First Author | Berry DM | Year | 2002 |
Journal | Curr Biol | Volume | 12 |
Issue | 15 | Pages | 1336-41 |
PubMed ID | 12176364 | Mgi Jnum | J:230362 |
Mgi Id | MGI:5758815 | Doi | 10.1016/s0960-9822(02)01038-2 |
Citation | Berry DM, et al. (2002) A high-affinity Arg-X-X-Lys SH3 binding motif confers specificity for the interaction between Gads and SLP-76 in T cell signaling. Curr Biol 12(15):1336-41 |
abstractText | A critical event in T cell receptor (TCR)-mediated signaling is the recruitment of hematopoietic-specific adaptor proteins that collect and transmit signals downstream of the TCR. Gads, a member of the Grb2 family of SH2 and SH3 domain-containing adaptors, mediates the formation of a complex between LAT and SLP-76 that is essential for signal propagation from the TCR. Here we examine the binding specificity of the Gads and Grb2 SH3 domains using peptide arrays and find that a nonproline-based R-X-X-K motif found in SLP-76 binds to the Gads carboxy-terminal SH3 domain with high affinity (K(D) = 240 +/- 45 nM). The Grb2 C-terminal SH3 domain also binds this motif, but with a 40-fold lower affinity than Gads. Single point mutations in either the relevant R (237) or K (240) completely abrogated SLP-76 association with Gads in vivo and impaired SLP-76 function. A chimeric Grb2 protein, possessing the C-terminal SH3 domain of Gads, was able to partially substitute for Gads in signaling downstream of the T cell receptor. These results provide a molecular explanation for the specific role of Gads in T cell receptor signaling, and identify a discrete subclass of SH3 domains whose binding is dependent on a core R-X-X-K motif. |