G1/S cyclin-dependent kinase regulates small GTPase Rho1p through phosphorylation of RhoGEF Tus1p in Saccharomyces cerevisiae

Keiko Kono; Satoru Nogami; Mitsuhiro Abe; Masafumi Nishizawa; Shinichi Morishita; David Pellman; Yoshikazu Ohya

doi:10.1091/mbc.e07-09-0950

G1/S cyclin-dependent kinase regulates small GTPase Rho1p through phosphorylation of RhoGEF Tus1p in Saccharomyces cerevisiae

Mol Biol Cell. 2008 Apr;19(4):1763-71. doi: 10.1091/mbc.e07-09-0950. Epub 2008 Feb 6.

Authors

Keiko Kono¹, Satoru Nogami, Mitsuhiro Abe, Masafumi Nishizawa, Shinichi Morishita, David Pellman, Yoshikazu Ohya

Affiliation

¹ Department of Integrated Biosciences, Graduate School of Frontier Sciences, University of Tokyo, Chiba 277-8562, Japan.

Abstract

Rho1p is an essential small GTPase that plays a key role in the morphogenesis of Saccharomyces cerevisiae. We show here that the activation of Rho1p is regulated by a cyclin-dependent kinase (CDK). Rho1p is activated at the G1/S transition at the incipient-bud sites by the Cln2p (G1 cyclin) and Cdc28p (CDK) complex, in a process mediated by Tus1p, a guanine nucleotide exchange factor for Rho1p. Tus1p interacts physically with Cln2p/Cdc28p and is phosphorylated in a Cln2p/Cdc28p-dependent manner. CDK phosphorylation consensus sites in Tus1p are required for both Cln2p-dependent activation of Rho1p and polarized organization of the actin cytoskeleton. We propose that Cln2p/Cdc28p-dependent phosphorylation of Tus1p is required for appropriate temporal and spatial activation of Rho1p at the G1/S transition.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Actins / metabolism
Binding Sites
CDC28 Protein Kinase, S cerevisiae / genetics
CDC28 Protein Kinase, S cerevisiae / metabolism
Cell Division
Cyclin-Dependent Kinases / genetics
Cyclin-Dependent Kinases / metabolism*
Cyclins / genetics
Cyclins / metabolism
Enzyme Activation
G1 Phase
Genes, Fungal
Guanine Nucleotide Exchange Factors / genetics
Guanine Nucleotide Exchange Factors / metabolism*
Models, Biological
Mutation
Phosphorylation
Recombinant Fusion Proteins / genetics
Recombinant Fusion Proteins / metabolism
S Phase
Saccharomyces cerevisiae / cytology
Saccharomyces cerevisiae / genetics
Saccharomyces cerevisiae / metabolism*
Saccharomyces cerevisiae Proteins / genetics
Saccharomyces cerevisiae Proteins / metabolism*
rho GTP-Binding Proteins / genetics
rho GTP-Binding Proteins / metabolism*

Substances

Actins
CLN2 protein, S cerevisiae
Cyclins
Guanine Nucleotide Exchange Factors
Recombinant Fusion Proteins
Saccharomyces cerevisiae Proteins
TUS1 protein, S cerevisiae
CDC28 Protein Kinase, S cerevisiae
Cyclin-Dependent Kinases
RHO1 protein, S cerevisiae
rho GTP-Binding Proteins