scholarly journals Purification of profilin from Saccharomyces cerevisiae and analysis of profilin-deficient cells.

1990 ◽  
Vol 110 (1) ◽  
pp. 105-114 ◽  
Author(s):  
B K Haarer ◽  
S H Lillie ◽  
A E Adams ◽  
V Magdolen ◽  
W Bandlow ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Actin Polymerization ◽  
Yeast Cells ◽  
Predicted Amino Acid Sequence ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Ellipsoidal Shape ◽  
Hydrolysis Of

We have isolated profilin from yeast (Saccharomyces cerevisiae) and have microsequenced a portion of the protein to confirm its identity; the region microsequenced agrees with the predicted amino acid sequence from a profilin gene recently isolated from S. cerevisiae (Magdolen, V., U. Oechsner, G. Müller, and W. Bandlow. 1988. Mol. Cell. Biol. 8:5108-5115). Yeast profilin resembles profilins from other organisms in molecular mass and in the ability to bind to polyproline, retard the rate of actin polymerization, and inhibit hydrolysis of ATP by monomeric actin. Using strains that carry disruptions or deletions of the profilin gene, we have found that, under appropriate conditions, cells can survive without detectable profilin. Such cells grow slowly, are temperature sensitive, lose the normal ellipsoidal shape of yeast cells, often become multinucleate, and generally grow much larger than wild-type cells. In addition, these cells exhibit delocalized deposition of cell wall chitin and have dramatically altered actin distributions.

scholarly journals LEA (late embryonic abundant)-like protein Hsp 12 (heat-shock protein 12) is present in the cell wall and enhances the barotolerance of the yeast Saccharomyces cerevisiae

2004 ◽  
Vol 377 (3) ◽  
pp. 769-774 ◽  
Author(s):  
Precious MOTSHWENE ◽  
Robert KARREMAN ◽  
Gail KGARI ◽  
Wolf BRANDT ◽  
George LINDSEY
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Heat Shock ◽  
Heat Shock Protein ◽  
Barometric Pressure ◽  
Yeast Cells ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Rapid Changes ◽  
Wild Type Yeast

Yeast cells Saccharomyces cerevisiae, late embryogenic abundant-like stress response protein Hsp 12 (heat-shock protein 12) were found by immunocytochemistry to be located both in the cytoplasm and in the cell wall, from where they could be extracted with dilute NaOH solutions. Yeast cells with the Hsp 12 gene disrupted were unable to grow in the presence of either 12 mM caffeine or 0.43 mM Congo Red, molecules known to affect cell-wall integrity. The volume of yeast cells were less affected by rapid changes in the osmolality of the growth medium when compared with the wild-type yeast cells, suggesting a role for Hsp 12 in the flexibility of the cell wall. This was also suggested by subjecting the yeast cells to rapid changes in barometric pressure where it was found that wild-type yeast cells were more resistant to cellular breakage.

Functional interaction between p21rap1A and components of the budding pathway in Saccharomyces cerevisiae

1992 ◽  
Vol 12 (9) ◽  
pp. 4084-4092
Author(s):  
P C McCabe ◽  
H Haubruck ◽  
P Polakis ◽  
F McCormick ◽  
M A Innis
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Mammalian Cells ◽  
Bound States ◽  
Yeast Cells ◽  
Temperature Sensitive ◽  
Wild Type ◽  
Amino Terminal ◽  
Loop Region

The rap1A gene encodes a 21-kDa, ras-related GTP-binding protein (p21rap1A) of unknown function. A close structural homolog of p21rap1A (65% identity in the amino-terminal two-thirds) is the RSR1 gene product (Rsr1p) of Saccharomyces cerevisiae. Although Rsr1p is not essential for growth, its presence is required for nonrandom selection of bud sites. To assess the similarity of these proteins at the functional level, wild-type and mutant forms of p21rap1A were tested for complementation of activities known to be fulfilled by Rsr1p. Expression of p21rap1A, like multicopy expression of RSR1, suppressed the conditional lethality of a temperature-sensitive cdc24 mutation. Point mutations predicted to affect the localization of p21rap1A or its ability to cycle between GDP and GTP-bound states disrupted suppression of cdc24ts, while other mutations in the 61-65 loop region improved suppression. Expression of p21rap1A could not, however, suppress the random budding phenotype of rsr1 cells. p21rap1A also apparently interfered with the normal activity of Rsrlp, causing random budding in diploid wild-type cells, suggesting an inability of p21rap1A to interact appropriately with Rsr1p regulatory proteins. Consistent with this hypothesis, we found an Rsr1p-specific GTPase-activating protein (GAP) activity in yeast membranes which was not active toward p21rap1A, indicating that p21rap1A may be predominantly GTP bound in yeast cells. Coexpression of human Rap1-specific GAP suppressed the random budding due to expression of p21rap1A or its derivatives, including Rap1AVal-12. Although Rap1-specific GAP stimulated the GTPase of Rsr1p in vitro, it did not dominantly interfere with Rsr1p function in vivo. A chimera consisting of Rap1A1-165::Rsr1p166-272 did not exhibit normal Rsr1p function in the budding pathway. These results indicated that p21rap1A and Rsr1p share at least partial functional homology, which may have implications for p21rap1A function in mammalian cells.

Evolution of ethylene by Saccharomyces cerevisiae as influenced by the carbon source for growth and the presence of air

1978 ◽  
Vol 24 (6) ◽  
pp. 637-642 ◽  
Author(s):  
K. C. Thomas ◽  
Mary Spencer
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Source ◽  
Ethylene Production ◽  
Atp Synthesis ◽  
Yeast Cells ◽  
Yeast Culture ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae ◽  
Absolute Requirement ◽  
Wild Type Yeast

Effects of the carbon source and oxygen on ethylene production by the yeast Saccharomyces cerevisiae have been studied. The amounts of ethylene evolved by the yeast culture were less than those detected in the blank (an equal volume of uninoculated medium), suggesting a net absorption of ethylene by the yeast cells. Addition of glucose to the lactate-grown yeast culture induced ethylene production. This glucose-induced stimulation of ethylene production was inhibited to a great extent by cycloheximide. Results suggested that the yeast cells in the presence of glucose synthesized an ethylene precursor and passed it into the medium. The conversion of this precursor to ethylene might be stimulated by oxygen. The fact that ethylene was produced by the yeast growing anaerobically and also by respiration-deficient mutants isolated from the wild-type yeast suggested that mitochondrial ATP synthesis was not an absolute requirement for ethylene biogenesis.

Translation initiation factor 5A and its hypusine modification are essential for cell viability in the yeast Saccharomyces cerevisiae

1991 ◽  
Vol 11 (6) ◽  
pp. 3105-3114
Author(s):  
J Schnier ◽  
H G Schwelberger ◽  
Z Smit-McBride ◽  
H A Kang ◽  
J W Hershey
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Peptide Bond ◽  
Translation Initiation Factor ◽  
Site Directed Mutagenesis ◽  
Yeast Cells ◽  
Initiation Factor ◽  
Mutant Form ◽  
Wild Type ◽  
Yeast Saccharomyces Cerevisiae

Translation intitiation factor eIF-5A (previously named eIF-4D) is a highly conserved protein that promotes formation of the first peptide bond. One of its lysine residues is modified by spermidine to form hypusine, a posttranslational modification unique to eIF-5A. To elucidate the function of eIF-5A and determine the role of its hypusine modification, the cDNA encoding human eIF-5A was used as a probe to identify and clone the corresponding genes from the yeast Saccharomyces cerevisiae. Two genes named TIF51A and TIF51B were cloned and sequenced. The two yeast proteins are closely related, sharing 90% sequence identity, and each is ca. 63% identical to the human protein. The purified protein expressed from the TIF51A gene substitutes for HeLa eIF-5A in the mammalian methionyl-puromycin synthesis assay. Strains lacking the A form of eIF-5A, constructed by disruption of TIF51A with LEU2, grow slowly, whereas strains lacking the B form, in which HIS3 was used to disrupt TIF51B, show no growth rate phenotype. However, strains with both TIF51A and TIF51B disrupted are not viable, indicating that eIF-5a is essential for cell growth in yeast cells. Northern (RNA) blot analysis shows two mRNA species, a larger mRNA (0.9 kb) transcribed from TIF51A and a smaller mRNA (0.8 kb) encoded by TIF51B. Under the aerobic growth conditions of this study, the 0.8-kb TIF51B transcript is not detected in the wild-type strain and is expressed only when TIF51A is disrupted. The TIF51A gene was altered by site-directed mutagenesis at the site of hypusination by changing the Lys codon to that for Arg, thereby producing a stable protein that retains the positive charge but is not modified to the hypusine derivative. The plasmid shuffle technique was used to replace the wild-type gene with the mutant form, resulting in failure of the yeast cells to grow. This result indicates that hypusine very likely is required for the vital in vivo function of eIF-5A and suggests a precise, essential role for the polyamine spermidine in cell metabolism.

scholarly journals A Role for Ubiquitination in Mitochondrial Inheritance in Saccharomyces cerevisiae

1999 ◽  
Vol 145 (6) ◽  
pp. 1199-1208 ◽  
Author(s):  
Harold A. Fisk ◽  
Michael P. Yaffe
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Site Directed Mutagenesis ◽  
Temperature Sensitive ◽  
Mitochondrial Inheritance ◽  
Wild Type ◽  
Gene Encoding ◽  
Yeast Saccharomyces Cerevisiae ◽  
Protein Ubiquitination ◽  
Ubiquitin Ligase Activity ◽  
Mitochondrial Distribution

The smm1 mutation suppresses defects in mitochondrial distribution and morphology caused by the mdm1-252 mutation in the yeast Saccharomyces cerevisiae. Cells harboring only the smm1 mutation themselves display temperature-sensitive growth and aberrant mitochondrial inheritance and morphology at the nonpermissive temperature. smm1 maps to RSP5, a gene encoding an essential ubiquitin-protein ligase. The smm1 defects are suppressed by overexpression of wild-type ubiquitin but not by overexpression of mutant ubiquitin in which lysine-63 is replaced by arginine. Furthermore, overexpression of this mutant ubiquitin perturbs mitochondrial distribution and morphology in wild-type cells. Site-directed mutagenesis revealed that the ubiquitin ligase activity of Rsp5p is essential for its function in mitochondrial inheritance. A second mutation, smm2, which also suppressed mdm1-252 defects, but did not cause aberrant mitochondrial distribution and morphology, mapped to BUL1, encoding a protein interacting with Rsp5p. These results indicate that protein ubiquitination mediated by Rsp5p plays an essential role in mitochondrial inheritance, and reveal a novel function for protein ubiquitination.

scholarly journals GAL11 protein, an auxiliary transcription activator for genes encoding galactose-metabolizing enzymes in Saccharomyces cerevisiae.

1988 ◽  
Vol 8 (11) ◽  
pp. 4991-4999 ◽  
Author(s):  
Y Suzuki ◽  
Y Nogi ◽  
A Abe ◽  
T Fukasawa
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Carbon Sources ◽  
Alpha Helix ◽  
Normal Function ◽  
Hybridization Experiment ◽  
Yeast Cells ◽  
Predicted Amino Acid Sequence ◽  
Wild Type ◽  
Transcription Activator ◽  
Galactose Utilization

Normal function of the GAL11 gene is required for maximum production of the enzymes encoded by GAL1, GAL7, and GAL10 (collectively termed GAL1,7,10) in Saccharomyces cerevisiae. Strains bearing a gal11 mutation synthesize these enzymes at 10 to 30% of the wild-type level in the induced state. In a DNA-RNA hybridization experiment, the gal11 effect was shown to be exerted at the transcription level. Yeast cells bearing the gal11 mutation were shown to grow on glycerol plus lactate more slowly than the wild type. We isolated recombinant plasmids carrying the GAL11 gene by complementation of the gal11 mutation. When the GAL11 locus was disrupted by insertion of the URA3 gene, the resulting yeast cells (gal11::URA3) exhibited phenotypes almost identical to those of the gal11 strains, with respect to both galactose utilization and growth on nonfermentable carbon sources. Deficiency of Gal4, the major transcription activator for GAL1,7,10, was epistatic over the gal11 defect. The Gal11 deficiency lowered the expression of GAL2 but not that of MEL1 or GAL80; expression of these genes is also known to be dependent on GAL4 function. We determined the nucleotide sequence of GAL11, which is predicted to encode a 107-kilodalton protein with stretches of polyglutamine and poly(glutamine-alanine). An alpha-helix-beta-turn-alpha-helix structure was found in a distal part of the predicted amino acid sequence. A possible role of the GAL11 product in the regulation of galactose-inducible genes is discussed.

Nuclear behaviour and cell wall composition in relation to budding in mutants of the yeast Saccharomyces cerevisiae

1986 ◽  
Vol 64 (1) ◽  
pp. 193-200 ◽  
Author(s):  
Mario Lachapelle ◽  
E. Roger Boothroyd
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Spindle Pole ◽  
Minor Role ◽  
Temperature Sensitive ◽  
Yeast Saccharomyces Cerevisiae ◽  
Bud Emergence ◽  
Spindle Elongation ◽  
10 Nm Filaments ◽  
A Minor

A temperature-sensitive, cell division cycle mutant (cdc24–1) and karyogamy-deficient (kar1) mutant of Saccharomyces cerevisiae, both of which can produce binucleate or multinucleate cells, were used to study certain aspects of budding, after fluorescent staining for mannan, chitin, and nuclei (DNA). In most binucleate cells the two nuclei lay close together and divided into the same bud. In a few, however, the nuclei were far apart and one or two buds were formed, each proximal to a nucleus. The proximity of daughter nuclei in most blocked cdc24–1 cells suggests a role for the CDC24 gene product in spindle elongation. The relationship between the nuclei and the number and location of buds supports the theory of a preponderant role for the nucleus in budding. Although buds develop preferentially in regions of low chitin content in kar1 heterokaryons, the ability of cdc24–1 cells to bud even with a uniformly high content of chitin and mannan suggests a minor role for these cell wall constituents in determining the sites of bud emergence. The chitin ring is not needed for bud emergence but seems to play a role in normal bud development and in septum formation. Electron microscopy of cdc24–1 cells blocked (37 °C) for 8 h and released (23 °C) for 30 min showed morphologically normal spindle pole bodies, cytoplasmic microtubules, and intranuclear spindles. Although the chitin ring was absent, the ring of 10-nm filaments was present, consistent with its proposed role in bud emergence.

scholarly journals Evidence for a Role for the Plasma Membrane in the Nanomechanical Properties of the Cell Wall as Revealed by an Atomic Force Microscopy Study of the Response of Saccharomyces cerevisiae to Ethanol Stress

2016 ◽  
Vol 82 (15) ◽  
pp. 4789-4801 ◽  
Author(s):  
Marion Schiavone ◽  
Cécile Formosa-Dague ◽  
Carolina Elsztein ◽  
Marie-Ange Teste ◽  
Helene Martin-Yken ◽  
...  
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Atomic Force Microscopy ◽  
Cell Wall ◽  
Cell Membrane ◽  
Yeast Cells ◽  
Ethanol Stress ◽  
Wild Type ◽  
Force Microscopy ◽  
Nanomechanical Properties ◽  
Atomic Force

ABSTRACTA wealth of biochemical and molecular data have been reported regarding ethanol toxicity in the yeastSaccharomyces cerevisiae. However, direct physical data on the effects of ethanol stress on yeast cells are almost nonexistent. This lack of information can now be addressed by using atomic force microscopy (AFM) technology. In this report, we show that the stiffness of glucose-grown yeast cells challenged with 9% (vol/vol) ethanol for 5 h was dramatically reduced, as shown by a 5-fold drop of Young's modulus. Quite unexpectedly, a mutant deficient in the Msn2/Msn4 transcription factor, which is known to mediate the ethanol stress response, exhibited a low level of stiffness similar to that of ethanol-treated wild-type cells. Reciprocally, the stiffness of yeast cells overexpressingMSN2was about 35% higher than that of the wild type but was nevertheless reduced 3- to 4-fold upon exposure to ethanol. Based on these and other data presented herein, we postulated that the effect of ethanol on cell stiffness may not be mediated through Msn2/Msn4, even though this transcription factor appears to be a determinant in the nanomechanical properties of the cell wall. On the other hand, we found that as with ethanol, the treatment of yeast with the antifungal amphotericin B caused a significant reduction of cell wall stiffness. Since both this drug and ethanol are known to alter, albeit by different means, the fluidity and structure of the plasma membrane, these data led to the proposition that the cell membrane contributes to the biophysical properties of yeast cells.IMPORTANCEEthanol is the main product of yeast fermentation but is also a toxic compound for this process. Understanding the mechanism of this toxicity is of great importance for industrial applications. While most research has focused on genomic studies of ethanol tolerance, we investigated the effects of ethanol at the biophysical level and found that ethanol causes a strong reduction of the cell wall rigidity (or stiffness). We ascribed this effect to the action of ethanol perturbing the cell membrane integrity and hence proposed that the cell membrane contributes to the cell wall nanomechanical properties.

scholarly journals Significant quantities of the glycolytic enzyme phosphoglycerate mutase are present in the cell wall of yeast Saccharomyces cerevisiae

2003 ◽  
Vol 369 (2) ◽  
pp. 357-362 ◽  
Author(s):  
Precious MOTSHWENE ◽  
Wolf BRANDT ◽  
George LINDSEY
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Wall ◽  
Cell Walls ◽  
Glycolytic Enzyme ◽  
Yeast Cells ◽  
Phosphoglycerate Mutase ◽  
Elevated Concentration ◽  
Yeast Saccharomyces Cerevisiae ◽  
Normal Morphology ◽  
Immunocytochemical Analysis

NaOH was used to extract proteins from the cell walls of the yeast Saccharomyces cerevisiae. This treatment was shown not to disrupt yeast cells, as NaOH-extracted cells displayed a normal morphology upon electron microscopy. Moreover, extracted and untreated cells had qualitatively similar protein contents upon disruption. When yeast was grown in the presence of 1M mannitol, two proteins were found to be present at an elevated concentration in the cell wall. These were found to be the late-embryogenic-abundant-like protein heat-shock protein 12 and the glycolytic enzyme phosphoglycerate mutase. The presence of phosphoglycerate mutase in the cell wall was confirmed by immunocytochemical analysis. Not only was the phosphoglycerate mutase in the yeast cell wall found to be active, but whole yeast cells were also able to convert 3-phosphoglycerate in the medium into ethanol, provided that the necessary cofactors were present.

Mating-defective ste mutations are suppressed by cell division cycle start mutations in Saccharomyces cerevisiae

1982 ◽  
Vol 2 (9) ◽  
pp. 1052-1063
Author(s):  
J R Shuster
Keyword(s):  
Saccharomyces Cerevisiae ◽  
Cell Division ◽  
Temperature Characteristic ◽  
Temperature Sensitive ◽  
Restrictive Temperature ◽  
Gene Products ◽  
Wild Type ◽  
Mating Pheromone ◽  
Yeast Saccharomyces Cerevisiae ◽  
Mating Pheromones

Temperature-sensitive mutants which arrest in the G1 phase of the cell cycle have been described for the yeast Saccharomyces cerevisiae. One class of these mutants (carrying cdc28, cdc36, cdc37, or cdc39) forms a shmoo morphology at restrictive temperature, characteristic of mating pheromone-arrested wild-type cells. Therefore, one hypothesis to explain the control of cell division by mating factors states that mating pheromones arrest wild-type cells by inactivating one or more of these CDC gene products. A class of mutants (carrying ste4, ste5, ste7, ste11, or ste12) which is insensitive to mating pheromone and sterile has also been described. One possible function of the STE gene products is the inactivation of the CDC gene products in the presence of a mating pheromone. A model incorporating these two hypotheses predicts that such STE gene products will not be required for mating in strains carrying an appropriate cdc lesion. This prediction was tested by assaying the mating abilities of double mutants for all of the pairwise combinations of cdc and ste mutations. Lesions in either cdc36 or cdc39 suppressed the mating defect due to ste4 and ste5. Allele specificity was observed in the suppression of both ste4 and ste5. The results indicate that the CDC36, CDC39, STE4, and STE5 gene products interact functionally or physically or both in the regulation of cell division mediated by the presence or absence of mating pheromones. The cdc36 and cdc39 mutations did not suppress ste7, ste11, or ste12. Lesions in cdc28 or cdc37 did not suppress any of the ste mutations. Other models of CDC and STE gene action which predicted that some of the cdc and ste mutations would be alleles of the same locus were tested. None of the cdc mutations was allelic to the ste mutations and, therefore, these models were eliminated.

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