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  • Saccharomyces cerevisiae  (98)
  • Springer  (98)
  • Annual Reviews
  • Blackwell Publishing Ltd
  • Cambridge University Press
  • 2005-2009
  • 1990-1994  (98)
  • 1980-1984
  • 1993  (55)
  • 1990  (43)
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  • Springer  (98)
  • Annual Reviews
  • Blackwell Publishing Ltd
  • Cambridge University Press
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  • 2005-2009
  • 1990-1994  (98)
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  • 1
    ISSN: 1432-0983
    Schlagwort(e): 2-oxoglutarate dehydrogenase ; Saccharomyces cerevisiae ; rad52-mediated chromosome loss
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Ogd1 mutants of Saccharomyces cerevisiae are deficient in mitochondrial 2-oxoglutarate dehydrogenase activity; they cannot grow on glycerol and produce an increased amount of organic acids during growth on glucose as substrate. Using gamma ray-induced rad52-mediated chromosome loss the ogd1 mutation can be assigned to chromosome IX. Tetrad analysis of crosses between ogd1 and other markers on chromosome IX revealed that the OGD1 gene maps on the left arm of this chromosome 1.9 cM from his5.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 2
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Orotate phosphoribosyl transferase ; Nucleotide sequence-5-phosphoribosyl 1-pyrophosphate (5PRPP)
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Orotate phosphoribosyl transferase (OPRTase) catalyses the transformation of orotate to OMP in the pyrimidine pathway. In the yeast Saccharomyces cerevisiae, the URA5 gene is known to encode this enzyme activity. In this paper we present the cloning and sequencing of a yeast gene, named URA10, encoding a second OPRTase enzyme. Comparison of the predicted amino acid sequences between URA5 and URA10 genes shows more than 75% similarity. These sequences have also been compared to those of Escherichia coli, Podospora anserina, Sordaria macrospora and Dictyostelium discoideum. Remarkable similarities in the primary structure of these proteins have been found. Gene disruption experiments revealed that URA10 gene expression is responsible for the leaky phenotype of a ura5 mutant. Assays of OPRTase activity in extracts from ura5 and ura10 mutants indicate that the URA10 product contributes only 20% of the total activity found in wild type cells.
    Materialart: Digitale Medien
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  • 3
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Mutants ; Farnesyl diphosphate synthetase ; Ergosterol
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Two yeast mutant strains auxotrophic for ergosterol and blocked in farnesyl diphosphate synthetase (EC 2.5.1.1) were isolated. Genetic analysis has shown that these mutant strains carry additional mutations in the ergosterol pathway besides erg20-1 and erg20-2 which affect FPP synthetase. The novel feature of these mutants is their ability to excrete prenyl alcohols (farnesol and geraniol). As geraniol is toxic for yeast cells, the above leaky mutations in FPP synthetase have to be associated with others in the sterol pathway, in order to slow down geraniol synthesis.
    Materialart: Digitale Medien
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  • 4
    ISSN: 1432-0983
    Schlagwort(e): Glucose oxidase ; Aspergillus ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary We report the cloning of the Aspergillus niger glucose oxidase gene and its use to elevate glucose oxidase productivity in A. niger by increasing the gene dosage. In addition, the gene has been introduced into A. nidulans where it provides the novel capacity to produce glucose oxidase. A plasmid, in which DNA encoding the mature form of glucose oxidase was preceded by a Saccharomyces cerevisiae secretion signal, effected high-level production of extracellular glucose oxidase in this yeast.
    Materialart: Digitale Medien
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  • 5
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 18 (1990), S. 401-403 
    ISSN: 1432-0983
    Schlagwort(e): Baking yeast ; Saccharomyces cerevisiae ; Dough leavening ; Benomyl
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary To investigate the leavening ability of yeast in dough, chromosome loss was induced by benomyl treatment in YOY1037, a diploid between a baking strain and a laboratory strain, and its effect on the leavening ability was studied. When benomyl-treated cells were spread on plates with a dye indicator for ploidy, about 20% of the visible colonies were stained dark blue or dark purple; the rest stained pale blue, similar to the diploid YOY1037. Strains showing the MATα phenotype, and non-galactose fermenting strains, apparently having lost particular chromosomes, were observed only in those with darkcoloured colonies. Strains with dark-coloured colonies showed a wider range of leavening ability than did those with pale-coloured colonies.
    Materialart: Digitale Medien
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  • 6
    ISSN: 1432-0983
    Schlagwort(e): Xylitol dehydrogenase gene ; Pichia stipitis ; Saccharomyces cerevisiae ; Xylose utilization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A P. stipitis cDNA library in λgt11 was screened using antisera against P. stipitis xylose reductase and xylitol dehydrogenase, respectively. The resulting cDNA clones served as probes for screening a P. stipitis genomic library. The genomic XYL2 gene was isolated and the nucleotide sequence of the 1089 bp structural gene, and of adjacent non-coding regions, was determined. The XYL2 open-reading frame codes for a protein of 363 amino acids with a predicted molecular mass of 38.5 kDa. The XYL2 gene is actively expressed in S. cerevisiae transformants. S. cerevisiae cells transformed with a plasmid, pRD1, containing both the xylose reductase gene (XYL1) and the xylitol dehydrogenase gene (XYL2), were able to grow on xylose as a sole carbon source. In contrast to aerobic glucose metabolism, S. cerevisiae XYL1-XYL2 transformants utilize xylose almost entirely oxidatively.
    Materialart: Digitale Medien
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  • 7
    ISSN: 1432-0983
    Schlagwort(e): Mutagen hyper-resistance ; Nitrogen mustard ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A screening of haploid yeast strains for enhanced resistance to nitrogen mustard (HN2) yielded a recessive mutant allele, hnm1, that conferred hyper-resistance (HYR) to HN2. Diploids, homo- or heterozygous for the HNM1 locus, exhibit normal wild-type like resistance while homozygosity for hnm1 leads to the phenotype HYR to HN2. The hnm1 mutation could be found in yeast strains proficient or deficient in different DNA repair systems. In these mostly HN2-sensitive haploid repair-deficient mutants, hnm1 acted as a partial suppressor of HN2 sensitivity. All isolated recessive mutations conferring hyper-resistance belonged to a single complementations group. The HYR to HN2 phenotype was maximally expressed in growing cells and was associated with reduced mutability by HN2. HNM1 most probably controls uptake of HN2 which would be impaired in the hnm1 mutants.
    Materialart: Digitale Medien
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  • 8
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; G418 resistance ; Gene cartridges ; Heterologous Gene expression
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Coding sequence cartridges for aminoglycoside phosphotransferase (APT) were isolated from bacterial transposon Tn903. When incorporated into a heterologous gene construction utilising the PGK1 promoter and terminator, the heterologous APT gene provided a G418-resistance determinant that functioned efficiently as a dominant marker for yeast in both multiple- and single-copy. Transformant colonies on selective medium appeared rapidly, within 36–48 h, and growth rate of the transformed cells was normal. A simple and highly sensitive radiolabelling assay for APT enzyme activity was developed for use with crude cell protein extracts. Enzyme activity units were equated to the amount of APT protein present in the cells, and the APT protein was shown to be stable in yeast. Heterologous APT expression was 130-fold reduced compared with homologous PGK1. This resulted from an estimated two-fold decrease in mRNA level and a 65-fold decrease in translation efficiency. The latter was unaffected by AUG sequence context change, but corresponded with a high frequency of minor codons in the APT-coding sequence. APT can be used as a semi-quantitative reporter of gene expression, whose useful features are in vivo detection via the G418-resistance phenotype and powerful cell-free assay.
    Materialart: Digitale Medien
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  • 9
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Episomal plasmid ; Copy number control ; Plasmid maintenance ; Glycolytic enzyme levels
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary This study demonstrates how varying the promoter strength of an essential gene on a yeast 2μORI-STB YEp multicopy vector can influence vector copy levels. A phosphoglycerate kinase gene (PGK) on this plasmid was made essential for fermentative growth by transformation into a pgk - yeast strain. When in these PGK- transformants the requirement for PGK expression was the sole selective criterion for plasmid maintenance, PGK promoter activity was inversely related to vector copy levels. Plasmids with an efficiently-transcribed PGK gene were maintained at approximately one copy per cell, whereas those lacking the UAS that normally directs high basal PGK transcription levels were present at up to 10–15 copies. All cultures of these PGK+ transformants contained only a low proportion of pgk - cells. Since mitotic loss of the plasmid arrests growth through loss of a functional PGK allele, PGK confers high stability to the YEp vector in such a pgk - genetic background. In this system YEp vector levels are probably influenced by PGK transcription because high expression of PGK is needed in rapid fermentative growth. Remarkably, low plasmid PGK promoter activity caused PGK mRNA levels slightly higher than those found in yeast with normal PGK regulation. A higher plasmid copy number is therefore not the only factor counteracting the effects of low PGK transcription, and it is possible that PGK mRNA becomes more stable in response to inefficient PGK transcription.
    Materialart: Digitale Medien
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  • 10
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Sporulation ; Inessential genes ; Genome organization
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The SPR6 gene of Saccharomyces cerevisiae encodes a moderately abundant RNA that is present at high levels only during sporulation. The gene contains a long open reading frame that could encode a hydrophilic protein approximately 21 kDa in size. This protein is probably produced by the yeast, because the lacZ gene of Escherichia coli is expressed during sporulation when fused to SPR6 in the expected reading frame. SPR6 is inessential for sporulation; mutants that lack SPR6 activity sporulate normally and produce viable ascospores. Nonetheless, the SPR6 gene encodes a function that is relevant to sporulating cells; the wild-type allele can enhance sporulation in strains that are defective for several SPR functions. SPR6 is located on chromosome V, 14.4 centimorgans centromere-distal to MET6.
    Materialart: Digitale Medien
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  • 11
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Nucleo-mitochondrial interactions ; Mitochondrial status ; Lycorine
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary In a previous paper we have shown that the alkaloid lycorine inhibits growth of rho +, mit - and rho -, strains of Saccharomyces cerevisiae, whereas strains devoid of mitochondrial DNA (rho o) are resistant to more than 200 μg/ml of the alkaloid. In this report we show that hypersuppressive petites are almost as resistant as rho o mutants, whereas isogenic rho - petites, which have retained tained longer segments of the genome, are sensitive to the drug.
    Materialart: Digitale Medien
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  • 12
    ISSN: 1432-0983
    Schlagwort(e): Schizosaccharomyces pombe ; Saccharomyces cerevisiae ; CaMV 35S promoter ; CaMV 35S terminator ; Heterologous expression
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Complementation of fission yeast mutants by plant genomic libraries could be a promising method for the isolation of novel plant genes. One important prerequisite is the functioning of plant promoters and terminators in Schizosaccharomyces pombe and Saccharomyces cerevisiae. Therefore, we studied the expression of the bacterial β-glucuronidase (GUS) reporter gene under the control of the Cauliflower Mosaic Virus (CaMV) 35S promoter and 35S terminator. We show here that S. pombe initiates transcription at exactly the same start site as was reported for tobacco. The 35S CaMV terminator is appropriately recognized leading to a polyadenylated mRNA of the same size as obtained in plant cells transformed with the same construct. Furthermore, the GUS-mRNA is translated into fully functional GUS protein, as determined by an enzymatic assay. Interestingly, expression of the 35S promoter in the budding yeast S. cerevisiae was found to be only moderate and about hundredfold lower than in S. pombe. To investigate whether different transcript stabilities are responsible for this enormous expression difference in the two yeasts, the 35S promoter was substituted by the ADH (alcohol dehydrogenase) promoter from fission yeast. In contrast to the differential expression pattern of the 35S promoter, the ADH promoter resulted in equally high expression rates in both fission and budding yeast, comparable to the 35S promoter in S. pombe. Since the copy number of the 35S-GUS constructs differs only by a factor of two in the two yeasts, it appears that differential recognition of the 35S promoter is responsible for the different transcription rates.
    Materialart: Digitale Medien
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  • 13
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 17 (1990), S. 537-541 
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Mitochondria ; Intron-encoded proteins ; Recombination
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The respiratory competency of a yeast strain devoid of mitchondrial introns is quite normal. However, it may be asked whether intron-encoded proteins participate in metabolisms other than those of mitochondrial introns. Using strains without mitochondrial introns we have answered two questions. The first was: does the absence of intron-encoded proteins abolsh mitochondrial recombination? The second was: do mitochondrial introns and intron-encoded proteins play a part in mitochondrial DNA rearrangements induced by ethidium bromide (rho- production)? We have shown that the introns and intron-encoded proteins are not essential essential components of either phenomenon.
    Materialart: Digitale Medien
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  • 14
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 18 (1990), S. 23-27 
    ISSN: 1432-0983
    Schlagwort(e): Protein translocation ; Saccharomyces cerevisiae ; Peroxisomes ; Overexpression
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Import of proteins into organelles usually requires a cis-acting targeting signal. Analysis of various hybrid proteins, consisting of mouse DHFR and parts of catalase A from Saccharomyces cerevisiae, revealed that fusion proteins containing the N-terminal 126 amino acids, or less, of catalase A remain in the cytosol whereas fusion proteins containing 140, or more, N-terminal amino acids of catalase A form large aggregates inside the cell. These protein bodies, which lack a surrounding membrane, copurified with peroxisomes on cell fractionation. The peroxisomal targeting signal of catalase A does not reside at the C-terminus or at the N-terminus.
    Materialart: Digitale Medien
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  • 15
    ISSN: 1573-0832
    Schlagwort(e): Nystatin ; amphotericin B ; amphotericin B methyl ester ; polyene antibiotics ; yeast ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Abstract Saccharomyces cerevisiae was cultured under anaerobiosis in semi-complete medium to which either palmitoleic or oleic acid was added. Cells were grown at 20 °C or 30 °C. The levels of total lipids, total sterols, and phospholipids were higher in cells grown at 20 °C than at 30 °C. The effects of nystatin (NYS), amphotericin B (AMB), and amphotericin B methyl ester (AME) were evaluated by determining cell viability and liberation of intracellular compounds. The loss of cell viability is higher in the first 30 minutes of incubation with the drugs and is the same regardless of the type of cells obtained. Low molecular weight compounds and ions such as K+ are liberated a few minutes after incubation with the drugs whereas proteins and substances absorbing at 260 nm are liberated later. Phosphate liberation comes after K+ and before compounds of higher molecular weights.
    Materialart: Digitale Medien
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  • 16
    ISSN: 1572-9699
    Schlagwort(e): 2-Deoxy-D-glucose transport ; polyphosphate ; Saccharomyces cerevisiae ; sugar phosphorylation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The role of polyphosphate in 2-deoxy-D-glucose transport was studied in yeast cells, pulse-labeled with [32P]orthophosphate, by comparing the concentrations and specific activities of polyphosphate, orthophosphate and 2-dGlc-phosphate. When 2-dGlc transport was measured under aerobic conditions, it appeared that polyphosphate replenished the orthophosphate pool, indicating that polyphosphate has, at least mainly, an indirect role in sugar phosphorylation. Also in cells with a reduced respiratory capacity, due to a treatment with antimycin A, no direct role for polyphosphate in 2-dGlc transport could be detected. Under these conditions, only a very limited breakdown of polyphosphate occurred, probably because of the small decrease in the orthophosphate concentration.
    Materialart: Digitale Medien
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  • 17
    Digitale Medien
    Digitale Medien
    Springer
    Cellular and molecular life sciences 46 (1990), S. 193-200 
    ISSN: 1420-9071
    Schlagwort(e): Saccharomyces cerevisiae ; protein toxin ; yeast toxin precursor ; protease processing ; lectin ; (1→6)-β-D-glucan ; receptor ; resistant mutants ; spheroplasts ; ion-permeable channels ; site-directed mutagenesis ; toxin functional domains
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Medizin
    Notizen: Summary The K1 killer toxin ofSaccharomyces cerevisiae is a secreted, virally-coded protein lethal to sensitive yeasts. Killer yeasts are immune to the toxin they produce. This killer system has been extensively examined from genetic and molecular perspectives. Here we review the biology of killer yeasts, and examine the synthesis and action of the protein toxin and the immunity component. We summarise the structure of the toxin precursor gene and its protein products, outline the proteolytic processing of the toxin subunits from the precursor, and their passage through the yeast secretory pathway. We then discuss the mode of action of the toxin, its lectin-like interaction with a cell wall glucan, and its probable role in forming channels in the yeast plasma membrane. In addition we describe models of how a toxin precursor species functions as the immunity component, probably by interfering with channel formation. We conclude with a review of the functional domains of the toxin structural gene as determined by site-directed mutagenesis. This work has identified regions associated with glucan binding, toxin activity, and immunity.
    Materialart: Digitale Medien
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  • 18
    ISSN: 1432-0983
    Schlagwort(e): Glucoamylase ; Gene cloning ; Hormoconis resinae ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A cDNA coding for glucoamylase P of Hormoconis resinae was cloned using a synthetic oligonucleotide probe coding for a peptide fragment of the purified enzyme and polyclonal anti-glucoamylase antibodies. Nucleotide-sequence analysis revealed an open reading frame of 1848 base pairs coding for a protein of 616 amino-acid residues. Comparison with other fungal glucoamylase amino-acid sequences showed homologies of 37–48%. The glucoamylase cDNA, when introduced into Saccharomyces cerevisiae under the control of the yeast ADC1 promoter, directed the secretion of active glucoamylase P into the growth medium.
    Materialart: Digitale Medien
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  • 19
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Dynamin ; Mitochondria ; GTP binding protein
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The isolation and characterization of MGM1, and yeast gene with homology to members of the dynamin gene family, is described. The MGM1 gene is located on the right arm of chromosome XV between STE4 and PTP2. Sequence analysis revealed a single open reading frame of 902 residues capable of encoding a protein with an approximate molecular mass of 101 kDa. Loss of MGM1 resulted in slow growth on rich medium, failure to grow on non-fermentable carbon sources, and loss of mitochondrial DNA. The mitochondria also appeared abnormal when visualized with an antibody to a mitochondrial-matrix marker. MGM1 encodes a dynamin-like protein involved in the propagation of functional mitochondria in yeast.
    Materialart: Digitale Medien
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  • 20
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 24 (1993), S. 307-312 
    ISSN: 1432-0983
    Schlagwort(e): Growth control ; Genetic mapping ; Molecular cloning ; Nucleo-mitochondrial interaction ; Saccharomyces cerevisiae ; Viability of petites
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The PEL1 gene of Saccharomyces cerevisiae is essential for the cell viability of mitochondrial petite mutants, for the ability to utilize glycerol and ethanol on synthetic medium, and for cell growth at higher temperatures. By tetrad analysis the gene was assigned to chromosome III, centromere proximal of LEU2. The PEL1 gene has been isolated and cloned by the complementation of a pel1 mutation. The molecular analysis of the chromosomal insert carrying PEL1 revealed that this gene corresponds to the YCL4W open reading frame on the complete DNA sequence of chromosome III. The putative Pel1 protein is characterized by a low molecular weight of approximately 17 kDa, a low codon adaptation index, and a high leucine content.
    Materialart: Digitale Medien
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  • 21
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Papaver somniferum L. ; ARS ; Mitochondrial DNA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The minimal fragment of mitochondrial DNA from Papaver somniferum L. (poppy) able to promote autonomous plasmid replication in the yeast Saccharomyces cerevisiae was sequenced. Sequence analysis of the 917-bp MK4/8 DNA fragment revealed a high AT content, and the presence of two 12-bp sequences differing from the ARS core consensus of S. cerevisiae only by a T and C insertion, respectively. The mitochondrial insert contains a further six 11-bp sequences with one mismatch to the S. cerevisiae core consensus, more then 20 related sequences with two base pair exchanges, numerous direct and inverted repeats, and many copies of a sequence motif called the ARS box. The original 4.2-kb mitochondrial DNA fragment, as well as the minimal 917-bp subfragment in vector pFL1-E (a variant of YIP5, lacking an origin of replication in yeast), were then tested for their ability to replicate autonomously in another fungus, Kluyveromyces lactis.
    Materialart: Digitale Medien
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  • 22
    ISSN: 1432-0983
    Schlagwort(e): 2-Oxoglutarate dehydrogenase ; Molecular cloning ; Saccharomyces cerevisiae ; Sequencing ; Suppressor ; Yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The activity of mitochondrial 2-oxoglutarate dehydrogenase in S. cerevisiae can be impaired either by the ogd1 or the kgd1 mutation. The OGD1 gene and two suppressor genes were isolated by complementation of the ogd1 mutant. The complementation of the kdg1 mutant by the OGD1 gene, an allelism test, and meiotic mapping, revealed that the ogd1 and kgd1 mutations are allelic. The two mutations were differentiated by the cloned suppressor gene which was able to partially complement ogd1, but not kgd1. The molecular analysis of the suppressor gene revealed its identity with the natural tRNA CAG Gln gene found in the upstream region of URA10.
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  • 23
    ISSN: 1432-0983
    Schlagwort(e): Yeast ; Saccharomyces cerevisiae ; Sporulation mutants ; Reporter genes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Reporter genes consisting of sporulation-specific promoters fused to lacZ were used as markers to monitor the sporulation pathway of the yeast Saccharomyces cerevisiae. Strains transformed with these lacZ gene fusions expressed β-galactosidase (assayable on plates using the substrate 5-bromo-4-chloro-3-indolyl-β-D-galactopyranoside, X-gal) in a sporulation-dependent manner. Mutagenesis experiments performed on transformed strains resulted in the recovery of a number of novel sporulation mutants. Three classes of mutants were obtained: those which overexpressed the reporter gene under sporulation conditions, those which did not express the gene under any conditions, and those which expressed the gene in vegetative cells not undergoing sporulation. On the basis of the blue colony-colour produced in the presence of X-gal these have been described as superblue, white, and blue vegetative mutants, respectively. These were further characterised using earlier reporter genes and other marker systems. This study established that the multicopy reporter plasmids chosen do not interfere with sporulation; they are valid tools for monitoring the pathway and they provide a way to isolate mutations not readily selected by other markers.
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  • 24
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 24 (1993), S. 461-464 
    ISSN: 1432-0983
    Schlagwort(e): Chromosome fragmentation ; MEL gene family ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Nine members, MEL2–MEL10, of the MEL gene family coding for α-galactosidase were physically mapped to the ends of the chromosomes by chromosome fragmentation. Genetic mapping of the genes supported the location of all the MEL genes in the left arm of their resident chromosomes.
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  • 25
    ISSN: 1432-0983
    Schlagwort(e): Yeast ; Saccharomyces cerevisiae ; Transformation ; Plasmid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We have compared a number of procedures for the transformation of whole cells of the yeast Saccharomyces cerevisiae and assessed the effects of dimethylsulphoxide (DMSO) or ethanol, both of which have been reported to enhance transformation efficiency. We find that simplified methods benefit from the addition of one of these compounds, and although differences are observed between strains as to the more beneficial reagent, peak transformation efficiency is, in general obtained with 10% DMSO or 10% EtOH. Increases of between six- and 50-fold are observed, despite a reduction in cell viability, and at this concentration the two compounds are not additive in their effects. The optimum level appears to depend on a balance between improved DNA uptake and reduced cell viability. As a result of this work we present a straightforward and rapid transformation procedure.
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  • 26
    ISSN: 1432-0983
    Schlagwort(e): Glycosylphosphatidylinositol anchored-protein ; Southern analysis ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The GGP1 gene encodes the only GPI-anchored glycoprotein (gp115) that has been purified todate in the budding yeast Saccharomyces cerevisiae. It is a single-copy gene whose deduced amino-acid sequence shares no significant homology to any other known protein. In this paper we report a Southern hybridization analysis of genomic DNA from different eukaryotic organisms to identify homologues of the GGP1 gene. We have analyzed DNA prepared from a unicellular green alga (Chlamydomonas eugametos), from two distantly related yeast species (Candida cylindracea and Schizosaccharomyces pombe), and from the common bean Phasoleus vulgaris. The moderate stringency of the experimental conditions and the high specificity of the probes used indicate that a single-copy of GGP1-related sequences exists in all these eukaryotic organisms. The chromosomal localization of the GGP1 gene in S. cerevisiae has also been determined.
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  • 27
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 23 (1993), S. 92-94 
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Gene mapping ; Idiomorphism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The STA2 (glucoamylase) gene of Saccharomyces cerevisiae has been mapped close to the end of the left arm of chromosome II. Meiotic analysis of a cross between a haploid strain containing STA2, and another strain carrying the melibiase gene MEL1 (which is known to be at the end of the left arm of chromosome II) produced parental ditype tetrads only. Since there is no significant DNA sequence similarity between the STA2 and MEL1 genes, or their respective flanking regions, we conclude that these two genes are carried by separate non-hybridizing sequences of chromosomal DNA, either of which can reside at the end of the left arm of chromosome II. By analogy with the mating-type locus of Neurospora crassa, we suggest that the STA2 and MEL1 genes are idiomorphs with respect to one another.
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  • 28
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Phospholipid synthesis ; Phospholipid-N-methyltransferase ; Mutant ; Over-expression
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract By functional complementation of the auxotrophic requirements for choline of a cdg1, cho2 double-mutant, by transformation with a genomic DNA library in a high copy number plasmid, two different types of complementing DNA inserts were identified. One type of insert was earlier shown to represent the CHO2 structural gene. In this report we describe the molecular and biochemical characterization of the second type of complementing activity. The transcript encoded by the cloned gene was about 1000-nt in length and was regulated in response to the soluble phospholipid precursors, inositol and choline. A gene disruption resulted in no obvious growth phenotype at 23°C or 30°C, but in a lack of growth at 37°C in the presence of monomethylethanolamine. Null-mutants exhibited an inositol-secretion phenotype, indicative of mutations in the lipid biosynthetic pathway. Complementation analysis, biochemical analysis of the phospholipid methylation pathway in vivo, and comparison of the restriction pattern of the cloned gene to published sequences, unequivocally identified the cloned gene as the OPI3 gene, encoding phospholipid-N-methyltransferase in yeast. When present in multiple copies the OPI3 gene efficiently suppresses the phospholipid methylation defect of a cho2 mutation. As a result of impaired synthesis of phosphatidylcholine, the INO1-deregulation phenotype is abolished in cho2 mutants transformed with the OPI3 gene on a high copy number plasmid. Taken together, these data demonstrate a significantly overlapping specificity of the OPI3 gene product for three sequential phospholipid methylation reactions in the de novo Ptd-Cho biosynthetic pathway.
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  • 29
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 23 (1993), S. 181-183 
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; c-myc epitope ; Fusion
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In order to facilitate the process of epitope-tagging of yeast proteins, we have constructed two Saccharomyces cerevisiae-Escherichia coli shuttle vectors that allow fusion of a sequence encoding an epitope of the human c-myc protein at the 3′ end of any gene. An example of the use of this technique is presented.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 30
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 23 (1993), S. 295-304 
    ISSN: 1432-0983
    Schlagwort(e): Meiosis ; Meiotic recombination ; Saccharomyces cerevisiae ; REC114
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Four new meiotic recombination genes were previously isolated by selecting for mutations that rescue the meiotic lethality of rad52 spo13 strains. One of these genes, REC114, is described here, and the data confirm that REC114 is a meiosis-specific recombination gene with no detectable function in mitosis. REC114 is located on chromosome XIII approximately 4,9 cM from CIN4. The nucleotide sequence reveals an open reading frame of 1262 bp, consensus intron splice sites close to the 3′ end, and indicates that the second exon codes for only seven amino acids. In the promoter region, a URS1 consensus sequence (TGGGCGGCTA), identical to the URS1 found in the promoter of SPO16, is present 93 bp upstream of the translation start site. Northern-blot hybridization demonstrates that REC114 is transcribed only during meiosis and that it is not expressed in the absence of the IME1 gene product, even when IME2 is constitutively expressed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 31
    ISSN: 1432-0983
    Schlagwort(e): Trehalase ; Trehalose-6-P synthase ; cAMP mutants ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The rise in cAMP level that follows the addition of glucose or 2,4-dinitrophenol (DNP) to stationaryphase cells of Saccharomyces cerevisiae was accompanied by a marked activation of trehalase (3-fold increase) and a concomitant deactivation of trehalose-6 phosphate synthase (50% of the basal levels). In glucose-grown exponential cells, which are deficient in glucose-induced cAMP signalling, the addition of glucose also prompted a decrease in trehalose-6 phosphate synthase, but had no effect on trehalase activity. Mutants defective in the RAS-adenylate cyclase pathway (ras1 ras2 bcy1 strain), as well as mutants containing greatly reduced protein kinase activity either cAMP-dependent (tpk w1 BCY1 strains) or cAMP-independent (tpk1 w1 bcy1 strains), were unable to show glucose- or DNP-induced trehalase activation but still displayed a clear decrease in trehalose-6 phosphate synthase activity upon addition of these compounds. These data suggest that the activity of trehalose-6 phosphate synthase, as opposed to that of trehalase, is not controlled by the cAMP signalling pathway “in vivo”. Trehalose-6 phosphate synthase was competitively inhibited by glucose (Ki=15 mM) and resulted unaffected by ATP in assays performed “in vitro”.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 32
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 23 (1993), S. 375-381 
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Isocitrate lyase ; Gene regulation ; Ethanol induction
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The ICL1 gene encoding the isocitrate lyase from Saccharomyces cerevisiae was cloned and sequenced. A reading frame of 557 amino acids showing significant similarity to isocitrate lyases from seven other species could be identified. Construction of icl1 null mutants led to growth defects on C2 carbon sources while utilization of sugars or C3 substrates remained unaffected. Using an ICL1-lacZ fusion integrated at the ICL1 locus, a more than 200-fold induction of β-galactosidase activity was observed after growth on ethanol when compared with glucose-repressed conditions. A preliminary analysis of the ICL1 upstream region identified a 364-bp fragment necessary and sufficient for this regulatory phenotype. Sequence motifs also present in the upstream regions of co-regulated genes were found within this region.
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    Standort Signatur Erwartet Verfügbarkeit
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  • 33
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 23 (1993), S. 392-396 
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Gene amplification ; ADH4 ; CUP1
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Primary gene amplification, i.e., mutation from one gene copy to multiple gene copies per genome, is important in genomic evolution, as a means of producing anti-cancer drug resistance, and is associated with the progression of tumor malignancy. Primary amplification has not been studied in normal eukaryotic cells because amplifications are extremely rare in these cells. A system has been developed to phenotypically identify co-amplifications of the ADH4 and CUP1 genes of Saccharomyces cerevisiae and 21 independent spontaneous amplifications have been isolated.
    Materialart: Digitale Medien
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  • 34
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 23 (1993), S. 414-422 
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Donation ; Gene conversion ; Double-strand break repair ; Heteroduplex DNA
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We have used transformation of yeast with lincarized plasmids to study the transfer of information to the unbroken chromosome during double-strand break repair. Using a strain which carried the wild-type HIS3 allele, and a linearized plasmid which carried a mutant his3 allele, we have obtained His- transformants. In these, double-strand break repair has resulted in precise transfer of genetic information from the plasmid to the chromosome. Such repair events, we suggest, are gene conversions which entail the formation of heteroduplex DNA on the (unbroken) chromosome. If this suggestion is correct, our results reflect the spatial distribution of such heteroduplex DNA. Transfer of information from the plasmid to the chromosome was obtained at a maximal frequency of 1.5% of the repair events, and showed a dependence with distance. Transformation to His- was also obtained with a 2-kbp insertion and with a deletion of 200 bp. The latter results suggest that gene conversion of large heterologies can occur via repair of a heteroduplex DNA intermediate.
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  • 35
    Digitale Medien
    Digitale Medien
    Springer
    Current genetics 24 (1993), S. 185-192 
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Cell cycle ; Transcription ; DNA replication
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In eukaryotic organisms, genes involved in DNA replication are often subject to some form of cell cycle control. In the yeast Saccharomyces cerevisiae, most of the DNA replication genes that have been characterized to date are regulated at the transcriptional level during G1 to S phase transition. A cis-acting element termed the MluI cell cycle box (or MCB) conveys this pattern of regulation and is common among more than 20 genes involved in DNA synthesis and repair. Recent findings indicate that the MCB element is well conserved among fungi and may play a role in controlling entry into the cell division cycle. It is evident from studies in higher systems, however, that transcriptional regulation is not the only form of control that governs the cell-cycle-dependent expression of DNA replication genes. Moreover, it is unclear why this general pattern of regulation exists for so many of these genes in various eukaryotic systems. This review summarizes recent studies of the MCB element in yeast and briefly discusses the purpose of regulating DNA replication genes in the eukaryotic cell cycle.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 36
    ISSN: 1432-0983
    Schlagwort(e): Saccharomyces cerevisiae ; Pentose-phosphate pathway ; Transketolase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Deletion mutants for the yeast transketolase gene TKL1 were constructed by gene replacement. Transketolase activity was below the level of detection in mutant crude extracts. Transketolase protein could be detected as a single protein band of the expected size by Western-blot analysis in wild-type strains but not in the delection mutant. Deletion of TKL1 led to a reduced but distinct growth in synthetic medium without an aromatic amino-acid supplement. We also isolated double and triple mutants for transketolase (tkl1), transaldolase (tal1), and glucose 6-phosphate dehydrogenase (zwf1) by crossing the different mutants. A tal1 tkl1 double mutant grew nearly like wild-type in rich medium. Only the tkl1 zwf1 double and the tal1 tkl1 zwf1 triple mutant grew more slowly than the wild-type in rich medium. This growth defect could be partly alleviated by the addition of xylulose but not ribose. The triple mutant still grew slowly on a synthetic mineral salts medium without a supplement of aromatic amino acids. This suggests the existence of an alternative but limited source of pentose phosphates and erythrose 4-phosphate in the tkl1 zwf1 double mutants. Hybridization with low stringency showed the existence of a sequence with homology to transketolase, possibly a second gene.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 37
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 154 (1990), S. 267-273 
    ISSN: 1432-072X
    Schlagwort(e): Yeast ; Saccharomyces cerevisiae ; (R)-2,3-Butanediol dehydrogenase ; Stereospecificity ; Gas chromatographic analysis of enantiomers
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A NAD-dependent (R)-2,3-butanediol dehydrogenase (EC 1.1.1.4), selectively catalyzing the oxidation at the (R)-center of 2,3-butanediol irrespective of the absolute configuration of the other carbinol center, was isolated from cell extracts of the yeast Saccharomyces cerevisiae. Purification was achieved by means of streptomycin sulfate treatment, Sephadex G-25 filtration, DEAE-Sepharose CL-6B chromatography, affinity chromatography on Matrex Gel Blue A and Superose 6 prep grade chromatography leading to a 70-fold enrichment of the specific activity with 44% yield. Analysis of chiral products was carried out by gas chromatographic methods via pre-chromatographic derivatization and resolution of corresponding diasteromeric derivatives. The enzyme was capable to reduce irreversibly diacetyl (2,3-butanediol) to (R)-acetoin (3-hydroxy-2-butanone) and in a subsequent reaction reversibly to (R,R)-2,3-butanediol using NADH as coenzyme. 1-Hydroxy-2-ketones and C5-acyloins were also accepted as substrates, whereas the enzyme was inactive towards the reduction of acetone and dihydroxyacetone. The relative molecular mass (M r) of the enzyme was estimated as 140 000 by means of gel filtration. On SDS-polyacrylamide gel the protein decomposed into 4 (identical) subunits of M r 35 000. Optimum pH was 6.7 for the reduction of acetoin to 2,3-butanediol and 7.2 for the reverse reaction.
    Materialart: Digitale Medien
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  • 38
    ISSN: 1432-072X
    Schlagwort(e): cAMP ; Cat mutants ; Glucose repression ; Glucose-induced ; Intracellular pH ; Ras ; Saccharomyces cerevisiae ; Signal transduction ; Trehalase ; Yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Addition of glucose to derepressed cells of the yeast Saccharomyces cerevisiae induces a transient, specific cAMP signal. Intracellular acidification in these cells, as caused by addition of protonophores like 2,4-dinitrophenol (DNP) causes a large, lasting increase in the cAMP level. The effect of glucose and DNP was investigated in glucose-repressed wild type cells and in cells of two mutants which are deficient in derepression of glucose-repressible proteins, cat1 and cat3. Addition of glucose to cells of the cat3 mutant caused a transient increase in the cAMP level whereas cells of the cat1 mutant and in most cases also repressed wild type cells did not respond to glucose addition with a cAMP increase. The glucose-induced cAMP increase in cat3 cells and the cAMP increase occasionally present in repressed wild type cells however could be prevented completely by addition of a very low level of glucose in advance. In derepressed wild type cells this does not prevent the specific glucose-induced cAMP signal at all. These results indicate that repressed cells do not show a true glucose-induced cAMP signal. When DNP was added to glucose-repressed wild type cells or to cells of the cat1 and cat3 mutants no cAMP increase was observed. Addition of a very low level of glucose before the DNP restored the cAMP increase which points to lack of ATP as the cause for the absence of the DNP effect. These data show that intracellular acidification is able to enhance the cAMP level in repressed cells. The glucose-induced artefactual increase occasionally observed in repressed cells is probably caused by the fact that their low intracellular pH is only restored after the ATP level has increased to such an extent that it is no longer limiting for cAMP synthesis. It is unclear why the artefactual increases are not always observed. Measurement of glucose- and DNP-induced activation of trehalase confirmed the physiological validity of the changes observed in the cAMP level. Our results are consistent with the idea that the glucose-induced signaling pathway contains a glucose-repressible protein and that the protein is located before the point where intracellular acidification triggers activation of the pathway.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 39
    ISSN: 1432-072X
    Schlagwort(e): Saccharomyces cerevisiae ; Catalase A ; Catalase T ; β-Oxidation ; Microbodies ; H2O2-Metabolism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The parental strain (A+T+) of Saccharomyces cerevisiae and mutants, deficient in catalase T (A+T−), catalase A (A−T+) or both catalases (A−T−), grew on ethanol and oleic acid with comparable doubling times. Specific activities of catalase were low in glucose- and ethanol-grown cells. In the two oleic acid-grown A+-strains (A+T+ and A+T−) high catalase activities were found; catalase activity invariably remained low in the A−T+ strain and was never detected in the A−T− strain. The levels of β-oxidation enzymes in oleic acid-grown cells of the parental and all mutant strains were not significantly different. However, cytochrome C peroxidase activity had increased 8-fold in oleic acid grown A− strains (A−T+ and A−T−) compared to parental strain cells. The degree of peroxisomal proliferation was comparable among the different strains. Catalase A was shown to be located in peroxisomes. Catalase T is most probably cytosolic in nature and/or present in the periplasmic space.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 40
    ISSN: 1432-072X
    Schlagwort(e): Saccharomyces cerevisiae ; Pyruvate decarboxylase ; Pyruvate kinase ; Signalling ; Glycolysis mutants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Pyruvate decarboxylase, PDCase, activity in wild-type yeast cells growing on ethanol is quite low but increases up to tenfold upon addition of glucose, less with galactose and only slightly with glycerol. PDCase levels in glycolysis mutant strains growing on ethanol or acetate were higher than in the wild-type strain. These levels correlated with the sum of the concentrations of three-carbon glycolytic metabolites. The highest accumulation was observed in a fructose bisphosphate aldolase deletion mutant concomintant with the highest PDCase activity wild-type level. On the other hand, the PDCase levels in the different mutants again correlated with the sum of the concentrations of the three-carbon glycolytic metabolites. This was interpreted to mean that full induction of PDCase activity requires the accumulation of hexose-and triosephosphates.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 41
    ISSN: 1432-072X
    Schlagwort(e): Saccharomyces cerevisiae ; Acetyl-CoA ; l-Lysine N6 ; acetytransferase ; Lysine catabolism
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The carbon catabolism of l-lysine starts in Saccharomyces cerevisiae with acetylation by an acetyl-CoA: l-lysine N6-acetyltransferase. The enzyme is strongly induced in cells grown on l-lysine as sole carbon source and has been purified about 530-fold. Its activity was specific for acetyl-CoA and, in addition to l-lysine, 5-hydroxylysine and thialysine act as acetyl acceptor. The following apparent Michaelis constants were determined: acetyl-CoA 0.8 mM, l-lysine 5.8 mM, dl-5-hydroxylysine 2.8 mM, l-thialysine 100 mM. The enzyme had a maximum activity at pH 8.5 and 37°C. Its molecular mass, estimated by sodium dodecyl sulphate-polyacrylamide gel electrophoresis, was 52 kDa. Since the native molecular mass, determined by gel filtration, was 48 kDa, the enzyme is a monomer.
    Materialart: Digitale Medien
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  • 42
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 153 (1990), S. 384-391 
    ISSN: 1432-072X
    Schlagwort(e): Saccharomyces cerevisiae ; Ethanol ; Acetic acid ; Cytoplasmic pH ; 31P-NMR ; 13C-NMR
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Cell suspensions of a respiratory deficient mutant of Saccharomyces cerevisiae were monitored by in vivo 31P and 13C Nuclear Magnetic Resonance in order to evaluate the effect of ethanol in intracellular pH and metabolism. In the absence of an added energy source, ethanol caused acidification of the cytoplasm, as indicated by the shift to higher field of the resonance assigned to the cytoplasmic orthophosphate. Under the experimental conditions used this acidification was not a consequence of an increase in the passive influx of H+. With cells energized with glucose, a lower value for the cytoplasmic pH was also observed, when ethanol was added. Furthermore, lower levels of phosphomonoesters were detected in the presence of ethanol, indicating that an early event in glycolysis is an important target of the ethanol action. Acetic acid was identified as responsible for the acidification of the cytoplasm, in experiments where [13C]ethanol was added and formation of labeled acetic acid was detected. The intracellular and the extracellular concentrations of acetic acid were respectively, 30 mM and 2 mM when 0.5% (120 mM) [13C]ethanol was added.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 43
    Digitale Medien
    Digitale Medien
    Springer
    Archives of microbiology 154 (1990), S. 544-549 
    ISSN: 1432-072X
    Schlagwort(e): Regulatory mutants ; Meiotic mapping ; Transcriptional regulation ; MAL genes ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The MAL1 locus of Saccharomyces cerevisiae comprises three genes necessary for maltose utilization: a regulatory (MALR), a maltose transport (MALT) and a maltase gene (MALS). A fine structure genetic map of the MAL1R gene was constructed and the order of mutations was confirmed by plasmid-mediated chromosomal recombination. The mutations cluster non-randomly within the 5′ half of the gene, where the putative DNA binding domain of the encoded protein is located. Only mutations mal1 R-22 and MAL1R-72 map in the 3′ terminal half of the gene; these mutations cause a different pattern of transcriptional regulation of plasmid-borne MAL6T genes. Experiments supporting a direct involvement of the MALR-encoded protein in carbon catabolite repression of MAL gene expression are reported.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 44
    Digitale Medien
    Digitale Medien
    Springer
    Molecular and cellular biochemistry 124 (1993), S. 131-140 
    ISSN: 1573-4919
    Schlagwort(e): Schizosaccharomyces pombe ; Saccharomyces cerevisiae ; H+-ATPase ; intracellular pH ; carboxy-seminaphthorhodafluor-1
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Abstract We examined cytoplasmic pH regulation inSchizosaccharomyces pombe andSaccharomyces cerevisiae using pH-sensitive fluorescent dyes. Of several different fluorescent compounds tested, carboxy-seminaphthorhodafluor-1 (C.SNARF-1) was the most effective. Leakage of C.SNARF-1 fromS. pombe was much slower than leakage fromC. cerevisiae. Using the pH-dependent fluorescence of C.SNARF-1 we showed that at an external pH of 7, mean resting internal pH was 7.0 forS. pombe and 6.6 forS. cerevisiae. We found that internal pH inS. pombe was maintained over a much narrower range in response to changes in external pH, especially at acidic pH. The addition of external glucose caused an intracellular alkalinization in both species, although the effect was much greater inS. cerevisiae than inS. pombe. The plasma membrane H+-ATPase inhibitor diethylstilbestrol reduced both the rate and extent of alkalinisation, with an IC50 of approximately 35 μM in both species. Amiloride also inhibited internal alkalinisation with IC50's of 745 μM forS. cerevisiae and 490 μM forS. pombe.
    Materialart: Digitale Medien
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  • 45
    ISSN: 1573-4919
    Schlagwort(e): bovine heart fatty acid-binding protein ; H-FABPc ; heterologous gene expression ; Saccharomyces cerevisiae ; GALIO promoter
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Medizin
    Notizen: Summary The unicellular eukaryotic microorganism, Saccharomyces cerevisiae, transformed with a plasmid containing a cDNA fragment encoding bovine heart fatty acid-binding protein (H-FABP) under the control of the inducible yeast GAL10 promoter, expressed FABP during growth on galactose. The maximum level of immunoreactive FABP, identical in size to native protein as judged from SDS-polyacrylamide gel electrophoresis, was reached after approximately 16 hours of induction. Analysis of particulate and soluble subcellular fractions showed that FABP was exclusively associated with the cytosol. FABP expressed in yeast cells was functional as was demonstrated by its capacity to bind 14C-oleic acid in an in vitro assay. Growth of the transformants on galactose as the carbon source was significantly retarded at 37°C. Whereas the fatty acid pattern of total lipids was not altered in transformed cells, desaturation of exogenously added 14C-palmitic acid was significantly reduced both at 30 and 37°C. The lowest percentage of radioactively labeled unsaturated fatty acids was found in the phospholipid fraction.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 46
    Digitale Medien
    Digitale Medien
    Springer
    Plant molecular biology 22 (1993), S. 1177-1180 
    ISSN: 1573-5028
    Schlagwort(e): abscisic acid ; developmental regulation ; heat shock proteins ; Oryza sativa ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Antibodies raised against yeast heat shock protein (HSP) 104 recognized a heat-inducible polypeptide with a molecular mass of 110 kDa in shoot tissue of young rice seedlings. Root tissue of the same age showed no immuno-reaction with yeast HSP 104 antibodies. The 110 kDa polypeptide of rice was also shown to be abscisic acid-inducible in young seedlings. Though this polypeptide was seen to be constitutively present in the flag leaf of 90-day-old field-grown plant, it was not much affected by either heat shock or abscisic acid in this case.
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    Standort Signatur Erwartet Verfügbarkeit
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  • 47
    Digitale Medien
    Digitale Medien
    Springer
    Journal of fluorescence 3 (1993), S. 241-244 
    ISSN: 1573-4994
    Schlagwort(e): Killer toxin K1 ; bromocresol purple staining ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Physik
    Notizen: Abstract Optimal assay conditions were established for the previously described method used to determine the activity ofSaccharomyces cerevisiae pore-forming killer toxin K1. The method is based on cell staining with bromocresol purple. Sensitive cells ofS. cerevisiae from the early exponential phase under nongrowth conditions and in the presence of glucose were the most convenient for determining the killer toxin activity. Maximum killing war reached when the suspension was buffered with 10 mM citrate-phosphate at pH 4.6.
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  • 48
    Digitale Medien
    Digitale Medien
    Springer
    The journal of membrane biology 116 (1990), S. 93-105 
    ISSN: 1432-1424
    Schlagwort(e): clathrin ; genetics ; Saccharomyces cerevisiae ; exocytosis ; endocytosis ; prohormone maturation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 49
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Ribosomal protein genes ; Transcription activation ; cAMP ; Growth control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The rate of ribosomal protein gene (rp-gene) transcription in yeast is accurately adjusted to the cellular requirement for ribosomes under various growth conditions. However, the molecular mechanisms underlying this co-ordinated transcriptional control have not yet been elucidated. Transcriptional activation of rp-genes is mediated through two different multifunctional trans-acting factors, ABF1 and RAP1. In this report, we demonstrate that changes in cellular rp-mRNA levels during varying growth conditions are not parallelled by changes in the in vitro binding capacity of ABF1 or RAP1 for their cognate sequences. In addition, the nutritional upshift response of rp-genes observed after addition of glucose to a culture growing on a non-fermentative carbon source turns out not to be the result of increased expression of the ABF1 and RAP1 genes or of elevated DNA-binding activity of these factors. Therefore, growth rate-dependent transcription regulation of rp-genes is most probably not mediated by changes in the efficiency of binding of ABF1 and RAP1 to the upstream activation sites of these genes, but rather through other alterations in the efficiency of transcription activation. Furthermore, we tested the possibility that cAMP may play a role in elevating rp-gene expression during a nutritional shift-up. We found that the nutritional upshift response occurs normally in several mutants defective in cAMP metabolism.
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  • 50
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 239 (1993), S. 28-32 
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; UV damage ; Mating type ; Inducible repair
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The prior UV irradiation of α haploid Saccharomyces cerevisiae with a UV dose of 25 J/m2 substantially increases the repairability of damage subsequently induced by a UV dose of 70 J/m2 given 1 h after the first irradiation. This enhancement of repair is seen at both the MATa and HMLα loci, which are, respectively, transcriptionally active and inactive in α haploid cells. The presence in the medium of the protein synthesis inhibitor, cycloheximide in the period between the two irradiations eliminated this effect. Enhanced repair still occurred if cycloheximide was present only after the final UV irradiation. This indicated that the first result is not due to cycloheximide merely blocking the synthesis of repair enzymes associated with a hypothetical rapid turnover of such molecules. The enhanced repairability is not the result of changes in chromatin accessibility without protein synthesis, merely caused by the repair of the damage induced by the prior irradiation. The data clearly show that a UV-inducible removal of pyrimidine dimers has occurred which involves the synthesis of new proteins. The genes known to possess inducible promoters, and which are involved in excision are RAD2, RAD7, RAD16 and RAD23. Studies with the rad7 and rad16 mutants which are defective in the ability to repair HMLα and proficient in the repair' of MATα showed that in rad7, preirradiation enhanced the repair at MATα, whereas in rad16 this increased repair of MATα was absent. The preirradiation did not modify the inability to repair HMLα in either strain. Thus RAD16 has a role in this inducible repair. Inducible repair is also absent in a rad2 strain which cannot repair MATα or HMLα after a single UV dose.
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  • 51
    ISSN: 1617-4623
    Schlagwort(e): Ty elements ; Saccharomyces cerevisiae ; Retrotransposon
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary To learn more about the variety of Ty elements capable of activating gene expression, we characterized 206 spontaneous Ty transpositions that activate the promoterless gene his3Δ4. Most of the Ty elements appear to be full-length, although a few deleted elements were recovered. Over 95% of the insertions belong to the Ty1 family, and the rest are Ty2 elements. The excessive number of Ty1 transpositions was unexpected because there are only 2-fold more Ty1 than Ty2 elements in the yeast strains used in the selection. However, there is 20-fold more Ty1 than Ty2 RNA present in these yeast strains. This difference in RNA level explains the greater number of Ty1 verses Ty2 transpositions at his3Δ4, because Ty elements transpose through an RNA intermediate. A similar association between the Ty transcript level and transpositional activation of his3Δ4 is obtained in cells expressing GAL1-promoted Ty2-H556 or Ty2-917 elements, but only if the element does not contain a marker. Genetically marked Ty2-H556NEO and-917NEO elements transpose into and activate his3Δ4 with the same efficiency as the previously characterized Ty1H3NEO element, but are underrepresented relative to the levels of TyNEO transcript. We also found that chromosomal Ty transcripts are even more abundant than previously estimated and comprise about 1% of total cellular RNA.
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    Standort Signatur Erwartet Verfügbarkeit
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  • 52
    ISSN: 1617-4623
    Schlagwort(e): Bacterial conjugation ; Cyanobacteria ; IncQ plasmids ; Saccharomyces cerevisiae ; DNA methylation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The promiscuous IncQ plasmid pKT210 (Cmr, Smr) is efficiently transferred by transpecific conjugation from Escherichia coli to the facultatively heterotrophic cyanobacterium Synechocystis PCC6803 when mobilized by a helper plasmid coding for IncP transfer functions. The IncQ plasmid is stably maintained in the cyanobacterium as an autonomously replicating multicopy plasmid with no detectable structural alterations and can be recovered by transformation back to E. coli when using a mcrA mcrB host. Thus, the replicative host-range of IncQ plasmids extends beyond purple bacteria to the distinct procaryotic taxon of cyanobacteria, allowing the use of these small plasmids as convenient cloning vectors in Synechocystis PCC6803 and presumably also in cyanobacteria that are not amenable to genetic transformation. In contrast, an IncQ plasmid bearing the TRP1 gene of Saccharomyces cerevisiae failed to replicate when transferred to that yeast by transformation.
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  • 53
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Sodium efflux ; Lithium efflux ; ATPase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The ENA2 gene encoding a P-type ATPase involved in Na+ and Li+ effluxes in Saccharomyces cerevisiae has been isolated. The putative protein encoded by ENA2 differs only in thirteen amino acids from the protein encoded by ENA1/PMR2. However, ENA2 has a very low level of expression and for this reason did not confer significant Li+ tolerance on a Li+ sensitive strain. ENA1 and ENA2 are the first two units of a tandem array of four highly homologous genes with probably homologous functions.
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  • 54
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 237 (1993), S. 375-384 
    ISSN: 1617-4623
    Schlagwort(e): Regulation of meiosis ; Saccharomyces cerevisiae ; IME1
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The IME1 gene of Saccharomyces cerevisiae is required for initiation of meiosis. Transcription of IME1 is detected under conditions which are known to induce initiation of meiosis, namely starvation for nitrogen and glucose, and the presence of MATa1 and MATα2 gene products. In this paper we show that IME1 is also subject to translational regulation. Translation of IME1 mRNA is achieved either upon nitrogen starvation, or upon G1 arrest. In the presence of nutrients, constitutively elevated transcription of IME1 is also sufficient for the translation of IME1 RNA. Four different conditions were found to cause expression of Imel protein in vegetative cultures: elevated transcription levels due to the presence of IME1 on a multicopy plasmid; elevated transcription provided by a Gal-IME1 construct; G1 arrest due to α-factor treatment; G1 arrest following mild heat-shock treatment of cdc28 diploids. Using these conditions, we obtained evidence that starvation is required not only for transcription and efficient translation of IME1, but also for either the activation of Ime1 protein or for the induction/activation of another factor that, either alone or in combination with Ime1, induces meiosis.
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  • 55
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 237 (1993), S. 449-459 
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Transcription ; spt mutants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Mutations in the SPT4 gene of Saccharomyces cerevisiae were isolated as suppressors of δ insertion mutations that interfere with adjacent gene transcription. Recent genetic evidence indicates that the SPT4 protein functions with two other proteins, SPT5 and SPT6, in some aspect of transcription initiation. In this work we have characterized the SPT4 gene and we demonstrate that spt4 mutations, like spt5 and spt6 mutations, cause changes in transcription. Using the cloned SPT4 gene, spt4 null mutations were constructed; in contrast to spt5 and spt6 null mutants, which are inviable, spt4 null mutants are viable and have an Spt− phenotype. The DNA sequence of the SPT4 gene predicts a protein product of 102 amino acids that contains four cysteine residues positioned similarly to those of zinc binding proteins. Mutational analysis suggests that at least some of these cysteines are essential for SPT4 function. Genetic mapping showed that SPT4 is a previously unidentified gene that maps to chromosome VII, between ADE6 and CLY8.
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  • 56
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 237 (1993), S. 463-466 
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; cyrl-2 ; Nonsense mutation ; CAMP
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary cyrl-2 is a temperature-sensitive mutation of the yeast adenylate cyclase structural gene, CYR1. The cyrl-2 mutation has been suggested to be a UGA mutation since a UGA suppressor SUP201 has been isolated as a suppressor of the cyrl-2 mutation. Construction of chimeric genes restricted the region containing the cyrl-2 mutation, and the cyrl-2 UGA mutation was identified at codon 1282, which lies upstream of the region coding for the catalytic domain of adenylate cyclase. Alterations in the region upstream of the cyrl-2 mutation site result in null mutations. The complete open reading frame of the cyrl-2 gene expressed under the control of the GAL1 promoter complemented cyrl-dl in a galactose-dependent manner. These results suggest that at the permissive temperature weak readthrough occurs at the cyrl-2 mutation site to produce low levels of active adenylate cyclase. An endogenous suppressor in yeast cells is assumed to be responsible for this readthrough.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 57
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 238 (1993), S. 6-16 
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; cAMP MKS1 ; GAL11
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In order to isolate genes that function downstream of the Ras-cAMP pathway in Saccharomyces cerevisiae, a YEp13-based genomic library was screened for clones that inhibit growth of cells with diminished A-kinase activity. One such gene, MKS1, was found to encode a hydrophilic 52 kDa protein that shares weak homology with the yeast SPT2/SIN1 gene product. Three lines of evidence suggest that the MKS1 gene product is a negative regulator downstream of the Ras-cAMP pathway: (i) overexpression of MKS1 inhibits growth of cyrl disruptant cells on YPD medium containing a low concentration of cAMP; (ii) overexpression of MKS1 does not affect TPK1 expression; and (iii) the temperature-sensitive cyrl-230 mutation is partially suppressed by mks1 disruption. The mks1 mutant shows similar phenotypes to gal11/spt13, i.e., it cannot grow on YPGal containing ethidium bromide at 25°C, or on YPGly or SGal at 37°C. The mks1 gal11 double mutant shows more marked phenotypic changes than the single mutants. These results suggest that MKS1 is involved in transcriptional regulation of several genes by cAMP.
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  • 58
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; AR07 gene ; Chorismate mutase ; GCN4 ; Transcriptional regulation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The gene AR07 encodes the monofunctional enzyme chorismate mutase, a branch point enzyme in the aromatic amino acid biosynthetic pathway in Saccharomyces cerevisiae. We investigated the transcription of the AR07 gene. Three 5′ ends at positions − 36, − 56 and − 73 and the 3′ end of the transcripts 146 bp downstream of the translational stop codon were mapped. As in the promoters of other aromatic amino acid biosynthetic genes, a recognition element for the GCN4 transcriptional activator of amino acid biosynthesis is located 425 base pairs (bp) upstream of the first transcriptional start point. This element binds GCN4 specifically in vitro. Northern analysis and determination of the specific enzyme activity reveals however, that the element is not sufficient to mediate transcriptional regulation by GCN4 in vivo. We thus suggest that in addition to a consensus sequence capable of binding the GCN4 protein other factors like, for example, chromatin structure, determine whether a recognition site for a transcription factor functions as an upstream activation sequence.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 59
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 240 (1993), S. 36-42 
    ISSN: 1617-4623
    Schlagwort(e): Yeast ; Saccharomyces cerevisiae ; DNA synthesis genes ; Cell cycle regulation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Two mutants have been isolated in Saccharomyces cerevisiae in which transcripts from at least CDC8, CDC9, CDC21 (TMP1) and POL1 genes are expressed constitutively in cells blocked at START by use of either α-pheromone or the cdc28 mutation. The transcripts from these genes also persist in mutant stationary phase cells; however, cell cycle regulation of these four DNA synthesis genes occurs normally in late G1. The mutation therefore does not appear to lie in the MCB-DSC1 (MBF) system that controls the periodic regulation of the genes, but must affect some control mechanism regulating basal levels of expression.
    Materialart: Digitale Medien
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  • 60
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Splicing ; Nuclear structure
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary We report on the characterization of the yeast prp20-1 mutant. In this temperature-sensitive mutant, multiple steps of mRNA metabolism are affected. The prp20-1 mutant strain showed alterations in mRNA steady-state levels, defective mRNA splicing and changes in transcription initiation or termination when shifted from the permissive to the non-permissive temperature. In addition, a change in the structure of the nucleus in these cells became apparent. Electron microscopy revealed an altered structure of the nucleoplasm of prp20-1 mutant cells when grown at the no-permissive temperature that was not observed in cells grown at the permissive temperature or in wild-type cells. The wild-type PRP20 gene was isolated and sequenced. The putative PRP20 protein has a molecular weight of 52 kDa. We found that the PRP20 gene is identical to the yeast SRM1 gene (Clark and Sprague 1989). In addition, the PRP20 protein sequence shows significant sequence similarity to the human RCC1 protein (Ohtsubo et al. 1987). This protein has been implicated in the control of chromosome condensation. Based on the phenotype of the prp20-1 mutant and the observed sequence similarity to the human RCC1 protein, we postulate that the yeast PRP20 protein is involved in the control of nuclear organization.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 61
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 224 (1990), S. 111-118 
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Translation ; Splicing ; Paromomycin
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The MSS51 gene product has been previously shown to be involved in the splicing of the mitochondrial pre-mRNA of cytochrome oxidase subunit I (COX1). We show here that it is specifically required for the translation of the COX1 mRNA. Furthermore, the paromomycin-resistance mutation (P inf454 supR ) which affects the 15 S mitoribosomal RNA, interferes, directly or indirectly, with the action of the MSS51 gene product. Possible roles of the MSS51 protein on the excision of COX1 introns are discussed.
    Materialart: Digitale Medien
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  • 62
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 224 (1990), S. 257-263 
    ISSN: 1617-4623
    Schlagwort(e): General Control ; Thermotolerance ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary In Saccharomyces cerevisiae starvation for a single amino acid activates the transcription of a set of genes belonging to different amino acid biosynthetic pathways (General Control, GC). We show that mutants affected in GC regulation are also affected in their response to thermal stress. Moreover, growth conditions that are known to induce heat shock proteins induce the GC response. However, unlike heat shock proteins, the transcriptional activator of GC, GCN4, is not induced after a short exposure to heat, and in gcn mutant strains induction of heat resistance is normal.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 63
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 220 (1990), S. 269-276 
    ISSN: 1617-4623
    Schlagwort(e): GABA ; Saccharomyces cerevisiae ; Transcription ; DNA sequence ; Zinc finger
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The UGA3 gene of Saccharomyces cerevisiae is required for 4-aminobutyric acid (GABA)-dependent induction of the UGA1, UGA2 and UGA4 genes which encode the two GABA catabolic enzymes and a GABA-specific permease, respectively. Measurements of UGA1-specific transcripts show that induction of UGA1 correlates with accumulation of its RNA and requires a functional UGA3 gene. A 2 kb DNA fragment complementing the uga3 mutation was isolated and shown to contain the UGA3 gene. The primary structure of the UGA3 encoded protein was deduced from the DNA sequence, and contains an N-terminal, cysteine-rich motif similar in sequence to regions found in other fungal regulatory proteins and which are supposed to form zinc finger structures involved in DNA binding. Mutations were identified in the UGA3 genes isolated from uninducible and constitutive uga3 alleles. One case of intragenic complementation between two uninducible uga3 mutants is reported, indicating a possible oligomeric structure for UGA3. The role of UGA3 is discussed in relation to its genetic properties and its predicted structure.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 64
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 220 (1990), S. 283-288 
    ISSN: 1617-4623
    Schlagwort(e): Chorismate mutase ; Saccharomyces cerevisiae ; Repression
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The Saccharomyces cerevisiae ARO7 gene was cloned by screening a wild-type gene bank for complementation of an aro7 auxotrophic mutant. In vitro mutagenesis of the isolated plasmid (pJFB1) gave several transformants resistant to levels of the phenylalanine analogue 2-thienylalanine inhibitory to the wild-type transformant. Chorismate mutase assays indicated that two of the mutants (J14-26IV6 and J14-26IV9) were resistant to feedback inhibition by tyrosine displayed by wild-type strains. Analysis of the effect of other aromatic amino acids on chorismate mutase activity showed that tryptophan counteracted this inhibition. Analysis of the effect of tyrosine in the growth medium on enzyme activity indicated that the wild-type ARO7 gene was repressed by tyrosine, a phenomenon not previously reported. Two of the 2-thienylalanine resistant mutants (J14-26IV3 and J14-26IV9) appeared to be resistant to this repression. Transcriptional analysis confirmed that the level of ARO7 transcript decreased with increasing tyrosine concentration. In stain J14-26IV9 the ARO7 transcript level was not affected. J14-26IV9, therefore, appears to be a double mutant, resistant to both feedback inhibition and repression by tyrosine.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 65
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 222 (1990), S. 87-96 
    ISSN: 1617-4623
    Schlagwort(e): Glucoamylase ; Sporulation ; Saccharomyces cerevisiae ; Saccharomyces cerevisiae var. diastaticus ; STA genes
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The single glucoamylase gene (SGA1) of the yeast Saccharomyces cerevisiae is expressed exclusively during the sporulation phase of the life cycle. Enzymatic studies and nucleic acid sequence comparisons have shown that the SGA1 glucoamylase is closely related to the secreted enzymes of S. cerevisiae var. diastaticus. The latter are encoded by any of three unlinked STA genes, which have been proposed to derive from the ancestral SGA1 form by genomic rearrangement. We show that the regulation of SGA1 is distinct from that of the other members of the STA gene family. SGA1 expression did not respond to STA10, the primary determinant of glucoamylase expression from STA2. Unlike STA2, SGA1 was not regulated directly by the mating type locus. Expression of SGA1 depended on the function of the MAT products in supporting sporulation and not on the formation of haploid progeny spores or on the composition of the mating type locus per se. We conclude that the STA genes acquired regulation by STA10 and MAT by the genomic rearrangements that led to their formation. This regulation is thus distinct from that of the ancestral SGA1 gene.
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    Standort Signatur Erwartet Verfügbarkeit
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  • 66
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 222 (1990), S. 169-175 
    ISSN: 1617-4623
    Schlagwort(e): Aspergillus nidulans ; Schizosaccharomyces pombe ; Saccharomyces cerevisiae ; Drug resistance ; β-tubulin mutation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Rhizoxin, an antibiotic, exhibits potent anti-mitotic activity against most eucaryotic cells including those of higher vertebrates, plants and fungi by binding to β-tubulin. ThebenA gene of three independently isolated rhizoxin-resistant (Rhir) mutants ofAspergillus nidulans was cloned, sequenced and compared with that of the wild-type, rhizoxin-sensitive (Rhis) strain. In all three Rhir mutants, the AAC codon for Asn-100 of thebenA β-tubulin gene was altered to ATC, coding for Ile. Sequence displacement experiments confirmed that the substitution of Ile for Asn-100 confers resistance to rhizoxin in this organism. The amino acid sequences of β-tubulin surrounding the 100th amino acid residue from the N-terminus including Asn-100 are highly conserved with a few exceptions. The fission yeastSchizosaccharomyces pombe and the budding yeastSaccharomyces cerevisiae are naturally occurring Rhir organisms whose β-tubulin genes encode Ile and Val respectively at the 100th amino acid residue. The Ile-100 ofS. pombe and the Val-100 ofS. cerevisiae were altered to Asn using site-directed mutagenesis and gene displacement techniques. The resultant haploid strains of these two yeasts uniquely expressing β-tubulin (Asn-100) instead of β-tubulin (Ile-100 or Val-100) were found to be Rhis. Haploid yeast expressing β-tubulin (Asn-100) is normal except for its sensitivity to rhizoxin. These results suggest that rhizoxin resistance has a common basis in both naturally occurring species and experimentally selected mutants in the substitution of Ile or Val for Asn-100 in β-tubulin.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 67
    ISSN: 1617-4623
    Schlagwort(e): Rhizopus aspartic proteinase ; Splicing of intron ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The intron of the Rhizopus aspartic proteinase gene (RNAP-I) was modified by in vitro mutagenesis and examined for its splicing efficiency in Saccharomyces cerevisiae. The wild-type intron of the RNAP-I gene was not spliced at all in spite of its structural similarity to introns of S. cerevisiae. The primary transcript of the RNAP-I gene was converted to correctly translatable mRNA only when the complete consensus sequence of S. cerevisiae introns (i.e. 5″-GTATGT-----TACTAAC-----TAG-3″) was introduced into its intron, although the efficiency of splicing was low. It is also shown that transformants carrying the RNAP-I gene with the complete consensus sequence of S. cerevisiae introns produce active RNAP-I protein.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 68
    ISSN: 1617-4623
    Schlagwort(e): Cochliobolus heterostrophus race T disease ; Maize cytoplasmic male sterility ; Mitochondria ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary We asked whether the mitochondrial T-urf13 gene, associated with the male sterility phenotype of T cytoplasm in maize, can be expressed in Saccharomyces cerevisiae and whether this expression can mimic the effects observed in maize. We introduced the universal code equivalent of the T-urf13 gene into the S. cerevisiae nucleus by transformation and directed its translation product into mitochondria by means of a fusion with the targeting presequence from Neurospora crassa ATPase subunit 9. We show that expression of the universal code equivalent of the T-urf13 gene in the yeast nucleus does indeed mimic its effects in maize: respiratory growth of yeast is inhibited, respiration-deficient cytoplasmic mutants accumulate and NADH oxidation of isolated mitochondria is uncoupled. All these effects are observed only if the mitochondrial targeting peptide and methomyl or HmT toxin are present.
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    Standort Signatur Erwartet Verfügbarkeit
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  • 69
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 223 (1990), S. 49-57 
    ISSN: 1617-4623
    Schlagwort(e): Neurospora crassa ; Heterologous gene expression ; Saccharomyces cerevisiae ; Domain independence ; TRP1
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The trifunctional TRP1 gene from Neurospora crassa (N-TRP1) was subcloned into the yeast-Escherichia coli shuttle vector YEp13 and expressed in Saccharomyces cerevisiae. The three activities of the N-TRP1 gene product were detected in yeast mutants that lacked either N-(5′-phosphoribosyl) anthranilate (PRA) isomerase or both the glutamine amidotransferase function of anthranilate synthase and indole-3-glycerol phosphate (InGP) synthase. The protein was detected on immunoblots only as the full length 83 kda product indicating that the trifunctional gene product was expressed in yeast primarily in a fully active, undegraded form. By placing the subcloned N-TRP1 gene under the control of the inducible PHO5 promoter from yeast, the expression of all three activities was increased to more than ten fold that of wild-type yeast and the overproduced protein could be visualized by SDS-polyacrylamide gel electrophoresis of crude extract and Coomassie Blue staining. Using the expression system described the effect of selective deletion of regions of the coding sequence of the N-TRP1 gene on expression of the three activities was tested. Expression of either the F- or C-domains, catalyzing respectively the PRA isomerase or InGP synthase activities, did not depend on the presence of the other domain in the active polypeptide. Furthermore, normal dimer formation occurred with a protein active for InGP synthase in a deletion derivative lacking most of the PRA isomerase domain, ruling out the hypothesis that interaction between the active site regions for PRA isomerase and InGP synthase accounted for dimer formation in the trifunctional product.
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  • 70
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 223 (1990), S. 97-106 
    ISSN: 1617-4623
    Schlagwort(e): Heat shock ; Saccharomyces cerevisiae ; Stationary phase ; cAMP ; Thermotolerance
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary We have isolated a new small heat shock gene, HSP12, from Saccharomyces cerevisiae. It encodes a polypeptide of predicted Mr 12 kDa, with structural similarity to other small heat shock proteins. HSP12 gene expression is induced several hundred-fold by heat shock and on entry into stationary phase. HSP12 mRNA is undetectable during exponential growth in rich medium, but low levels are present when cells are grown in minimal medium. Analysis of HSP12 expression in mutants affected in cAMP-dependent protein phosphorylation suggests that the gene is regulated by cAMP as well as heat shock. A disruption of the HSP12 coding region results in the loss of an abundant 14.4 kDa protein present in heat shocked and stationary phase cells. It also leads to the induction of the heat shock response under conditions normally associated with low-level HSP12 expression. The HSP12 disruption has no observable effect on growth at various temperatures, nor on the ability to acquire thermotolerance.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 71
    ISSN: 1617-4623
    Schlagwort(e): Heat shock response ; HSP70 ; Saccharomyces cerevisiae ; RAS-CAMP pathway ; Multicopy suppressor of ira1
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: abstract The MSI3 gene was isolated as a multicopy suppressor of the heat shock-sensitive phenotype of the iral mutation, which causes hyperactivation of the RAS-cAMP pathway. Overexpression of MSI3 also suppresses the heat shock-sensitive phenotype of the bcyl mutant. Determination of the DNA sequence of MSI3 revealed that MSI3 can encode a 77.4 kDa protein related to the HSP70 family. The amino acid sequence of Msi3p is about 30% identical to that of the Ssalp of Saccharomyces cerevisiae. This contrasts with the finding that members of the HSP70 family generally show at least 50% amino acid identity. The consensus nucleotide sequence of the heat shock element (HSE) was found in the upstream region of MSI3. Moreover, the steady-state levels of the MSI3 mRNA and protein were increased upon heat shock. These results indicate that the MSI3 gene encodes a novel HSP70-like heat shock protein. Disruption of the MSI3 gene was associated with a temperature sensitive growth phenotype but unexpectedly, thermotolerance was enhanced in the disruptant.
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  • 72
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 241 (1993), S. 657-666 
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Pyruvate decarboxylase ; Transcription ; Glucose induction ; Autoregulation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The regulatory gene PDC2 was identified in a screen for mutations affecting pyruvate decarboxylase activity in yeast. I have cloned and sequenced this gene. The predicted protein of 925 amino acids has no homology to any sequence in the databases. However, the protein sequence is rich in asparagine and serine residues, as is often found for transcriptional regulators. The PDC2 deletion mutant exhibits a phenotype very similar to, but more severe than that of the point mutant: a strongly reduced pyruvate decarboxylase specific activity, slow, respiration-dependent growth on glucose, and accumulation of pyruvate. The activity of other glycolytic enzymes seems to be unaffected by the pdc2Δ mutation. Synthesis of pyruvate decarboxylase is regulated by PDC2 at the transcriptional level. Expression of the major structural gene for pyruvate decarboxylase, PDC1, is strongly reduced in pdc2Δ mutants. Transcription of the generally more weakly expressed PDC5 gene appears to be entirely abolished. However, glucose induction of pyruvate decarboxylase synthesis is unaffected. Thus, PDC2 is either important for a high basal level of PDC gene expression or it plays a positive role in the autoregulation that controls expression of PDC1 and PDC5.
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    Standort Signatur Erwartet Verfügbarkeit
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  • 73
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 241 (1993), S. 680-684 
    ISSN: 1617-4623
    Schlagwort(e): Nitrogen mustard resistance ; Regulation of choline permease ; Co-regulation ; Phospholipid biosynthesis ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract An 815 by region of the promoter of the Saccharomyces cerevisiae gene CTR/HNM1, encoding choline permease was sequenced and its regulatory function analysed by deletion studies in an in-frame promoter-lacZ construct. In addition to the TATA box, a 10 by motif (consensus 5′-CATGTGAAAT-3′) was found to be mandatory for CTR/HNM1 expression. This ‘decamer’ motif is located between nucleotides −262 and −271 and is identical in 9 of 10 by with the regulatory motif found in the S. cerevisiae INO1 and CHO1 genes. Constructs with the 10 by sequence show high constitutive expression, while elimination or alterations at three nucleotide positions, of the decamer motif in the context of an otherwise unchanged promoter leads to total loss of β-galactosidase production. Expression of the CTR/HNM1 gene in wild-type cells is regulated by the phospholipid precursors inositol and choline; no such influence is seen in cells bearing mutations in the phospholipid regulatory genes INO2, INO4, and OPI1. There is no regulation by INO2 and OPI1 in the absence of the decamer motif. However constructs not containing this sequence (promoter intact to positions −213 or −152) are still controlled by INO4. Other substrates of the choline permease, i.e. ethanolamine, nitrogen mustard and nitrogen half mustard do not regulate expression of CTR/HNM1.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 74
    ISSN: 1617-4623
    Schlagwort(e): Texas maize cytoplasmic male sterility ; Saccharomyces cerevisiae ; Mitochondria ; Image and flow cytometry ; 3,3′-Dihexyloxacarbocyanine iodide
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The urf13TW gene, which is derived from the mitochondrial T-urf13 gene responsible for Texas cytoplasmic male sterility in maize, was expressed in Saccharomyces cerevisiae by targeting its translation product into mitochondria. Analysis by oxygraphy at the population level revealed that in the presence of methomyl the oxygen uptake of intact yeast cells carrying the targeted protein is strongly stimulated only with ethanol as respiratory substrate and not with glycerol, lactate, pyruvate, or acetate. When malate is the substrate oxidized by isolated mitochondria, interaction between the targeted protein and methomyl results in significant inhibition of oxygen uptake. This inhibition is eliminated and oxygen uptake is stimulated by subsequent addition of NAD+. Using 3,3′-dihexyloxacarbocyanine iodide [DiOC6(3)] as probe, interactive laser scanning and flow cytometry, which permit analysis at the individual cell level, demonstrated that specific staining of the mitochondrial compartment is obtained and that DiOC6(3) fluorescence serves as a measure of the membrane potential. Finally, it was shown that, as in T cytoplasm maize mitochondria, HmT toxin and methomyl dissipate the membrane potential of yeast mitochondria that carry the foreign protein. Furthermore, the results suggest that the HmT toxin and methomyl response is related to the plasmid copy number per cell and that the deleterious effect induced by HmT toxin is stronger than that of methomyl.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 75
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 237 (1993), S. 49-57 
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Nuclear pet mutants ; Mitochondrial transcription ; Mutant RNA polymerase ; Specificity factor
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The temperature-sensitive yeast mutant pet-ts798 is characterized by an altered mitochondrial transcription apparatus. The mutation has previously been shown to map in the RP041 gene encoding the core enzyme of mitochondrial RNA polymerase. In the present study the rpo41/pet-ts798 allele was cloned and sequenced, demonstrating that the mutant phenotype is caused by a single amino acid change in a conserved region of the core polymerase. The nuclear gene MTF1, previously isolated as a high copy suppressor of mutant rpo41/pet-ts798, and its gene product were characterized in more detail. Import of a MTF1-COXIV fusion protein in vivo and also import studies with in vitro synthesized MTF1 precursors indicate that MTF1 is a mitochondrial protein and that no apparent cleavage occurs during its import into mitochondria. DNA-binding assays demonstrate that the MTF1 protein alone interacts with DNA in a non-specific manner. An antibody directed against specificity factor MTF1 was raised and used for immunological quantification experiments. The results indicate that suppression is mediated by an increased level of MTF1 protein in mitochondria of the rpo41/pet-ts798 mutant. Possible implications of this finding for the mechanism of suppression are discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 76
    ISSN: 1617-4623
    Schlagwort(e): DNA bending ; Autonomously replicating sequence ; Saccharomyces cerevisiae ; Basidiomycete ; Linear plasmid
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Previous studies have indicated that DNA bending is a general structural feature of sequences (ARSs) from cellular DNAs of yeasts and nuclear and mitochondrial genomic DNAs of other eukaryotes that are capable of autonomous replication in Saccharomyces cerevisiae. Here we showed that bending activity is also tightly associated with S. cerevisiae ARS function of segments cloned from mitochondrial linear DNA plasmids of the basidiomycetes Pleurotus ostreatus and Lentinus edodes. Two plasmids, designated pLPO2-like (9.4 kb), and pLPO3 (6.6 kb) were isolated from a strain of P. ostreatus. A 1029 by fragment with high-level ARS activity was cloned from pLPO3 and it contained one ARS consensus sequence (A/T)TTTAT(A/G)TTT(A/T) indispensable for activity and seven dispersed ARS consensus-like (10/11 match) sequences. A discrete bent DNA region was found to lie around 500 by upstream from the ARS consensus sequence (T-rich strand). Removal of the bent DNA region impaired ARS function. DNA bending was also implicated in the ARS function associated with a 1430 by fragment containing three consecutive ARS consensus sequences which had been cloned from the L. edodes plasmid pLLE1 (11.0 kb): the three consecutive ARSs responsible for high-level ARS function occurred in, and immediately adjacent to, a bent DNA region. A clear difference exists between the two plasmid-derived ARS fragments with respect to the distance between the bent DNA region and the ARS consensus sequence(s).
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    Standort Signatur Erwartet Verfügbarkeit
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  • 77
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 237 (1993), S. 306-310 
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Gene replacement ; Donation
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary We describe here a new method for the introduction of non-selectable alleles into Saccharomyces cerevisiae, gene replacement by donation. This method only requires the availability of an autonomously replicating, selectable plasmid containing the allele to be introduced into yeast. The plasmid is digested at a restriction site (or sites) within this allele, and introduced into yeast by transformation. In the course of double-strand break repair, the entering plasmid donates genetic information to the chromosome, replacing the chromosomal allele in a gene conversion-like event. Gene replacement events are identified by a phenotypic screen of the transformants. When necessary, the transforming plasmid may be subsequently lost by segregation during permissive growth. We have studied several parameters affecting the utility of this protocol as a method of gene replacement. Together with our previous results, the results show gene replacement by donation to be a useful, facile method, yielding gene replacement in up to 1.5% of transformants.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 78
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Formaldehyde hyper-resistance ; Alcohol dehydrogenase ; Glutathione ; Inducibility
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary A 3.7 kb DNA fragment of yeast chromosome IV has been sequenced that contains the SFA gene which, when present on a multi-copy plasmid in Saccharomyces cerevisiae, confers hyper-resistance to formaldehyde. The open reading frame of SFA is 1158 by in size and encodes a polypeptide of 386 amino acids. The predicted protein shows strong homologies to several mammalian alcohol dehydrogenases and contains a sequence characteristic of binding sites for NAD. Overexpression of the SFA gene leads to enhanced consumption of formaldehyde, which is most probably the reason for the observed hyper-resistance phenotype. In sfa:LEU2 disruption mutants, sensitivity to formaldehyde is correlated with reduced degradation of the chemical. The SFA gene shares an 868 by divergent promoter with UGX2 a gene of yet unknown function. Promoter deletion studies with a SFA promoter-lacZ gene fusion construct revealed negative interference on expression of SFA by upstream sequences. The upstream region between positons − 145 and − 172 is totally or partially responsible for control of inducibility of SFA by chemicals such as formaldehyde (FA), ethanol and methyl methanesulphonate. The 41 kDa SFA-encoded protein was purified from a hyper-resistant transformant; it oxidizes long-chain alcohols and, in the presence of glutathione, is able to oxidize FA. SFA is predicted to code for a long-chain alcohol dehydrogenase (glutathione-dependent formaldehyde dehydrogenase) of the yeast S. cerevisiae.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 79
    ISSN: 1617-4623
    Schlagwort(e): Intrachromosomal and interchromosomal recombination ; Saccharomyces cerevisiae ; RAD18
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The frequency of intra- and interchromosomal recombination was determined in RAD18 and rad18 deletion and rad18-3 mutant strains. It was found that spontaneous interchromosomal recombination at trp5, his1, ade2, and MAT was elevated 10- to 70-fold in the rad18-3 and rad18Δ mutants as compared to the RAD + strains. On the other hand the frequencies of spontaneous intrachromosomal recombination for the his3Δ3′, his3Δ5′ and the his4C −, his4A − duplications and for heterothallic mating type switching were only marginally elevated in the rad18 deletion mutant, and recombination between ribosomal DNA repeats was only 2-fold elevated in the rad18-3 mutant. These differences may be due to a haploid versus diploid specific difference. However interchromosomal recombination was elevated 40-fold and intrachromosomal recombination was only marginally (1.5-fold) elevated in a diploid homozygous for rad18Δ, arguing against a haploid versus diploid specific difference. Possible explanations for the difference in the elevated levels of intra- versus interchromosomal spontaneous recombination are discussed.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 80
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 238 (1993), S. 315-324 
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Nuclear gene ; Mitochondrial enzyme ; Lactate dehydrogenase ; Flavoprotein
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In Saccharomyces cerevisiae the utilization of lactate occurs via specific oxidation of l- and d-lactate to pyruvate catalysed by l-lactate ferricytochrome c oxidoreductase (L-LCR) (EC 1.1.2.3) encoded by the CYB2 gene, and d-lactate ferricytochrome c oxidoreductase (D-LCR) (EC 1.1.2.4), respectively. We selected several lactate− pyruvate+ mutants in a cyb2 genetic background. Two of them were devoid of D -LCR activity (dld mutants, belonging to the same complementation group). The mutation mapped in the structural gene. This was demonstrated by a gene dosage effect and by the thermosensitivity of the enzyme activity of thermosensitive revertants. The DLD gene was cloned by complementation for growth on d-, l-lactate in the strain WWF18-3D, carrying both a CYB2 disruption and the dld mutation. The minimal complete complementing sequence was localized by subcloning experiments. From the sequence analysis an open reading frame (ORF) was identified that could encode a polypeptide of 576 amino-acids, corresponding to a calculated molecular weight of 64000 Da. The deduced protein sequence showed significant homology with the previously described microsomal flavoprotein l-gulono-γ-lactone oxidase isolated from Rattus norvegicus, which catalyses the terminal step of l-ascorbic acid biosynthesis. These results are discussed together with the role of L-LCR and D-LCR in lactate metabolism of S. cerevisiae.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 81
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; DNA amplification ; Minisatellites ; VNTR ; MS1
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Minisatellites comprise arrays of tandemly repeated short DNA sequences which show extensive variation in repeat unit number. The mechanisms that underlie this length variation are not understood. In order to study processes influencing length changes of minisatellites, we integrated the human minisatellite MS1 into a haploid strain of the yeast Saccharomyces cerevisiae. Frequent spontaneous generation of MS1 alleles with new lengths were observed in this yeast strain. Hence it is concluded that recombination between members of a pair of homologous chromosomes is not a prerequisite for the generation of length changes in MS1 in yeast.
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  • 82
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 223 (1990), S. 407-416 
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Schizosaccharomyces pombe ; Transcription initiation ; ADH gene ; TATA sequence
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The roles of the TATA element and sequences near the mRNA initiation site in specifying the location of initiation sites in Saccharomyces cerevisiae were examined, using the Schizosaccharomyces pombe ADH gene. The importance of spacing was demonstrated by analysis of a series of deletions that removed from 8–50 bp between the TATA element and ATG translation initiation site of this gene. Primer extension mapping showed that increasing deletion length is associated with a progressive shift downstream in the location of the initiation sites. The distance of a given site from the promoter affected the relative ability of the site to be utilized for initiation. For this gene, a permissive region for transcription initiation exists between 55 and 125 bases downstream of the TATA element, and a zone of 75–115 bases allows maximal usage of an initiation site. The presence of a TATA sequence was shown to be necessary in S. cerevisiae for maintaining the location of this “window” of initiation. The TATA sequence is essential for function of the gene in S. pombe. This gene, as well as the majority of the 63 S. cerevisiae genes surveyed, uses initiation sites which fit a PyAA/T(Pu) consensus. Cis-acting mutations were recovered which restored ADH activity to a deletion allele that initiates its mRNAs downstream of the ATG. DNA sequence and transcript analysis with these mutants confirmed the requirement of proper spacing and conformity of initiation sites to the PyAA/T(Pu) consensus for efficient transcript initiation.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 83
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 223 (1990), S. 449-456 
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Gene regulation ; TUF ; Pyruvate decarboxylase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary The upstream activation site of the pyruvate decarboxylase gene, PDC1, of Saccharomyces cerevisiae contains an RPG box, and mediates the increase in expression of a PDC1-lacZ fusion gene during growth on glucose. Oligonucleotide replacement experiments indicate that the RPG box functions as an absolute activator of expression, but other elements (possibly CTTCC repeats) are required for carbon source regulation, and maximal expression. Gel retardation and oligonucleotide competition experiments suggest that the DNA binding factor TUF interacts with the RPG box in the upstream region of PDC1. Binding of TUF factor is not carbon source dependent in in vitro experiments, and is probably not responsible for glucose induction of PDC1 expression.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 84
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Centromere and promoter factor ; Chromatin ; SPT ; Transcription
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract In Saccharomyces cerevisiae, the CPF1 gene encodes a ccntromere binding protein that also plays a role in transcription; cpf1 strains are methionine auxotrophs. In this paper we describe four strains that are methionine prototrophs despite containing a defective CPF1 gene. These strains, which contain mutations at either the SPT21, RPD1 (SINS), RPD3 or CCR4 loci, have defective centromere function and a chromatin structure around the CDEI elements in the MET25 promoter characteristic of strains lacking CPF1. This indicates that the roles of CPF1 in transcription, centromere function and chromatin modulation around CDEI sites are different. We propose that CPF1 functions to overcome the repressing action, mediated via inactive chromatin, of proteins such as SPT21 or RPDI (SIN3) on gene expression. The absence of proteins such as SPT21 or RPD1 (SIN3) relieves this respression and explains how methionine prototrophy is restored in the absence of CPF1.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 85
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 240 (1993), S. 414-418 
    ISSN: 1617-4623
    Schlagwort(e): Cruciform DNA ; Endonuclease ; Mitochondria ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract We have found a cruciform cutting endonuclease in the yeast, Saccharomyces cerevisiae, which localizes to the mitochondria. This activity apparently is associated with the mitochondrial inner membrane since the activity is not released into solution by osmolysis, in contrast to the matrix enzyme, isocitrate dehydrogenase. The cruciform cutting activity appears to be encoded by CCE1. This gene has been shown to encode one of the major cruciform cutting endonucleases present in a yeast cell. In ccel strains, which lack CCE1 endonuclease activity, the mitochondrial cruciform cutting endonucleolytic activity is also absent. Since CCE1 is allelic to MGT1, a gene required for the highly biased transmission of petite mitochondrial DNA in crosses between ϱ+ and hypersuppressive ϱ− cells, it seems likely that the CCE1 endonuclease functions within mitochondria.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 86
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 241 (1993), S. 213-224 
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Mitochondria ; Transcriptional regulation ; Protein phosphorylation ; Stringent response
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Using various mutant strains and nutritional manipulations, we investigated a potential role for cyclic AMP (cAMP) in the regulation of mitochondrial (mt) gene expression in the yeast Saccharomyces cerevisiae. In RAS mutants known to have either abnormally low or high cellular levels of this nucleotide, we show that both mt transcription rate and overall mt transcript levels vary directly with cellular cAMP levels. We further show that nutritional downshift of actively growing cells causes a severe, rapid fall in cAMP levels, and that this fall is concomitant with the stringent mt transcriptional curtailment that we and others have previously shown to follow this nutritional manipulation. In in vitro mt transcription assays using intact organelles from downshifted and actively growing cells, stringently curtailed mt gene expression can be restored to 75% of control levels by addition of cAMP to the assay mix. Consistent with these observations a RAS2 vall9mutant strain, which cannot adjust cAMP levels in response to external stimuli, shows no mt stringent response following nutritional downshift. We also demonstrate a significant but transient increase in both mt transcript levels and mt transcription rate following shift of actively respiring wild-type cells to glucose-based medium, a manipulation known to cause a short-lived pulse of cAMP in yeast; similar manipulation of the RAS2 vall9mutant strain generates no such response. Taken together all these observations indicate that cellular cAMP levels are involved in the regulation of mt transcription in yeast. Moreover, the lack of a mt stringent transcriptional response following downshift in a strain in which the BCY1 gene had been insertionally inactivated suggests that cAMP may influence mt transcription via a mt cAMP-dependent protein kinase. These results link mt gene expression with mechanisms governing growth control and nutrient adaptation in yeast, and they provide a means by which nit gene expression might be coordinated with that of related nuclear genes.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 87
    ISSN: 1617-4623
    Schlagwort(e): Mating pheromone ; Saccharomyces cerevisiae ; Signal transduction ; STE5 ; Ste20 protein kinase
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The β and γ subunits of the mating response G-protein in the yeast Saccharomyces cerevisiae have been shown to transmit the mating pheromone signal to downstream components of the pheromone response pathway. A protein kinase homologue encoded by the STE20 gene has recently been identified as a potential G βγ , target. We have searched multicopy plasmid genomic DNA libraries for high gene dosage suppressors of the signal transduction defect of ste20 mutant cells. This screen identified the STE5 gene encoding an essential component of the pheromone signal transduction pathway. We provide genetic evidence for a functional interrelationship between the STE5 gene product and the Ste20 protein kinase. We have sequenced the STE5 gene, which encodes a predicted protein of 917 amino acids and is specifically transcribed in haploid cells. Transcription is slightly induced by treatment of cells with pheromone. Ste5 has homology with Fart, a yeast protein required for efficient mating and the pheromone-inducible inhibition of a G1 cyclin, Cln2. A STE5 multicopy plasmid is able to suppress the signal transduction defect of farl null mutant cells suggesting that Ste5, at elevated levels, is able functionally to replace Fart. The genetically predicted point of function of Ste5 within the pheromone signalling pathway suggests that Stc5 is involved in the regulation of a Gβγ-activated protein kinase cascade which links a G-protein coupled receptor to yeast homologues of mitogen-activated protein kinases.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 88
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 241 (1993), S. 280-286 
    ISSN: 1617-4623
    Schlagwort(e): Yeast RAS ; RAS-CAMP pathway ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract A mutant allele of RAS1 that dominantly interferes with the wild-type Ras function in the yeast Saccharomyces cerevisiae was discovered during screening of mutants that suppress an ira2 disruption mutation. A single amino acid substitution, serine for glycine at position 22, was found to cause the mutant phenotype. The inhibitory effect of the RAS1 Ser22 gene could be overcome either by overexpression of CDC25 or by the ira2 disruption mutation. These results suggest that the RAS1Ser22 gene product interferes with the normal interaction of Ras with Cdc25 by forming a dead-end complex between Ras1Ser22 and Cdc25 proteins.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 89
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; RNA polymerase II ; Cyclins ; Transcription ; Cell cycle
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Saccharomyces cerevisiae cells harboring the temperature-sensitive mutation rpo21-4, in the gene encoding the largest subunit of RNA polymerase II, were shown to be partially impaired for cell-cycle progress at a permissive temperature, and to become permanently blocked at the cell-cycle regulatory step, START, at a restrictive temperature. The rpo21-4 mutation was lethal in combination with cdc28 mutations in the p34 protein kinase gene required for START. Transcripts of the CLN1 and CLN2 genes, encoding G1-cyclin proteins that, along with p34, are necessary for START, were decreased in abundance by the rpo21-4 mutation at a restrictive temperature. Increased G1-cyclin production, by expression of the CLN1 or CLN2 genes from a heterologous GAL promoter, overcame the rpo21-4 — mediated START inhibition, but such mutant cells nevertheless remained unable to proliferate at a restrictive temperature. These findings reveal that START can be particularly sensitive to an impaired RNA polymerase II function, presumably through effects on G1-cyclin expression.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 90
    ISSN: 1617-4623
    Schlagwort(e): Transcriptional activators ; O2 gene ; Zea mays ; bZIP proteins ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract The aim of this research was to determine whether the structural homology between the O2 gene, a maize transcriptional activator, and the GCN4 gene, a yeast transcriptional factor, is reflected at the level of function. The O2 cDNA was cloned in the yeast expression vector pEMBLyex4 under the control of a hybrid, inducible promoter, and used to transform the yeast Saccharomyces cerevisiae. Transformed yeast cells produced O2 mRNA and a polypeptide immunoreactive with anti-O2 antibodies during growth in galactose. The heterologous protein was correctly translocated into the yeast nuclei, as demonstrated by immunofluorescence, indicating that the nuclear targeting sequences of maize are recognized by yeast cells. Further experiments demonstrated the ability of O2 to rescue a gcn4 mutant grown in the presence of aminotriazole, an inhibitor of the HIS3 gene product, suggesting that O2 activates the HIS3 gene, gene normally under control of GCN4. It was shown that the O2 protein is able to trans-activate the HIS4 promoter in yeast cells and binds to it in vitro. The sequence protected by O2, TGACTC, is also the binding site for GCN4. Finally, the expression of O2 protein in yeast did not produce alterations during batch growth at 30° C, while transformants expressing O2 protein showed a conditionally lethal phenotype when grown in galactose at 36° C; this phenotype mimics the behaviour of gcd mutants. The results support the idea that basic mechanisms of transcription control have been highly conserved in eukaryotes.
    Materialart: Digitale Medien
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  • 91
    Digitale Medien
    Digitale Medien
    Springer
    Molecular genetics and genomics 236 (1993), S. 443-447 
    ISSN: 1617-4623
    Schlagwort(e): Saccharomyces cerevisiae ; Protein kinases ; Protein Kinase C ; Growth control
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Summary Probes derived from cDNAs encoding isozymes of rat protein kinase C (PKC) were used to screen the genome of the budding yeast Saccharomyces cerevisiae. We reported previously the isolation of the yeast PKC1 gene, a homolog of the α, β, and γ subspecies of mammalian PKC. Here we report the isolation and genetic characterization of a pair of previously described genes (YPK1 and YPK2) which are predicted to encode protein kinases that share 90% amino acid identity with each other and 44–46% identity with various isozymes of PKC throughout their putative catalytic domains. Deletion of YPK2 resulted in no apparent phenotypic defect, but loss of YPK1 resulted in slow growth. Cells deleted for both YPK1 and YPK2 were defective in vegetative growth, indicating that the protein kinases predicted to be encoded by these genes are functionally overlapping and play an essential role in the proliferation of yeast cells. The YPK1 gene was mapped to the left arm of chromosome XI and YPK2 was mapped to the right arm of chromosome XIII.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 92
    ISSN: 1573-6881
    Schlagwort(e): Rieske iron-sulfur protein, RIP1 ; Saccharomyces cerevisiae ; mitochondria ; bc 1 complex ; QCR9 ; iron-sulfur cluster, mitochondrial targeting
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie , Physik
    Notizen: Abstract The iron-sulfur protein of the cytochromebc 1 complex oxidizes ubiquinol at center P in the protonmotive Q cycle mechanism, transferring one electron to cytochromec 1 and generating a low-potential ubisemiquinone anion which reduces the low-potential cytochromeb-566 heme group. In order to catalyze this divergent transfer of two reducing equivalents from ubiquinol, the iron-sulfur protein must be structurally integrated into the cytochromebc 1 complex in a manner which facilitates electron transfer from the iron-sulfur cluster to cytochromec 1 and generates a strongly reducing ubisemiquinone anion radical which is proximal to theb-566 heme group. This radical must also be sequestered from spurious reactivities with oxygen and other high-potential oxidants. Experimental approaches are described which are aimed at understanding how the iron-sulfur protein is inserted into center P, and how the iron-sulfur cluster is inserted into the apoprotein.
    Materialart: Digitale Medien
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  • 93
    Digitale Medien
    Digitale Medien
    Springer
    World journal of microbiology and biotechnology 9 (1993), S. 583-586 
    ISSN: 1573-0972
    Schlagwort(e): Cell-free extracts ; plasmids ; recombination ; Saccharomyces cerevisiae ; topo-isomerase mutants
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract Cell-free extracts of the yeast Saccharomyces cerevisiae can be used to catalyse the recombination of bacterial plasmids in vitro. Recombination between homologous plasmids containing different mutations in the gene encoding tetracycline resistance is detectable by the appearance of tetracycline-resistance following transformation of the recombinant plasmid DNA into Escherichia coli DH5. This in vitro recombination system was used to determine the involvement of eukaryotic topo-isomerases in genetic recombination. Cell-free extracts prepared from a temperature-sensitive topo-isomerase II mutant (top2-1) of S. cerevisiae yielded tetracycline-resistant recombinants, when the recombination assays were performed at both a non-restrictive temperature (30°C) and the restrictive temperature (37°C). This result was obtained whether or not ATP was present in the recombination buffer. Extracts from a non-conditional topo-isomerase I mutant (top1-1) of S. cerevisiae yielded tetracycline-resistant recombinants, as did a temperature-sensitive double mutant (top2-1/top1-8) at the restrictive temperature. The results of this study indicate that neither topo-isomerase I nor topo-isomerase II was involved in the recombinational activity examined.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 94
    Digitale Medien
    Digitale Medien
    Springer
    World journal of microbiology and biotechnology 9 (1993), S. 662-663 
    ISSN: 1573-0972
    Schlagwort(e): Biosynthesis ; invertase ; molasses ; Saccharomyces cerevisiae ; yeast
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract Biosynthesis of invertase by Saccharomyces cerevisiae 01K32 was inversely proportional to the concentration of sugarcane blackstrap molasses included in the medium. In a fermenter, an intracellular invertase activity of 440 U/g dry cells was obtained.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 95
    Digitale Medien
    Digitale Medien
    Springer
    Antonie van Leeuwenhoek 58 (1990), S. 277-282 
    ISSN: 1572-9699
    Schlagwort(e): Saccharomyces cerevisiae ; killer toxin K28 ; glycoprotein ; O-glycosylation ; β-elimination ; α-toxin antibodies
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract Killer toxin K28, a 16 kd protein secreted by the wine yeast Saccharomyces cerevisiae strain 28, was reversibly bound by a column of Concanavalin A-Sepharose, confirming its glycoprotein nature. HPLC analysis of acid hydrolyzates of K28 toxin as well as Western-blots of β-eliminated and/or endo H-treated killer toxin preparations probed with polyclonal α-toxin antibodies revealed that the carbohydrate moiety of K28 consists of D-mannose only, which is O-glycosidically linked via Ser/Thr residues to the protein part. The change in gel mobility of K28 after β-elimination was caused by a decrease in molecular mass of about 1,800, corresponding to a carbohydrate moiety of 10 mannose residues per killer toxin molecule.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 96
    Digitale Medien
    Digitale Medien
    Springer
    Antonie van Leeuwenhoek 63 (1993), S. 343-352 
    ISSN: 1572-9699
    Schlagwort(e): alcoholic fermentation ; chemostat culture ; Crabtree effect ; respiration ; Saccharomyces cerevisiae ; yeasts
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie
    Notizen: Abstract An overview is presented of the steady- and transient state kinetics of growth and formation of metabolic byproducts in yeasts.Saccharomyces cerevisiae is strongly inclined to perform alcoholic fermentation. Even under fully aerobic conditions, ethanol is produced by this yeast when sugars are present in excess. This so-called ‘Crabtree effect’ probably results from a multiplicity of factors, including the mode of sugar transport and the regulation of enzyme activities involved in respiration and alcoholic fermentation. The Crabtree effect inS. cerevisiae is not caused by an intrinsic inability to adjust its respiratory activity to high glycolytic fluxes. Under certain cultivation conditions, for example during growth in the presence of weak organic acids, very high respiration rates can be achieved by this yeast.S. cerevisiae is an exceptional yeast since, in contrast to most other species that are able to perform alcoholic fermentation, it can grow under strictly anaerobic conditions. ‘Non-Saccharomyces’ yeasts require a growth-limiting supply of oxygen (i.e. oxygen-limited growth conditions) to trigger alcoholic fermentation. However, complete absence of oxygen results in cessation of growth and therefore, ultimately, of alcoholic fermentation. Since it is very difficult to reproducibly achieve the right oxygen dosage in large-scale fermentations, non-Saccharomyces yeasts are therefore not suitable for large-scale alcoholic fermentation of sugar-containing waste streams. In these yeasts, alcoholic fermentation is also dependent on the type of sugar. For example, the facultatively fermentative yeastCandida utilis does not ferment maltose, not even under oxygen-limited growth conditions, although this disaccharide supports rapid oxidative growth.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 97
    Digitale Medien
    Digitale Medien
    Springer
    Journal of chemical ecology 16 (1990), S. 1399-1408 
    ISSN: 1573-1561
    Schlagwort(e): Allelopathy ; emulsions ; monoterpenes ; Saccharomyces cerevisiae ; yeast ; suspensions ; droplet size ; toxicity
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Chemie und Pharmazie
    Notizen: Abstract The toxic effects of the allelopathic nonsubstituted monoterpenes β-pinene and limonene on yeast,Saccharomyces cerevisiae, were proportional to the size of the monoterpene droplets in suspension. Both the toxic effects and the size of the droplets in suspension were decreased by adding different solvents with the monoterpene as follows: dimethylsulfoxide – dimethylformamide ≫ ethanol 〉 dioxane. Oxygen consumption was inhibited about 80% by 1 mM β-pinene added in dimethylsulfoxide but less than 10% when β-pinene was added in dioxane. Parallel decreases in droplet size and toxic effects of either monoterpene were also induced by hydrating the monoterpene-dimethylformamide or monoterpene-dimethylsulfoxide before addition to yeast. Molecular aggregation may be a mechanism to potentiate the allelopathic properties of monoterpenes when these associate with diverse soil components.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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  • 98
    Digitale Medien
    Digitale Medien
    Springer
    World journal of microbiology and biotechnology 9 (1993), S. 70-72 
    ISSN: 1573-0972
    Schlagwort(e): Beer ; brewing ; non-head forming ale yeast ; Saccharomyces cerevisiae
    Quelle: Springer Online Journal Archives 1860-2000
    Thema: Biologie , Werkstoffwissenschaften, Fertigungsverfahren, Fertigung
    Notizen: Abstract The physiological characteristics of two strains of brewery ale yeasts,Saccharomyces cerevisiae, with sedimentation abilities, were investigated to see if the strains were suitable for lager beer production. Compared with typical industrial ale strains ofS. cerevisiae and lager strains ofS. uvarum (nowS. cerevisiae), the investigated strains differ in fermentation dynamics, as well as in biological properties. The differences, however, particularly between the two strains and the lager brewing yeasts, were not significant.
    Materialart: Digitale Medien
    Standort Signatur Erwartet Verfügbarkeit
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