Association of the adaptor molecule LAT with CD4 and CD8 coreceptors identifies a new coreceptor function in T cell receptor signal transduction.

ABSTRACT: Linker for activation of T cells (LAT) is an adaptor protein whose tyrosine phosphorylation is critical for transduction of the T cell receptor (TCR) signal. LAT phosphorylation is accomplished by the protein tyrosine kinase ZAP-70, but it is not at all clear how LAT (which is not associated with the TCR) encounters ZAP-70 (which is bound to the TCR). Here we show that LAT associates with surface CD4 and CD8 coreceptors and that its association is promoted by the same coreceptor cysteine motif that mediates Lck binding. In fact, LAT competes with Lck for binding to individual coreceptor molecules but differs from Lck in its preferential association with CD8 rather than CD4 in CD4(+)CD8(+) thymocytes. Importantly, as a consequence of LAT association with surface coreceptors, coengagement of

SUBMITTER: Bosselut R 

PROVIDER: S-EPMC2195704 | biostudies-literature | 1999 Nov

REPOSITORIES: biostudies-literature