| First Author | Kawakatsu T | Year | 2005 |
| Journal | J Biol Chem | Volume | 280 |
| Issue | 6 | Pages | 4940-7 |
| PubMed ID | 15485841 | Mgi Jnum | J:96880 |
| Mgi Id | MGI:3573813 | Doi | 10.1074/jbc.M408710200 |
| Citation | Kawakatsu T, et al. (2005) Vav2 as a Rac-GDP/GTP exchange factor responsible for the nectin-induced, c-Src- and Cdc42-mediated activation of Rac. J Biol Chem 280(6):4940-7 |
| abstractText | Nectins are Ca2+-independent immunoglobulin-like cell-cell adhesion molecules that form homo- and hetero-trans-dimers (trans-interactions). Nectins first form cell-cell contact and then recruit cadherins to the nectin-based cell-cell contact sites to form adherens junctions cooperatively with cadherins. In addition, the trans-interactions of nectins induce the activation of Cdc42 and Rac small G proteins, which enhances the formation of adherens junctions by forming filopodia and lamellipodia, respectively. The trans-interactions of nectins first recruit and activate c-Src at the nectin-based cell-cell contact sites. c-Src then phosphorylates and activates FRG, a Cdc42-GDP/GTP exchange factor (GEF) for Cdc42. The activation of both c-Src and Cdc42 by FRG is necessary for the activation of Rac, but the Rac-GEF responsible for this activation of Rac remains unknown. We showed here that the nectin-induced activation of Rac was inhibited by a dominant negative mutant of Vav2, a Rac-GEF. Nectins recruited and tyrosine-phosphorylated Vav2 through c-Src at the nectin-based cell-cell contact sites, whereas Cdc42 was not necessary for the nectin-induced recruitment of Vav2 or the nectin-induced, c-Src-mediated tyrosine phosphorylation of Vav2. Cdc42 activated through c-Src then enhanced the GEF activity of tyrosine-phosphorylated Vav2 on Rac1. These results indicate that Vav2 is a GEF responsible for the nectin-induced, c-Src-, and Cdc42-mediated activation of Rac. |
