Showing papers on "Yeast published in 1978"
TL;DR: This work has used recently developed hybridization and restriction endonuclease mapping techniques to demonstrate directly the presence of the transforming DNA in the yeast genome and also to determine the arrangement of the sequences that were introduced.
Abstract: A stable leu2- yeast strain has been transformed to LEU2+ by using a chimeric ColE1 plasmid carrying the yeast leu2 gene. We have used recently developed hybridization and restriction endonuclease mapping techniques to demonstrate directly the presence of the transforming DNA in the yeast genome and also to determine the arrangement of the sequences that were introduced. These studies show that ColE1 DNA together with the yeast sequences can integrate into the yeast chromosomes. This integration may be additive or substitutive. The bacterial plasmid sequences, once integrated, behave as a simple Mendelian element. In addition, we have determined the genetic linkage relationships for each newly introduced LEU2+ allele with the original leu2- allele. These studies show that the transforming squences integrate not only in the leu2 region but also in several other chromosomal locations.
2,179 citations
TL;DR: These plasmids have been used to develop a method for transforming a leu2 strain of S. cerevisiae to Leu+ with high frequency and contained multiple plasmid copies which were recovered by transformation in E. coli.
Abstract: Chimaeric plasmids have been constructed containing a yeast plasmid and fragments of yeast nuclear DNA linked to pMB9, a derivative of the ColEl plasmid from E. coli. Two plasmids were isolated which complement leuB mutations in E. coli. These plasmids have been used to develop a method for transforming a leu2 strain of S. cerevisiae to Leu+ with high frequency. The yeast transformants contained multiple plasmid copies which were recovered by transformation in E. coli. The yeast plasmid sequence recombined intramolecularly during propagation in yeast.
1,243 citations
TL;DR: The results suggest that the binding activity of a mannose-specific lectin on the surface of E. coli can be quantitated directly on intact organisms, and the observed variations in the amount of mannosed-binding activity among human isolates accounts for the variation in adherence of the organisms toMannose residues on epithelial cells.
Abstract: The mannose-binding activity of several isolates of Escherichia coli was monitored by aggregometry with mannan-containing yeast cells. The velocity of yeast cell aggregation was found to correlate with the ability of the organisms to adhere to human epithelial cells. Mannose or its derivatives specifically inhibited or reversed epithelial cell adherence and yeast cell aggregation. Most of the adherent bacteria could be displaced within 30 min from the epithelial cells with methyl alpha-d-mannopyranoside, but not with other sugars tested. Cultures of E. coli were fractionated into nonadherent and adherent populations by adsorption with epithelial cells followed by elution of the adherent bacteria with methyl alpha-d-mannopyranoside. When the methyl alpha-d-mannopyranoside-displaced organisms were washed free of the sugar, they exhibited a high degree of mannose-binding activity and were heavily piliated. In contrast, the nonadherent fraction of organisms lacked detectable mannose-binding activity and were devoid of pili. Our results suggest that the binding activity of a mannose-specific lectin on the surface of E. coli can be quantitated directly on intact organisms, and the observed variations in the amount of mannose-binding activity among human isolates accounts for the variation in adherence of the organisms to mannose residues on epithelial cells.
312 citations
TL;DR: Yeast poly(adenylic acid)-containing messenger ribonucleic acid isolated from two strains of Saccharomyces cerevisiae was fractionated by preparative polyacrylamide gel electrophoresis in the presence of formamide and in vitro synthesized polypeptides were identified by tryptic peptide analysis.
Abstract: Yeast poly(adenylic acid)-containing messenger ribonucleic acid isolated from two strains of Saccharomyces cerevisiae was fractionated by preparative polyacrylamide gel electrophoresis in the presence of formamide. Three messenger ribonucleic acids, present at high intracellular concentration, were electrophoretically eluted from the polyacrylamide gels and translated in a wheat germ cell-free extract. The in vitro synthesized polypeptides were identified by tryptic peptide analysis. Messenger ribonucleic acids coding for enolase and glyceraldehyde-3-phosphate dehydrogenase were isolated from commercially grown baker's yeast (strain F1), and messenger ribonucleic acid coding for phosphoglycerate kinase was isolated from Saccharomyces cerevisiae (ATCC 24657). Significant differences in the spectrum of abundant messenger ribonucleic acids isolated from commercially grown baker's yeast (strain F1) and strain 24657 were observed. When both strains were grown under identical conditions, however, the spectrum of messenger ribonucleic acid isolated from the cells is indistinguishable.
281 citations
TL;DR: The ease with which the bacterial cell can achieve functional high-level gene expression from cloned yeast DNA indicates that there are no significant barriers preventing expression of many yeast genes in E. coli.
230 citations
01 Jan 1978
TL;DR: In this article, the Metabolism of Sterols in Yeast was investigated and the results showed that it is a function of the number of chromosomes in the Yeast population.
Abstract: (1978). Metabolism of Sterols in Yeast. CRC Critical Reviews in Microbiology: Vol. 6, No. 4, pp. 301-341.
200 citations
TL;DR: Centrifugal elutriation was used to separate cells of Saccharomyces cerevisiae in balanced exponential growth according to position in the cell cycle, and all the examined proteins showed an exponentially increasing rate of synthesis.
Abstract: Centrifugal elutriation was used to separate cells of Saccharomyces cerevisiae in balanced exponential growth according to position in the cell cycle. Macromolecular synthesis was examined. DNA synthesis was found to be periodic, but RNA and protein synthesis showed an exponential increase in rate. Two-dimensional electrophoresis was used to determine the rate of synthesis of individual proteins, with 111 of the more abundant cellular proteins selected for analysis from among the more than 1000 proteins that migrate in the system. All the examined proteins showed an exponentially increasing rate of synthesis.
196 citations
TL;DR: Chitin synthesis was studied in both yeast and hyphae of the dimorphic fungus Candida albicans, and enzyme activity was found to be located on the inner side of the plasma membrane.
Abstract: Chitin synthesis was studied in both yeast and hyphae of the dimorphic fungus Candida albicans. Incorporation of N-acetyl-d-[1-(3)H]glucosamine ([(3)H]GluNAc) into an acid-alkali-insoluble fraction was 10 times greater in hyphal-phase cells. A crude preparation of chitin synthetase was obtained from sonically treated protoplasts of both forms of Candida. Enzyme activity, which was determined by using [(14)C]UDP-GLuNAc as a substrate, was exclusively associated with the 80,000 x g pellet from sonically treated protoplasts of both forms. It was determined that enzyme activity (nanomoles of [(14)C]UDP-GluNAc incorporated per milligram of protein) was approximately 2 times greater in hyphae versus yeast cells. Enzyme activity in both yeast and hyphae increased six- to sevenfold when the enzyme preparations were preincubated with trypsin. A vacuolar fraction, obtained from yeast cells but not from hyphae, stimulated enzyme activity when incubated with either yeast or hyphal enzyme preparations. Membrane fractions from protoplasts coated with [(3)H]concanavalin A before disruption were isolated by Renografin density gradient centrifugation. Chitin synthetase activity was preferentially associated with the concanavalin A-labeled fraction, suggesting that the enzyme was located on the plasma membrane. In addition, enzyme activity in protoplasts treated with cold glutaraldehyde before disruption was significantly greater than in protoplasts that were sonically disrupted and then treated with cold glutaraldehyde, indicating that the enzyme resides on the inner side of the plasma membrane.
187 citations
TL;DR: In this article, an elicitor of glyceollin accumulation in soybeans (Glycine max L) has been isolated from a commercially available extract of brewers' yeast, and compositional and structural analysis showed the elicitor to be a glucan containing terminal, 3-, 6-, and 3,6linked glucosyl residues.
Abstract: An elicitor of glyceollin accumulation in soybeans (Glycine max L.) has been isolated from a commercially available extract of brewers' yeast. Yeast is not a known pathogen of plants. The elicitor was isolated by precipitation in 80% (v/v) ethanol followed by column chromatography on DEAE-cellulose, sulfopropyl-Sephadex, and concanavalin A-Sepharose. Compositional and structural analysis showed the elicitor to be a glucan containing terminal, 3-, 6-, and 3,6-linked glucosyl residues. The yeast elicitor stimulates the accumulation of glyceollin in the cotyledons and hypocotyls of soybeans when as little as 15 nanograms or 100 nanograms of the elicitor is applied to the respective tissues. The yeast elicitor is very similar in both structure and absolute elicitor activity to an elicitor isolated from the mycelial walls of Phytophthora megasperma var. sojae, a pathogen of soybeans. These and other results of this laboratory suggest that plants are able to respond to the presence of a wide range of fungi by recognizing, as foreign to the plant, structural polysaccharides of the mycelial walls of the fungi.
169 citations
TL;DR: The inhibition of polyphenylalanine synthesis by reticulocyte ribosomes and enzymic translocation of peptidyl-tRNA by yeast polysomes can be reversed by increasing concentrations of EF-2 suggesting a relationship between the binding sites ofEF-2 and hygromycin B on the ribosome.
163 citations
TL;DR: Twenty-five mutants altered in this control have been isolated which have the same growth rate as wild type but divide at a smaller cell size.
Abstract: The control co-ordinating cell division with cell growth has been investigated in the fission yeast Schizosaccharomyces pombe Twenty-five mutants altered in this control have been isolated which have the same growth rate as wild type but divide at a smaller cell size The mutants define two genes wee 1 and wee 2, both of which are involved in a control initiating mitosis when the cell attains a critical size
TL;DR: In the budding yeast Saccharomyces cerevisiae, each bud appears within a ring of chitin formed in the cell wall of the mother cell, but temperature-sensitive mutants defective in gene cdc24 synthesize ch itin at restrictive temperatures, but do not organize it into the discrete rings found in normal cells.
Abstract: In the budding yeast Saccharomyces cerevisiae, each bud appears within a ring of chitin formed in the cell wall of the mother cell. Temperature-sensitive mutants defective in gene cdc24 synthesize chitin at restrictive temperatures, but do not organize it into the discrete rings found in normal cells, nor do they form buds. The chitin ring or an annular precursor structure may play an essential role in reinforcing the region of the cell wall involved in budding.
TL;DR: A precursor of yeast tRNATyr is isolated and shown that it contains an intervening sequence identical to that found in the gene for tR NATyr, which is functionally inactive as it cannot be aminoacylated and the anticodon is not accessible for hydrogen bonding.
Abstract: We have isolated a precursor of yeast tRNATyr and shown that it contains an intervening sequence identical to that found in the gene for tRNATyr. The conformation of pre-tRNATyr is similar to that of mature tRNATyr except for the anticodon loop. The loop is sensitive to endonucleolytic cleavage by S1 nuclease near to the ends of the intervening sequence. This pre-tRNA is functionally inactive as it cannot be aminoacylated and the anticodon is not accessible for hydrogen bonding. A crude nuclear extract from yeast contains an excision-ligase activity which will process pre-tRNATyr into mature tRNATyr.
TL;DR: It is suggested that a single arginine residue per subunit of enolase is necessary for enzymatic activity and is located at or near the substrate binding site (active site).
TL;DR: The iso-1-cytochrome c gene of yeast has been identified and cloned using a synthetic oligodeoxynucleotide as a hybridization probe and a DNA sequence in perfect correspondence with the known protein sequence was yielded.
TL;DR: It can be concluded that the NADPH-cytochrome c reduct enzyme is assigned for the cytochrome P-450 reductase of yeast, which could also reduce the detergent-solubilized cy tochrome b5 of yeast.
TL;DR: RNA metabolism must have a key role in the regulation of the cell cycle when exposed to chelating agents o-phenanthroline or 8-hydroxyquinoline, and the primary effect of these agents is on rRNA synthesis.
01 Jan 1978
TL;DR: In this paper, yeast fermentations were carried out at 20°C with defined media containing a mixture of amino acids totaling 225 mg/L. Radioactive substrates were added individually to the media prior to the...
Abstract: Ale yeast fermentations were carried out at 20° C with defined media containing a mixture of amino acids totaling 225 mg/L. Radioactive substrates were added individually to the media prior to the ...
TL;DR: In this paper, yeast fermentations were carried out at 20°C with defined media containing a mixture of amino acids totaling 225 mg/L. Radioactive substrates were added individually to the media prior to the...
Abstract: Ale yeast fermentations were carried out at 20° C with defined media containing a mixture of amino acids totaling 225 mg/L. Radioactive substrates were added individually to the media prior to the ...
TL;DR: A method for enzymatic glycogen determination in yeast cells without need for prior disruption of the cell walls has been developed and has been successfully tested with several strains of Saccharomyees cerevisiae and S. carlsbergensis.
TL;DR: Yeast sterol mutants exposed to crystal violet demonstrated greater dye uptake than the wild type and exposure for 10 min to hypertonic cation solutions showed a greater decrease in cell viability for mutants than for wild type.
Abstract: Yeast sterol mutants exposed to crystal violet demonstrated greater dye uptake than the wild type. In addition, exposure for 10 min to hypertonic cation solutions showed a greater decrease in cell viability for mutants than for wild type.
TL;DR: The observations suggest that the volatile chromium fraction in brewer's yeast is biologically important, whereas the active component of these yeast preparations is probably a precursor of GTF, and the synthetic factors are similar to, but not identical with, the active GTF fraction extracted from brewer’s yeast.
Abstract: Glucose tolerance factor (GTF) is thought to be volatile in the dry state at certain temperatures. This property allowed us to measure the stable and the volatile chromium contents of three brewer9s yeast GTF preparations and to investigate the possible relationship between the volatile chromium content and its biologic activity. Two forms of chromium were found in brewer9s yeast extracts by flameless atomic absorption spectroscopy using two different methods of sample preparation. Three brewer9s yeast GTF preparations were found to contain total Cr concentrations ranging from 0.40 to 0.81 μg. per milligram dry weight and volatile Cr concentrations ranging from 0.02 to 0.39 μg. per milligram dry weight. The biologic response obtained with each GTF preparation was linearly related to the concentration of volatile chromium present. These observations suggest that the volatile chromium fraction in brewer9s yeast is biologically important, whereas the active component of these yeast preparations is probably a precursor of GTF. The metabolic effects of synthetic chromium-nicotinic add-ammo acid complexes and a brewer9s yeast GTF preparation were compared in normal and genetically diabetic mice. The synthetic preparations mimicked the effects of brewer9s yeast GTF by lowering plasma glucose and triglyceride concentrations, although at different time courses. In addition, biologically active synthetic complexes have been synthesized and may contain no volatile chromium. Synthetic complexes of chromium-nicotinic acid-amino acids lowered blood glucose by only IS to 20 per cent in normal mice as against a 36 per cent reduction with brewer9s yeast GTF. Further, a synthetic product produced a significant reduction in the elevated plasma concentrations of glucose and triglycerides in genetically diabetic mice (18 and 26 per cent, respectively). This is in contrast to the 29 per cent reduction in plasma glucose and a 56 per cent reduction in plasma triglycerides produced by GTF prepared from brewer9s yeast. These findings suggest that the synthetic factors are similar to, but not identical with, the active GTF fraction extracted from brewer9s yeast.
TL;DR: The mechanism by which iron uptake is facilitated by the siderophore rhodotorulic acid in the yeast Rhodotorula pilimanae was investigated and it is proposed that RA exchanges the ferric ion at the cell surface with a membrane-bound chelating agent that completes the active transport of iron into the cell.
Abstract: The mechanism by which iron uptake is facilitated by the siderophore rhodotorulic acid (RA) in the yeast Rhodotorula pilimanae was investigated with radioactively labeled Fe and RA and kinetically inert, chromic-substituted RA complexes The weight of the evidence supports a model in which RA mediates iron transport to the cell but does not actually transport iron into the cell It is proposed that RA exchanges the ferric ion at the cell surface with a membrane-bound chelating agent that completes the active transport of iron into the cell Uptake of 55Fe in ferric rhodotorulate was much more rapid than uptake of RA itself Two exchange-inert chromic complexes of RA showed no uptake
TL;DR: The different responses of the yeasts to anaerobic conditions, with respect to their enzymic activity, sugar uptake and CO2 production, consistently showed that the Kluyver effect resulted from the requirement of transport for oxygen, and this seems to be the common explanation throughout theYeasts.
Abstract: Summary: Of the yeasts that ferment D-glucose anaerobically, over 40% can use certain glycosides and D-galactose oxidatively, but cannot ferment them. This phenomenon is here called the Kluyver effect. More than half the yeast species described which exhibit this effect do so with more than one substrate. Yeasts showing the effect with maltose, cellobiose and D-galactose were compared with fermenting strains, to determine whether enzyme inactivation or cessation of sugar uptake was responsible. The different responses of the yeasts to anaerobic conditions, with respect to their enzymic activity, sugar uptake and CO2 production, consistently showed that the Kluyver effect resulted from the requirement of transport for oxygen, and this seems to be the common explanation throughout the yeasts.
TL;DR: During the fission yeast cell cycle, the rate of polyadenylated messenger RNA synthesis doubles when the cell reaches a critical size, which maintains average mRNA content in balance with total cell mass during exponential growth, even in cells growing at different absolute growth rates per cell.
Abstract: During the fission yeast cell cycle, the rate of polyadenylated messenger RNA synthesis doubles when the cell reaches a critical size. This size-related control maintains average mRNA content in balance with total cell mass during exponential growth, even in cells growing at different absolute growth rates per cell.
TL;DR: A simple means of immobilizing yeast in a gel of calcium alginate is described, and this procedure can render such strains sufficiently flocculent to allow their use in continuous tower fermenters.
Abstract: A simple means of immobilizing yeast in a gel of calcium alginate is described. Immobilization occurs over a wide range of yeast/alginate ratios, and by varying this ratio it is possible to control the size of the immobilized yeast flocs. Non-flocculent strains of yeast can be immobilized by this procedure and remain viable for long periods of time. The procedure can render such strains sufficiently flocculent to allow their use in continuous tower fermenters.
TL;DR: It can be calculated that about 85% of the yeast genome is represented in this collection of recombinant plasmids containing insertions of yeast nuclear DNA cloned in Escherichia coli.
TL;DR: Analysis of SPBs at various stages of the cell cycle showed that newly replicated SPBs had the capacity to nucleate microtubules and may mean that in G1-arrested cells, the SPB is associated with microtubule attachment sites of the yeast chromatin.
Abstract: Spindle pole bodies (SPBs) were isolated from the yeast Saccharomyces cerevisiae by an adaptation of the Kleinschmidt monolayer technique. Spheroplasts prepared from the cells were lysed on an air-water interface. Spread preparations were picked up on grids, transferred to experimental test solutions, and prepared for whole-mount electron microscopy. Using purified exogenous tubulin from porcine brain tissue, the isolated SPBs were shown to nucleate the assembly of microtubules in vitro. Microtubule growth was directional and primarily onto the intranuclear face of the SPB. Neither the morphology nor the microtubule-initiating capacity of the SPB was affected by treatment with the enzymes DNase, RNase, or phospholipase although both properties were sensitive to trypsin. Analysis of SPBs at various stages of the cell cycle showed that newly replicated SPBs had the capacity to nucleate microtubules. SPBs isolated from exponentially growing cells initiated a subset of the yeast spindle microtubules equivalent to the number of pole-to-pole microtubules seen in vivo. However, SPBs isolated from cells in stationary phase and therefore arrested in G1 nucleated a number of microtubules equal to the total chromosomal and pole-to-pole tubules in the yeast spindle. This may mean that in G1-arrested cells, the SPB is associated with microtubule attachment sites of the yeast chromatin.