bluuebunny/crossref_metadata_2025_split huggingface dataset:
Isolation of a CDC25 family gene, MSI2/LTE1, as a multicopy suppressor of ira1
Authors: Shirayama Masaki , Matsui Yasushi , Tanaka Kazuma , Toh‐E Akio 
Published: May 2005

AbstractWe have identified MS12 as a gene of Saccharomyces cerevisiae which, when on a multicopy vector, suppresses the heat shock sensitivity caused by the loss of the IRA1 product, a negative regulator of the RAS protein. The multicopy MSI2 also suppresses the heat shock sensitivity of cells with the RAS2val19 mutation but not those with the bcy1 mutation, suggesting that the MSI2 protein may interfere with the activity of the RAS protein. The sequence analysis of MSI2 reveals that it is identical to LTE1 belonging to the CDC25 family: CDC25, SCD25 and BUD5, each of which encodes a guanine nucleotide exchange factor for the ras superfamily gene products. Deletion of the entire MSI2 coding region reveals that MSI2 is not essential but the disruptant shows a cold‐sensitive phenotype. Under the non‐permissive conditions, more than 70% of the msi2 disruptants arrested at telophase as large budded cells with two nuclei divided completely and elongated spindles, indicating that the msi2 deletion is a cell division cycle mutation. These results suggest that MSI2 is involved in the termination of M phase and that this process is regulated by a ras superfamily gene product.
A search for an essential function of the replication origin ARS1 in the life cycle of Saccharomyces cerevisiae
Authors: Kirpekar Finn , Friis Jørgen , Gulløv Kay 
Published: May 2005

AbstractWe have investigated the significance of the chromosomal replication origin, ARS1, during the entire life cycle of yeast. This was done by substituting the chromosomal copy with a series of ars1 deletion mutants. It was shown that the ARS1 replication origin is not essential for mitotic or premeiotic DNA replication since no effect on growth, chromosomal loss rate and spore viability was observed in the ars1 mutant strains. We conclude that replication origins are abundantly, present in the yeast genome and that the removal of a single replication origin is compensated for by replication forks emanating from neighbouring origins.
Mating pheromone‐induced expression of the MAT1‐Pm gene of Schizosaccharomyces pombe: Identification of signalling components and characterization of upstream controlling elements
Authors: Aono Toshiya , Yanai Hiroyuki , Miki Futaba , Davey John , Shimoda Chikashi 
Published: May 2005

AbstractTranscription of the mat1‐Pm gene of Schizosaccharomyces pombe controlling entry into meiosis is stimulated by the mating pheromone, M‐factor. We have studied its expression by monitoring β‐galactosidase activity in cells carrying a plasmid‐borne mat1‐Pm/lacZ fusion construct. Stimulation required the M‐factor receptor (Map3) and other proteins (Gpa1, Byr1, Byr2 and Spk1) thought to be involved in propagating the pheromone signal within the cell. Mutational activation of gpa1 encoding an α subunit of the receptor‐coupled heterotrimeric G protein causes full expression of mat1‐Pm even in the absence of pheromone, suggesting that Gpa1 is a key signal transmitter. Furthermore, an activated ras1val17 mutant exhibited a much stronger level of induction than wild‐type cells, though full expression needs M‐factor treatment. Deletion analysis of the mat1‐Pm promoter region identified a stretch of 21 bp that is shown to play a critical role in controlling expression. This region lies just upstream of a TATA‐like box and contains a TR‐box (TTCTTTGTTY) motif which is the recognition site of a putative transcription factor Ste11. Point mutations in the TR‐box motif abolished the expression of mat1‐Pm/lacZ. Almost no expression of mat1‐Pm was detected in a ste11 deletion mutant, whereas overproduction of Ste11 greatly increased the expression.
A fission yeast gene encoding a protein that preferentially associates with curved DNA
Authors: Yamada Hisami , Mori Hideki , Momoi Hiroyuki , Nakagawa Yoshiyuki , Ueguchi Chiharu , Mizuno Takeshi 
Published: May 2005

AbstractWe searched for fission yeast (Schizosaccharomyces pombe) proteins that preferentially bind to a synthetic curved DNA sequence, by means of a DNA‐binding gel shift assay in the presence of an excess amount of a non‐curved DNA sequence as a competitor. We identified such a protein in S. pombe. The protein, thus purified, has an apparent molecular weight of 42 000, as estimated by sodium dodecyl sulfate‐polyacrylamide gel electrophoresis. It was suggested that this protein (42 K‐protein) recognizes and binds to a curved DNA structure in a given nucleotide sequence, although it also binds to a non‐curved DNA sequence with lower affinity. As its putative coding sequence, a 1·9‐kilobase genomic DNA from S. pombe was cloned and sequenced. Sequencing of a cDNA clone also revealed the existence of an open reading frame, with no intron, encoding a 381‐amino‐acid protein with a calculated molecular mass, 41 597. This protein appears to be located in the nucleus. The predicted protein sequence revealed that the 42 K‐protein exhibits no significant similarity to any other known proteins, except to a hypothetical protein of Caenorhabditis elegans.
II. Yeast sequencing reports. Sequence analysis of a 31 kb DNA fragment from the right arm of Saccharomyces cerevisiae chromosome II
Authors: Van Der Aart Quirina J. M. , Ydesteensma H. , Barthe Christophe , Doignon François , Aigle Michel , Crouzet Marc 
Published: May 2005

AbstractThe nucleotide sequence of a 31 352 bp fragment from chromosome II of Saccharomyces cerevisiae has been determined and analysed. The fragment originates from the right arm of chromosome II, located between the GAL7,10,1 and the PHO3,5 loci, at a distance of about 130 kb from the centromere. The sequence contains a tRNA tandem repeat and 17 open reading frames (ORFs) larger than 100 amino acids. One of them extends into adjacent DNA and is incomplete. The two tRNA genes, coding for a tRNAasp and a tRNAarg, and three of the ORFs, had been sequenced previously, i.e. HSP26, SEC18, and UBC4. Four other ORFs showed similarity with yeast genes; amino acid transporter genes, the RAD54, SNF2 and STH1 family, the SPS2 gene and the bromodomain of SPT7, respectively. Two showed homology with sequences from other organisms, i.e. with a Plasmodium falciparum gene encoding a surface antigen and with a gene from Saimirine herpes virus respectively. Three ORFs, YBR0726, YBR0735 and YBR0740 are completely contained in YBR0727, YBR0734 and YBR0739 respectively, and thus probably do not represent real genes. Two ORFs, YBR0727 and YBR0745 most likely contain an intron. The sequences have been deposited in the EMBL data library under Accession Number X76294.
Glucose metabolism and ethanol production in adh multiple and null mutants of Kluyveromyces lactis
Authors: Saliola Michele , Bellardi Silvia , Marta Isabella , Falcone Claudio 
Published: May 2005

AbstractFour genes coding for alcohol dehydrogenase (ADH) activities were identified in Kluyveromyces lactis. Due to the presence in this yeast of multiple ADH isozymes, mutants in the individual genes constructed by gene replacement yielded no clear phenotype. We crossed these mutants and developed a screening procedure which allowed us to identify strains lacking several ADH activities. The analysis of the adh triple mutants revealed that each activity confers to the cell the ability to grow on ethanol as the sole carbon source. On the contrary, adh null strains failed to grow on this substrate, indicating that no other important ADH activities are present in K. lactis cells. In the adh null mutants we also found a residual production of ethanol, as has been reported to be the case in Saccharomyces cerevisiae. This production showed a ten‐fold increase when the K1ADHI activity was reintroduced in the null mutant and cells were cultivated under oxygen‐limiting conditions. Differently from S. cerevisiae, glycerol is poorly accumulated in K. lactis adh null mutants.
Molecular characterization of a gene that confers 2‐deoxyglucose resistance in yeast
Authors: Sanz Pascual , Randez‐Gil Francisca , Prieto José Antonio 
Published: May 2005

AbstractWe have isolated a gene whose expression enables yeast cells to overcome the inhibition of growth produced by the presence of 2‐deoxyglucose. The gene contains an open reading frame of 738 bp that may code for a protein of 27 100 Da. Cells carrying this gene contain high levels of a specific 2‐deoxyglucose‐6‐phosphate phosphatase. The expression of this phosphatase is increased by the presence of 2‐deoxyglucose and is constant along the growth curve. The sequence reported here has the GenBank accession number U03107.
Expression and in vivo determination of firefly luciferase as gene reporter in Saccharomyces cerevisiae
Authors: Vieites J. M. , Navarro‐García F. , Pérez‐Díaz R. , Pla J. , Nombela C. 
Published: May 2005

AbstractThe LUC gene coding for Photinus pyralis firefly luciferase was cloned in different yeast episomal plasmids in order to assess its possibilities as an in vivo reporter gene. Activity of the enzyme in transformed cells in vivo was measured by following light emission and assay conditions optimized in intact cells, with regard to oxygen concentration, temperature, cell concentration in assay mixtures and external ATP concentration. Among the factors tested, light emission was drastically influenced by the external pH in the assay (which resulted in a ten‐fold amplification signal) and by substrate permeability. The growth phase of the cells was also important for the level of activity detected. Cloning of firefly luciferase gene under the control of different yeast‐regulated promoters (ADH1, GAL1–10) enabled us to measure their strength which correlated well with previously described data. We conclude that firefly luciferase is an adequate gene reporter for the in vivo sensitive determination of gene expression and promoter strength in yeast.
The TYE7 gene of Saccharomyces cerevisiae encodes a putative bHLH‐LZ transcription factor required for Tyl‐mediated gene expression
Authors: Löhning Corinna , Ciriacy Michael 
Published: May 2005

AbstractIn Saccharomyces cerevisiae, expression of a gene adjacent to the retrotransposon Ty1 is often mediated by Ty‐internal sequences. We have identified novel mutants, tye7, which are affected in Ty1‐mediated expression of ADH2 through a Ty1 sequence distal to the 5′ long terminal repeat sequence. The TYE7 gene has been isolated and characterized. It encodes a 33 kDa protein whose N‐terminal third is extremely rich in serine residues (28%). Within its C‐terminal sequence, a remarkable similarity to Myc and Max proteins can be found. Thus, TYE7 is a potential member of the basic region/helix‐loop‐helix/leucine‐zipper protein family. TYE7 function is not essential for growth. It may primarily function as a transcriptional activator in Ty1‐mediated gene expression, as has been confirmed by the activation of reporter gene expression by a LexA‐TYE7 hybrid protein. ADH2 activation by defined Ty1 derivatives revealed that TYE7 acts positively through the more distal Ty1 enhancer element (region D), and negatively in a region between A (the 5′ proximal enhancer element) and D.
A novel structural form of the 2 micron plasmid of the yeast Saccharomyces cerevisiae
Authors: Petes Thomas D. , Williamson D. H. 
Published: May 2005

AbstractDNA was isolated from cells of Saccharomyces cerevisiae incubated under conditions that enriched for DNA replication intermediates. A novel form of the 2 μm plasmid was detected, in which two monomeric or dimeric circles were joined by a linear double‐stranded segment of variable length. We suggest that this molecule is a consequence of site‐specific recombination within a dimeric DNA molecule during DNA replication. The existence of this molecule provides supporting physical evidence for a variant of the model of 2 μ plasmid amplification first proposed by Futcher (1986).
Assessment of pheromone production and response in fission yeast by a halo test of induced sporulation
Authors: Egel Richard , Willer Martin , Kjærulff Søren , Davey John , Nielsen Olaf 
Published: May 2005

AbstractWe describe a rapid, sensitive and semi‐quantitative plate assay for monitoring pheromone activity in the fission yeast Schizosaccharomyces pombe. It is based on the observation that meiosis requires stimulation by pheromone and exploits diploid strains that will only sporulate after addition of exogenous pheromone. The tester strains are heterozygous for mating type, are non‐switching, and are mutated in one of the early subfunctions (either mat1‐Mc or mat1‐Pc), so that meiosis is only induced after exposure to exogenous pheromone (M‐factor or P‐factor, respectively). Pheromone activity is assessed as an iodine‐positive halo of sporulation surrounding the pheromone source, and the width of the halo is related to the amount of pheromone being produced. The assay is sufficiently sensitive to monitor the low amount of M‐factor produced by an M mam1 strain, and its sensitivity towards P‐factor is greatly increased by using a hyper‐sensitive tester strain lacking the Sxa2 protease that is believed to degrade this pheromone. We also demonstrate that the production of P‐factor is very much stimulated by exposure of P cells to M‐factor.
Transcript map of two regions from chromosome XI of Saccharomyces cerevisiae for interpretation of systematic sequencing results
Authors: Fairhead Cécile , Dujon Bernard 
Published: May 2005

AbstractA detailed and systematic transcript map is a first and necessary step to characterize new genes revealed by systematic sequencing. Chromosome XI of Saccharomyces cerevisiae contains 331 open reading frames (ORFs) of which 44% are of unknown function (Dujon et al., 1994). As a first study towards complete transcript analysis of chromosome XI, we have extracted RNA from three isogenic strains (a, α and 2 n) grown in three standard laboratory media, and have analysed them using contiguous probes covering two regions of 17 and 19 kilobases, respectively. All 20 predicted ORFs in the sequences correspond to expressed genes, six of which have no predicted function. Four short ORFs which were suspected as not being real genes on the basis of their sequence are not expressed in our growth conditions. An additional transcript which does not correspond to a large ORF was found. Steady‐state RNA level of most ORFs is 10 to 100 times than that of the actin gene, only three are transcribed in comparable amounts. Three ORFs show variable levels of transcripts in the different growth conditions, all patterns being different from one another. Extrapolation of these results to systematic transcript analysis of chromosome XI and other yeast chromosomes is presented.
Generation of glycerophospholipid molecular species in the yeast Saccharomyces cerevisiae. Fatty acid pattern of phospholipid classes and selective acyl turnover at sn‐1 and sn‐2 positions
Authors: Wagner S. , Paltauf F. 
Published: May 2005

AbstractAcyl chains linked to phospholipids of the yeast, Saccharomyces cerevisiae, are mainly C16:1 and C18:1 accompanied by minor amounts of C14:0, C16:0 and C18:0. In view of this rather simple fatty acid composition, the question arose whether in yeast, as in higher eukaryotes, fatty acyl groups were characteristically distributed among the sn‐1 and sn‐2 positions of distinct phospholipid classes. Analysis of fatty acids linked to the sn‐1 and sn‐2 positions of the major phospholipids showed that indeed saturated fatty acyl groups predominated in the sn‐1 positions. While the percentage of saturated fatty acids was low (10%) in phosphatidylcholine (PtdCho) and phosphatidylethanolamine (PtdEtn) from cells grown on rich medium, it was higher in phosphatidylserine (PtdSer) (25%) and highest in phosphatidylinositol (PtdIns) (41%). Oleate was mainly linked to position sn‐2, while palmitoleate predominated in position sn‐1. Striking differences in the fatty acid distribution of phospholipids that are metabolically closely related (e.g. PtdSer and PtdEtn, PtdEtn and PtdCho, and PtdIns and PtdSer) suggest that pathways must exist for the generation of distinct phospholipid molecular species within the different phospholipid classes. The highly selective incorporation of exogenous [14C]palmitic acid (90%) and [3H]oleic acid (99%) into the sn‐2 position of PtdCho, and the preferential incorporation of these fatty acids into the sn‐2 position of PtdEtn (70 and 90%, respectively, for palmitic and oleic acid) are compatible with the postulate that phospholipase A2‐mediated deacylation followed by reacylation of the lysophospholipids is involved in the generation of phospholipid species in yeast.
Genome renewal: A new phenomenon revealed from a genetic study of 43 strains of Saccharomyces cerevisiae derived from natural fermentation of grape musts
Authors: Mortimer Robert K. , Romano Patrizia , Suzzi Giovanna , Polsinelli Mario 
Published: May 2005

AbstractWe have analyzed by genetic means 43 strains of Saccharomyces that had been isolated from fermenting grape musts in Italy. Twenty eight of these strains were isolated from 28 cellars in the Region of Emilia Romagna. The other 15 strains came from 5 fermentations at four cellars near the city of Arpino, which is located south and east of Rome.We found that 20 of the 28 strains from Emilia Romagna were heterozygous at from one to seven loci. The balance were, within the limits of our detection, completely homozygous. All these strains appeared to be diploid and most were homozygous for the homothallism gene (HO/HO). Spore viability varied greatly between the different strains and showed an inverse relation with the degree of heterozygosity.Several of the strains, and in particular those from Arpino, yielded asci that came from genetically different cells. These different cells could be interpreted to have arisen from a heterozygote that had sporulated and, because of the HO gene, yielded homozygous diploid spore clones. We propose that natural wine yeast strains can undergo such changes and thereby change a multiple heterozygote into completely homozygous diploids, some of which may replace the original heterozygous diploid. We call this process ‘genome renewal’.
The nucleotide sequence and initial characterization of pyruvate decarboxylase from the yeast Hanseniaspora uvarum
Authors: Holloway Paul , Subden Ronald E. 
Published: May 2005

AbstractWe have isolated a pyruvate decarboxylase (PDC) gene from the yeast Hanseniaspora uvarum using the Saccharomyces cerevisiae PDC1 gene as a probe. The nucleotide sequence of this gene was determined and compared to PDC genes from yeast and other organisms. The H. uvarum PDC gene is more than 70% identical to the S. cerevisiae PDC isozymes and possesses a putative thiamine diphosphate binding site. The PDC enzyme was purified and partially characterized. The H. uvarum PDC was very similar to other known PDCs; the Km for pyruvate was 0·75 mM, and the enzyme is a homotetramer with subunits of Mr = 57 000. The sequence has been submitted to GenBank under Accession No. U13635.
Transcriptional regulation of the Saccharomyces cerevisiae HXK1, HXK2 and GLK1 genes
Authors: Herrero P. , Galíndez J. , Ruiz N. , Martínez‐Campa C. , Moreno F. 
Published: May 2005

AbstractIn Saccharomyces cerevisiae, the transcriptional regulation of most glycolytic genes has been extensively studied. By contrast, little is known about the transcriptional control of the three glucose‐phosphorylating enzymes, although this catalytic reaction has an important role in the regulation of cell metabolism. In this paper, we describe the transcriptional regulation of the HXK1, HXK2 and GLK1 genes in the hope of revealing differences in the steady‐state levels of mRNA associated with a particular carbon source used in the culture medium. Our results provide evidence supporting a differential expression of the three genes depending on the carbon source used for growth. We have also studied the induction and repression kinetics of mRNA expression for the HXK1, HXK2 and GLK1 genes.
Molecular cloning of the plc1+ gene of Schizosaccharomyces pombe, which encodes a putative phosphoinositide‐specific phospholipase C
Authors: Andoh Tomoko , Yoko‐O Takehiko , Matsui Yasushi , Toh‐E Akio 
Published: May 2005

AbstractExploiting the polymerase chain reaction, we have isolated a gene that encodes a putative phosphoinositide‐specific phospholipase C (PLC) of the fission yeast Schizosaccharomyces pombe. Inspection of the nucleotide sequence of the gene revealed an open reading frame that can encode a polypeptide of 899 amino acid residues with a calculated molecular mass of 102 kDa. This putative polypeptide contains both the X and Y regions that are conserved among three classes of mammalian PLC, and also contains a presumptive Ca2+‐binding site (an E‐F hand motif). The structure of the putative protein is most similar to that of the δ class of PLC isozymes. To investigate the role of this gene, designated plc1+, gene disruption was carried out by interrupting the coding region with the ura4+ marker. Growth of plc1 cells was temperature‐sensitive in rich medium, and cells could not grow in synthetic medium. Expression of the PLC1 gene of Saccharomyces cerevisiae suppressed the growth defect phenotype of plc1− cells, a strong suggestion that the plc1+ gene encodes PLC. The PLC1 sequence appears in the public data libraries, DDBJ GenBank, EMBL under the following Accession Number: D38309.
Physical map locations of the phospholipid biosynthetic structural and regulatory genes of Saccharomyces cerevisiae
Authors: Anderson Melanie S. , Kanipes Margaret I. , Jackson John C. , Yates Jonathan , Henry Susan A. , Lopes John M. 
Published: May 2005

AbstractHere we report the physical map locations of five genes required for phospholipid biosynthesis in Saccharomyces cerevisiae. These include four structural genes (INO1, CHO2, OP13 and PIS1) and one global negative regulatory gene (UME6). Collectively, this information completes the mapping of all phospholipid biosynthetic structural and regulatory genes identified to date.
Cloning and sequencing of the URA5 gene from the yeast Yarrowia lipolytica
Authors: Sánchez Manuel , Prado Marciano , Iglesias Francisco J. , Domínguez Angel 
Published: May 2005

AbstractThe URA5 gene of Yarrowia lipolytica encoding the orotate phosphoribosyl transferase (OPRTase, EC2.4.2.10) was isolated by target integration in a mutant strain originally named ura2.21. The nucleotide sequence of the gene predicts a protein with high similarities with the OPRTases from Saccharomyces cerevisiae, Podospora anserina and Escherichia coli and to a lesser extent with that of Dictyostelium discoideum. The transcription start point has been mapped by primer extension analysis and indicates the existence of a long leader sequence in the corresponding mRNA. Northern‐blot hybridization revealed the URA5 transcript to be approximately 0·94 kb. Deletion of the URA5 gene in Y. lipolytica produced a leaky phenotype similar to the one described for the ura5 mutation in S. cerevisiae. The URA5 gene of Y. lipolytica was able to complement functionally the ura5 mutation of S. cerevisiae. The sequence presented here has been submitted to the EMBL data library under Accession Number Z22571.