RRC ID 12547
著者 Tatebe H, Nakano K, Maximo R, Shiozaki K.
タイトル Pom1 DYRK regulates localization of the Rga4 GAP to ensure bipolar activation of Cdc42 in fission yeast.
ジャーナル Curr Biol
Abstract BACKGROUND:In the fission yeast Schizosaccharomyces pombe, cell growth takes place exclusively at both ends of the cylindrical cell. During this highly polarized growth, microtubules are responsible for the placement of the cell-end marker proteins, the Tea1-Tea4/Wsh3 complex, which recruits the Pom1 DYRK-family protein kinase. Pom1 is required for proper positioning of growth sites, and the Deltapom1 mutation brings about monopolar cell growth.
RESULTS:Pom1 kinase physically interacts with Rga4, which has a GAP (GTPase-activating protein) domain for Rho-family GTPase. Genetic and biochemical evidence indicates that Rga4 functions as GAP for the Cdc42 GTPase, an evolutionarily conserved regulator of F-actin. CRIB (Cdc42/Rac interactive binding)-GFP microscopy has revealed that GTP-bound, active Cdc42 is concentrated to growing cell ends accompanied by developed F-actin structures, where the Rga4 GAP is excluded. The monopolar Deltapom1 mutant fails to eliminate Rga4 from the nongrowing cell end, resulting in monopolar distribution of GTP-Cdc42 to the growing cell end. However, mutational inactivation of Rga4 allows Cdc42 to be active at both ends of Deltapom1 cells, suggesting that mislocalization of Rga4 in the Deltapom1 mutant contributes to its monopolar phenotype.
CONCLUSIONS:Pom1 kinase recruited to cell ends by the Tea1-Tea4/Wsh3 complex is essential for proper localization of a GAP for Cdc42, Rga4, which ensures bipolar localization of GTP-bound, active Cdc42. Because of the established role of Cdc42 in F-actin formation, these observations provide a new insight into how the microtubule system achieves localized formation of F-actin to generate cell polarity.
巻・号 18(5)
ページ 322-30
公開日 2008-3-11
DOI 10.1016/j.cub.2008.02.005
PII S0960-9822(08)00146-2
PMID 18328707
PMC PMC2277499
MeSH Actins / metabolism Cell Enlargement Cell Polarity / physiology* Cytoskeleton / physiology* GTPase-Activating Proteins / metabolism* Microtubules / metabolism Phosphorylation Protein Kinases / genetics Protein Kinases / metabolism* Protein Serine-Threonine Kinases / metabolism Protein-Tyrosine Kinases / metabolism Schizosaccharomyces / enzymology* Schizosaccharomyces pombe Proteins / metabolism* cdc42 GTP-Binding Protein / metabolism*
IF 9.601
引用数 102
WOS 分野 BIOCHEMISTRY & MOLECULAR BIOLOGY CELL BIOLOGY
リソース情報
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