title: Critical role of the interleukin 2 (IL-2) receptor gamma-chain-associated Jak3 in the IL-2-induced c-fos and c-myc, but not bcl-2, gene induction.
abstract: The interleukin 2 receptor (IL-2R) consists of three subunits, the IL-2R alpha, IL-2R beta c, and IL-2R gamma c chains. Two Janus family protein tyrosine kinases (PTKs), Jak1 and Jak3, were shown to associate with IL-2R beta c and IL-2R gamma c, respectively, and their PTK activities are increased after IL-2 stimulation. A Jak3 mutant with truncation of the C-terminal PTK domain lacks its intrinsic kinase activity but can still associate with IL-2R gamma c. In a hematopoietic cell line, F7, that responds to either IL-2 or IL-3, overexpression of this Jak3 mutant results in selective inhibition of the IL-2-induced activation of Jak1/Jak3 PTKs and of cell proliferation. Of the three target nuclear protooncogenes of the IL-2 signaling, c-fos and c-myc genes, but not the bcl-2 gene, were found to be impaired. On the other hand, overexpression of the dominant negative form of the IL-2R gamma c chain, which lacks most of its cytoplasmic domain, in F7 cells resulted in the inhibition of all three protooncogenes. These results provide a further molecular basis for the critical role of Jak3 in IL-2 signaling and also suggest a Jak PTK-independent signaling pathway(s) for the bcl-2 gene induction by IL-2R.
authors.affiliation: Institute of Molecular and Cellular Biology, Osaka University, Japan.
authors.forename: A
authors.initials: A
authors.lastname: Kawahara
authors.forename: Y
authors.initials: Y
authors.lastname: Minami
authors.forename: T
authors.initials: T
authors.lastname: Miyazaki
authors.forename: J N
authors.initials: JN
authors.lastname: Ihle
authors.forename: T
authors.initials: T
authors.lastname: Taniguchi
mesh_terms: D000818:Animals; D002455:Cell Division / Q000187:drug effects; D002460:Cell Line; D005786:Gene Expression Regulation; D006412:Hematopoietic Stem Cells; D006801:Humans; D007376:Interleukin-2 / Q000494:pharmacology*; D053616:Janus Kinase 3; D051379:Mice; D009154:Mutation; D011401:Promoter Regions, Genetic; D011505:Protein-Tyrosine Kinases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D011518:Proto-Oncogene Proteins / Q000096:biosynthesis*; D019253:Proto-Oncogene Proteins c-bcl-2; D016760:Proto-Oncogene Proteins c-fos / Q000096:biosynthesis; D016271:Proto-Oncogene Proteins c-myc / Q000096:biosynthesis; D015375:Receptors, Interleukin-2 / Q000378:metabolism*; D015398:Signal Transduction; D015533:Transcriptional Activation
chemical_list: D007376:Interleukin-2; D011518:Proto-Oncogene Proteins; D019253:Proto-Oncogene Proteins c-bcl-2; D016760:Proto-Oncogene Proteins c-fos; D016271:Proto-Oncogene Proteins c-myc; D015375:Receptors, Interleukin-2; D011505:Protein-Tyrosine Kinases; C507933:JAK3 protein, human; C507935:Jak3 protein, mouse; D053616:Janus Kinase 3