Dynamic13C-labeling experiments prove important differences in protein turnover rate between twoSaccharomyces cerevisiaestrains (original) (raw)

Modulation of protein synthesis and degradation maintains proteostasis during yeast growth at different temperatures

Biochimica et biophysica acta, 2017

To understand how cells regulate each step in the flow of gene expression is one of the most fundamental goals in molecular biology. In this work, we have investigated several protein turnover-related steps in the context of gene expression regulation in response to changes in external temperature in model yeast Saccharomyces cerevisiae. We have found that the regulation of protein homeostasis is stricter than mRNA homeostasis. Although global translation and protein degradation rates are found to increase with temperature, the increase of the catalytic activity of ribosomes is higher than the global translation rate suggesting that yeast cells adapt the amount of translational machinery to the constraints imposed by kinetics in order to minimize energy costs. Even though the transcriptional machinery is subjected to the same constraints, we observed interesting differences between transcription and translation, which may be related to the different energy costs of the two processes...

Comparative proteomic analysis of transition of saccharomyces cerevisiae from glucose-deficient medium to glucose-rich medium

Proteome Science, 2012

Background When glucose is added to Saccharomyces cerevisiae grown in non-fermentable carbon sources, genes encoding ribosomal, cell-cycle, and glycolytic proteins are induced. By contrast, genes involved in mitochondrial functions, gluconeogenesis, and the utilization of other carbon sources are repressed. Glucose also causes the activation of the plasma membrane ATPase and the inactivation of gluconeogenic enzymes and mitochondrial enzymes. The goals of this study were to use the iTRAQ-labeling mass spectrometry technique to identify proteins whose relative levels change in response to glucose re-feeding and to correlate changes in protein abundance with changes in transcription and enzymatic activities. We used an experimental condition that causes the degradation of gluconeogenic enzymes when glucose starved cells are replenished with glucose. Identification of these enzymes as being down-regulated by glucose served as an internal control. Furthermore, we sought to identify new ...

Characterization of Yeast Protein Enzymatic Hydrolysis and Autolysis in Saccharomyces cerevisiae and Kluyveromyces marxianus

2015

Protein recovery under sonication treatment and autolysis, also protein hydrolysis progress during enzymatic hydrolysis (using trypsin and chymotrypsin) and autolysis (using endogenous enzymes) were investigated in Saccharomyces cerevisiae and Kluyveromyces marxianus. Crude protein content of dried yeast cells were 53.22% and 45.6% for S.cerevisiae and K.marxianus, respectively. After 96 hrs of autolysis in the presence of ethyl acetate, protein recovery reached 59.74% and 77.18% for S. cerevisiae and K. marxianus, respectively and it was 53.66% and 55.17% for sonication treatment. The yeast protein solution obtained by sonication was hydrolyzed by trypsin and chymotrypsin. Autolysis, produced hydrolysates with higher degree of hydrolysis (DH) values as compared to the enzymatic hydrolysis. After 96 hours autolysis, DH increased to 48.75% and 39.51% for S. cerevisiae and K. marxianus respectively. Chymotrypsin was significantly more effective on K. marxianus protein with the DH valu...