The Rho-GAP Bem2p plays a GAP-independent role in the morphogenesis checkpoint

Autor: Trevin R. Zyla, John N. McMillan, Daniel J. Lew, Aron R. Marquitz, Jacob C. Harrison, Indrani Bose
Rok vydání: 2002
Předmět:
G2 Phase
Saccharomyces cerevisiae Proteins
Cell cycle checkpoint
GTPase-activating protein
MAP Kinase Signaling System
Genes
Fungal
Molecular Sequence Data
Morphogenesis
Cell Cycle Proteins
Saccharomyces cerevisiae
Biology
Article
General Biochemistry
Genetics and Molecular Biology
Fungal Proteins
Reproduction
Asexual
Cell polarity
Amino Acid Sequence
CHEK1
Phosphorylation
Molecular Biology
Mitosis
Metaphase
cdc42 GTP-Binding Protein
Saccharomyces cerevisiae
Fungal protein
Base Sequence
Sequence Homology
Amino Acid
General Immunology and Microbiology
ras-GRF1
General Neuroscience
GTPase-Activating Proteins
Cell Polarity
Protein-Tyrosine Kinases
G2-M DNA damage checkpoint
Bridged Bicyclo Compounds
Heterocyclic
Protein Structure
Tertiary
Cell biology
Genes
cdc
Thiazoles
Thiazolidines
Mitogen-Activated Protein Kinases
Protein Tyrosine Phosphatases
CDC28 Protein Kinase
S cerevisiae
Protein Processing
Post-Translational
Sequence Alignment
Zdroj: The EMBO Journal. 21:4012-4025
ISSN: 1460-2075
DOI: 10.1093/emboj/cdf416
Popis: The Saccharomyces cerevisiae morphogenesis checkpoint delays mitosis in response to insults that impair actin organization and/or bud formation. The delay is due to accumulation of the inhibitory kinase Swe1p, which phosphorylates the cyclin-dependent kinase Cdc28p. Having screened through a panel of yeast mutants with defects in cell morphogenesis, we report here that the polarity establishment protein Bem2p is required for the checkpoint response. Bem2p is a Rho-GTPase activating protein (GAP) previously shown to act on Rho1p, and we now show that it also acts on Cdc42p, the GTPase primarily responsible for establishment of cell polarity in yeast. Whereas the morphogenesis role of Bem2p required GAP activity, the checkpoint role of Bem2p did not. Instead, this function required an N-terminal Bem2p domain. Thus, this single protein has a GAP-dependent role in promoting cell polarity and a GAP-independent role in responding to defects in cell polarity by enacting the checkpoint. Surprisingly, Swe1p accumulation occurred normally in bem2 cells, but they were nevertheless unable to promote Cdc28p phosphorylation. Therefore, Bem2p defines a novel pathway in the morphogenesis checkpoint.
Databáze: OpenAIRE
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