JAK3 mediates c-myc gene expression induced by interleukin-2

C-myc gene expression can be rapidly induced by IL-2 through intracellular signal transduction which is triggered by the interaction between IL-2 and its receptor (IL-2R). JAK3 which associates to the intracellular domain of IL-2R gamma may play a critical role in this process. To reveal the action of JAK3 in c-myc induction, a chimeric receptor gene IL-2R alpha/gamma/Delta NJAK3 is constructed which consists of extracellular domain derived from IL-2R alpha subunit (IL-2R alpha), the transmembrane sequence derived from IL-2R gamma and the cytoplasmic domain derived from the catalytic domain of JAK3 (Delta NJAK3), and then trhnsfccted this chimeric gene into mouse fibroblast cell line L929 beta which had been transfected with IL-2R beta gene and stably expressed IL-2R beta in high level. In the transfectants coexpressing IL-2R beta and alpha/gamma/Delta NJAK3, the stimulation of IL-2 could intensively induce c-myc gene expression. Because the whole cytoplasmic domain of IL-2R gamma which could recruit signaling molecules was replaced by JAK3 and the c-myc could be still induced by IL-2 in this situation, the results here gave the direct evidence demonstrating that JAK3 plays an important role in c-myc gene expression induced by IL-2.