IL-2-INDUCED GENE-EXPRESSION OF PROTEIN-TYROSINE-PHOSPHATASE LC-PTP REQUIRES ACIDIC AND SERINE-RICH REGIONS WITHIN IL-2 RECEPTOR-BETA CHAIN

A protein-tyrosine phosphatase LC-PTP is preferentially expressed in hematopoietic cells and is an early response gene in lymphokine stimulated cells, Here,,ve found the LC-PTP mRNA induction by IL-2 was markedly inhibited by several tyrosine kinase inhibitors, The induction required both the acidic and serine-rich regions of the IL-2 receptor beta chain (IL-2R beta) in mouse IL-3-dependent pro-B BAF-B03 transfectants. This is strikingly different from the induction of c-myc gene expression, which requires the serine-rich region alone, In addition, overexpression of activated-lck or -Raf kinases resulted in augmented LC-PTP mRNA expression in myeloid cell line 32D transfectants, Considering the previous findings that the acidic region of the LL-2R beta is responsible for association with Lck and activation of Raf kinase, IL-2-induced expression of LC-PTP mRNA may be primarily transduced through a Lck-Raf mediated signaling pathway.