Tyrosines in the carboxyl terminus regulate Syk kinase activity and function.

ABSTRACT: The Syk tyrosine kinase family plays an essential role in immunoreceptor tyrosine-based activation motif (ITAM) signaling. The binding of Syk to tyrosine-phosphorylated ITAM subunits of immunoreceptors, such as FcepsilonRI on mast cells, results in a conformational change, with an increase of enzymatic activity of Syk. This conformational change exposes the COOH-terminal tail of Syk, which has three conserved Tyr residues (Tyr-623, Tyr-624, and Tyr-625 of rat Syk). To understand the role of these residues in signaling, wild-type and mutant Syk with these three Tyr mutated to Phe was expressed in Syk-deficient mast cells. There was decreased FcepsilonRI-induced degranulation, nuclear factor for T cell activation and NFkappaB activation with the mutated Syk together with reduced phosphorylat

SUBMITTER: de Castro RO 

PROVIDER: S-EPMC2924109 | biostudies-literature | 2010 Aug

REPOSITORIES: biostudies-literature