論文 - 詳細
| RRC ID | 45942 |
|---|---|
| 著者 | Chan E, Nance J. |
| タイトル | Mechanisms of CDC-42 activation during contact-induced cell polarization. |
| ジャーナル | J Cell Sci |
| Abstract |
Polarization of early embryos provides a foundation to execute essential patterning and morphogenetic events. In Caenorhabditis elegans, cell contacts polarize early embryos along their radial axis by excluding the cortical polarity protein PAR-6 from sites of cell contact, thereby restricting PAR-6 to contact-free cell surfaces. Radial polarization requires the cortically enriched Rho GTPase CDC-42, which in its active form recruits PAR-6 through direct binding. The Rho GTPase activating protein (RhoGAP) PAC-1, which localizes specifically to cell contacts, triggers radial polarization by inactivating CDC-42 at these sites. The mechanisms responsible for activating CDC-42 at contact-free surfaces are unknown. Here, in an overexpression screen of Rho guanine nucleotide exchange factors (RhoGEFs), which can activate Rho GTPases, we identify CGEF-1 and ECT-2 as RhoGEFs that act through CDC-42 to recruit PAR-6 to the cortex. We show that ECT-2 and CGEF-1 localize to the cell surface and that removing their activity causes a reduction in levels of cortical PAR-6. Through a structure-function analysis, we show that the tandem DH-PH domains of CGEF-1 and ECT-2 are sufficient for GEF activity, but that regions outside of these domains target each protein to the cell surface. Finally, we provide evidence suggesting that the N-terminal region of ECT-2 may direct its in vivo preference for CDC-42 over another known target, the Rho GTPase RHO-1. We propose that radial polarization results from a competition between RhoGEFs, which activate CDC-42 throughout the cortex, and the RhoGAP PAC-1, which inactivates CDC-42 at cell contacts. |
| 巻・号 | 126(Pt 7) |
| ページ | 1692-702 |
| 公開日 | 2013-4-1 |
| DOI | 10.1242/jcs.124594 |
| PII | jcs.124594 |
| PMID | 23424200 |
| PMC | PMC3647442 |
| MeSH | Animals Caenorhabditis elegans / genetics Caenorhabditis elegans / metabolism* Caenorhabditis elegans Proteins / genetics Caenorhabditis elegans Proteins / metabolism* Cell Polarity / genetics Cell Polarity / physiology Guanine Nucleotide Exchange Factors / genetics Guanine Nucleotide Exchange Factors / metabolism Rho Guanine Nucleotide Exchange Factors cdc42 GTP-Binding Protein / genetics cdc42 GTP-Binding Protein / metabolism* |
| IF | 4.573 |
| 引用数 | 21 |
| WOS 分野 | CELL BIOLOGY |
| オルトメトリクス指標 |
オルトメトリクス指標項目
|
| 各媒体での言及数の合計 | 0 |
| リソース情報 | |
| 線虫 | tm3663 |