Search results for "SIAE"
showing 10 items of 787 documents
Rot1 plays an antagonistic role to Clb2 in actin cytoskeleton dynamics throughout the cell cycle.
2007
ROT1 is an essential gene whose inactivation causes defects in cell cycle progression and morphogenesis in budding yeast. Rot1 affects the actin cytoskeleton during the cell cycle at two levels. First, it is required for the maintenance of apical growth during bud growth. Second, Rot1 is necessary to polarize actin cytoskeleton to the neck region at the end of mitosis; because of this defect, rot1 cells do not properly form a septum to complete cell division. The inability to polarize the actin cytoskeleton at the end of mitosis is not due to a defect in the recruitment of the polarisome scaffold protein Spa2 or the actin cytoskeleton regulators Cdc42 and Cdc24 in the neck region. Previous …
The MAPK Hog1 recruits Rpd3 histone deacetylase to activate osmoresponsive genes
2003
Regulation of gene expression by mitogen-activated protein kinases (MAPKs) is essential for proper cell adaptation to extracellular stimuli. Exposure of yeast cells to high osmolarity results in rapid activation of the MAPK Hog1, which coordinates the transcriptional programme required for cell survival on osmostress. The mechanisms by which Hog1 and MAPKs in general regulate gene expression are not completely understood, although Hog1 can modify some transcription factors. Here we propose that Hog1 induces gene expression by a mechanism that involves recruiting a specific histone deacetylase complex to the promoters of genes regulated by osmostress. Cells lacking the Rpd3-Sin3 histone deac…
Response of the Saccharomyces cerevisiae Mpk1 Mitogen-Activated Protein Kinase Pathway to Increases in Internal Turgor Pressure Caused by Loss of Ppz…
2004
ABSTRACT The Mpk1 pathway of Saccharomyces cerevisiae is a key determinant of cell wall integrity. A genetic link between the Mpk1 kinase and the Ppz phosphatases has been reported, but the nature of this connection was unclear. Recently, the Ppz phosphatases were shown to be regulators of K + and pH homeostasis. Here, we demonstrate that Ppz-deficient strains display increased steady-state K + levels and sensitivity to increased KCl concentrations. Given these observations and the fact that K + is the major determinant of intracellular turgor pressure, we reasoned that the connection between PPZ1 and - 2 and MPK1 was due to the combination of increased internal turgor pressure in Ppz-defic…
Performance of industrial strains of Saccharomyces cerevisae during wine fermentation is affected by manipulation strategies based on sporulation.
2002
Genetic manipulation of industrial wine yeast strains has become an essential tool for both the study of the molecular mechanisms underlaying their physiology and the improvement of their fermentative properties. The construction of null mutants for any gene in these usually diploid strains, by using a procedure based on sporulation of a heterozygote lacking one copy of the gene of interest, has been tested as an alternative to the tedious work of sequential disruption of the complete set of copies. Our results indicate that most of the homozygotes resulting from sporulation of wine yeast strains are defective in glucose consumption under microvinification conditions in synthetic must and p…
Yeast contains multiple forms of histone acetyltransferase.
1989
We have assayed several methods to quantitatively recover yeast histone acetyltransferases in an attempt to study the multiplicity of enzymatic activities. Two methods, namely (NH4)2SO4 precipitation and salt dissociation of chromatin in 0.5 M NaCl, yielded convenient preparations of total histone acetyltransferases. DEAE-Sepharose chromatography of the crude extracts resulted in the separation of three peaks of activity when total yeast histones were used as substrate. However, the scanning of the enzymatic activity toward individual histones along the chromatography, achieved by determining the specific activity of the individual histones after incubating whole histones and [14C]acetyl-Co…
Expression of a Truncated Yeast Ccc1 Vacuolar Transporter Increases the Accumulation of Endogenous Iron
2021
Iron is an essential micronutrient for all eukaryotic organisms because it participates as a redox cofactor in multiple metabolic processes. Iron bioavailability is highly restricted due to the low solubility of its oxidized form, frequently leading to iron deficiency anemia. The baker’s yeast Saccharomyces cerevisiae is used as a model organism for iron homeostasis studies, but also as a food supplement and fermentative microorganism in the food industry. Yeast cells use the vacuolar Ccc1 transporter to detoxify and store excess iron in the vacuoles. Here, we modulate CCC1 expression and properties to increase iron extraction from the environment. We show that constitutive expression of fu…
Site specificity of pea histone acetyltransferase B in vitro.
1993
Histone acetyltransferase B from pea embryonic axes has been purified approximately 300-fold by a combination of chromatographic procedures, including affinity chromatography on histone-agarose. The enzyme preparation has been used for the in vitro transfer of acetyl groups from [1-14C]acetyl-CoA to non-acetylated pea histone H4. Up to three acetyl groups can be introduced into the histone. The resulting mono-, di-, and triacetylated H4 isoforms were separated and sequenced to determine the acetylated sites. Only sites 5, 12, and 16 were used by histone acetyltransferase B, but no clear preference among them was observed. The absence of modification of other potentially acetylatable sites i…
Characterization of the Viable but Nonculturable (VBNC) State in Saccharomyces cerevisiae
2013
The Viable But Non Culturable (VBNC) state has been thoroughly studied in bacteria. In contrast, it has received much less attention in other microorganisms. However, it has been suggested that various yeast species occurring in wine may enter in VBNC following sulfite stress.In order to provide conclusive evidences for the existence of a VBNC state in yeast, the ability of Saccharomyces cerevisiae to enter into a VBNC state by applying sulfite stress was investigated. Viable populations were monitored by flow cytometry while culturable populations were followed by plating on culture medium. Twenty-four hours after the application of the stress, the comparison between the culturable populat…
Functional Connection Between the Clb5 Cyclin, the Protein Kinase C Pathway and the Swi4 Transcription Factor in Saccharomyces cerevisiae
2005
Abstract The rsf12 mutation was isolated in a synthetic lethal screen for genes functionally interacting with Swi4. RSF12 is CLB5. The clb5 swi4 mutant cells arrest at G2/M due to the activation of the DNA-damage checkpoint. Defects in DNA integrity was confirmed by the increased rates of chromosome loss and mitotic recombination. Other results suggest the presence of additional defects related to morphogenesis. Interestingly, genes of the PKC pathway rescue the growth defect of clb5 swi4, and pkc1 and slt2 mutations are synthetic lethal with clb5, pointing to a connection between Clb5, the PKC pathway, and Swi4. Different observations suggest that like Clb5, the PKC pathway and Swi4 are in…
Physical and Genetic Interactions Link the Yeast Protein Zds1p with mRNA Nuclear Export
2005
Eukaryotic gene expression requires the export of mRNA from the nucleus to the cytoplasm. The DEAD box protein Dbp5p is an essential export factor conserved from yeast to man. A fraction of Dbp5p forms a complex with nucleoporins of the cytoplasmic filaments of the nuclear pore complex. Gfd1p was identified originally as a multicopy suppressor of the rat8-2 ts allele of DBP5. Here we reported that Dbp5p and Gfd1p interact with Zds1p, a protein previously identified as a multicopy suppressor in several yeast genetic screens. By using the two-hybrid system, we showed that Zds1p interacts in vivo with both Gfd1p and Dbp5p. In vitro binding experiments revealed that Gfd1p and Dbp5p bind directl…