Search results for "Saccharomyce"
showing 10 items of 875 documents
Impact of High pH Stress on Yeast Gene Expression: A Comprehensive Analysis of mRNA Turnover During Stress Responses.
2015
Environmental alkalinisation represents a stress condition for yeast Saccharomyces cerevisiae, to which this organism responds with extensive gene expression remodelling. We show here that alkaline pH causes an overall decrease in the transcription rate (TR) and a fast destabilisation of mRNAs, followed by a more prolonged stabilisation phase. In many cases, augmented mRNA levels occur without the TR increasing, which can be attributed to mRNA stabilisation. In contrast, the reduced amount of mRNAs is contributed by both a drop in the TR and mRNA stability. A comparative analysis with other forms of stress shows that, unlike high pH stress, heat-shock, osmotic and oxidative stresses present…
Specific Defects in Different Transcription Complexes Compensate for the Requirement of the Negative Cofactor 2 Repressor in Saccharomyces cerevisiae
2007
Abstract Negative cofactor 2 (NC2) has been described as an essential and evolutionarily conserved transcriptional repressor, although in vitro and in vivo experiments suggest that it can function as both a positive and a negative effector of transcription. NC2 operates by interacting with the core promoter and components of the basal transcription machinery, like the TATA-binding protein (TBP). In this work, we have isolated mutants that suppress the growth defect caused by the depletion of NC2. We have identified mutations affecting components of three different complexes involved in the control of basal transcription: the mediator, TFIIH, and RNA pol II itself. Mutations in RNA pol II in…
Phylogenetic origin and transcriptional regulation at the post-diauxic phase of SPI1, in Saccharomyces cerevisiae
2012
15 pages, 4 figures, supplementary material
A DNA region ofTorulaspora delbrueckii containing theHIS3 gene: sequence, gene order and evolution
2003
We cloned a genomic DNA fragment of the yeast Torulaspora delbrueckii by complementation of a Saccharomyces cerevisiae his3 mutant strain. DNA sequence analysis revealed that the fragment contained two complete ORFs, which share a high similarity with S. cerevisiae His3p and Mrp51p, respectively. The cloned TdHIS3 gene fully complemented the his3 mutation of S. cerevisiae, confirming that it encodes for the imidazoleglycerol-phosphate dehydrate of T. delbrueckii. Two additional ORFs, with a high homology to S. cerevisiae PET56 and DED1 genes, were mapped upstream and downstream from TdHIS3 and TdMRP51, respectively. This genetic organization is analogous to that previously found in Saccharo…
Urmylation and tRNA thiolation functions of ubiquitin-like Uba4·Urm1 systems are conserved from yeast to man
2015
AbstractThe ubiquitin-like protein Urm1 from budding yeast and its E1-like activator Uba4 have dual roles in protein urmylation and tRNA thiolation pathways. To study whether these are conserved among eukaryotes, we used gene shuffles to replace the yeast proteins by their human counterparts, hURM1 and hUBA4/MOCS3. As judged from biochemical and genetical assays, hURM1 and hUBA4 are functional in yeast, albeit at reduced efficiencies. They mediate urmylation of the peroxiredoxin Ahp1, a known urmylation target in yeast, and support tRNA thiolation. Similar to hUBA4, yeast Uba4 itself is modified by Urm1 and hURM1 suggesting target overlap between eukaryal urmylation pathways. In sum, our st…
Investigation of a Killer Strain of Zygosaccharomyces Bailii
1993
Summary: The yeast Zygosaccharomyces bailii strain 412 was found to liberate a killer toxin (KT412) lethal to sensitive strains of Saccharomyces cerevisiae and Candida glabrata. Culture supernatants of the killer strain were concentrated by ultrafiltration and the extracellular protein was purified by gel filtration and ion-exchange chromatography. Gel filtration and SDS-PAGE of the electrophoretically homogeneous killer protein indicated an apparent molecular mass of 10 kDa. The killer toxin KT412 is probably not glycosylated since it did not show any detectable carbohydrate structures. KT412 was bound to sensitive but not to resistant yeast cells. The mannan, and not the glucan, fraction …
Lateral reorganization of plasma membrane is involved in the yeast resistance to severe dehydration
2010
International audience; In this study, we investigated the kinetic and the magnitude of dehydrations on yeast plasma membrane (PM) modifications because this parameter is crucial to cell survival. Functional (permeability) and structural (morphology, ultrastructure, and distribution of the protein Sur7-GFP contained in sterol-rich membrane microdomains) PM modifications were investigated by confocal and electron microscopy after progressive (non-lethal) and rapid (lethal) hyperosmotic perturbations. Rapid cell dehydration induced the formation of many PM invaginations followed by membrane internalization of low sterol content PM regions with time. Permeabilization of the plasma membrane occ…
Role of Pir1 in the construction of the Candida albicans cell wall
2004
Searches in a Candida albicans database (http://genolist.pasteur.fr/CandidaDB/) identified two Individual Protein Files (IPF 15363 and 19968) whose deduced amino acid sequences showed 42 % and 45 % homology with Saccharomyces cerevisiae Pir4. The two DNA sequences are alleles of the same gene (CaPIR1) but IPF 19968 has a deletion of 117 bases. IPF 19968 encodes a putative polypeptide of 364 aa, which is highly O-glycosylated and has an N-mannosylated chain, four cysteine residues and seven repeats. Both alleles are expressed under different growth conditions and during wall construction by regenerating protoplasts. The heterozygous mutant cells are elongated, form clumps of several cells an…
The distribution of active RNA polymerase II along the transcribed region is gene-specific and controlled by elongation factors.
2010
In order to study the intragenic profiles of active transcription, we determined the relative levels of active RNA polymerase II present at the 3'- and 5'-ends of 261 yeast genes by run-on. The results obtained indicate that the 3'/5' run-on ratio varies among the genes studied by over 12 log(2) units. This ratio seems to be an intrinsic characteristic of each transcriptional unit and does not significantly correlate with gene length, G + C content or level of expression. The correlation between the 3'/5' RNA polymerase II ratios measured by run-on and those obtained by chromatin immunoprecipitation is poor, although the genes encoding ribosomal proteins present exceptionally low ratios in …
Hyperphosphorylation of Msn2p and Msn4p in response to heat shock and the diauxic shift is inhibited by cAMP in Saccharomyces cerevisiae.
2000
In response to various stresses, as well as during the diauxic transition, the Msn2p and Msn4p transcription factors of Saccharomyces cerevisiae are activated and induce a large set of genes. This activation is inhibited by the Ras/cAMP/PKA (cAMP-dependent protein kinase) pathway. Here we show by immunoblotting experiments that Msn2p and Msn4p are phosphorylated in vivo during growth on glucose, and become hyperphosphorylated at the diauxic transition and upon heat shock. This hyperphosphorylation is correlated with activation of Msn2/4p-dependent transcription. An increased level of cAMP prevents and reverses these hyperphosphorylations, indicating that kinases other than PKA are involved.…