Search results for "VISIA"
showing 10 items of 764 documents
AcetyltransferaseSAS2and sirtuinSIR2,respectively, control flocculation and biofilm formation in wine yeast
2014
Cell-to-cell and cell-to-environment interactions of microorganisms are of substantial relevance for their biotechnological use. In the yeast Saccharomyces cerevisiae, flocculation can be an advantage to clarify final liquid products after fermentation, and biofilm formation may be relevant for the encapsulation of strains of interest. The adhesion properties of wine yeast strains can be modified by the genetic manipulation of transcriptional regulatory proteins, such as histone deacetylases, and acetylases. Sirtuin SIR2 is essential for the formation of mat structures, a kind of biofilm that requires the expression of cell-wall protein FLO11 as its deletion reduces FLO11 expression, and ad…
Energetic aspects of intramolecular coupling between the nucleotide binding site and the distal switch II region of the yeast RAS2 protein
1994
AbstractWe have studied the interaction of the yeast RAS2 protein with guanine nucleotides using energetic parameters for the dissociation of RAS·nucleotide complexes. The results indicated that a Gly → Ser substitution at position 82 led to an altered interaction with GppNHp and, to a lesser extent, also with GDP. It was also possible to conclude that structural perturbation of Gly82 can stimulate nucleotide release by decreasing the energetic barrier for nucleotide dissociation. This, together with the observation that residues 80 and 81 are involved in the response of RAS to nucleotide exchange factors without affecting GDP binding per se, suggests a potential mechanism for exchange fact…
A short-range gradient of histone H3 acetylation and Tup1p redistribution at the promoter of the Saccharomyces cerevisiae SUC2 gene.
2003
Chromatin immunoprecipitation assays are used to map H3 and H4 acetylation over the promoter nucleosomes and the coding region of the Saccharomyces cerevisiae SUC2 gene, under repressed and derepressed conditions, using wild type and mutant strains. In wild type cells, a high level of H3 acetylation at the distal end of the promoter drops sharply toward the proximal nucleosome that covers the TATA box, a gradient that become even steeper on derepression. In contrast, substantial H4 acetylation shows no such gradient and extends into the coding region. Overall levels of both H3 and H4 acetylation rise on derepression. Mutation of GCN5 or SNF2 lead to substantially reduced SUC2 expression; in…
The relative importance of transcription rate, cryptic transcription and mRNA stability on shaping stress responses in yeast
2012
It has been recently stated that stress-responding genes in yeast are enriched in cryptic transcripts and that this is the cause of the differences observed between mRNA amount and RNA polymerase occupancy profiles. Other studies have shown that such differences are mainly due to modulation of mRNA stabilities. Here we analyze the relationship between the presence of cryptic transcripts in genes and their stress response profiles. Despite some of the stress-responding gene groups being indeed enriched in specific classes of cryptic transcripts, we found no statistically significant evidence that cryptic transcription is responsible for the differences observed between mRNA and transcription…
Study of the First Hours of Microvinification by the Use of Osmotic Stress-response Genes as Probes
2002
Summary When yeast cells are inoculated into grape must for vinification they find stress conditions because of osmolarity, which is due to very high sugar concentration, and pH lower than 4. In this work an analysis of the expression of three osmotic stress induced genes ( GPD1 , HSP12 and HSP104 ) under microvinification conditions is shown as a way to probe those stress situations and the regulatory mechanisms that control them. The results indicate that during the first hours of microvinification there is an increase in the GPD1 mRNA levels with a maximum about one hour after inoculation, and a decrease in the amount of HSP12 and HSP104 mRNAs, although with differences between them. The…
The ATC1 gene encodes a cell wall-linked acid trehalase required for growth on trehalose in Candida albicans.
2004
After screening a Candida albicans genome data base, the product of an open reading frame (IPF 19760/CA2574) with 41% identity to Saccharomyces cerevisiae vacuolar acid trehalase (Ath1p) was identified and named Atc1p. The deduced amino acid sequence shows that Atc1p contains an N-terminal hydrophobic signal peptide and 20 potential sites for N-glycosylation. C. albicans homozygous mutants that lack acid trehalase activity were constructed by gene disruption at the two ATC chromosomal alleles. Analysis of these null mutants shows that Atc1p is localized in the cell wall and is required for growth on trehalose as a carbon source. An Atc1p endowed with acid trehalase activity was obtained by …
Unveiling novel interactions of histone chaperone Asf1 linked to TREX-2 factors Sus1 and Thp1
2014
13 páginas, 7 figuras, 2 yablas
Ubiquitin ligase Rsp5p is involved in the gene expression changes during nutrient limitation inSaccharomyces cerevisiae
2009
Rsp5p is an essential ubiquitin ligase involved in many different cellular events, including amino acid transporters degradation, transcription initiation and mRNA export. It plays important role in both stress resistance and adaptation to the change of nutrients. We have found that ubiquitination machinery is necessary for the correct induction of the stress response SPI1 gene at the entry of the stationary phase. SPI1 is a gene whose expression is regulated by the nutritional status of the cell and whose deletion causes hypersensitivity to various stresses, such as heat shock, alkaline stress and oxidative stress. Its regulation is mastered by Rsp5p, as mutations in this gene lead to a lo…
Yeast HAT1 and HAT2 deletions have different life-span and transcriptome phenotypes
2005
AbstractHAT-B is a yeast histone acetyltransferase composed of Hat1, Hat2 and Hif1 proteins. We demonstrate that a hat2 mutant or a hat1hat2 double mutant, but not a hat1 mutant, have an extended life-span. Transcriptome analysis shows that the single hat mutants are not very different from wild type. However, the comparison of the hat1 and hat2 transcriptomes shows that they are different. The hat1hat2 double mutant shows a transcriptional phenotype similar to that of the hat1 mutant but strongly enhanced. These results indicate that Hat2p could have additional functions in the cell to those of Hat1p.
Saccharomyces cerevisiae Glutaredoxin 5-deficient Cells Subjected to Continuous Oxidizing Conditions Are Affected in the Expression of Specific Sets …
2004
The Saccharomyces cerevisiae GRX5 gene codes for a mitochondrial glutaredoxin involved in the synthesis of iron/sulfur clusters. Its absence prevents respiratory growth and causes the accumulation of iron inside cells and constitutive oxidation of proteins. Null ⌬grx5 mu- tants were used as an example of continuously oxidized cells, as opposed to situations in which oxidative stress is instantaneously caused by addition of external oxi- dants. Whole transcriptome analysis was carried out in the mutant cells. The set of genes whose expression was affected by the absence of Grx5 does not significantly overlap with the set of genes affected in respiratory petite mutants. Many Aft1-dependent ge…