Distinct roles for Syk and ZAP-70 during early thymocyte development.

ABSTRACT: The spleen tyrosine kinase (Syk) and zeta-associated protein of 70 kD (ZAP-70) tyrosine kinases are both expressed during early thymocyte development, but their unique thymic functions have remained obscure. No specific role for Syk during beta-selection has been established, and no role has been described for ZAP-70 before positive selection. We show that Syk and ZAP-70 provide thymocytes with unique and separable fitness advantages during early development. Syk-deficient, but not ZAP-70-deficient, thymocytes are specifically impaired in initial pre-TCR signaling at the double-negative (DN) 3 beta selection stage and show reduced cell-cycle entry. Surprisingly, and despite overlapping expression of both kinases, only ZAP-70 appears to promote sustained pre-TCR/TCR signaling during the DN4

SUBMITTER: Palacios EH 

PROVIDER: S-EPMC2118636 | biostudies-literature | 2007 Jul

REPOSITORIES: biostudies-literature