Protein synthesis during transition and stationary phases under glucose limitation in Saccharomyces cerevisiae.
Metabolic changes have been investigated during continuous growth of yeast cells inoculated in glucose-containing medium until the cells entered the stationary phase in response to glucose exhaustion. Well in advance of glucose exhaustion, a transition phase was observed, characterized by a decrease in the growth rate and a progressive reduction of protein and RNA accumulation. Two-dimensional gel analysis of the proteins synthesized during this stage showed that the pattern of proteins remained similar to that of log-phase cells. When the cells entered the stationary phase, protein accumulation was 10% of that in log-phase cells, and incorporation of labeled RNA precursor was undetectable. Analysis of protein synthesis gave evidence that the synthesis of 95% of the proteins present in log-phase cells was arrested in stationary-phase cells. Among the 20 proteins whose synthesis continues throughout the stationary phase were identified actin, aldehyde dehydrogenase, enolase, hexokinase, glyceraldehyde-3-phosphate dehydrogenase, and five heat shock proteins. In addition, the synthesis of six new proteins was observed. The occurrence of these new proteins in stationary-phase cells is presumed to result from the release of carbon catabolite repression due to glucose exhaustion.
D002244:Carbon / Q000378:metabolism; D002463:Cell Membrane Permeability; D004591:Electrophoresis, Polyacrylamide Gel; D005656:Fungal Proteins / Q000096:biosynthesis*; D005947:Glucose / Q000502:physiology*; D006238:Haploidy; D007399:Interphase; D007700:Kinetics; D008715:Methionine / Q000378:metabolism; D012331:RNA, Fungal / Q000096:biosynthesis; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000502:physiology*; D014498:Uracil / Q000378:metabolism
D005656:Fungal Proteins; D012331:RNA, Fungal; D014498:Uracil; D002244:Carbon; D008715:Methionine; D005947:Glucose