Search results for "ISIA"
showing 10 items of 1032 documents
Assessing Chronological Aging in Saccharomyces cerevisiae
2012
Saccharomyces cerevisiae is one of the most studied model organisms for the identification of genes and mechanisms that affect aging. The chronological lifespan (CLS) assay, which monitors the survival of a non-dividing population, is one of the two methods to study aging in yeast. To eliminate potential artifacts and identify genes and signaling pathways that may also affect aging in higher eukaryotes, it is important to determine CLS by multiple methods. Here, we describe these methods as well as the assays to study macromolecular damage during aging in yeast, with a focus on genomic instability.
Subcellular localization and nucleosome specificity of yeast histone acetyltransferases
1991
We have previously reported [López-Rodas et al. (1989) J. Biol. Chem. 264, 19028-19033] that the yeast Saccharomyces cerevisiae contains four histone acetyltransferases, which can be resolved by ion-exchange chromatography, and their specificity toward yeast free histones was studied. In the present contribution we show that three of the enzymes are nuclear, type A histone acetyltransferases and they are able to acetylate nucleosome-bound histones. They differ in their histone specificity. Enzyme A1 acetylates H2A in chicken nucleosomes, although it is specific for yeast free H2B; histone acetyltransferase A2 is highly specific for H3, and histone acetyltransferase A3 preparations acetylate…
Properties of the yeast nuclear histone deacetylase.
1994
A nuclear histone deacetylase from yeast was partially purified and some of its characteristics were studied. Histone deacetylase activity was stimulated in vitro by high-mobility-group nonhistone chromatin proteins 1 and 2 and ubiquitin and inhibited by spermine and spermidine, whereas n-butyrate had no significant inhibitory effect. Like the mammalian enzyme, partially purified histone deacetylase from yeast was strongly inhibited by trichostatin A. However, in crude extract preparations the yeast enzyme was not inhibited and treatment with trichostatin in vivo did not show any effect, either on the histone acetylation level or on cell viability. At low ionic strength, the enzyme can be i…
Yeast mRNA cap-binding protein Cbc1/Sto1 is necessary for the rapid reprogramming of translation after hyperosmotic shock.
2011
Global translation is inhibited in Saccharomyces cerevisiae cells under osmotic stress; nonetheless, osmostress-protective proteins are synthesized. We found that translation mediated by the mRNA cap-binding protein Cbc1 is stress-resistant and necessary for the rapid translation of osmostress-protective proteins under osmotic stress.
Mixed-ligand copper(ii)–sulfonamide complexes: effect of the sulfonamide derivative on DNA binding, DNA cleavage, genotoxicity and anticancer activity
2013
Four ternary complexes, [Cu(L1)2(bipy)] (1) [HL1 = N-(6-chlorobenzo[d]thiazol-2-yl)-4-methylbenzenesulfonamide], [Cu(L2)2(bipy)] (2) [HL2 = N-(benzo[d]thiazol-2-yl)-4-methylbenzenesulfonamide], [Cu(L3)2(bipy)]·1/2H2O (3) [HL3 = N-(5,6-dimethylbenzo[d]thiazol-2-yl)-4-methylbenzenesulfonamide] and [Cu(L4)2(bipy)] (4) [HL4 = N-(5,6-dimethylbenzo[d]thiazol-2-yl)benzenesulfonamide], were prepared and then characterized by X-ray crystallography, spectroscopy and magnetic measurements. Whereas the molecular structure of 1 and 2 consists of a discrete monomeric copper(II) species with a distorted square planar geometry, that of 3 and 4 consists of two independent molecules. In 3, both molecules pre…
The yeast mitogen-activated protein kinase Slt2 is involved in the cellular response to genotoxic stress
2012
Abstract Background The maintenance of genomic integrity is essential for cell viability. Complex signalling pathways (DNA integrity checkpoints) mediate the response to genotoxic stresses. Identifying new functions involved in the cellular response to DNA-damage is crucial. The Saccharomyces cerevisiae SLT2 gene encodes a member of the mitogen-activated protein kinase (MAPK) cascade whose main function is the maintenance of the cell wall integrity. However, different observations suggest that SLT2 may also have a role related to DNA metabolism. Results This work consisted in a comprehensive study to connect the Slt2 protein to genome integrity maintenance in response to genotoxic stresses.…
Adenine auxotrophy--be aware: some effects of adenine auxotrophy in Saccharomyces cerevisiae strain W303-1A.
2013
Adenine auxotrophy is a commonly used genetic marker in haploid yeast strains. Strain W303-1A, which carries the ade2-1 mutation, is widely used in physiological and genetic research. Yeast extract-based rich medium contains a low level of adenine, so that adenine is often depleted before glucose. This could affect the cell physiology of adenine auxotrophs grown in rich medium. The aim of our study was to assess the effects of adenine auxotrophy on cell morphology and stress physiology. Our results show that adenine depletion halts cell division, but that culture optical density continues to increase due to cell swelling. Accumulation of trehalose and a coincident 10-fold increase in desicc…
Saccharomyces cerevisiae Rds2 transcription factor involvement in cell wall composition and architecture
2008
Although the cell wall is very important in yeasts, relatively little is known about the relationship between its structure and function. In Saccharomyces cerevisiae, a family of 55 transcription factor proteins unique to fungi, so-called zinc cluster proteins, has been described. Of these, Rds2 has been identified as an activator/inhibitor of gluconeogenesis. However, previous studies have pointed out additional roles for this protein, specifically, in the modulation of cell-wall architecture and drug sensitivity. In this work, evidence regarding the role of Rds2 as a regulator of cell-wall architecture and composition is presented based on phenotypical analysis of the cell walls prepared …
Biogenesis of the Yeast Cell Wall
1984
Yeast cells are covered by a rigid structure that protects the protoplast from osmotic changes and gives the characteristic shape to the cell. Studies on the composition of the wall of several species of yeast and other fungi have shown that they contain mainly polysaccharides with minor amounts of other materials. A completely rigid and continuous wall, nevertheless, would render growth impossible because cell extension would be restricted, so that an equilibrium must exist between softening (partial degradation) of wall and incorporation of new material into free ends of the polymers. From these considerations, it seems clear that the walls must be structurally and enzymatically a complex…
GAL4-responsive UAS- tau as a tool for studying the anatomy and development of the Drosophila central nervous system
1997
To improve the quality of cytoplasmic labelling of GAL4-expressing cells in Drosophila enhancer-trap and transgenic strains, a new GAL4-responsive reporter UAS-tau, which features a bovine tau cDNA under control of a yeast upstream activation sequence (UAS), was tested. Tau, a microtubule-associated protein, is distributed actively and evenly into all cellular processes. Monoclonal anti-bovine Tau antibody reveals the axonal structure of the labelled cells with detail similar to that of Golgi impregnation. We demonstrate that the UAS-tau system is especially useful for studying processes of differentiation and reorganisation of identified neurones during postembryonic development.