Interleukin 2‐induced activation of JAK3: Possible involvement in signal transduction for c‐myc induction and cell proliferation

Abstract

We have investigated the role of JAK3 in interleukin 2 (IL‐2)‐induced signal transduction with a human T cell line, ED40515(−), lacking expression of the IL‐2 receptor γ chain and its sublines transfected with wild‐type or mutant cDNAs of the IL‐2 receptor γ chain. Our results demonstrated that the membrane‐proximal cytoplasmic region, encompassing the src homology region 2 (SH2)‐like subdomain, of the γ chain is essential for association and activation of JAK3. Furthermore, IL‐2‐induced activation of JAK3 paralleled induction of the c‐myc gene and DNA synthesis but not induction of the c‐fos and c‐jun genes. These results support the hypothesis that JAK3 plays a pivotal role in the IL‐2 receptor‐mediated signals for cell growth.