| First Author | Yoshida K | Year | 2000 |
| Journal | J Biol Chem | Volume | 275 |
| Issue | 32 | Pages | 24945-52 |
| PubMed ID | 10823839 | Mgi Jnum | J:383743 |
| Mgi Id | MGI:8327684 | Doi | 10.1074/jbc.M909012199 |
| Citation | Yoshida K, et al. (2000) Mediation by the protein-tyrosine kinase Tec of signaling between the B cell antigen receptor and Dok-1. J Biol Chem 275(32):24945-52 |
| abstractText | A variety of growth factor receptors induce the tyrosine phosphorylation of a nonreceptor protein-tyrosine kinase Tec as well as that of a Tec-binding protein of 62 kDa. Given the similarity in properties between this 62-kDa protein and p62(Dok-1), the possibility that these two proteins are identical was investigated. Overexpression of a constitutively active form of Tec in a pro-B cell line induced the hyperphosphorylation of endogenous Dok-1. Tec also associated with Dok-1 in a phosphorylation-dependent manner in 293 cells. Tec mediated marked phosphorylation of Dok-1 both in vivo and in vitro, and this effect required both the Tec homology and Src homology 2 domains of Tec in addition to its kinase activity. Expression of Dok-1 in 293 cells induced inhibition of Ras activity, suggesting that Dok-1 is a negative regulator of Ras. In the immature B cell line Ramos, cross-linking of the B cell antigen receptor (BCR) resulted in tyrosine phosphorylation of Dok-1, and this effect was markedly inhibited by expression of dominant negative mutants of Tec. Furthermore, overexpression of Dok-1 inhibited activation of the c-fos promoter induced by stimulation of the BCR. These results suggest that Tec is an important mediator of signaling from the BCR to Dok-1. |
