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  • 1
    Electronic Resource
    Electronic Resource
    Species-specific aggregation factor in sponges (1978)
    Springer
    Development genes and evolution 184 (1978), S. 29-40 
    Details
    ISSN: 1432-041X
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Summary Isolated cells from the siliceous spongeGeodia cydonium have been studied with respect to their partition behaviour in a two-phase aqueous polymer system. With this method it is possible to determine subtle changes in the cell surface charge. Addition of a homologous aggregation factor to the isolated cells lowers the partition rate, a finding which indicates that after binding of the aggregation factor to the cells their surface charge is reduced. The partition rate of the cells is strongly correlated with their content of membranebound sialic acid. Sixty-nine percent of the total, membrane-bound hexuronic acid is associated with the aggregation receptor; 1.8×107 aggregation receptor molecules are present on the surface of one cell which means that the average surface density amounts to 2.8×105 molecules per μm2. Removal of the aggregation receptor molecules from the cell surface results in a decrease of the partition rate in the two-phase system. After charging the receptor-depleted cells with soluble aggregation receptor, the partition behaviour of these cells can be reconstituted.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00848667
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  • 2
    Electronic Resource
    Electronic Resource
    Experimental Indication in Favor of the Introns-Late Theory: The Receptor Tyrosine Kinase Gene from the Sponge Geodia cydonium (1997)
    Springer
    Journal of molecular evolution 44 (1997), S. 242 -252 
    Details
    ISSN: 1432-1432
    Keywords: Key words:Geodia cydonium— Sponge — Metazoan protein molecules
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract. We have analyzed the gene that encodes receptor tyrosine kinase (RTK) from the marine sponge Geodia cydonium, which belongs to the most ancient and simple metazoan groups, the Porifera. RTKs are enzymes found only in metazoa. The sponge gene contains two introns in the extracellular part of the protein. However, the rest of the protein (transmembrane and intracellular part), including the tyrosine kinase (TK)-domain, is encoded by a single exon. In contrast, all TK genes, so far known only from higher animals (vertebrates), contain several introns especially in the TK-domain. The TK-domain of G. cydonium shows similarity with numerous members of receptor as well as nonreceptor TKs. Phylogenetic analysis of the sponge TK-domain indicates that this enzyme branched off first from the common tree of metazoan TK proteins. Consequently, we assume that introns, found in the TK-domains of genes from higher animals, were inserted into these genes after splitting off the sponge taxa from other metazoan organisms (over 600 million years ago). Our results support the view that ancient genes were not ``in pieces.''
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00006141
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  • 3
    Electronic Resource
    Electronic Resource
    Phylogenetic Position of the Hexactinellida Within the Phylum Porifera Based on the Amino Acid Sequence of the Protein Kinase C from Rhabdocalyptus dawsoni (1998)
    Springer
    Journal of molecular evolution 46 (1998), S. 721-728 
    Details
    ISSN: 1432-1432
    Keywords: Key words: Glass sponge —Rhabdocalyptus dawsoni— Hexactinellida — Protein kinase C — Phylogeny — Molecular systematics — Molecular evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract. Recent analyses of genes encoding proteins typical for multicellularity, especially adhesion molecules and receptors, favor the conclusion that all metazoan phyla, including the phylum Porifera (sponges), are of monophyletic origin. However, none of these data includes cDNA encoding a protein from the sponge class Hexactinellida. We have now isolated and characterized the cDNA encoding a protein kinase C, belonging to the C subfamily (cPKC), from the hexactinellid sponge Rhabdocalyptus dawsoni. The two conserved regions, the regulatory part with the pseudosubstrate site, the two zinc fingers, and the C2 domain, as well as the catalytic domain were used for phylogenetic analyses. Sequence alignment and construction of a phylogenetic tree from the catalytic domains revealed that the yeast Saccharomyces cerevisiae and the protozoan Trypanosoma brucei are at the base of the tree, while the hexactinellid R. dawsoni branches off first among the metazoan sequences; the other two classes of the Porifera, the Calcarea (the sequence from Sycon raphanus was used) and the Demospongiae (sequences from Geodia cydonium and Suberites domuncula were used), branch off later. The statistically robust tree also shows that the two cPKC sequences from the higher invertebrates Drosophila melanogaster and Lytechinus pictus are most closely related to the calcareous sponge. This finding was also confirmed by comparing the regulatory part of the kinase gene. We suggest, that (i) within the phylum Porifera, the class Hexactinellida diverged first from a common ancestor to the Calcarea and the Demospongiae, which both appeared later, and (ii) the higher invertebrates are more closely related to the calcareous sponges.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00006353
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  • 4
    Electronic Resource
    Electronic Resource
    Phylogenetic relationship of ubiquitin repeats in the polyubiquitin gene from the marine sponge Geodia cydonium (1994)
    Springer
    Journal of molecular evolution 39 (1994), S. 369-377 
    Details
    ISSN: 1432-1432
    Keywords: Ubiquitin ; Phylogeny ; Sponges ; Geodia cydonium ; Evolution strategy
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Ubiquitin is a 76-residue protein which is highly conserved among eukaryotes. Sponge (Porifera) ubiquitin, isolated from Geodia cydonium, is encoded by a gene (termed GCUBI) with six repeats, GCUBI-1 to GCUBI-6. All repeat units encode the same protein (with one exception: GCUBI-4 encodes ubiquitin with a change of Leu to Val at position 71). On the nt level the sequences of the six repeats differ considerably. All changes (except in GCUBI-4) are silent substitutions, which do not affect the protein structure. However, there is one major difference between the repeats: Codons from both codon families (TCN and AGPy) are simultaneously used for the serine at position 65. Using this characteristic the repeats were divided into two groups: Group I: GCUBI-1,3 (TCT codon) and GCUBI-5 (TCC); Group II: GCUBI-2,4,6 (AGC codon). Mutational analysis suggests that the sponge polyubiquitin gene evolved from an ancestral monoubiquitin gene by gene duplication and successive tandem duplications. The ancestral monoubiquitin gene most probably coded for threonine (ACC) at position 65. The first event, duplication of the monoubiquitin gene, happened some 110 million years ago. Since sponges from the genus Geodia are known from the Cretaceous (145 million) to recent time, it is very likely that all events in the evolution of polyubiquitin gene occurred in the same genus. Alignment data of the “consensus” ubiquitin nt sequences of different animals (man to protozoa) reflect very well the established phylogenetic relationships of the chosen organisms and show that the sponge ubiquitin gene branched off first from the multicellular organisms.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00160269
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  • 5
    Electronic Resource
    Electronic Resource
    Molecular evolution of the Metazoan protein kinase C multigene family (1996)
    Springer
    Journal of molecular evolution 43 (1996), S. 374-383 
    Details
    ISSN: 1432-1432
    Keywords: Sponges ; Geodia cydonium ; Serine/threonine kinases ; Phylogeny ; Molecular systematics ; Molecular evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract Protein kinases C (PKCs) comprise closely related Ser/Thr kinases, ubiquitously present in animal tissues; they respond to second messengers, e.g., Ca2+ and/or diacylglycerol, to express their activities. Two PKCs have been sequenced fromGeodia cydonium, a member of the lowest multicellular animals, the sponges (Porifera). One spongeG. cydonium PKC, GCPKC1, belongs to the “novel” (Ca2+-independent) PKC (nPKC) subfamily while the second one, GCPKC2, has the hallmarks of the “conventional” (Ca2+-dependent) PKC (cPKC) subfamily. The alignment of the Ser/Thr catalytic kinase domains, of the predicted as sequences for these cDNAs with respective segments from previously reported sequences, revealed highest homology to PKCs from animals but also distant relationships to Ser/Thr kinases from protozoa, plants, and bacteria. However, a comparison of the complete structures of the sponge PKCs, which are-already-identical to those of nPKCs and cPKCs from higher metazoa, with the structures of protozoan, plant, and bacterial Ser/Thr kinases indicates that the metazoan PKCs have to be distinguished from the nonmetazoan enzymes. These data indicate that metazoan PKCs have a universal common ancestor which they share with the nonmetazoan Ser/Thr kinases with respect to the kinase domain, but they differ from them in overall structural composition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF02339011
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  • 6
    Electronic Resource
    Electronic Resource
    Molecular Evolution of the Metazoan Protein Kinase C Multigene Family (1996)
    Springer
    Journal of molecular evolution 43 (1996), S. 374-383 
    Details
    ISSN: 1432-1432
    Keywords: Key words: Sponges —Geodia cydonium— Serine/threonine kinases — Phylogeny — Molecular systematics — Molecular evolution
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology
    Notes: Abstract. Protein kinases C (PKCs) comprise closely related Ser/Thr kinases, ubiquitously present in animal tissues; they respond to second messengers, e.g., Ca2+ and/or diacylglycerol, to express their activities. Two PKCs have been sequenced from Geodia cydonium, a member of the lowest multicellular animals, the sponges (Porifera). One sponge G. cydonium PKC, GCPKC1, belongs to the ``novel'' (Ca2+-independent) PKC (nPKC) subfamily while the second one, GCPKC2, has the hallmarks of the ``conventional'' (Ca2+-dependent) PKC (cPKC) subfamily. The alignment of the Ser/Thr catalytic kinase domains, of the predicted aa sequences for these cDNAs with respective segments from previously reported sequences, revealed highest homology to PKCs from animals but also distant relationships to Ser/Thr kinases from protozoa, plants, and bacteria. However, a comparison of the complete structures of the sponge PKCs, which are—already—identical to those of nPKCs and cPKCs from higher metazoa, with the structures of protozoan, plant, and bacterial Ser/Thr kinases indicates that the metazoan PKCs have to be distinguished from the nonmetazoan enzymes. These data indicate that metazoan PKCs have a universal common ancestor which they share with the nonmetazoan Ser/Thr kinases with respect to the kinase domain, but they differ from them in overall structural composition.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/PL00006096
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  • 7
    Electronic Resource
    Electronic Resource
    Molecular cloning and primary structure of a Rhesus (Rh)-like protein from the marine sponge Geodia cydonium (1997)
    Springer
    Immunogenetics 46 (1997), S. 493-498 
    Details
    ISSN: 1432-1211
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  In humans, the 30 000 M r Rhesus (Rh) polypeptide D (RhD) is a dominant antigen (Ag) of the Rh blood group system. To date, an Rh-like protein has been found in chimpanzees, gorillas, gibbons, and rhesus monkeys. Related to the 30 000 M r Rh Ag protein are two polypeptides of 50 000 M r , the human 50 000 M r Rh Ag and the RhD-like protein from Caenorhabditis elegans. The function of all these proteins is not sufficiently known. Here we characterize a cDNA clone (GCRH) encoding a putative 57 000 M r polypeptide from the marine sponge Geodia cydonium, which shares sequence similarity both to the RhD Ag and the Rh50 glycoprotein. The sponge Rh-like protein comprises 523 aa residues; hydropathy analysis hints at the presence of ten transmembrane domains. An N-terminal hydrophobic cleavage signal sequence is missing, suggesting that the first membrane-spanning domain of the sponge Rh-like protein acts as a signal-anchor sequence. The sponge Rh-like protein, like the human Rh50, lacks the CLP motif which is characteristic of the 30 000 M r RhD. In addition, the hydropathy profile of the sponge Rh-like protein is of a similar size and shape as that of human Rh50. This data indicates that the RhD and its structurally related Rh50 glycoprotein, which are highly immunogenic in humans, share a common ancestral molecule with the G. cydonium Rh-like protein.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050310
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  • 8
    Electronic Resource
    Electronic Resource
    Cloning and expression of new receptors belonging to the immunoglobulin superfamily from the marine sponge Geodia cydonium (1999)
    Springer
    Immunogenetics 49 (1999), S. 751-763 
    Details
    ISSN: 1432-1211
    Keywords: Key words Sponges ; Geodia cydonium ; Ig-like domains ; Immune system ; Invertebrates
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Abstract  A cDNA encoding a receptor tyrosine kinase (RTK) was previously cloned and expressed from the marine sponge (Porifera) Geodia cydonium. In addition to the two intracellular regions characteristic for RTKs, two immunoglobulin (Ig)-like domains are found in the extracellular part of the sponge RTK. In the present study it is shown that no further Ig-like domain is present in the upstream region of the cDNA as well as of the gene hitherto known from the sponge RTK. Two different full-length cDNAs have been isolated and characterized in the present study, which possess two Ig-like domains, one transmembrane segment, and only a short intracellular part, without a TK domain. The two deduced polypeptides were preliminarily termed sponge adhesion molecules (SAM). The longer form of the SAM, GCSAML, encodes a deduced aa sequence, GCSAML, which comprises in the open reading frame 505 amino acids (aa) and has a calculated M r of 53911. The short form, GCSAMS, has 313 aa residues and an M r of 33987. The two Ig-like domains in GCSAML and GCSAMS are highly similar to the corresponding Ig-like domains in the RTKs from G. cydonium; the substitutions on both the aa and nt level are restricted to a few sites. Phylogenetic analyses revealed that the Ig-like domain 1 is similar to the human Ig lambda chain variable region, while the Ig-like domain 2 is related more closely to the human Ig heavy chain variable region. Transplantation experiments (autografting) were performed to demonstrate that the level of expression of the two new genes, GCSAML and GCSAMS, is upregulated during the self/self fusion process. Immunohistochemical analyses using antibodies raised against the two Ig-like domains demonstrate a strong expression in the fusion zone between graft and host. This finding has been supported by northern blotting experiments that revealed that especially GCSAML is strongly upregulated after autografting (up to 12-fold); the expression of GCSAMS reaches a value of 5-fold if compared with the controls. The results presented here demonstrate that the expression of the new molecules described, comprising two Ig-like domains, is upregulated during the process of autograft fusion.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/s002510050549
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  • 9
    Electronic Resource
    Electronic Resource
    Sponge cell aggregation (1980)
    Springer
    Molecular and cellular biochemistry 29 (1980), S. 131-143 
    Details
    ISSN: 1573-4919
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Chemistry and Pharmacology , Medicine
    Notes: Summary Dissociated sponge cell system has proved to be a useful model to study the process of cell aggregation both on cellular and subcellular level. The purpose of this review is to discuss recent results obtained from experiments with the marine sponge Geodia cydonium. Dissociated cells form functional aggregates during a process which can be sub-divided into three phases: first, formation of small primary aggregates in the presence of Ca2+; second, formation of secondary aggregates in the presence of an aggregation factor and third, reconstitution of a functional system of watercontaining channels by rearrangement in the secondary aggregates. On subcellular level a series of macromolecules are known which are involved in the control of aggregation and separation of sponge cells: Aggregation factor, aggregation receptor, anti-aggregation receptor, glucuronidase, ß-glucuronosyltransferase, ß- ß-galactosidase and a lectin. These components might be linked in the following sequence: (a) Activation of the aggregation receptor by its enzymic glucuronylation; (b) Adhesive recognition of the cells, mediated by the aggregation factor and the glucuronylated aggregation receptor; (c) Inactivation of the aggregation receptor by its deglucuronylation with the membrane-associated ß-glucuronidase; (d) Cell separation due to either the loss of the recognition site (glucuronic acid) of the aggregation receptor for the aggregation factor or to an inactivation of the aggregation factor by the anti-aggregation receptor. The activity of the anti-aggregation receptor is most likely controlled by the Geodia lectin. The events leading to cell-cell recognition cause a change in the following metabolic events: Increase of oxygen uptake, decrease of cyclic AMP level, increase of cyclic GMP level and stimulation of programmed syntheses.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF00420285
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  • 10
    Electronic Resource
    Electronic Resource
    Two different aggregation principles in reaggregation process of dissociated sponge cells (Geodia cydonium) (1974)
    Springer
    Cellular and molecular life sciences 30 (1974), S. 899-902 
    Details
    ISSN: 1420-9071
    Source: Springer Online Journal Archives 1860-2000
    Topics: Biology , Medicine
    Notes: Zusammenfassung Chemisch dissoziierte Zellen des KieselschwammesGeodia cydonium reaggregieren aufgrund zweier verschiedenr Reaggregationsprinzipien. Der Aggnegationsfaktor, auf den die Primäraggregation zurückgeht, ist membrangebunden und wird durch Proteasen nicht inaktiviert. Der sekundäre Aggregationsfaktor wurde 500fach angereichert. Das Molekulargewicht dieses Aggregationsfaktors beträgt etwa 20000 Daltons; er ist mit einem ringförmigen Makromolekül (2×109 Daltons) assoziiert.
    Type of Medium: Electronic Resource
    URL: http://dx.doi.org/10.1007/BF01938348
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