bluuebunny/crossref_metadata_2025_split huggingface dataset:
Molecular cloning of the γ‐glutamylcysteine synthetase gene of Saccharomyces cerevisiae
Authors: Ohtake Yasuyuki , Yabuuchi Seizou 
Published: May 2005

AbstractThe 4·4 kb SphI DNA fragment (GSH1) that complements the γ‐glutamylcysteine synthetase‐deficient mutation (gsh1) of Saccharomyces cerevisiae YH1 was cloned into vector plasmid YEp24. Gene disruption of the cloned fragment confirmed that this segment was the same gene as gsh1. Mutant strain YH1 with this plasmid not only restored γ‐glutamylcysteine synthetase (GSH‐1) activity but the glutathione content and the growth rate. DNA sequence analysis of the SphI fragment showed that the GSH1 structural gene contained 2034 bp and predicted a polypeptide of 678 amino acids. The deduced amino acid sequence had about a 45% homology to that of rat kidney GSH‐I, but a very low homology (about 26%) to that of Escherichia coli GSH‐I. Northern analysis showed that GSH1 had been transcribed into an approximately 2·7 kb mRNA fragment. Southern analysis showed that GSH1 mapped at chromosome X.
Dosage‐dependent translational suppression in yeast Saccharomyces cerevisiae
Authors: Chernoff Yury O. , Inge‐Vechtomov Sergey G. , Derkach Irina L. , Ptyushkina Marina V. , Tarunina Olga V. , Dagkesamanskaya Adilya R. , Ter‐Avanesyan Michael D. 
Published: May 2005

AbstractThe overexpression of SUP35 (SUP2) wild‐type gene, caused by increase of its copy number, induces an omnipotent suppression similar to the phenotype of mutants for this gene. The effectt of extra‐SUP35 was detected for moderate or even low copy number. Moreover, overdosage of the fragment including only the 5′‐flanking region and N‐terminal 100 bp of protein‐coding sequence of SUP35 leads to allosuppression. Multi‐SUP35 gene was also icompatible with extrachromosomal suppressor factor ψ, presumbaly because of high level of mistranslation. The suppressor effect caused by overdosage of another gene, SUP45 (SUP1), is much lower and can be detected only for one construction which is derived from high copy number plasmid. Suppression induced by extra‐SUP35 and especially by extra‐SUP45 is affected by the cell environment. A model predicting that the balance of gene products is a key for regulation of translational fidelity is discussed.
Genetic homology between Saccharomyces cerevisiae and its sibling species S. paradoxus and S. bayanus: Electrophoretic karyotypes
Authors: Naumov Gennadi I. , Naumova Elena S. , Lantto Raija A. , Louis Edward J. , Korhola Matti 
Published: May 2005

AbstractChromosomal DNAs of many monosporic strains of the biological species Saccharomyces cerevisiae, S. paradoxus and S. bayanus were analysed using contour‐clamped homogeneous electric field electrophgoresis. SSouthern blot hybridization with eight cloned S. cerevisiae genes (ADC1, CUP1, GAL4, LEU2, rDNA, SUC2, TRP1 and URA3) assigned to different chromosomes was used to study homology and chromosomal location of the genes three sibiling species. A comparative study of Ty1, Ty2 and telomere‐associated Y' sequences having multiple chromosomal location was also done.Chromosome length polymorphism was found in cultured strains of S. cerevisiae. Wild S. cerevisiae and S. paradoxus strains yielded chromosome banding patterns very similar to each other, The karyotype pattern of S. bayanus was readily distinguishable from that of S. cerevisiae and S. paradoxus. Southern blot analysis revealed a low degree of homology between the S. cerevisiae genes studied and the corresponding S. paradoxus and S. bayanus genes. The number of chromosomes appears to be 16 in all three species.
Yeast flocculation: Receptor definition by mnn mutants and concanavalin A
Authors: Stratford Malcolm 
Published: May 2005

AbstractYeast flocculation involves the binding of surface lectins on flocculent yeasts, to carbohydrate receptors present as constituents of yeast cell walls. Receptors were investigated by coflocculation of flocculent strains of Saccharomyces cerevisiae, both Flo 1 and NewFlo phenotypes, to known mnn mutants which vary in the wall mannan structure. Strong coflocculation was found with mnn1, mnn4, mnn9 and control strains, while very little coflocculation was found with mnn2 and mnn5 strains. In constrast, aggregation of these muatants by concanavalin A, a lectin with similar sugar inhibition to NewFlo phenotype flocculation, showed strong aggregation of mnn1, mnn4, and mnn5 strains and poor aggregation of mnn2 and mnn9 strains.The mmn mutant data suggested that flocculation receptorss were the outer‐chain mannan side‐branches, two or three mannose residues in length, confirming an earlier theory based on sugar inhibition data. The similarities and differences between flocculation and concanavalin A aggregation are discussed.
Rag−mutations involved in glucose metabolism in yeast: Isolation and genetic characterization
Authors: Wésolowski‐Louvel M. , Prior C. , Bornecque D. , Fukuhara H. 
Published: May 2005

AbstractSome natural isolates and many laboratory strains of the yeast Kluyveromyces lactis cannot grow on glucose when respiration is inhibited by antimycin A. The ability or inability to grow on glucose in the absence of mitochondrial respiration has been called Rag+ or Rag− phenotype (resistance to antimycin on glucose, respectively). Rag− strains, unable to grow on glucose in the presence of the respiratory drug, behave as if they were defective in fermentation. The Rag phenotype was first found to be determined by variant alleles of either of the two nuclear genes, RAG1 and RAG2, which code for a low‐affinity glucose transport protein and for phosphoglucose isomerase, respectively. These findings suggested that the Rag− phenotype can be used to obtain mutations of genes involved in glucose metabolism in K. lactis. We thus looked for other Rag− mutants. Seventy‐four mutants were isolated and genetically characterized. All of the mutations were nuclear recessive alleles, defining 11 new complementation groups, which we designate rag3 through rag13.
VYeast sequencing reports. AFG1, a new member of the SEC18–NSF, PAS1, CDC48–VCP, TBP family of ATPases
Authors: Lee Yang‐Ja , Wickner Reed B. 
Published: May 2005

AbstractWe have sequenced a gene that encodes a 377 amino acid putative protein with an ATPase motif typical of the protein family including SEC18p (NSF = N‐ethyl maleimide‐sensitive fusion protein; vesicle‐mediated endoplasmic reticulum to Golgi protein transfer), PAS1p (peroxisome assembly), CDC48p (VCP = valosin‐containing protein; cell cycle) and TBP1 (Tat‐binding protein). This gene, AFG1 for ATPase family, gene, also has substantial homology to these proteins outside the ATPase domain. AFG1 is located on chromosome V imediately centromere‐proximal to M AK10.
Polyamines and cell wall organization in Saccharomyces cerevisiae
Authors: Miret J. J. , Solari A. J. , Barderi Patricia A. , Goldemberg Sara H. 
Published: May 2005

AbstractCells of Saccharomyces cerevisiae 179‐5, an ornithine decarboxylase mutant (spe‐1), showed several ultrastructural abnormalities when cultivated in the absence of polyamines. Besides the appearance of microvacuole‐like spaces in the cytoplasm and of deformed nuclei, the most important alterations seemed to be located in the cell wall, which was thicker and of heterogeneous texture, and in the cell membrane, of irregular contour. These modifications could not be evoked by general stress conditions elicited by lack of nutrients. The relative levels of cell wall polysaccharides were altered in polyamine‐deprived organisms, giving an envelope with increased mannan and decreased glucan content; this cell wall was incompletely attacked by the lytic enzyme zymolyase. Polyamine depletion led also to some abnormalities in the budding pattern. The above observations suggest the involvement of polyamines in the correct structure and organization of the yeast cell.
Identification and genetic mapping of CHL genes controlling mitotic chromosome transmission in yeast
Authors: Kouprina N. , Tsouladze A. , Koryabin M. , Hieter P. , Spencer F. , Larionov V. 
Published: May 2005

AbstractEight independent chl (chromosome loss) mutants were isolated using yeast haploid strain disomic for chromosome III. In these mutants, chromosome III is lost during mitosis 50‐fold more frequently than in the wild‐type strains. chl mutants are also incapable of stable maintenance of circular and linear artificial chromosomes. Seven of the eight mutations are recessive, and one is semidominant. Complementation tests placed these mutants into six complementation groups (chl11 through chl16). Based on tetrad analysis, chl12, chl14 and chl15 correspond to mutations in single nuclear genes. Tetrad analysis of the other mutants was not possible due to poor spore viability. Complementation analysis was also carried out between collection of chl mutants and ctf mutants (chromosome transmission fidelity) (Spencer et al., 1990). The chl3, chl4, chl8, chl12 and chl15 mutants were unable to complement ctf3, ctf17, ctf12, ctf18 and ctf4, respectively. Three CHL genes were mapped by tetrad analysis. The CHL3 gene is placed on the right arm of chromosome XII, between the ILV5 (33·3 cM) and URA4 (21·8 cM) loci. The CHL10 gene is located on the left arm of chromosome VI, 12·5 cM from the centromere. The CHL15 gene is tightly linked to the KAR3 marker of the right arm of chromosome XVI (8·8 cM). The mapping data indicate that these three genes differ from other genes known to affect chromosome stability in mitosis. Therefore, the total number of the CHL genes identified (including those described by us earlier) is 13 (CHL1–CHL10, CHL12, CHL14 and CHL15).
Stress resistance of yeast cells is largely independent of cell cycle phase
Authors: Elliott Beth , Futcher Bruce 
Published: May 2005

AbstractRapidly growing cells of Saccharomyces cerevisiae are sensitive to heat shock, while non‐growing stationary phase cells are highly resistant. We find that slowly growing cells have an intermediate degree of heat shock resistance that can be nearly as great as that of stationary phase cells. This resistance is correlated both with slow growth and with carbon catabolite derepression. Slowly growing cells also showed resistance to Zymolyase digestion of their cell walls. The stress resistance is a property of all the cells in the culture, and cell cycle position makes little difference to the degree of stress resistance. At least some of the properties normally associated with stationary phase cells do not require residence in stationary phase or any other particular compartment of the cell cycle. Stress resistance may be due to a diverse set of physiological adaptations available to cells regardless of their position in the cell cycle. That is, although stress resistance and stationary phase are often correlated, neither is the cause of the other.
Targeting of a heterologous protein to the cell wall of Saccharomyces cerevisiae
Authors: Schreuder Maarten P. , Brekelmans Stephan , Van Den Ende Herman , Klis Frans M. 
Published: May 2005

AbstractThe sexual adhesion protein of Saccharomyces cerevisiae MATα cells, α‐agglutinin, could not be extracted from the cell wall with hot sodium dodecyl sulfate (SDS), but became soluble after digestion of the cell with laminarinase. This indicates that it is intimately associated with cell wall glucan. A fusion protein was constructed consisting of the signal sequence of yeast invertase, guar α‐galactosidase, and the C‐terminal half of the α‐agglutinin. Most of the fusion protein was incorporated in the cell wall. A small amount could be extracted with SDS, but most of it could only be extracted with laminarinase. On the other hand, cells containing a construct consisting of the signal sequence of invertase and α‐galactosidase released most of the α‐galactosidase into the medium and all cell wall‐associated α‐galactosidase was released by SDS. Labelling with antibodies showed that the α‐galactosidase part of the fusion protein was exposed on the surface of the cell wall. The results demonstrate that the C‐terminal half of the α‐agglutinin contains the information needed to incorporate a protein into the cell wall.
A comparative study on the transport of L(‐)malic acid and other short‐chain carboxylic acids in the yeast Candida utilis: Evidence for a general organic acid permease
Authors: Cássio Fernanda , LeñO Cecília 
Published: May 2005

AbstractCells of the yeast Candida utilis grown in medium with short‐chain mono‐, di‐ or tricarboxylic acids transported L(‐)malic acid by two transport systems at pH 3·0. Results indicate that probably a proton symport for the ionized form of the acid and a facilitated diffusion for the undissociated form were present. Dicarboxylic acids such as succinic, fumaric, oxaloacetic and α‐ketoglutaric acids were competitive inhibitors of the malic acid for the high‐affinity system, suggesting that these acids used the same transport system. In turn, competitive inhibition uptake studies of labelled carboxylic acid in the low‐affinity range indicated that this system was non‐specific and able to accept not only carboxylic (mono‐, di‐ or tri‐) acids but also some amino acids. Additionally, under the same growth conditions, C. utilis produced two mediated transport systems for lactic acid: a proton symport for the anionic form which appeared to be a common monocarboxylate carrier and a facilitated diffusion system for the undissociated acid displaying a substrate specificity similar to that observed for the low‐affinity dicarboxylic acid transport. The mediated carboxylic acid transport systems were inducible and subjected to repression by glucose. In glucose‐grown cells the undissociated dicarboxylic acids entered the cells slowly by simple diffusion. Repressed glucose‐grown cells were only able to produce both transport systems if an inducer, at low concentration (0·5%, w/v), was present during starvation in buffer. This process was inhibited by the presence of cycloheximide indicating that induction requires de novo protein synthesis. If a higher acid concentration was used, only the low‐affinity transport system was detectable, showing that the high‐affinity system was also repressed by high concentrations of the inducer.
Effects of growth with ethanol on fermentation and membrane fluidity of Saccharomyces cerevisiae
Authors: Lloyd David , Morrell Suzie , Carlsen Helle N. , Degn Hans , James Phillip E. , Rowlands Christopher C. 
Published: May 2005

AbstractSaccharomyces cerevisiae HSc was grown with ethanol at concentrations up to 10% (v/v). The immediate effects of additions of externally added ethanol on CO2 production and O2 consumption of washed organisms were studied by stopped‐flow membrane inlet quadrupole mass spectrometry. Fermentative activities of organisms grown with ethanol (0–5% v/v) showed similar sensitivities to inhibition by ethanol, whereas those grown with 10% (v/v) ethanol had become protected and were markedly less sensitive.The fluidity of subcellular membrane fractions was measured by determination of the temperature dependence of the rotational order parameter of the spin label 5‐doxyl stearic acid (free radical) by electron spin resonance. Mitochondria prepared from yeasts grown with 0, 7 and 9% (v/v) ethanol showed similar overall fluidity, although differences in temperature‐dependent behaviour indicate altered lipid composition or lateral phase separations. On the other hand the microsomal fraction from organisms grown with 9% ethanol showed a remarkable increase in fluidity. These data suggest that the protective effects of growth with ethanol near the limit of tolerance on fermentative activities may arise from altered plasma membrane fluidity properties.
Theoretical analysis of the effects of mitotic crossover in large yeast populations
Authors: Krafzig Dirk , Klawonn Frank , Gutz Herbert 
Published: May 2005

AbstractIn a diploid yeast population which is heterozygous for a given marker, A1A2, mitotic crossover (mit. c.o.) between the centromere and the marker will give rise to homozygous daughter cells, A1A1 and A2A2. Since this causes a decrease in the frequency of A1A2 cells, mit. c.o. is an important population genetic process in vegetatively propagated yeast cultures. The effect of mit. c.o. is counteracted by mutations and, in the case of heterosis, by selection. We present a mathematical analysis of these interactions.
GUT2, a gene for mitochondrial glycerol 3‐phosphate dehydrogenase of Saccharomyces cerevisiae
Authors: Rønnow Birgitte , Kielland‐Brandt Morten C. 
Published: May 2005

AbstractA gut2 mutant of Saccharomyces cerevisiae is deficient in the mitochondrial glycerol 3‐phosphate dehydrogenase and hence cannot utilize glycerol. Upon transformation of a gut2 mutant strain with a low‐copy yeast genomic library, hybrid plasmids were isolated which complemented the gut2 mutation. The nucleotide sequence of a 3·2 kb PstI‐XhoI fragment complementing a gut2 mutant strain is presented. The fragment reveals an open reading frame (ORF) encoding a polypeptide with a predicted molecular weight of 68·8 kDa. Disruption of the ORF leads to a glycerol non‐utilizing phenotype. A putative flavin‐binding domain, located at the amino terminus, was identified by comparison with the amino acid sequences of other flavoproteins. The cloned gene has been mapped both physically and genetically to the left arm of chromosome IX, where the original gut2 mutation also maps. We conclude that the presented ORF is the GUT2 gene and propose that it is the structural gene for the mitochondrial glycerol 3‐phosphate dehydrogenase.
Ultrastructural changes in yeast following heat shock and recovery
Authors: Webster Deborah L. , Watson Kenneth 
Published: May 2005

AbstractThe effects of heat shock and heat stress on the ultrastructure of Saccharomyces cerevisiae is reported. Following a mild heat shock, referred to as an increase in temperature from 25°C to 37°C for 30 min, we observed contraction of the nucleolus, formation of electron‐dense particles (90 nm) in mitochondria and heat‐shock granules (30–40 nm) in the cytoplasm. The electron‐dense particles in the mitochondria were similar in appearance to those previously reported in plant cells exposed to elevated temperatures. In a heat‐sensitive yeast strain, the nucleolus was severely aggregated after a mild heat shock, a treatment which hardly affected relatively more heat‐resistant strains. The nucleolus was aggregated in all strains after a more severe heat stress (50°C for 2 or 4 min). When cells were observed during a recovery period after heat stress it was found that nucleolar ultrastructure was regained more rapidly in cells that were previously heat shocked compared to cells that were stressed directly with no prior heat shock.
Sequencing and functional analysis of a 32 560 bp segment on the left arm of yeast chromosome II. Identification of 26 open reading frames, including the KIP1 and SEC17 genes
Authors: Scherens Bart , El Bakkoury Mohamed , Vierendeels Fabienne , Dubois Evelyne , Messenguy Francine 
Published: May 2005

AbstractWe report here the DNA sequence of a segment (α1006.13: YBLO5) of chromosome II of Saccharomyces cerevisiae, extending over 32·5 kb. The segment contains 26 open reading frames (ORFs) from YBLO501 to YBLO526. YBL0505 corresponds to the SEC17 gene and YBL0521 to the KIP1 gene. YBL0516 contains an intron, YBL0513 shows homology with the RAT protein phosphatase and YBL0526 contains a zinc‐finger motif. Disruption of 14 genes by insertion of a URA3 cassette has been performed and these mutants were analysed for their mating and sporulation ability, and for their growth on different carbon sources. YBL0515 and YBL0526 ORFs seem to be involved in the sporulation process.
XI. Yeast sequencing reports. Analysis of an 11·7 kb DNA fragment of chromosome XI reveals a new tRNA gene and four new open reading frames including a leucine zipper protein and a homologue to the yeast mitochondrial regulator ABF2
Authors: Purnelle Bénédicte , Skala Jacek , van Dyck Luc , Goffeau André 
Published: May 2005

AbstractWe report the nucleotide sequence of an 11·7 kb fragment from the left arm of Saccharomyces cerevisiae chromosome XI. Analysis reveals a new tRNA for valine and four unknown open reading frames among which YKL245 shows homology with a yeast mitochondrial regulatory protein and YKL244, YKL246 and YKL247 are unknown.
Selectable marker replacement in Saccharomyces cerevisiae
Authors: Vidal Marc , Gaber Richard F. 
Published: May 2005

AbstractSelectable markers integrated by the ‘gamma’ deletion method (Sikorski and Hieter, 1989) can be efficiently replaced in vivo with other markers by transformation with homologous plasmids. Transformation frequencies in experiments designed to replace original selectable markers with an alternate marker were high and molecular analysis confirmed that all transformants that exhibited the expected phenotypes (loss of the original prototrophy and gain of the alternate prototrophy) resulted from homologous recombination between plasmid sequences at the target locus. This technique involves no plasmid construction and greatly facilitates the generation of yeast cells containing multiple gene disruptions.
Positioning of cell growth and division after osmotic stress requires a map kinase pathway
Authors: Brewster Jay L. , Gustin Michael C. 
Published: May 2005

AbstractThe yeast Saccharomyces cerevisiae has a genetic program for selecting and assembling a bud site on the cell cortex. Yeast cells confine their growth to the emerging bud, a process directed by cortical patches of actin filaments within the bud. We have investigated how cells regulate budding in response to osmotic stress, focusing on the role of the high osmolarity glycerol response (HOG) pathway in mediating this regulation. An increase in external osmolarity induces a growth arrest in which actin filaments are lost from the bud. This is followed by a recovery phase in which actin filaments return to their original locations and growth of the original bud resumes. After recovery from osmotic stress, haploid cells retain an axial pattern of bud site selection while diploids change their bipolar budding pattern to an increased bias for forming a bud on the opposite side of the cell from the previous bud site. Mutants lacking the mitogen‐activated protein (MAP) kinase encoded by HOG1 or the MAP kinase kinase encoded by PBS2 (previously HOG4) show a similar growth arrest after osmotic stress. However, in the recovery phase, the mutant cells (a) do not restart growth of the original bud but rather start a new bud, (b) fail to restore actin filaments to the original bud but move them to the new one, and (c) show a more random budding pattern. These defects are elicited by an increase in osmolarity and not by other environmental stresses (e.g., heat shock or change in carbon source) that also cause a temporary growth arrest and shift in actin distribution. Thus, the HOG pathway is required for repositioning of the actin cytoskeleton and the normal spatial patterns of cell growth after recovery from osmotic stress.