Cell cycle and growth regulation in RAS2 mutant cells of Saccharomyces cerevisiae.
Yeast cells carrying ras2 temperature-sensitive mutations undergo a specific arrest in the prereplicative unbudded phase of the cell cycle when they are shifted to non-permissive temperatures. At 36.5 degrees C, in spite of their abnormally large cell size, bulk protein synthesis and accumulation rates are depressed in ras2 temperature-sensitive cells in comparison with isogenic wild type. At the same temperature, total RNA synthesis and accumulation rates are much more inhibited, suggesting that a defective Ras2/cAMP pathway alters the coordination between RNA and protein synthesis rates. The preferential RNA synthesis inhibition is correlated to a specific inhibition of the synthesis of the 35S rRNA precursor. These findings, taken together with the results of previous analyses, are in favour of a control by the cAMP pathway on rRNA biosynthesis.
Baroni
M D
MD
Dipartimento di Fisiologia e Biochimica Generali, Università degli Studi, Milano.
Marconi
G
G
Monti
P
P
Alberghina
L
L
D002453:Cell Cycle; D000242:Cyclic AMP / Q000378:metabolism; D005656:Fungal Proteins / Q000235:genetics; D009154:Mutation; D012335:RNA, Ribosomal / Q000096:biosynthesis; D012441:Saccharomyces cerevisiae / Q000166:cytology / Q000235:genetics / Q000254:growth & development*; D029701:Saccharomyces cerevisiae Proteins; D013696:Temperature; D018631:ras Proteins
D005656:Fungal Proteins; D012335:RNA, Ribosomal; D029701:Saccharomyces cerevisiae Proteins; D000242:Cyclic AMP; C489015:RAS2 protein, S cerevisiae; D018631:ras Proteins