The large N-terminal domain of Cdc25 protein of the yeast Saccharomyces cerevisiae is required for glucose-induced Ras2 activation
2007; Oxford University Press; Volume: 7; Issue: 8 Linguagem: Inglês
10.1111/j.1567-1364.2007.00300.x
ISSN1567-1364
AutoresChiara Paiardi, Fiorella Belotti, Sonia Colombo, Renata Tisi, Enzo Martegani,
Tópico(s)Enzyme Structure and Function
ResumoThe Saccharomyces cerevisiae CDC25 gene encodes a guanine nucleotide exchange factor for Ras proteins whose catalytic domain is highly homologous to Ras-guanine nucleotide exchange factors from higher eukaryotes. In this study, glucose-induced Ras activation and cAMP response were investigated in mutants lacking the N-terminal domain of Cdc25 or where the entire CDC25 coding sequence was substituted by an expression cassette for a mammalian guanine nucleotide exchange factor catalytic domain. Our results suggest that an unregulated, low Ras guanine nucleotide exchange factor activity allows a normal glucose-induced cAMP signal that appears to be mediated mainly by the Gpr1/Gpa2 system, but it was not enough to sustain the glucose-induced increase of Ras2-GTP normally observed in a wild-type strain.
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