phase, as the endoplasm streamed forward, the fibrillar framework disintegrated gradually and finally disappeared almost completely, remaining only around the nodes in some cases.The fibrillar patterns in the posterior region, which consists of ramified strands, showed no conspicuous rhythmic change with alternation of the streaming direction.
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    Masthead (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060101
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    Fungal nuclear behavior analysed by ultraviolet microbeam irradiation (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 35-47 
    Details
    ISSN: 0886-1544
    Keywords: microbeam ; microtubules ; nucleus ; cytoskeleton ; motility ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: During hyphal tip growth in the fungus Basidiobolus magnus, nuclei normally maintain a constant distance from the advancing cell apex by continuously migrating forward. It is not known whether the mechanism that produces nuclear movement also mediates nuclear positioning, or whether these two processes are under separate control. By irradiating small cytoplasmic regions with an ultraviolet microbeam, the coordination between movement and positioning could be disrupted. Regardless of the distance of the target from the nucleus, anterior irradiations (those ahead of the nucleus) caused the nucleus to stop or move backwards, whereas posterior (behind the nucleus) irradiations caused an acceleration in the nuclear velocity. The nucleus retained its ability to move following irradiation, so there was only loss of control over normal positioning. These results suggest that movement and positioning are mediated by different mechanisms. Quantitative microtubule analysis demonstrated that microtubules in the target region had been depolymerized, but in other regions of the cell they were apparently normal. We suggest that the depolymerization of microtubules affects nuclear movement by altering the tensile strength of the cytoplasm, and that cytoskeletal tension mediate nuclear positioning.We also found that accelerated nuclear movement could occur when most of the microtubules surrounding the nucleus were depolymerized. A comparison of the microtubule population surrounding the nucleus in unirradiated versus irradiated cells suggested that microtubules move with nuclei. Therefore, the nucleus does not appear to move via a direct interaction with microtubules.
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    Evidence for functional differences between two flagellar dynein ATPases (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 586-594 
    Details
    ISSN: 0886-1544
    Keywords: sea urchin sperm ; motilily ; two dynein ATPases ; force generation ; power output ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Energy coupling in flagellar motility was investigated using demembranated, reactivated sea urchin spermatozoa (Arbacia punctulata). The ATP-dependence of ATPase activity was investigated for ATP concentrations ranging from 4 μM to 600 μM ATP. Using Eadie-Scatchard plot analysis, we identified two axonemal dynein ATPase activities. Their apparent Michaelis constants were calculated to be equal to 4 μM and 161 μM ATP, and they were referred to, respectively, as the high-affinity dynein ATPase (HADA) and the low-affinity dynein ATPase (LADA). Investigation of movement-coupled ATPase activity (difference between the ATPase activities of reactivated and broken, immotile spermatozoa) indicated that HADA and LADA were both 65% movement-coupled. The apparent Michaelis constants of movement-coupled HADA and LADA, 12 μM and 271 μM ATP, respectively, were two- to four-fold greater than the apparent Michaelis constants of movement-uncoupled HADA and LADA. The apparent Michaelis constants for force generation and beat frequency of reactivated spermatozoa were determined to be 24 μM and 290 μM ATP, respectively. These results raise the possibility that flagellar force generation is controlled primarily by movement-coupled HADA, and that flagellar beat frequency is controlled primarily by movement-coupled LADA. Thus, mechanochemical activity in flagellar motility may be divided between two enzymatically and functionally distinct classes of flagellar dyneins.
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    Evidence for regulation of lamellipodial and tail contraction of glycerinated chicken embryonic fibroblasts by myosin light chain kinase (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 640-648 
    Details
    ISSN: 0886-1544
    Keywords: cell model ; lamellipodia ; phosphorylation ; Ca2+-dependent contraction ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Permeabilized cell models of muscle and nonmuscle cells have proven useful for examining the regulation of actin, myosin, and other cytoskeletal proteins during cell contraction. Upon addition of Ca2+ and ATP, glycerinated chick embryonic skin fibroblasts retract their tails and lamellipodia. Ca2+-independent contractions are obtained by preincubation of cell models in Ca2+ ATPγS, followed by EGTA and ATP addition, or by addition of trypsin-treated myosin light chain kinase that no longer requires Ca2+ for reactivation. By pretreating cells before glycerination with colchicine, it is possible to study lamellipodial contraction independent of tail contraction. Similar responses to ATPγS pretreatment and unregulated myosin light chain kinase are observed in cells that only contain lamellipodia. SDS-PAGE electrophoresis of glycerinated fibroblasts incubated in ATPγ35S and Ca2+ shows that only two major proteins are thiophosphorylated, and that one of them, a band that comigrates with the 20K MW light chain of myosin, is thiophosphorylated in a Ca2+-dependent manner. Since the rate of tail contraction is several-fold faster after Ca2+ and ATPγS pretreatment or incubation in excess myosin light chain kinase, myosin light chain phosphorylation may be a rate-limiting step during contraction.
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    Video analysis of chemotactic locomotion of stored human polymorphonuclear leukocytes (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 485-491 
    Details
    ISSN: 0886-1544
    Keywords: PMN chemotaxis ; PMN storage ; PMN locomotion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Previous studies of the storage of polymorphonuclear leukocytes (PMNs) have used an empirical approach to define “optimal” conditions. To date, no storage conditions have been described which satisfactorily preserve the chemotactic function of PMNs beyond 24 h. In an effort to define the precise nature of the storage lesion, we studied the chemotactic locomotion of freshly isolated PMNs and PMNs which had been suspended in citrate-phosphate-dextrose-adenine (CPD-Al) plasma and stored in PVC bags, at 20-22°C for 24 h. We used time-lapse video recording and computer image analysis to quantitate the motion of PMNs migrating under agarose. The positions of individual motile cells were traced at 1-min intervals for 5 min. The following parameters were used to quantitate migration: (1) speed (distance/min), (2)) persistence of locomotion index (velocity/speed), (3) orientation angle (the angle of the vector describing the next displacement of a cell relative lo a direct line toward the chemoattractant), and (4) chemotropic index (cosine of the orientation angle). After 24 h of storage, the following changes were observed: (1) fewer cells migrated, (2) (he speed of migrating cells was reduced by 25%, (3) the persistence of locomotion index decreased by 7%, which indicates that migrating cells made slightly more/wider turns, and (4) the chemotropic index was decreased by 30%, which indicates that migrating cells were less accurate in their orientation toward the chemoattractant. Apparently, the storage of PMNs selectively impairs the ability of some cells to orient accurately in a chemotactic gradient and changes the distribution of these locomotor parameters within the population.
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    Theoretical analysis of radioactivity profiles during fast axonal transport: Effects of deposition and turnover (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 620-627 
    Details
    ISSN: 0886-1544
    Keywords: radiolabeled organelle profile ; retrograde transport system ; anterograde transport system ; turnover ; nodes of Ranvier ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In a preceding study [Blum, J.J., and Reed, M.C. (1985): Cell Motil. 5:507-527], factors responsible for the shape and velocity of the leading edge of the radiolabeled organelle profile were analyzed, but processes that might influence the shape of the plateau-like region behind the advancing wave were ignored. It is now shown that deposition of material from the fast transport system into membrane-associated structures, degradation of such deposited material and its return to the soma by the retrograde transport system, or leakage of radiolabeled material from the axon can account for the shape of the plateau. Furthermore, these processes are compatible with the maintenance of such structural inhomogeneities as the nodes of Ranvier.
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    Calmodulin and caimodulin-binding proteins in the morphological transformation of sea urchin coelomocytes (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 604-619 
    Details
    ISSN: 0886-1544
    Keywords: coelomocytes ; cytoskelton ; calmodulin-binding proteins ; alpha-spectrin ; shape transformation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Sea urchin coelomocytes contain an actin-based cytoskeleton that undergoes major organizational changes as the cells transform from one morphology (petaloid) to another (filopodial). The molecular mechanisms directing and regulating this cytoskeletal reorganization are not well understood; Ca2+ has been implicated, but the specific targets of its action have not been identified. Since the effect of Ca2+ on a variety of cellular processes has been shown to be mediated by the Ca2+-binding protein calmodulin, we investigated the role of this protein in coelomocyte morphological transformation. The calmodulin inhibitory drugs trifluoperazine, chlorpromazine, and calmidazolium were shown to inhibit coelomocyte morphological transformation in response to hypotonic shock in a dosedependent fashion and at concentrations consistent with their reported potencies as anti-calmodulin agents. Calmodulin isolated from coelomocytes using trifluorophenothiazine affinity chromatography co-migrates with bovine brain calmodulin on 15% SDS-polyacrylamide gels and demonstrates a characteristic shift in electrophoretic mobility in the presence of Ca2+. Another diagnostic for calmodulin, Ca2+-dependent activation of exogenous 3':5' cyclic AMP phosphodiesterase, was demonstrated by whole coelomocyte homogenates, heat-treated homogenates, and the affinity purified coelomocyte protein. Localization of calmodulin in coelomocytes by indirect immunofluorescence reveals an association of calmodulin, at least in part, with the actin-based cytoskeleton. Calmodulin-binding polypeptides with estimated relative mobilities of 240,000, 195,000, 170,000, 70,000, 60,000, 30,000, and 20,000 daltons were identified using 125I-calmodulin overlay procedures. Ca2+-dependent calmodulin-binding in these preparations was demonstrated for all but the Mr 30,000 and 20,000 coelomocyte polypeptides. The majority of the calmodulin-binding proteins identified in whole petaloid coelomocyte preparations are also found in Triton X-100 insoluble cytoskeletal fractions. Immunoblotting with antiserum raised against chicken erythrocyte alpha-spectrin suggests that the 240,000 Mr calmodulin-binding polypeptide corresponds to coelomocyte alpha-spectrin. This protein was enriched in isolated coelomocyte filopodia where, we propose, it serves an analogous function to its counterpart in erythrocytes, in linking the actin-cytoskeleton to the plasma membrane. Thus, calmodulin is present in coelomocytes and possibly participates in the morphological transformation of these cells through regulation of cytoskeletal and/or membrane-cytoskeletal interactions.
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    Actomyosin dynamics in chemotactic amoeboid movement of Dictyostelium (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 662-673 
    Details
    ISSN: 0886-1544
    Keywords: motility ; chemotaxis ; myosin ; cytoskeleton ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Under some physiological conditions, amoeboid cells are known to display a vectorial movement in response to chemotactic signals. Recent cell biological studies demonstrated the establishment of myosin filaments in Dictyostelium and indicate that the site of the motive force production is primarily localized at the posterior cortex. Furthermore, the traction force at the side body of a polarized amoeba is thought to play an essential role for the amoeboid movement. It is also suggested that certain dynamic activities of the actomyosin-based cytoskeletal system are related to the establishment of mechanochemical transducing elements transiently organized during the chemotaxis. This review focuses on recent selective studies on the chemotactic movement of Dictyostelium, which is coupled with rapid redistribution of myosin filaments, and probably mediated by a transient phosphorylation of myosin.
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    Effects of colcemid and taxol on microtubules and intermediate filaments in chick embryo fibroblasts (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 324-338 
    Details
    ISSN: 0886-1544
    Keywords: microtubules (MTs) ; Intermediate Filaments (IFs) ; taxol ; Colcemid ; IF-cables ; IF-skeins ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Reports on how changes in microtubule (MT) distribution or polymerization affect the distribution of intermediate filaments (IFs) differ. Therefore, we have used cytoimmunofluorescence techniques and electron microscopy to systematically examine and compare the arrangements of MTs and IFs in cultures of chick embryo fibroblasts under the following conditions: at different times during the cell cycle, in the presence of Colcemid or of taxol, in the presence of both drugs in succession or simultaneously in varying ratios, and during recovery from treatment with Colcemid or taxol.We have found that depolymerization of MTs by 1 μM Colcemid resulted in the rapid formation of massive IF-cables, structures distinct from “collapsed IFs” or “juxtanuclear coils.” Neither the rapid formation of IF-cables nor their dispersion during recovery required protein synthesis. Cells treated with 10 μM taxol rapidly formed MT-bundles, as well as aggregates of intertwining IFs, termed “IF-skeins.” MT-bundles and IF-skeins displayed strikingly complementary distributions. This reciprocal distribution of packed MTs and IFs was also obvious in untreated anaphase and telophase cells. When 10 μM taxol and 1 μM Colcemid were applied simultaneously, the complementary distributions of MT-bundles and IF-skeins mimicked those in taxol alone. This ability of taxol to block Colcemid's effects was concentration dependent Decreasing the taxol:Colcemid ratio allowed the depolymerization of MTs, which correlated with the formation of IF-cables.
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    Evidence for an interaction between the cell surface and intermediate filaments in cultured fibroblasts (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 389-405 
    Details
    ISSN: 0886-1544
    Keywords: cell membrane complex ; extracellular matrix ; fibronectin ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Intermediate filaments (IF) were found in close proximity to the plasma membrane in substrate attached baby hamster kidney cells (BHK-21) and chick embryo fibroblasts (CEF) as well as cells removed from their substrate in the absence of trypsin. However, in cells removed with trypsin, it appeared that IF had retracted away from the membrane. In cells with abundant extracellular matrix (ECM), colchicine induced massive cables of IF, which appeared to interact with specialized areas of the inner plasma membrane. In cells lysed to extract most microfilaments and cytoplasmic constituents, the intact IF network which remained was closely associated with the ECM. From these ultrastructural observations it was concluded that IF interact in some way with a “cell membrane complex” defined as comprising the plasma membrane and molecules attached to its inner and outer surfaces.In order to investigate the possibility that components of the membrane complex may co-isolate with IF, native intermediate filaments (NIF) were prepared. In addition to the structural subunits and other associated polypeptides, a ∼220 kd species which reacted specifically with antibodies directed against the ECM protein fibronectin (FN) was observed; 220 kd was still present after NIF were isolated under pH conditions where FN is more soluble, suggesting that its presence was not simply due to the coprecipitation of two insoluble proteins. Immunofluorescence and immunogold localization confirmed that FN is a component of the cell membrane complex with which IF appeared to interact.
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    Malorientation and abnormal segregation of chromosomes during recovery from Colcemid and Nocodazole (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 419-427 
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    ISSN: 0886-1544
    Keywords: colcemid ; nocodazole ; kinetochores ; microtubules ; spermatocytes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Reversal of meiotic arrest in crane-fly spermatocytes by U.V. irradiation of Colcemid-arrested cells or by rinsing Nocodazole-arrested cells in fresh buffer results in the induction of chromosome malorientation. Malorientations observed among Colcemid-recovering and Nocodazole-recovering spermatocytes at frequencies higher than normally observed in untreated cells included associations of sister kinetochores of half-bivalents with both spindle poles (amphitely), in contrast with associations of sisters with only one pole (syntely) as is usually found during the first meiotic division. In several cases, prior to anaphase onset, maloriented bivalents appeared unusually tilted with respect to the spindle axis, and during anaphase they gave rise to laggard half-bivalents that did not segregate during anaphase along with half-bivalents having proper syntelic orientation. The results parallel previous findings obtained during cold recovery, and the properties of the drugs used here suggest that their action on microtubules, although reversible, induces malorientation during recovery from meiotic arrest.
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    Effects of pteridines on the filopodia of Dictyotelium discoideum vegetative amoebae (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 479-484 
    Details
    ISSN: 0886-1544
    Keywords: motility ; chemotaxis ; chemoattractant ; cytoskeleton ; folic acid ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Living vegetative amoebae of NC-4H Dictyostelium discoideum were studied to determine if a variety of pteridines had any effect on the filopodia. We observed that production, elongation, and branching of these filopodia were stimulated by pteridines that are chemoattractants for cells of this strain. This stimulation occurs at chemotactically effective concentrations and is observed before motility is evident. A relationship between filopodia and chemoattractant signal processing is discussed.
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    Rhamnolipid from Pseudomonas aeruginosa inactivates mammalian tracheal ciliary axonemes (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 502-509 
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    ISSN: 0886-1544
    Keywords: respiratory cilia ; dynein ; ATPase ; cystic fibrosis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Isolated ciliary axonemes from pig trachea were exposed to increasing concentrations of purified Pseudomonas aeruginosa rhamnolipid. This is a defined ciliary system allowing observation of direct impairment of functional axonemes. Axonemal motility and ATPase activity were decreased in proportion to rhamnolipid concentrations. ATPase-associated proteins observed in sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE) and dynein arms seen in ultrastructural cross sections progressively disappeared from axonemes with exposure to rhamnolipid. These four independent measures establish that the rhamnolipid removes the ATPase-containing outer dynein arms from the ciliary axoneme, thereby rendering the axoneme immotile.
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    Announcing a 1987 UCLA symposium (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. i 
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    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    Robert Day Allen (1927-1986): An appreciation (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 249-255 
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    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    Regulation of cell motility, morphology, and growth by sulfated glycosaminoglycans (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 273-281 
    Details
    ISSN: 0886-1544
    Keywords: heparin ; glycosaminoglycans ; fibronectin ; cell growth factors ; cell migration ; cell adhesion ; cell morphology ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Due to the recent observation that heparin binds to several growth factors and cell adhesion molecules, the effect of heparin on biological processes governed by growth factors and cell adhesion molecules was investigated. Pharmacological doses of heparin were found to alter cell growth rate, cellular morphology, and cell motility.Concentrations (μg/ml) of heparin or dextran sulfate decreased cell growth rate, but not the final cell density attained in plateau phase. The effect of heparin on cell growth rate was most pronounced when cells were cultured in low concentrations of serum. A heparin-induced decrease in cell growth rate could be reversed by addition of platelet-derived growth factor (PDGF), a heparin-binding growth factor.Heparin altered the morphology of all cell lines studied to various degrees. The effect of heparin on cell morphology was quantitated by measuring the heparin-induced change in cell surface area. HT-1080 and HeLa cells nearly doubled in surface area upon exposure to 10μg/ml heparin. Since several heparin-binding cell adhesion proteins mediate both cell spreading and cell migration, the influence of heparin on cell migration was investigated with an improved version of the phagokinetic track technique. Low concentrations of heparin and dextran sulfate were found to increase the rate of cell migration in a dose-dependent fashion.Since the quantitative effect of heparin on cell growth rate, morphology, and migration depends on the cell line studied, it is suggested that three separate phenomena may be involved. The results presented indicate a central role for sulfated glycosaminoglycans in the control of both cell growth and cell-cell interactions.
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    The stabilization of microtubules in isolated spindles by tubulin-colchicine complex (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 282-290 
    Details
    ISSN: 0886-1544
    Keywords: mitosis ; microtubules ; colchicine ; isolated mitotic spindles ; birefringence ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have analyzed the effect of colchicine and tubulin dimer-colchicine complex (T-C) on microtubule assembly in mitotic spindles. Cold- and calcium-labile mitotic spindles were isolated from embryos of the sea urchin Lytechinus variegatus employing EGTA/glycerol stabilization buffers. Polarization microscopy and measurements of spindle birefringent retardation (BR) were used to record the kinetics of microtubule assembly-disassembly in single spindles. When isolated spindles were perfused out of glycerol stabilizing buffer into a standard in vitro microtubule reassembly buffer (0.1 M Pipes, pH 6.8, 1 mM EGTA, 0.5 mM MgCl2, and 0.5 mM GTP) lacking glycerol, spindle BR decreased with a halftime of 120 s. Colchicine at 1 mM in this buffer had no effect on the rate of spindle microtubule disassembly. Inclusion of 20 μM tubulin or microtubule protein, purified from porcine brain, in this buffer resulted in an augmentation of spindle BR. Interestingly, in the presence of 20 μM T-C, spindle BR did not increase, but was reversibly stabilized; subsequent perfusion with reassembly buffer without T-C resulted in depolymerization. This behavior is striking in contrast to the rapid depolymerization of spindle microtubules induced by colchicine and T-C in vivo. These results support the current view that colchicine does not directly promote microlubule depolymerization. Rather, it is T-C complex that alters microtubule assembly, by reversibly binding to microtubules and inhibiting elongation.In vivo, colchicine can induce depolymerization of nonkinetochore spindle microtubules within 20 s. In vitro, colchicine blocks further microtubule assembly, but does not induce rapid disassembly. The rate of tubulin dissociation from spindle microtubules in vitro in reassembly buffer without soluble tubulin is about 20 times slower than the rate of dissociation in vivo when assembly is blocked abruptly by T-C. The rate of tubulin dissociation from the spindle microtubules may determine their response to T-C, since the tubulin dissociation rate in vivo is about 12 times faster than the rate measured here for spindle microtubules in standard microtubule reassembly buffer at physiological temperature.
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    Effects of vanadate on the assembly and disassembly of purified tubulin (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 314-323 
    Details
    ISSN: 0886-1544
    Keywords: vanadate ; microtubules ; tubulin polymerization ; taxol ; dynein ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Sodium-orthovanadate (100-700 μM) added to purified pig brain microtubule protein (molar ratios 13-90 moles vanadate/mole tubulin) inhibits to a considerable extent the assembly (up to 65%) and the disassembly rates (up to 60%) of microtubules, as determined by turbidimetry. Vanadate added to preformed microtubules did not appreciably alter the turbidity level of the samples, however, the disassembly rates were decreased in the same manner as when vanadate was added prior to polymerization. Microtubule protein kept on ice for 3-6 hours became more susceptible to vanadate than freshly prepared protein. The effect of vanadate was independent of the GTP concentration at which the polymerization assays were performed (0.025 to 1 mM GTP). In the presence of taxol, which increases the rate and extent of microtubule formation, vanadate had no effect on assembly rates. Disassembly was inhibited, however, much less than in the presence of vanadate alone. Electron microscopy and polyacrylamide gel electrophoresis did not reveal differences between microtubules prepared in the presence or in the absence of vanadate. This is consistent with the notion that vanadate does not interfere with the interaction between tubulin and the high-molecular weight microtubule-associated proteins. Apparently vanadate brings about an allosteric change of the microtubule protein(s) resulting in the abnormal polymerization kinetics of tubulin found in our study. The above results may be relevant for studies where the effects of vanadate on intracellular motility are interpreted as being solely due to a specific inhibition of ATPases.
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    Editorial (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 82-82 
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    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    In vitro movements of actin and myosin filaments from muscle (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 159-162 
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    ISSN: 0886-1544
    Keywords: superprecipitation ; actomyosin ; F-actin bundle ; unidirectional sliding ; sliding velocity ; dark field microscopy ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Unidirectional sliding of myosin filaments along F-actin bundles was produced with purified muscle actin and myosin in the presence of ATP. The velocity of myosin filament sliding was independent of myosin filament length. This result supports a recent hypothesis that long distance movement of myosin cross-bridge can be induced by splitting of one ATP molecule [Yanagida, Arata, and Oosawa, 1985. Nature. 316:366-369; Higashi-Fujime. 1985. J. Cell Biol., 101:2335-2344].
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    Bivalent orientation and behavior in crane-fly spermatocytes recovering from cold exposure (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 492-501 
    Details
    ISSN: 0886-1544
    Keywords: chromosome orientation ; prometaphase ; meiosis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: At metaphase in crane-fly primary spermatocytes, the two sister kinetochores at the centromere of each homologue in a bivalent normally are adjacent and face the same pole; one homologue has all its kinetochore microtubules (kMTs) extending toward one pole and its partner has all its kMTs extending toward the opposite pole. In contrast, during recovery from exposure to 2°C, one or both homologues in many metaphase bivalents had bipolar malorientations: all kMTs of one kinetochore extended toward one pole and some or all those of its sister extended toward the other. Metaphase sister kinetochores that had most of their kMTs extending toward the same pole were adjacent, and those with most extending toward opposite poles were separated from each other. Distances between homologous centromeres were similar to those in properly oriented bivalents. Maloriented bivalents were tilted relative to the spindle axis, and analysis of living cells showed that tilted configurations were rare during prometaphase in untreated cells but frequently arose in cold-recovering cells as initial configurations, then persisted through metaphase. This was in contrast to unipolar configurations of bivalents (configurations suggesting orientation of both homologous centromeres toward the same pole), which always reoriented shortly after the configuration arose. We conclude that in cold-recovering cells, bipolar malorientations are more stable than unipolar malorientations, and the orientation process is affected such that bipolar malorientations arise in bivalents upon initial interaction with the spindle and persist through metaphase.
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    Protein-protein interactions in the 18S ATPase of Chlamydomonas outer dynein arms (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 510-520 
    Details
    ISSN: 0886-1544
    Keywords: flagella ; motility ; dynein substructure ; microtubules ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: When outer-row dynein arms are extracted from Chlamydomonas flagellar axonemes, they dissociate into two ATPase complexes with sedimentation coefficients of 12S and 18S. We immunized mice with 18S dynein and generated a library of monoclonal antibodies against the polypeptides in this complex. Antibodies were selected which specifically recognize the 18S α- and β-heavy chains and the 83,000-dalton and 70,000-dalton intermediate chains. These antibodies were isolated and characterized for their ability to recognize determinants on both denatured antigens and native 18S dynein; 18S dynein was dissociated in stepwise fashion into smaller aggregates with ionic and nonionic detergents and the resulting subcomplexes were isolated by precipitation with specific monoclonal antibodies. The smallest aggregates isolated were heterodimers between the α-chain and a 16,000-dalton light chain and between the two intermediate chains. Additional close associations of the β-heavy chain with an 18,000-dalton light chain and 70,000-dalton intermediate chain, and a weaker interaction between the intermediate chain heterodimer and light chains of 21,000 daltons and 12,500 daltons, were also observed. We present a model of 18S dynein substructure based upon this information.
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    Cytoskeletal architecture and motility in a giant freshwater amoeba, Reticulomyxa (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 521-533 
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    ISSN: 0886-1544
    Keywords: intracellular organelle transport ; microtubules ; microfilaments ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Reticulomyxa is a large, multinucleated freshwater protozoan with striking intracellular transport. Cyloplasmic streaming and saltatory movements of individual organelles (at rates of up to 25 μm/sec) are observed within the naked cell body and the extensive reticulate peripheral network of fine cytoplasmic strands. As demonstrated by video-enhanced light microscopy, individual organelles move only when associated with cytoskeletal linear elements. The linear elements are composed of mixed colinear bundles of microtubules and actin filaments, which form the backbone of the reticulopodial network. The constant branching, sprouting, and fusion of network stands suggest unique membrane properties and an unusually dynamic cytoskeleton. The electrophoretic mobility of Reticulomyxa tubulins and the lack of crossreactivity with several antibodies known to react with many plant and animal tubulins suggest that they may differ from other tubulins more widely than might be expected. Reticulomyxa's large size, the rapidity and pervasiveness of the two forms of transport, and the simple and ordered cytoskeleton make the organism well suited for future studies on the mechanisms of intracellular transport.
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    Is the hemidesmosome a half desmosome? An immunological comparison of mammalian desmosomes and hemidesmosomes (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 560-569 
    Details
    ISSN: 0886-1544
    Keywords: hemidesmosome ; desmosome ; cell junction ; autoantibodies ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Although the mammalian epidermal basal cell hemidesmosome bears some superficial resemblance to one half of a desmosome at the ultrastructural level, examination of the structure of the electron-dense submembranous plaques of the hemidesmosome and desmosome reveals that they differ with respect to their overall morphology and dimensions. Based on these findings, we wondered whether components of the desmosome are present in the hemidesmosome. In order to determine this we prepared a number of stratified squamous epithelial tissues for indirect immunofluorescence using antibody preparations directed against known desmosome components including desmoplakin and certain glycoproteins. These antibody preparations do not show reaction with hemidesmosomes by indirect immunofluorescence criteria. We have also utilized bullous pemphigoid (BP) autoantibodies that have been shown to recognize hemidesmosomes in mammalian skin cells [Mutasim et al., J. Invest. Derm., 84:47-53, 1985]. Double label indirect immunofluorescence observations of neonatal mouse skin prepared using desmoplakin antibodies and BP autoantibodies reveal that hemidesmosomes that are stained by the BP autoantibodies are not recognized by the desmoplakin antibodies. We confirmed these findings at the ultrastructural level by indirect immunogold localization of desmoplakin antibodies and BP autoantibodies. Therefore, the hemidesmosome does not appear to be one half of a desmosome and may possess a very different molecular organization relative to the desmosome. We raise the possibility that the variability between the hemidesmosome and desmosome that we detect at the morphological and immunological level may reflect the functional differences of these two types of junctions.
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    Isolation of cilia from porcine tracheal epithelium and extraction of dynein arms (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 25-34 
    Details
    ISSN: 0886-1544
    Keywords: respiratory cilia ; dynein ; ATPases ; porcine trachea ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Milligram amounts of mammalian ciliary axonemes were isolated from porcine tracheas. These were reactivated upon addition of ATP, indicating intact functional capability with a mean beat frequency at 37°C of 8.2 Hz. Electron microscopy showed typical ultrastructure of the isolated demembranated axonemes. Electrophoresis into polyacrylamide gradient gels containing sodium dodecyl sulfate revealed reproducible protein profiles from ten different tracheal preparations. Four major protein bands were observed in the 300-330 K molecular weight region, as well as tubulin at 51-54K. Extraction of the isolated tracheal axonemes with 0.6M KCl removed the outer dynein arms seen in electron microscopic cross-section of axonemes, preferentially solubilized two of the high molecular weight proteins at 320 and 330 K, and resulted in a three- to four-fold increase in ATPase specific activity. Sedimentation of the dialyzed salt extract on a 5-30% sucrose density gradient and subsequent fractionation yielded two peaks of ATPase activity. The faster migrating, 19S major ATPase peak correlated with the 320 and 330 K proteins, and two other proteins at 81 and 67 K. The slower sedimenting, 12S minor ATPase peak corresponded to a 308 K protein and two smaller proteins at 33 and 48 K. Thus, the outer dynein arm of tracheal cilia appeared to be associated with at least two high molecular weight proteins. These results demonstrate that adequate quantities of functionally intact axonemes can be reproducibly isolated from porcine tracheas, allowing further fractionation and analysis of mammalian cilia.
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    Parameters of the ciliary cycle under membrane voltage control (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 89-95 
    Details
    ISSN: 0886-1544
    Keywords: Ciliary inclination ; bending reorientation ; power stroke ; ciliary amplitude ; angular velocity ; unipolar sliding transfer ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Axial views of depolarization- and hyperpolarization-dependent activation of the frontal cirri of Stylonychia were cinematically recorded at high rate (250 frames/s) under voltage-clamp. Images of a cirrus performing the cycle were processed by using computer assistance. In responding to the polarity and amplitude of the voltage signal, a cirrus inclines proximally with a particular angle and orientation. The ciliary cycle-always counterclockwise-is superimposing upon steady inclination. Correction for inclination allowed the assessment of the directional change rate and, after inclusion of the amplitude data, the determination of the ciliary angular velocity during the cycle. The method serves to isolate a new ciliary parameter: inclination, and to register precisely parameters of the cycle which may be meaningful for the understanding of the sliding mechanism.
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    Regulation of sperm flagellar movement by protein phosphorylation and dephosphorylation (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 83-88 
    Details
    ISSN: 0886-1544
    Keywords: sea urchin ; spermatozoa ; Triton model ; protein kinase ; cyclic AMP ; phosphoprotein phosphatase ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Flagellar motility of Triton models of sea urchin spermatozoa was reactivated by cyclic AMP-dependent protein kinase and a protein factor, termed motility activator, both of which were prepared from the detergent-extract of sea urchin spermatozoa. It was shown that phosphorylation of the motility activator by the protein kinase is necessary for the reactivation of flagellar motility [Ishiguro et al, J. Cell Biol. 92:777-782, 1982; Murofushi et al, in “Biological Functions of Microtubules and Related Structures,” Academic Press, 1982]. Reactivating factor was also detected in a KCI-extract of the axoneme fraction devoid of the detergent-extractable materials. The activity of this factor was also cyclic AMP- and protein kinase-dependent. Furthermore, when freshly prepared Triton models were treated with phosphoprotein phosphatase prepared from bovine cardiac muscle, the flagellar motility was drastically suppressed. This inhibition of the motility was partially recovered by the addition of cyclic AMP and protein kinase to the phosphatase-treated models.
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    Duplication of the flagellar apparatus and cytoskeletal microtubule system in the alga Polytomella (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 122-127 
    Details
    ISSN: 0886-1544
    Keywords: microtubules ; rootlets ; monoclonals ; immunofluorescence ; mitosis ; cytokinesis ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have used immunofluorescence staining with monoclonal antibodies to tubulin and to components of the flagellar basal apparatus to examine duplication of the basal apparatus and the microtubule system assembled from it during cell division in the quadriflagellate alga Polytomella. The monoclonal antitubulin, prepared against Polytomella flagellar axonemes, detects Polytomella and mammalian tubulin by immunoblotting. By immunofluorescence and immunogold electron microscopy, it detects all microtubular structures that have been described in Polytomella. One of the antibodies generated using the isolated basal apparatus as immunogen appears to stain four of the eight basal body rootlets and is used in this study to detect early stages in the duplication of the flagellar apparatus. A cytoplasmic microtubule system is present, the elongate morphology of the cell is maintained, and the cells are motile throughout mitosis. The closed mitotic spindle forms perpendicular to the long axis of the cell. During mitosis, the newly formed basal bodies mature and four additional elongating flagella appear. Following mitosis, the eight flagella segregate into two groups, which begin to separate towards opposite poles of the cell. Concomitant with this separation, the rootlets of the parental basal apparatus separate and new rootlets are detected. We suggest that the components of the parental flagellar apparatus are segregated equally to the daughter cells. An interphase cytoskeletal microtubule array is assembled from each basal apparatus, and the morphology of the two cells is progressively established during cytokinesis.
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    URL: http://dx.doi.org/10.1002/cm.970060209
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    Microtubule-dependent reticulopodial motility: Is there a role for actin? (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 146-152 
    Details
    ISSN: 0886-1544
    Keywords: Allogromia ; microtubules ; microtubule-associated protein (MAP-2) ; actin ; cyanideinsensitive respiration ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We summarize our recent immunocytochemical characterization of the reticulopodial cytoskeleton of two allogromiid foraminifers and our pharmacologic dissection of its motility. The reticulopodial microtubule cytoskeleton stained with an antiserum to brain microtubule-associated protein 2. Polymeric actin was localized in the reticulopodia by rhodamine-phalloidin staining. Microtubule inhibitors reversibly inhibited all aspects of motility; cytochalasins induced altered morphology and disorganization of motility but did not inhibit pseudopodial movements or intracellular transport. Simultaneous application of KCN and salicylhydroxamic acid (an alternative oxidase inhibitor) rapidly blocked all movement, indicating that motility is dependent on metabolic energy and that an alternative oxidative pathway functions in allogromiids. Micromanipulation and laser microsurgical experiments revealed tension throughout the reticulopodium. Our results suggest that microtubules are active components of the reticulopodial motile machinery. Actin may mediate substrate adhesion, whole-cell locomotion, pseudopodial tension, and coordination of the microtubule-based motility.
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    Structural evidence for contractile units in the giant smooth muscle cell of Beröe (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 153-158 
    Details
    ISSN: 0886-1544
    Keywords: giant smooth muscle fiber ; ctenophore ; myofilaments ; ultrastructure ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Bundles of giant smooth muscle fibers of the ctenophore Beröe have been stretched up to four times their initial length and then examined by transmission electron microscopy. Stretching induces the segregation of actin and thick (myosinlike) filaments into separate domains. The thick filaments domains are made of 20-30 filaments, with a regular spacing identical to that of nonstretched fibers. A moderate stretching permits the visualization of microtendons associating actin filament bundles to hyaluronidase-resistant condensations of the extracellular matrix. It is deduced from these observations that Beröe giant smooth muscle fibers possess myofibrils which attach at both ends upon the sarcolemmal membrane. Each myofibril is probably made of two long actin filament bundles (of approximately 150 filaments) and short (2-3 μm) myosinlike bundles (of approximately 30 filaments).
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    URL: http://dx.doi.org/10.1002/cm.970060213
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    Alteration of the distribution of intermediate filaments in PtK1 cells by acrylamide II: Effect on the organization of cytoplasmic organelles (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 15-24 
    Details
    ISSN: 0886-1544
    Keywords: cytoskeleton ; keratin ; vimentin ; microtubules ; saltatory movements ; motility ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The distribution and motility of cytoplasmic particles was examined in PtK1 cells in which intermediate filament networks had been disrupted by acrylamide. In these cells, particles (mitochondria and vesicles) accumulated near the cell center although saltatory movements continued. This left a broad sheet of agranular cytoplasm at the periphery of the cell. Particles were capable of movement into this sheet. Intermediate filaments were absent in the peripheral cytoplasm although microtubules remained in a normal configuration. Particles apparently move along the microtubules. These results indicate that particle movement along microtubules is not dependent upon the normal configuration of intermediate filaments. It is suggested that intermediate filaments are necessary for normal organelle distribution and serve as a matrix with which particles can associate to maintain position.
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    The lack of interaction between vinculin and actin (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 48-55 
    Details
    ISSN: 0886-1544
    Keywords: vinculin ; actin ; adhesion plaques ; cytoskeleton ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Vinculin was purified from chicken gizzard by a modification of the method of Feramisco and Burridge [1980; J Biol Chem 255:1194]. Vinculin did not alter the viscosity of actin as measured in an Ostwald viscometer, nor did it affect actin polymerization as measured with the fluorescent NBD-actin assay. Sedimentation experiments demonstrated that vinculin did not bind to actin, and electron microscopy of negatively stained specimens indicated that vinculin did not aggregate actin filaments into bundles. These results suggest that vinculin, by itself, does not interact with actin at least under commonly used conditions to assay actin-protein interactions in vitro.
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    Abnormal distribution of the periaxonemal structures in a human sperm flagellar dyskinesia (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 68-76 
    Details
    ISSN: 0886-1544
    Keywords: sperm movement ; human spermatozoa ; periaxonemal structure ; flagellum ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The spermatozoa from four infertile patients showing a flagellar dyskinesia due to abnormal flagellar wave development have been studied by light and transmission electron microscopy (TEM) for flagellar morphology. No axonemal anomalies were found but modification of the periaxonemal structures was observed. The results of a stereological analysis revealed abnormal extension of the individual dense fibres along the axoneme in the four cases as compared with a control group. The order of termination of those structures was therefore altered. However, the overall fibre extension was the same in both groups (ie, 60% of the principal piece). The number and the location of the longitudinal columns were also modified, the predominant anomaly being the presence of a single column. The possible influence of those structural anomalies on the pattern of sperm movement is discussed. Our observations seem to agree with a previous hypothesis of the literature, that the dense fibres might play a role in flagellar flexibility. More particularly, we suggest that the abnormal extension of dense fibres No. 2, 3, and 4 and the symmetric distribution of the dense fibres on both sides of the plane of beating may alter the flagellar curvature amplitude and the cell rotation frequency.
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    Patterns of flagellar wave propagation in Crithidia oncopelti at increased viscosities (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 99-104 
    Details
    ISSN: 0886-1544
    Keywords: flagella ; wave shapes ; motility ; calcium ; adaptation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: In its normal culturing environment, the trypanosomid flagellate Crithidia oncopelti propagates basally-directed planar waves, but may under certain conditions exhibit base-to-tip wave propagation in what is regarded as an avoidance response. The beat frequency and wave shape in both modes of beating are dependent on the viscosity of the swimming medium; viscosity may also influence the direction of wave propagation. If Crithidia experience a sudden increase in viscosity, there is a marked increase in the proportion of the population that is seen to exhibit wave propagation from base to tip; this proportion gradually decreases with time until the whole sample has reverted to “normal” beating. In a single organism, the resumption of normal beating is not accomplished in a single transition but by a series of switches between the forward and reverse modes. The interval of time between successive switches appears to be random, while the length of time spent in base-to-tip wave propagation gradually decreases. Despite the randomness of the switching process, its rate when averaged over successive time intervals is found to be constant at a particular viscosity and also dependent on it. The precise manner by which this organism is able to control its direction of wave propagation is unclear. However, the switching behavior it exhibits during the period of adaptation to an increased mechanical loading of the flagellum may reflect a process that characterizes a facet of this controlling mechanism.
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    Cell shape and organization of F-actin and microtubules in randomly moving and stationary amebae of Dictyostelium discoideum (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 176-185 
    Details
    ISSN: 0886-1544
    Keywords: Dictyostelium discoideum ; video and fluorescence microscopy ; random ameboid movement ; stationary mitotic amebae ; cytoskeleton ; microtubule center ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We investigated, by video-light microscopy and fluorescence microscopy with probes specific for microtribules (MTs) and F-actin, the relationship between cytoskeletal elements, cell shape and behavior of vegetative, undifferentiated amebae of Dictyostelium discoideum, strain NC-4. In an unconstrained situation, as on the underside of a coverglass in a thin layer of liquid medium, interphase cells moved around randomly in a polypodial or monopodial fashion. Locomotion was characterized by the formation of pseudodigits, rounded or pointed pseudopodia, and retraction fibers. F-actin occurred in all these structures, as well as in a thin cortical layer. Microtubules extended into some of the cellular extensions rich in F-actin. Pseudopodial activity, but not locomotion, also took place at the interface between medium and air, demonstrating that ameboid movement requires contact with a solid substrate. Stationary mitotic amebae on glass were studded with continuously changing, peripheral spike-shaped filopodia that also contained F-actin. During telophase and cytokinesis the spikes were gradually replaced by pseudopodia in transition to the fully motile phase.In live cells, the nucleus-associated body (NAB), which is at the center of the complex of cytoplasmic MTs [CMTC; term from Brinkley, Fuller, and Highfield, 1975] was in a rather fixed position; it did not orient in a concerted fashion to follow changes in the direction of cell movement. In amebae fixed and processed for fluorescence microscopy after a period of recorded movement, the NAB was not preferentially positioned with respect to the nucleus and the direction of movement. It is unlikely that the NAB exerts a directional control during randon ameboid movement. The complex of cytoskeletal MTs must be very dynamic or flexible to adjust to the rapid changes of cell shape.
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    Prelimlnary report on the ultrastructural organization of the contractile appendix of Tontonia appendiculariformis (ciliophora oligotrichina) (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 217-224 
    Details
    ISSN: 0886-1544
    Keywords: contractile system ; microfilaments ; microtubules ; endoplasmic reticulum ; ciliophora ; oligotrichina ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Tontonia appendiculariformis is a marine planktonic ciliate with a long tail. The tail can contract rapidly, becoming transformed into an oval mass one-twentieth of its original length. The highly complex ulrastructure of the tail is described here in detail. A large part of the volume of the tail contains numerous more or less parallel membranous tubes. The membrane of the tubes has numerous invaginations and is probably derived from the smooth endoplasmic reticulum. This tubular material forms a continuous layer around the tail, interrupted in only one region, which contains cilia. Associated with the cilia are basal fibres with a periodically banded appearance. The tubular layer forms several folds separated by hyaloplasm containing many mitochondria. The pellicle of the tail is thrown into numerous pleats. It comprises a perilemma, a plasmalemma, and complex alveoli, but epiplasm and microtubules are absent. The alveoli appear to form septa within the folds of the layer of membranous tubes. In the region where the tail is attached to the body of the ciliate there are conspicuous bundles of microtubules and microfilaments. The membranous tubes and septa appear to be connected to small bundles of microfilaments, which presumably represent the contractile material. However, we consider the membranous tubes as potentially active in producing the change in shape. Although the structure of the tail of Tontonia is unique, there are certain similarities to the stalk of the Tintinnina and also to the motile extension of the dinoflagellate Erythropsidinium.
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    Regulation of ciliary motility by membrane potential in Paramecium: A role for cyclic AMP (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 256-272 
    Details
    ISSN: 0886-1544
    Keywords: ciliary motility ; cAMP regulation ; swimming speed ; membrane potential ; detergent models ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The membrane potential of Paramecium controls the frequency and direction of the ciliary beat, thus determining the cell's swimming behavior. Stimuli that hyperpolarize the membrane potential increase the ciliary beat frequency and therefore increase forward swimming speed. We have observed that (1) drugs that elevate intracellular cyclic AMP increased swimming speed 2-3-fold, (2) hyperpolarizing the membrane potential by manipulation of extracellular cations (e.g., K+) induced both a transient increase in, and a higher sustained level of cyclic AMP compared to the control, and (3) the swimming speed of detergent-permeabilized cells in MgATP was stimulated 2-fold by the addition of cyclic AMP. Our results suggest that the membrane potential can regulate intracellular cAMP in Paramecium and that control of swimming speed by membrane potential may in part be mediated by cAMP.
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    Cytoskeletal architecture of reactivated crayfish axons, with special reference to crossbridges among microtubules and between microtubules and membrane organelles (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 458-468 
    Details
    ISSN: 0886-1544
    Keywords: cytoskeleton ; axoplasm ; fast flow ; quick-freeze ; deep-etch ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Bidirectional organelle movements were observed in fresh and permeabilizedreactivated (0.02% saponin, 5 mM Mg++ ATP) walking leg axons of crayfish with video-enhanced contrast, differential interference contrast (AVEC-DIC) microscopy; and the cytoskeletal organization of those axons was studied with quickfreeze, deep-etch electron microscopy (QF,DE) to understand the structure of the microtubule (MT) domain and to determine the basic cytoskeletal structures necessary for organelle transport in vivo. Vesicles and mitochondria moved bidirectionally in the central parts of fresh or permeabilized-reactivated axons. Although the axoplasm of the fresh axon was composed of longitudinally oriented microtubules and granular materials in which membrane organelles were embedded, a network of fine strands existed in the core of the granular materials. Crossbridges between membrane organelles and microtubules were present. In the central part of reactivated axons, the cytoskeleton consisted of microtubules, highly anastomosing networks of fine strands (6.6 ± 1.4 nm in width) that crosslinked the microtubules with each other, and relatively short, straight crossbridges (25 ± 3.9 nm in length, 5.5 ± 2.1 nm in width) crosslinking membrane organelles with microtubules. It has been shown that a 270KD microtubule associated protein (MAP) could be a main component of crossbridges between MTs [Hirokawa, 1986]. Hence the dynamic conformational change of crossbridges between membrane organelles and microtubules could play an important role when membrane organelles are transported.
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    Masthead (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986) 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cm.970060601
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    Alpha-actinin accumulation in the cortex of echinoderm eggs during fertilization (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 549-559 
    Details
    ISSN: 0886-1544
    Keywords: activation ; microinjection ; polar body ; sea urchin eggs ; starfish oocytes ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Redistribution of alpha-actinin during fertilization was investigated by means of the microinjection of fluorescently labeled egg alpha-actinin in the sea urchin, Hemicentrotus pulcherrimus. Upon fertilization, labeled alpha-actinin accumulated locally around the sperm binding site, where the fertilization cone formed soon afterwards. The accumulation propagated all over the cortex within 10 sec after a latent period of 10-20 sec. When an egg in Na-free seawater was injected with both alpha-actinin and calcium buffer (intracellular free Ca2+ concentration = 9 μM), the accumulation of alpha-actinin was similar to that in normal seawater, which suggests that the accumulation did not depend on the increase in intracellular pH but only on the increase in the intracellular free Ca2+ concentration. In immature oocytes the accumulation was detected in the cortical region, including the huge protruding cytoplasm where the sperm entered. When labeled egg alpha-actinin was injected into starfish (Asterias amurensis) oocytes followed by insemination, it accumulated in the cortical layer in a manner similar to the case of sea urchin, except that the accumulation in fertilization cones of maturing oocytcs or reception cones of immature oocytes appeared ringlike and rodlike, respectively. Moreover, just after the arrival of the meiotic apparatus, egg alpha-actinin accumulated in the cortical region, where the formation of the polar body was expected. This suggests that the meiotic apparatus somehow induced the differentiation of the cortex so as to form a polar body. It is concluded that the cortical region where alpha-actinin accumulated coincided with the microfilament-rich region. This suggests that alpha-actinin plays a role in forming the cortical meshwork of actin filaments.
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    Cyclical bending of two outer-doublet microtubules in frayed axonemes of Chlamydomonas (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 580-585 
    Details
    ISSN: 0886-1544
    Keywords: flagella ; microtubules ; Chlamydomonas ; bending movement ; oscillation ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: When detergent-extracted cell models of Chlamydomonas reinhardtii were left in the presence of 1 mM Mg-ATP for more than 30 minutes flagellar axonemes tended to become frayed into fine bundles of microtubules. Under such conditions, bundles made up of a pair of outer-doublet microtubules displayed oscillatory bending movements of low (〈 2 Hz) frequencies. The two doublet microtubules underwent association-dissociation cycles coupled with gross bending movement. A model is presented to explain this phenomenon by unidirectional sliding interaction between the two microtubules.
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    Cell surface displacement during euglenoid movement and its computer simulation (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 186-192 
    Details
    ISSN: 0886-1544
    Keywords: Euglena ; pellicular strip ; cell shape ; sliding ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We recently showed by videomicroscopy that adjacent pellicular strips slide relative to each other without contraction during S-shaped bending movement in Euglena fusca (Suzaki and Williamson, 1985). In order to validate this sliding strip mechanism for other species and other shape changes, a theoretical analysis and a computer simulation were carried out. Some of the commonly observed euglenoid cell shapes (rounded. S-shaped, and embryo-like shapes) were generated. Our results suggest that Euglena probably achieves a variety of cell shape changes by means of locally regulated sliding between adjacent pellicular strips of constant length and width.
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    The mechanical behavior of doublet microtubules simulated by helical modelsThis work is a tribute to the memory of Donald P. Costello, whose observations have stimulated this work. (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 209-216 
    Details
    ISSN: 0886-1544
    Keywords: uniplanar flagella ; doublet microtubules ; doublet interaction ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: The structural and mechanical properties of the helix-shaped isolated doublet microtubules described by Costello [Biol. Bull. 145:279-291, 1973], Zobel [J. Cell Biol. 59:573-94, 1973], and Miki-Noumura and Kamiya [Exp. Cell Res. 97:451-53, 1976, J. Cell Biol 81:355-60, 1979] are simulated by a left-handed superhelix model that consists of two intertwined springlike helices with a slight difference in their pitches. It is shown by combinations of two and more superhelices of this kind that the straight shape of the doublets in the axoneme is the consequence of a position-dependent mechanical coil-coil interaction between interconnected doublets whose curvatures bend against one another. A counterclockwise torsion changes the sense of the superhelix from the left-handed form with a smaller pitch (L2) to the right-handed form with a larger pitch (R3). The coil-coil interaction of L helices with R helices results in uniplanar, meanderlike shapes or in flattened helices. The one-sided distribution of L and R doublets as described for sperm axonemes by Costello [Biol. Bull. 145:279-91, 1973] may therefore be responsible for the uniplanar. meanderlike shape of these flagella.
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    Sperm chemotaxis in siphonophores: Identification and biochemical properties of the attractant (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 225-228 
    Details
    ISSN: 0886-1544
    Keywords: Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
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    URL: http://dx.doi.org/10.1002/cm.970060222
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    The use of submicroscopic gold particles combined with video contrast enhancement as a simple molecular probe for the living cell (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 105-113 
    Details
    ISSN: 0886-1544
    Keywords: video-microscopy ; colloidal gold ; immunocytochemistry ; microtubules ; receptors ; saltatory motion ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We describe a new approach to probe the molecular biology of the living cell that uses small colloidal gold particles coupled to specific ligands. They are visualized in cells by bright-field, video enhanced contrast microscopy. We describe the basic aspects of the technique and provide examples of applications to intracellular motility, cell membrane dynamics, receptor translocation, internalization, and intracellular routing. We also provide examples of the use of this approach in immunospecific labelling of cells and tissue sections.
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    Polarized cytoplasmic movement and inhibition of saltations induced by calcium-mediated effects of microbeams in fungal hyphae (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 136-145 
    Details
    ISSN: 0886-1544
    Keywords: cytoplasmic movement ; microbeam ; Ca++ ; fungi ; saltatory movement ; cytoskeleton ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: We have investigated the mechanisms that hyphae of the fungus Basidiobolus magnus use to accomplish bulk movement of their cytoplasm and saltatory organelle movements. When cells were irradiated with an ultraviolet microbeam, cytoplasmic contraction occurred. The posterior cytoplasm (toward the septum) always moved forward toward the irradiated area, whereas anterior cytoplasm (between the cell tip and target) never contracted back toward the site of irradiation. Thus, there is an intrinsic polarity in the cytoplasm. Irradiations also arrested saltatory movements. The effects of irradiation on both saltations and cytoplasmic movement appear to be mediated by Ca++. Chelating exogenous Ca++ before irradiation eliminated contractions and prevented the inhibition of saltations. Furthermore, the effects of irradiation could be duplicated by using the Ca++ ionophore A23187. We relate the present results to our previous report on the effects of irradiation on the cytoskeleton [McKerracher and Heath, 1986]. We conclude that two separate cytoskeletal networks exist in fungal cells, and that an actin-containing network generates bulk cytoplasmic movement.
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    Motility and centrosomal organization during sea urchin and mouse fertilization (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 163-175 
    Details
    ISSN: 0886-1544
    Keywords: centrosomes ; fertilization ; mice ; microfilaments ; microtubules ; mitosis ; pericentriolar material ; sea urchins ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Motility and the behavior and inheritance of centrosomes are investigated during mouse and sea urchin fertilization. Sperm incorporation in sea urchins requires microfilament activity in both sperm and eggs as tested with Latrunculin A, a novel inhibitor of microfilament assembly. In contrast the mouse spermhead is incorporated in the presence of microfilament inhibitors indicating an absence of microfilament activity at this stage. Pronuclear apposition is arrested by microfilament inhibitors in fertilized mouse oocytes. The migrations of the sperm and egg nuclei during sea urchin fertilization are dependent on microtubules organized into a radial monastral array, the sperm aster. Microtubule activity is also required during pronuclear apposition in the mouse egg, but they are organized by numerous egg cytoplasmic sites. By the use of an autoimmune antibody to centrosomal material, centrosomes are detected in sea urchin sperm but not in unfertilized eggs. The sea urchin centrosome expands and duplicates during first interphase and condenses to form the mitotic poles during division. Remarkably mouse sperm do not appear to have the centrosomal antigen and instead centrosomes are found in the unfertilized oocyte. These results indicate that both microfilaments and microtubules are required for the successful completion of fertilization in both sea urchins and mice, but at different stages. Furthermore they demonstrate that centrosomes are contributed by the sperm during sea urchin fertilization, but they might be maternally inherited in mammals.
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    Motility mechanisms in the actinopods (Protozoa): A review with particular attention to axopodial contraction/extension, and movement of nonactin filament systems (1986)
    New York, NY : Wiley-Blackwell
    Cell Motility and the Cytoskeleton 6 (1986), S. 198-208 
    Details
    ISSN: 0886-1544
    Keywords: saltatory transport ; Life and Medical Sciences ; Cell & Developmental Biology
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Biology , Medicine
    Notes: Several motility phenomena displayed by members of the Heliozoa, Radiolaria, and Acantharia (Protozoa, Actinopoda) are reviewed. These phenomena include (1) cytoplasmic streaming, internal saltatory motion, and transport of particles at the cell surface; (2) axopod contraction and extension; and (3) contraction of nonactin filament systems.Cytoplasmic streaming and saltatory motion require energy derived from oxidative phosphorylation. In addition, calcium appears to be involved in the regulation of these movements, and a role for calmodulin is suggested. At present, the molecular basis for these motility phenomena remains obscure.We have focused our attention on the rapid contraction of axopods and stalk in the marine heliozoan Actinocoryne contractilis (Febvre-Chevalier: J. Marine Biol. Assoc. U.K. 60:901-928, 1980). Contraction is accompanied by the cataclysmic breakdown of microtubules. For this species, a Na+ and Ca2+-dependent action potential precedes axopod contraction. A lack of contraction in Ca2+-free media (10-7 M Ca2+) suggests that Ca2+ fluxes across the cell membrane are required.Motile phenomena associated with nonactin filaments of fibrous systems in actinopods, especially in the myonemes of the acantharians (Febvre and Febvre-Chevalier: Biol. Cell. 44:283-304, 1982) are also examined. In vitro contraction of these filaments is CA2+ dependent and ATP independent' cycles of contraction and extension are caused by Ca2+-dependent conformational changes in pairs of twisted filaments. In vivo, the Ca2+ dependent contraction of these myonemes may be independent of direct mitochondrial control, but metabolic ATP and calmodulin may be required to regulate the level of free cytoplasmic calcium.
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    Niederkoordinierte Phosphorverbindungen, 45. Gemischt substituierte Bismethylenphosphorane durch Einwirkung von Carbenoiden auf Phosphaalkene (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1977-1985 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Low Coordinated Phosphorus Compounds, 45. Mixed Substituted Bismethylenephosphoranes by the Reaction of Carbenoides with PhosphaalkenesThe known methylenephosphanes 1a-e react with lithio-α-chloroorganyls 2a, b to give the bismethylenephosphoranes 3a-f in high yields. The compounds 3c-f represent the first mixed substituted λ5σ3-bismethylenephosphoranes, that except 3e, f could be isolated. Products 3e, f rearrange to the new phosphiranes 6a, b. The reaction of the methylenephosphane 1b with diphenyldiazomethane (4) leads via spectroscopic conceivable dihydrodiazaphosphole 5 to compound 3e. The course of the reactions, the spectroscopic data as well as the X-ray structure analyses of 3d and 6a are discussed.
    Notes: Aus der Reaktion der bekannten Methylenphosphane 1a-e mit Lithio-α-chlororganylen 2a, b erhält man in sehr guten Ausbeuten die Bismethylenphosphorane 3a-f. Die Verbindungen 3c-f sind die ersten gemischt substituierten Vertreter der λ5σ3-Bismethylenphosphorane, die mit Ausnahme von 3e, f isoliert werden können. Die Verbindungen 3e, f lagern in die neuen Phosphirane 6a, b um. Die Reaktion des Methylenphosphans 1b mit Diphenyldiazomethan (4) verläuft über ein spektroskopisch erfaßbares Dihydrodiazaphosphol 5 zum Produkt 3e. Die Reaktionsverläufe, die spektroskopischen Daten sowie die Röntgenstrukturen von 3d und 6a werden diskutiert.
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    Gehinderte Ligandbewegungen in Übergangsmetallkomplexen, XXXIII. (η2- und η4-Dien)[2-(η5-cyclopentadienyl)ethyl]molybdän-Carbonyle (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 1994-2005 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Hindered Ligand Movements in Transition Metal Complexes, XXXIII. (η2- and η4-Diene)[2-(η5-cyclopentadienyl)ethyl]molybdenum CarbonylsTricarbonyl[2-(η5-cyclopentadienyl)ethyl]molybdenum (1) reacts photochemically with 1,3-butadiene (2), (E)-1,3-pentadiene (3) or 2-methyl-1,3-butadiene (4), respectively, to give the corresponding η2- and η4-diene complexes. Stepwise, dicarbonyl[2-(η5-cyclopentadienyl)ethyl](η2-diene)molybdenum (5, 8, 11) and carbonyl[2-(η5cyclopentadienyl)ethyl](η4-diene)-molybdenum (6, 9, 12) are formed. Insertion of 1,3-butadiene into the Mo—C-σ-bond of 5 yields dicarbonyl[6-(η5-cyclopentadienyl)-η3-(E)-2-hexenyl]molybdenum (7) as a by-product. Similarily, 8 reacts to the corresponding [6-(η5-cyclopentadienyl)-η3-(E,E)-1-methyl-2-hexenyl] chelate complex 10. The η2-diene ligands in 5, 8, 11 show hindered rotation around the axis through the center of the center of the coordinated CC-double bond and the central atom. Two different rotamers can be observed at low temperatures. The energy barriers were determined by band shape analyses to be ΔG300300≠ = 62.0 ± 0.2 kJ/mol for 5, ΔG280≠ = 66.2 ± 0.2 kJ/mol for 8, and ΔG298≠ = 61.0 ± 0.2 kJ/mol for 11. Complex 9 is obtained in one, 12 in both of the two possible diastereomeric forms.
    Notes: Tricarbonyl[2-(η5-cyclopentadienyl)ethyl]molybdän (1) reagiert photochemisch mit 1,3-Butadien (2), (E)-1,3-Pentadien (3) bzw. 2-Methyl-1,3-butadien (4) zu den korrespondierenden η2- und η4-Dien-Komplexen. Stufenweise werden Dicarbonyl[2-(η5-cyclopentadienyl)ethyl](η2-dien)molybdän (5, 8, 11) und Carbonyl[2-(η5-cyclopentadienyl)ethyl](η4-dien)molybdän (6, 9, 12) gebildet. Insertion des 1,3-Butadiens in die Mo—C-σ-Bindung von 5 ergibt Dicarbonyl[6-(η5-cyclopentadienyl)-η3-(E)-2-hexenyl]molybdän (7) als Nebenprodukt. Gleichermaßen reagiert 8 zu dem entsprechenden [6-(η5-Cyclopentadienyl)-η3-(E,E)-1-methyl-2-hexenyl]-Chelatkomplex 10. Die η2-Dien-Liganden in 5, 8, 11 zeigen gehinderte Rotation um die Achse durch die Mitte der CC-Doppelbindung und das Zentralatom. Zwei unterschiedliche Rotamere können bei tiefen Temperaturen beobachtet werden. Die Energiebarrieren wurden durch Linienform-Analyse zu ΔG300≠ = 62.0 ± 0.2 kJ/mol für 5, ΔG280≠ = 66.2 ± 0.2 kJ/mol für 8 und ΔG298≠ = 61.0 ± 0.2 kJ/mol für 11 ermittelt. Komplex 9 ist in einer, 12 in beiden der zwei möglichen diastereomeren Formen erhältlich.
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    Über sterisch gehinderte freie Radikale, XV. Das erste unsymmetrische Dimere aus zwei stabilen Radikalen: 3-(tert-Butylphenylmethylen)-6-(triphenylmethyl)-1,4-cyclohexadien aus tert-Butyldiphenylmethyl und Triphenylmethyl (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2006-2012 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Sterically Hindered Free Radicals, XV. The First Unsymmetrical Dimer from Two Different Stable Radicals: 3-(tert-Butylphenylmethylene)-6-(triphenylmethyl)-1,4-cyclohexadiene from tert-Butyldiphenylmethyl and TriphenylmethylThe quinonoid title compound 6 is formed in an equilibrium to 95% and can be isolated, when the two title radicals 1 and 3 are generated in solution. The reason for this is the sterically less strained position of the bulky tBu group at the sp2-C atom of the methylene group. The structure of 6 is proved by 1,5-H migration giving 8 and autoxidation of the latter at -10°C giving tBuOH and 4-tritylbenzophenone (12). The synthesis of several analogous compounds are described.
    Notes: Die chinoide Titelverbindung 6 entsteht im Gleichgewicht zu 〉95% und kann isoliert werden, wenn die beiden Titelradikale 1 und 3 in Lösung erzeugt werden. Ursache hierfür ist die räumlich günstigere Unterbringung der sperrigen tBu-Gruppe am sp2-C-Atom der Methylengruppe. Die Struktur von 6 wird durch 1,5-H-Verschiebung zu 8 sowie dessen Autoxidation bei -10°C zu tBuOH und 4-Tritylbenzophenon (12) bewiesen. Synthesen analoger Verbindungen werden beschrieben.
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    Stereoselective synthesis of alcohols, XXIII. Transfer of chirality on addition of (α-chloroallyl)boronates to aldehydes (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2013-2024 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Stereoselektive Synthese von Alkoholen, XXIII. Chiralitätsübertragung bei der Addition von (α-Chlorallyl)boronsäureestern an AldehydeDie Darstellung des (α-Chlorallyl)boronsäureesters 4 mit 92% e.e. wird beschrieben. Seine Addition an achirale Aldehyde ergab die Homoallylkohole 6 mit 82-92% e.e. Bei der Addition von ent-4 an Isopropylidenglycerinaldehyd (22) führte die kooperative Diastereoseitendifferenzierung zum Produkt 23 hoher Diastereomerenreinheit. In der Reaktion von 4 mit 22 ergab die Stereokontrolle durch das Reagenz den Alkohol 25 mit einer Diastereomerenreinheit von 77%.
    Notes: The preparation of the (α-chloroallyl)boronate 4 of 92% e.e. is described. Its addition to achiral aldehydes resulted in the homoallyl alcohols 6 of 82-92% e.e. Cooperative diastereoface selectivity on addition of ent-4 to isopropylideneglyceraldehyde (22) gave the product 23 of high diastereomeric purity. Reagent control of stereoselectivity on addition of 4 to 22 resulted in 25 of 77% diastereomeric purity.
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    Reaktionen mit Aziridinen, 36. Arenhydride, 2. SN2- und SET-Reaktionen von N-Acylaziridinen mit Diphenylmethanid und „Naphthalinhydrid“ (Anion von Dihydronaphthalin) (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2050-2054 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Reactions with Aziridines, 36 Arene Hydrides 2. SN2 and SET Reactions of N-Acylaziridines with Diphenylmethanide and „Naphthalene Hydride“ (Anion of Dihydronaphthalene)Diphenylmethane is incompletely deprotonated by sodium naphthalenide in THF so that some „naphthalene hydride“ 4 (anion of 1,4-dihydronaphthalene) remains present in the deprotonation equilibrium. The generated diphenylmethanide anion 3a reacts with the N-acylaziridines 6a-c to form the expected amidoethyl derivatives 7a-c in yields of less than 50%. The formation of by-products from 6b and 6c can be rationlized on the basis of classic ionic mechanisms. However, for 6a the by-product N-ethylbenzamide clearly points to a SET mechanism with „naphthalene hydride“ 4 as the electron source and with the radical 8 as a hydrogen source.
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    URL: http://dx.doi.org/10.1002/cber.19861190624
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    Der Einfluß von Phenylgruppen auf die Homokonjugation im Bicyclo[3.2.1]octa-3,6-dien-2-yl-Anion. Eine 13C-NMR-Studie (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2025-2049 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: The Effect of Phenyl Groups on the Homoconjugation in the Bicyclo[3.2.1]octa-3,6-dien-2-yl Anion. A 13C NMR StudyThe effects of deuterium atoms in the positions 2 and 4 of exo-6-bromo- (11) and endo-6-methoxytricyclo[3.2.1.02,7]oct-3-ene (12) as well as exo-4-methoxybicyclo[3.2.1]octa-2,6-diene (13) on their 13C chemical shifts are in line with the previous interpretation of the effects in correspondingly deuterated bicyclo[3.2.1]octa-3,6-dien-2-yl anions 1, and thus provide evidence for the homoconjugative interaction in 1. 3-Phenylbicyclo[3.2.1]octa-2,6-diene (16) and endo- (19a) as well as exo-4-phenylbicyclo[3.2.1]octa-2,6-diene (19b) have been prepared from bicyclo[3.2.1]oct-6-en-3-one (14) and bicyclo[3.1.0]hex-2-ene-endo-6-carbaldehyde (17), respectively. 2,4-Diphenylbicyclo[3.2.1]octa-2,6-diene (6) and 19a, b were deprotonated by methyllithium and n-butyllithium, respectively, whereas the proton abstraction from tricyclo[6.3.1.02,7]dodeca-2,4,6,9-triene (4) and from 16 required potassium tert-butoxide/n-butyllithium. As products the corresponding bicyclo[3.2.1]octa-3,6-dien-2-yl anion derivatives have been identified. By means of potassium tert-butoxide/n-butyllithium 19a, b were converted into 21K, i.e. the anion with K+ as counterion. The NMR spectra of 21Li turned out to depend upon the temperature in the range between +45 and -30°C in contrast to those of 21K. The 13C NMR spectra of the anions and of the corresponding hydrocarbons are discussed in detail in relation to the spectra of the unsubstituted species 1 and 2. In particular, the wide variations of the chemical shifts of C-6,7 depending upon the substituents of the allylic moiety of the bicyclo[3.2.1]octa-3,6-dien-2-yl anion system give strong support for the bishomoaromatic nature of these anions.
    Notes: Die Effekte von Deuteriumatomen in den Positionen 1 und 4 von exo-6-Brom- (11) und endo-6-Methoxytricyclo[3.2.1.02,7]oct-3-en (12) sowie exo-4-Methoxybicyclo[3.2.1]octa-2,6-dien (13) auf deren 13C-chemische Verschiebungen stützen die frühere Interpretation der Effekte bei entsprechend deuterierten Bicyclo[3.2.1]octa-3,6-dien-2-yl-Anionen 1 und belegen so die homokonjugative Wechselwirkung in 1.  -  Ausgehend von Bicyclo[3.2.1]oct-6-en-3-on (14) und Bicyclo[3.1.0]hex-2-en-endo-6-carbaldehyd (17) stellte man 3-Phenyl- (16) bzw. endo-4-Phenyl-(19a) und exo-4-Phenylbicyclo[3.2.1]octa-2,6-dien (19b) dar. 2,4-Diphenylbicyclo[3.2.1]octa-2,6-dien (6) und 19a, b wurden mit Methyllithium bzw. n-Butyllithium, Tricyclo[6.3.1.02,7]dodeca-2,4,6,9-tetraen (4) sowie 16 mit Kalium-tert-butoxid/n-Butyllithium deprotoniert, wobei die entsprechenden Bicyclo[3.2.1]octa-3,6-dien-2-yl-Anionderivate 7, 21Li, 5 und 22 entstanden. Aus 19a, b wurde mit Kalium-tert-butoxid/n-Butyllithium auch 21K, d. h. das zugehörige Anion mit K+ als Gegenion erhalten. Die NMR-Spektren von 21Li erwiesen sich im Gegensatz zu jenen von 21K im Bereich von +45 bis -30°C als temperaturabhängig. Die 13C-NMR-Spektren der Anionen und der zugehörigen Kohlenwasserstoffe werden im Vergleich mit den Spektren der unsubstituierten Verbindungen 1 und 2 ausführlich diskutiert. Insbesondere die starken Variationen der chemischen Verschiebungen von C-6,7 in Abhängigkeit von den Substitutenten am Allylteil des Bicyclo[3.2.1]octa-3,6-dien-2-yl-Anionsystems bieten ein starkes Argument für die bishomoaromatische Natur dieser Anionen.
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    Masthead (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986) 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190701
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  • 86
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    3-Alkylchinolizinium-iodide aus metalliertem α-Picolin und 3-Ethoxyacroleinen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2062-2065 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: 3-Alkylquinolizinium Iodides from Metalated α-Picoline and 3-Ethoxyacroleins2-Alkylquinolizinium iodides 4 are obtained in good overall yields by treating lithiated 2-methylpyridine 1 with 2-alkyl-3-ethoxyacroleins 2. 3-Alkyl-4-ethoxy-1-(2-pyridyl)-3-buten-2-ols 3 are isolated as primary products which readily cyclize to give the title compounds 4 upon heating in aqueous hydrogen iodide.
    Additional Material: 3 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19861190627
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  • 87
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    Functionally substituted vinyl carbanions, 29. Reaction of a β-lithiated acrylate with oxetanes as electrophiles (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2066-2068 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: Funktionell substituierte Vinylcarbanionen, 29. Reaktion einer β-lithiierten Acrylsäure mit Oxetanen als Electrophilβ-Lithiiertes β-(Ethylthio)acrylat 1A reagiert mit den Oxetanen 2 bzw. (±)-5 in Anwesenheit von Bortrifluorid-Ether zu den entsprechenden γ-hydroxypropyl-substituierten Derivaten 3 bzw. 6. Von den 2-Alkyl/phenyl-3-ethoxy-oxetanen (±)-5 reagieren die erythro-Derivate deutlich rascher als die threo-Derivate.
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    URL: http://dx.doi.org/10.1002/cber.19861190628
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  • 88
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    1,3-Dioxetanylium-Ionen als Zwischenstufe bei der anodischen Oxidation O-benzoylierter α-Hydroxyessigsäuren? (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2173-2177 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Anodic Oxidation of O-Benzoylated α-Hydroxyacetic Acids Concerning the Structure of the Cationic IntermediateAnodic oxidation of ([carbonyl-18O]benzoyloxy)acetic acid (1b) at graphite electrodes in methanol leads to the substitution product methoxymethyl benzoate (3) as well as the fragmentation product methyl benzoate (4) recovering all labeled oxygen in the carbonyl groups. This result proves that the 1,3-dioxetanylium ion 2′ is not involved in the non-Kolbe electrolysis of O-benzoylated α-hydroxyacetic acids. The cationic intermediate 2 is of open-chain structure.
    Notes: Die anodische Oxidation von ([Carbonyl-18O]Benzoyloxy)essigsäure (1b) an Graphitelektroden in Methanol liefert unter Erhaltung des markierten Sauerstoffs in der Carbonylposition das Substitutionsprodukt Benzoesäure-methoxymethylester (3) und das Fragmentierungsprodukt Benzoesäure-methylester (4). Damit wird die Beteiligung eines 1,3-Dioxetanylium-Ions 2′ an der Elektrolyse von O-benzoylierten α-Hydroxyessigsäuren ausgeschlossen. Die kationische Zwischenstufe 2 ist offenkettig.
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    URL: http://dx.doi.org/10.1002/cber.19861190712
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  • 89
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    Neue Synthesen von 2-Acylbenzofuranen, 2-Acylindolen, 2-Indolycarbonsäureestern und 2-Chinolonen durch intramolekulare Wittig-Reaktion (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2069-2074 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Notes: New Syntheses of 2-Acylbenzofurans, 2-Acylindoles, 2-Indolylcarboxylates, and 2-Quinolones by Intramolecular Wittig ReactionThe title compounds are obtained by intramolecular Wittig reaction of 2-(α-ketoacyloxy)-, 2-(α-ketoacylamino)-, or 2-[(ω-alkoxycarbonylacyl)amino]benzyltriphenylphosphonium salts, respectively.
    Additional Material: 2 Tab.
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    URL: http://dx.doi.org/10.1002/cber.19861190629
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  • 90
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    Beiträge zur Chemie des Bors, 173. Über Salze des Bis(diisopropylamino)bor(1+)-Kations (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2075-2079 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Contributions to the Chemistry of Boron, 173. Salts of the Bis(diisopropylamino)boron(1+) CationBromobis(diisopropylamino)borane (1) reacts with aluminium and gallium tribromide to produce stable salts of type [(iPr2N)2B]EBr4 (2, 3). Silver triflate converts 1 into bis(diisopropylamino)[(trifluoromethyl)sulfonyloxy]borane (4), while silver tetratriflatoborate produces a mixture of 4 with the salt [(iPr2N)2B]B(OSO2CF3)4 (6). Furthermore (diisopropylamino)bis[(trifluoromethyl)sulfonyloxy]borane (7) is formed.
    Notes: Bis(diisopropylamino)borbromid (1) reagiert mit Aluminium-oder Galliumtribromid zu den stabilen Salzen [(iPr2N)2B]EBr4 (2, 3), während 1 mit Silber-triflat Bis(diisopropylamino)-[(trifluormethyl)sulfonyloxy]boran (4) liefert. Silber-tetratriflatoborat setzt sich mit 1 zu einem Gemisch von 4 mit dem Salz [(iPr2N)2B]B(OSO2CF3)4 (6) um. Ferner entsteht (Diisopropylamino)bis[(trifluormethyl)sulfonyloxy]boran (7).
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190702
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  • 91
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    Synthese und physikalische Eigenschaften neuer 1,3-Dithiolylium-4-methanide und 1,3-Thiazolium-5-methanide (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2094-2103 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthesis and Physical Properties of Novel 1,3-Dithiolylium-4-methanides and 1,3-Thiazolium-5-methanidesThe synthesis and physical properties of the novel title compounds of type 9 from carboxylic acid derivatives 3 and CH acidic compounds 4 are described.
    Notes: Die Synthese und physikalischen Eigenschaften der neuen Titelverbindungen vom Typ 9 aus Carbonsäure-Derivaten 3 und CH-aciden Verbindungen 4 werden beschrieben.
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    URL: http://dx.doi.org/10.1002/cber.19861190704
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  • 92
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    Neue schwefelverbrückte Dreiringverbindungen vom Typ der Dianion-sulfide und der Thiocarbonyl-ylide (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2104-2113 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Novel Sulfur-bridged Three-membered Ring Compounds of the Type of the Dianion Sulfides and of the Thiocarbonyl YlidesReaction of the potassium salts of the thiodeltates 4a,b with the deltaines 5a,b results in the formation of novel dianion sulfide salts 1a-c. Thiocarbonyl ylide 7a-d and 8a-d, respectively, with cyclopropenium and deltate functions are prepared by the reaction of the thiones 6a-d with the deltaines 5a,b or of the cyclopropenium salt 9 with the potassium thiodeltate 4a. Interestingly, treatment of the sulfur-bridged dianion 1d with the dication 10 also yields the thiocarbonyl ylide 7d. The spectroscopic data of the new compounds 1, 7, and 8 are discussed, the 13C NMR data of the thiocarbonyl ylides are compared with those of the dianion and dikation sulfides.
    Notes: Neue Dianion-sulfide 1a-c entstehen bei der Reaktion der Kaliumsalze von Thiodeltaten 4a,b mit den Deltainen 5a,b. Die Darstellung neuer Thiocarbonyl-ylide 7a-d bzw. 8a-d mit Cyclopropenium- und Deltatfunktionen gelingt durch Umsetzung der Thione 6a-d mit den Deltainen 5a,b oder aus dem Cyclopropenium-Salz 9 mit dem Kalium-thiodeltat 4a. Interessanterweise entsteht das Thiocarbonyl-ylid 7d auch durch Umsetzung des schwefelverbrückten Dianions 1d mit dem Dikation 10. Die spektrometrischen Daten der neuen Verbindungen 1,7 und 8 werden diskutiert und die 13C-NMR-Daten der Thiocarbonyl-ylide mit denen der Dianion- und Dikation-sulfide verglichen.
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    URL: http://dx.doi.org/10.1002/cber.19861190705
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    Metallaheterocumulene, IV. 2-Azaallyliden-Komplexe  -  neuartige Verbindungen mit einem gewinkelten CNCR2-Fragment als Komplexligand (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2080-2093 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Metallaheterocumulenes, IV. 2-Azaallylidene Complexes  -  Novel Compounds with a Bent CNCR2 Fragment as Complex Ligand(2-Azoniaallenylidene)pentacarbonyltungsten tetrabromoaluminate complexes [(CO)5W(CNCR2)]+AlBr4- (2-AlBr4) (CR2=C(C6H4Br-4)2 (a), CPh2 (b), C(C6H4OMe-4)2 (c), C(C6H4)2O (d), C(2,4,6-C6H2Me3)2 (e)) Which are synthesized by the reaction of (CO)5W[C(OEt)N=CR2] (1) with AlBr3, react with freshly distilled tetrahydrofuran to give neural trans-bromo(2-azaallylidene) complexes trans-Br(CO)4W(CNCR2) (3) and small amounts of (CO)5W—C≡N—[CR2]2—N≡C—W(CO)5 (4). The compounds 4 correspond to the product of a reductive dimerization of two cations 2. If 1b (or the corresponding methoxy compound 5) reacts with BBr3 instead of AlBr3/THF 4b is the main product. The spectroscopic data of 3 and the results of an X-ray analysis of 3b show that the replacement of a CO ligand in the cations 2 by Br- with formation of 3 results in a drastic change of the bonding situation within the CNCR2 ligand. 3a-e are the first compounds in which a strongly bent CNCR2 fragment functions as a complex ligand. The aminocarbyne complex trans-Br(CO)4W≡CNPh2 (7) was synthesized by BBr3-induced fragmentation of (CO)5W[C(NPh2)N=C(Ph)OMe] (6).
    Notes: (2-Azoniaallenyliden)pentacarbonylwolfram-tetrabromoaluminat-Komplexe [(CO)5W(CNCR2)]+AlBr4- (2-AlBr4) (CR2=C(C6H4Br-4)2 (a), CPh2 (b), C(C6H4OMe-4)2 (c), C(C6H4)2O (d), C(2,4,6-C6H2Me3)2 (e))  -  darstellbar durch Umsetzung von (CO)5W[C(OEt)N=CR2] (1) mit Albr3  -  reagieren mit frisch destillierten Tetrahydrofuran zu neutralen trans-Bromo(2-azaallyliden)-Komplexen trans-Br(CO)4W(CNCR2) (3) und wenig (CO)5W—C≡N—[CR2]2—N≡C—W(CO)5 (4). Die Verbindungen 4. entsprechen dem Produkt einer reduktiven Dimerisierung zweier Kationen 2. 4b wird zum Hauptprodukt der Umsetzung, wenn 1b (oder der entsprechende Methoxy-Komplex 5) mit BBr3 anstatt AlBr3/THF umgesetzt wird. Wie die spektroskopischen Daten von 3 sowie die Ergebnisse der an 3b durchgeführten Röntgenstrukturanalyse zeigen, führt der Austausch eines CO-Liganden in den Kationen 2 gegen Br- unter Bildung von 3 zu einer drastischen Veränderung der Bindungsverhältnisse im CNCR2-Liganden. 3a-e sind die ersten Verbindungen, in denen ein stark gewinkeltes CNCR2-Fragment als Komplexligand fungiert. Durch BBr3-induzierte Fragmentierung von (CO)5W[C(NPh2)N=C(Ph)OMe] (6) wurde der Aminocarbin-Komplex trans-Br(CO)4W≡CNPh2 (7) dargestellt.
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    Reaktionen von Cyanformamidinen mit Hexafluoraceton (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2127-2134 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Reaction of Cyanoformamidines with HexafluroacetoneHexafluoroacetone(HFA) reacts with N,N-dialkylcyanoformamidines in one step under mild conditions to form 4-(dialkylamino)-2,5-dihydro-5-imino-2,2-bis(trifluoromethyl)oxazoles 1a-d. 1a,b react further with HFA to yield the N′-(hydroxyhexafluoroisopropyl)-substituted derivatives 2a,b. Under the catalytic influence of copper powder in DMF 1a,b, rearrange to give 1,2-dihydro-2,2-bis(trifluromethyl)-5H-imidazol-5-ones 3a,b in good yields. The activation parameters of the hindered rotation of the C-4—N bond of 1a,c and 3a are reported.
    Notes: Hexafluoraceton (HFA) reagiert mit N,N-Dialkylcyanformamidinen in einem Reaktionsschritt unter milden Bedingungen zu 4-(Dialkylamino)-2,5-dihydro-5-imino-2,2-bis(trifluormethyl)oxazolen 1a-d. 1a,b könne mit weiterem HFA zu den N′-(hydroxyhexafluorisopropyl)substituierten Derivaten 2a,b umgesetzt werden. Unter der katalytischen Wirkung von Kupferpulver in DMF gelingt die Umlagerung von 1a,b in 1,2-Dihydro-2,2-bis(trifluormethyl)-5H-imidazol-5-one 3a,b in guten Ausbeuten. Von 1a,c und 3a wurden durch 1H-DNMR-Untersuchungen die Aktivierungsparameter der gehinderten Rotation um die C-4—N-Bindung bestimmt.
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    URL: http://dx.doi.org/10.1002/cber.19861190707
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    Heterocyclische β-Enaminoester, 41. Vinylogieprinzip bei 6,7-Dihydro-1H-azepinen; Cycloaddition und neuartige Umlagerung zu 2,3,3a,7a-Tetrahydroindolen.  -  Thermische [2 + 2]-Cycloadditionen mit 4-R-TAD (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2114-2126 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Heterocyclic β-Enamino Esters, 41. Vinylogeous Principle on 6,7-Dihydro-1H-azepines; Cycloaddition and Novel Rearrangement to 2,3,3a,7a-Tetrahydroindoles.  -  Thermal [2 + 2]-Cycloadditions with 4-R-TADThe conjugated π-Systems of 6,7-dihydrooxepines, -thiepines, and -azepines (1-5) show a remarkable alternance of their 13C NMR shifts. In a cycloaddition-ring enlargement sequence the 6,7-dihydroazepine 3 reacts with acetylenedicarboxylates at the 4,5-double bond to afford first the intermediary 8,9-dihydro-1H-azonines 6B. These give in turn the indoles 7a,b via thermal 6π-electron cyclization. Under subsequent rearrangement 2,3,3a,7a-tetrahydroindoles 8a,b are formed. The structure of 8a is established by X-ray diffraction. In a polar [2 + 2]-cycloaddition 4-R-1,2,4-triazoline-3,5-dione (4-R-TAD) gives with 3 and 5 the [1,2,4]triazolo[1′,2′:1,2]diazet-[3,4-d]azepines 10a-d and 11a,b resp., and with the bis-TAD 12 the 2:1-adduct 13. Treatment of 10a with phenyl isocyanate originates the carbodiimide 14 which is converted with basic ring closure into the pyrimido[4,5-b]azepine 15.
    Notes: 6,7-Dihydrooxepine, -thiepine und -azepine (1-5) zeigen eine ausgeprägte Alternanz ihrer 13C-NMR-Verschiebungen im konjugierten π-System. Das 6,7-Dihydroazepin 3 reagiert mit Acetylendicarbonsäureestern zunächst unter Cycloaddition-Ringerweiterung an der 4,5-Doppelbindung zu den intermediären 8,9-Dihydro-1H-azoninen 6b. Diese ergeben sogleich unter thermischem 6π-Elektronenringschluß die Indole 7a,b. Nach erneuter Umlagerung entstehen 2,3,3a,7a-Tetrahydroindole 8a,b; die Konstitution von 8a wird durch Röntgenstrukturanalyse ermittelt. Mit 4-R-1,2,4-Triazolin-3,5-dionen (4-R-TAD) entstehen aus 3 und 5 in polarer [2 + 2]-Cycloaddition die [1,2,4]Triazolo[1′,2′:1,2]diazet[3,4-d]azepine 10a-d und 11a,b mit dem Bis-TAD 12 das 2:1-Addukt 13. 10a ergibt mit Phenylisocyanat das Carbodiimid 14 und beim basischen Ringschluß das Pyrimido[4,5-b]azepin 15.
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    Neue Reagenzien, XXXVII. (α-Lithioalkyl)diphenylarsanoxide: Synthese und Anwendung zur indirekten nucleophilen Haloalkylierung (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2135-2142 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Reagents, XXXVII. (α-Lithioalkyl)diphenylarsane Oxides: Synthesis and Application for the Indirect Nucleophilic HaloalkylationDue to ready accessibility and high nucleophilicity (α-lithioalkyl)diphenylarsane oxides (2) are favorable reagents for the synthesis of many organoarsenic compounds. In organic synthesis they are recommendable as reagents for indirect nucleophilic haloalkylation reactions (Hal=Cl, Br, I).
    Notes: (α-Lithioalkyl)diphenylarsanoxide (2) sind wegen ihrer bequemen Zugänglichkeit und hohen Nucleophilie günstige Reagenzien zur Darstellung zahlreicher Organoarsenverbindungen. In der organischen Synthese sind sie als Reagenzien für indirekte nucleophile Haloalkylierungen (Hal=Cl, Br, I) empfehlenswert.
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    Neue Reagenzien, XXXVIII. Über die extreme Diastereoselektivität bei der Addition von (α-Lithioalkyl)diphenylarsanoxiden an Benzaldehyd und Acetophenon (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2143-2149 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Reagents, XXXVIII. Addition of (α-Lithioalkyl)diphenylarsane Oxides to Benzaldehyde and Acetophenone with Extreme DiastereoselectivityIn contrast to α-lithiated alkyldiphenylphosphane oxides, the α-lithiated alkyldiphenylarsane oxides 3a and b react extremely diastereoselectively with benzaldehyde to give the alcohols erythro-4a and erythro-4b, respectively. Analogously, 3b reacts extremely diastereoselectively with acetophenone, whereas by reaction with aliphatic aldehydes a mixture of two diastereomeric alcohols (erythro:threo = 1.5-1.7:1) is formed.
    Notes: Im Gegensatz zu α-lithiierten Alkyldiphenylphosphanoxiden reagieren die α-lithiierten Alkyldiphenylarsanoxide 3a und b hoch diastereoselektiv mit Benzaldehyd zu den Alkoholen erythro 4a bzw. erythro-4b. Auch mit Acetophenon reagiert 3b extrem diastereoselektiv, während bei der Umsetzung mit aliphatischen Aldehyden ein Diastereomeren-Gemisch anfällt (erythro:threo = 1.5-1.7:1).
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    Neue Reagenzien, XXXIX. Optimierung der Diastereo- und Aldehydselektivität von Horner-Reagenzien durch Modifizierung der Struktur (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2150-2158 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: New Reagents, XXXIX. Optimization of the Diastereo- and Aldehyde Selectivity of Horner-Type Reagents by Modification of the StructureIntroduction of an ortho-substituent in the phenyl residues of (α-lithiobutyl)diphenylphosphane oxide (7) increases the diastereoselectivity in the reaction with benzaldehyde. (α-Lithiobutyl)bis(2-methoxyphenyl)phosphane oxide (9) gave the erythro-product 12 even exclusively by reacting with benzaldehyde.  -  Exchange of the lithium atom of (lithiomethyl)-diphenylphosphane oxide (17) for chromium or titanium brought about much better aldehyde selectivity in competition experiments with benzaldehyde and acetophenone.
    Notes: Durch Einführung eines ortho-Substituenten in die Phenylreste von (α-Lithiobutyl)diphenylphosphanoxid (7) wird die Diastereoselektivität bei der Umsetzung mit Benzaldehyd gesteigert. (α-Lithiobutyl)bis(2-methoxyphenyl)phosphanoxid (9) reagierte mit Benzaldehyd sogar ausschließlich zum erythro-Produkt 12.  -  Der Austausch des Lithiumatoms von (Lithiomethyl)diphenylphosphanoxid (17) gegen Chrom oder Titan führte zu stark erhöhter Aldehydselektivität bei Konkurrenzversuchen mit dem Substratpaar Benzaldehyd/Acetophenon.
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    Enantioselective diastereospecific synthesis of anti-α-alkyl-β-hydroxy esters through cuprate opening of glycidic esters (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2178-2190 
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    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Enantioselektive diastereospezifische Synthese von anti-α-Alkyl-β-hydroxycarbonsäureestern durch Cuprat-Ringöffnung von GlycidesternEine über die Zwischenglieder 4-7 ablaufende diastereospezifische Kettenverlängerung von Aldehyden 1 zu anti-α-Alkyl-β-hydroxyestern 2 wird beschrieben. Durch Verwendung der Sharpless-Epoxidierung kann 2 mit Enantiomerenüberschüssen von 〉90% in Form beider Antipoden erhalten werden.
    Notes: A diastereospecific chain elongation of the aldehydes 1 of anti-α-alkyl-β-hydroxy esters 2 via the intermediates 4-7 is described. By means of the Sharpless epoxidation, 2 may be obtained with 〉90% ee in either enantiomer.
    Additional Material: 4 Tab.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190713
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  • 100
    Electronic Resource
    Electronic Resource
    Synthesen mit Cyclobutadienen, 13. Azapentafulvene aus 2,3,4-Tri-tert-butylcyclobutadien-1-carbonsäureestern und Isonitrilen (1986)
    Weinheim : Wiley-Blackwell
    Berichte der deutschen chemischen Gesellschaft 119 (1986), S. 2159-2172 
    Details
    ISSN: 0009-2940
    Keywords: Chemistry ; Inorganic Chemistry
    Source: Wiley InterScience Backfile Collection 1832-2000
    Topics: Chemistry and Pharmacology
    Description / Table of Contents: Synthese with Cyclobutadienes, 13. Azapentafulvenes from 2,3,4-Tri-tert-butylcyclobutadiene-1-carboxylic Esters and IsonitrilesFrom kinetically stabilized cyclobutadienes 6a and b and isonitriles 7a-c the azapentafulvenes 9a-d are obtained. In contrast, 6a reacts with 7d exclusively to form the constitution isomeric azapentafulvene 11e. Both isomers (9f and 11f) are realized in the reaction of 6a with 7e. The structural assignment of the isomers 9 and 11 is based on 13C NMR investigations as well as on an X-ray analysis performed for 9a. Hydrolysis of 9 and 11 yields the tri-tert-butyl substituted cyclopentadienones 20a,b and 21. By photochemical means 21 is transformed into the isomer 20a, which can also be obtained directly from the cyclobutadiene 6a and carbon monoxide.
    Notes: Aus den kinetisch stabilisierten Cyclobutadienen 6a bzw. b und den Isonitrilen 7a-c erhält man die Azapentafulvene 9a-d. Im Gegensatz dazu reagiert 6a mit 7d ausschließlich unter Bildung des konstitutionsisomeren Azapentafulvens 11e. Beide Möglichkeiten (9f und 11f) werden bei der Umsetzung von 6a mit 7e wahrgenommen. Die Strukturzuordnung der Isomeren 9 und 11 beruht auf 13C-NMR-Untersuchungen sowie auf der Röntgenstrukturanalyse für 9a. Hydrolyse von 9 und 11 macht die tri-tert-butylsubstituierten Cyclopentadienone 20a,b und 21 zugänglich. Photochemisch läßt sich 21 in das Isomere 20a umwandeln, das auch unmittelbar aus dem Cyclobutadien 6a und Kohlenmonoxid erhalten werden kann.
    Additional Material: 1 Ill.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1002/cber.19861190711
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