title: Interleukin-2 promoter activation in T-cells expressing activated Ha-ras.
abstract: Antigen triggering of the T-cell receptor results in an accumulation of activated GTP-bound p21ras protein. To assess the role of ras protein in T-cell activation we have cotransfected the murine thymoma line EL4 with a construct capable of expressing a constitutively active, oncogenic form of Ha-ras and a reporter construct containing the human interleukin-2 promoter fused upstream of the bacterial gene for chloramphenicol acetyltransferase. We show that the ras oncoprotein contributes to interleukin-2 promoter activation. Its pattern of synergism with a calcium ionophore or the lymphokine interleukin-1 indicates that it replaces a signal mediated by protein kinase C. Interleukin-2 promoter activity in the presence of ras oncoprotein was inhibited by H7, a potent inhibitor of protein kinase C, but not by HA1004, an inhibitor of cyclic nucleotide-dependent kinase, suggesting that protein kinase C mediates the ras effect. In addition, we show that in these cells, expression of activated ras results in activation of a synthetic promoter containing several copies of an NF kappa B binding site.
authors.affiliation: Department of Evolutionary Biology, University of Siena, Italy.
authors.forename: C T
authors.initials: CT
authors.lastname: Baldari
authors.forename: G
authors.initials: G
authors.lastname: Macchia
authors.forename: J L
authors.initials: JL
authors.lastname: Telford
mesh_terms: D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D000818:Animals; D015500:Chloramphenicol O-Acetyltransferase / Q000378:metabolism; D007376:Interleukin-2 / Q000235:genetics*; D007546:Isoquinolines / Q000494:pharmacology; D008213:Lymphocyte Activation; D051379:Mice; D016328:NF-kappa B / Q000378:metabolism; D010879:Piperazines / Q000494:pharmacology; D010957:Plasmids; D011401:Promoter Regions, Genetic / Q000187:drug effects; D011493:Protein Kinase C / Q000037:antagonists & inhibitors; D016283:Proto-Oncogene Proteins p21(ras) / Q000378:metabolism*; D012334:RNA, Neoplasm / Q000378:metabolism; D011948:Receptors, Antigen, T-Cell / Q000187:drug effects; D013449:Sulfonamides; D013601:T-Lymphocytes / Q000276:immunology*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014162:Transfection; D014407:Tumor Cells, Cultured
chemical_list: D007376:Interleukin-2; D007546:Isoquinolines; D016328:NF-kappa B; D010879:Piperazines; D012334:RNA, Neoplasm; D011948:Receptors, Antigen, T-Cell; D013449:Sulfonamides; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; C043204:N-(2-guanidinoethyl)-5-isoquinolinesulfonamide; D015500:Chloramphenicol O-Acetyltransferase; D011493:Protein Kinase C; D016283:Proto-Oncogene Proteins p21(ras); D013755:Tetradecanoylphorbol Acetate