| First Author | Fusaki N | Year | 1997 |
| Journal | J Biol Chem | Volume | 272 |
| Issue | 10 | Pages | 6214-9 |
| PubMed ID | 9045636 | Mgi Jnum | J:159094 |
| Mgi Id | MGI:4441153 | Doi | 10.1074/jbc.272.10.6214 |
| Citation | Fusaki N, et al. (1997) Interaction between Sam68 and Src family tyrosine kinases, Fyn and Lck, in T cell receptor signaling. J Biol Chem 272(10):6214-9 |
| abstractText | The Src family protein-tyrosine kinase, Fyn, is associated with the T cell receptor (TCR) and plays an important role in TCR-mediated signaling. We found that a human T cell leukemia virus type 1-infected T cell line, Hayai, overexpressed Fyn. To identify the molecules downstream of Fyn, we analyzed the tyrosine phosphorylation of cellular proteins in the cells. In Hayai, a 68-kDa protein was constitutively tyrosine-phosphorylated. The 68-kDa protein was coimmunoprecipitated with various signaling proteins such as phospholipase C gamma1, the phosphatidylinositol 3-kinase p85 subunit, Grb2, SHP-1, Cbl, and Jak3, implying that the protein might function as an adapter. Purification and microsequencing of this protein revealed that it was the RNA-binding protein, Sam68 (Src associated in mitosis, 68 kDa). Sam68 was associated with the Src homology 2 and 3 domains of Fyn and also those of another Src family kinase, Lck. CD3 cross-linking induced tyrosine phosphorylation of Sam68 in uninfected T cells. These data suggest that Sam68 participates in the signal transduction pathway downstream of TCR-coupled Src family kinases Fyn and Lck in lymphocytes, that is not only in the mitotic pathway downstream of c-Src in fibroblasts. |
