title: Regulation of human involucrin promoter activity by a protein kinase C, Ras, MEKK1, MEK3, p38/RK, AP1 signal transduction pathway.
abstract: Involucrin is a marker of keratinocyte terminal differentiation. Our previous studies show that involucrin mRNA levels are increased by the keratinocyte differentiating agent, 12-O-tetradecanoylphorbol-13-acetate (TPA) (Welter, J. F., Crish, J. F., Agarwal, C., and Eckert, R. L. (1995) J. Biol. Chem. 270, 12614-12622). We now study the signaling cascade responsible for this regulation. Protein kinase C and tyrosine kinase inhibitors inhibit both the TPA-dependent mRNA increase and the TPA-dependent increase in hINV promoter activity. The relevant response element is located within the promoter proximal regulatory region and includes an AP1 site, AP1-1. Co-transfection of the hINV promoter with dominant negative forms of Ras, MEKK1, MEK1, MEK7, MEK3, p38/RK, and c-Jun inhibit the TPA-dependent increase. Wild type MEKK1 enhances promoter activity and the activity can be inhibited by dominant negative MEKK1, MEK1, MEK7, MEK3, p38/RK, and c-Jun. In contrast, wild type Raf-1, ERK1, ERK2, MEK4, or JNK1 produced no change in activity and the dominant negative forms of these kinases failed to suppress TPA-dependent transcription. Treatment with an S6 kinase (S6K) inhibitor, or transfection with constitutively active S6K produced relatively minor changes in promoter activity, ruling out a regulatory role for S6K. These results suggest that activation of involucrin transcription involves a pathway that includes protein kinase C, Ras, MEKK1, MEK3, and p38/RK. Additional pathways that transfer MEKK1 activation via MEK1 and MEK7 also may function, but the downstream targets of these kinases need to be identified. AP1 transcription factors appear to be the ultimate target of this regulation.
authors.affiliation: Department of Physiology and Biophysics, Case Western Reserve University School of Medicine, Cleveland, Ohio 44106-4970, USA.
authors.forename: T
authors.initials: T
authors.lastname: Efimova
authors.forename: P
authors.initials: P
authors.lastname: LaCelle
authors.forename: J F
authors.initials: JF
authors.lastname: Welter
authors.forename: R L
authors.initials: RL
authors.lastname: Eckert
mesh_terms: D001483:Base Sequence; D017871:Calcium-Calmodulin-Dependent Protein Kinases / Q000378:metabolism*; D002478:Cells, Cultured; D005786:Gene Expression Regulation; D017930:Genes, Reporter; D006801:Humans; D015603:Keratinocytes / Q000166:cytology / Q000378:metabolism; D008156:Luciferases / Q000235:genetics; D048369:MAP Kinase Kinase 1; D048371:MAP Kinase Kinase 3; D048688:MAP Kinase Kinase 7; D048728:MAP Kinase Kinase Kinase 1; D008297:Male; D020929:Mitogen-Activated Protein Kinase Kinases / Q000378:metabolism; D020928:Mitogen-Activated Protein Kinases; D008954:Models, Biological; D011401:Promoter Regions, Genetic; D011493:Protein Kinase C / Q000378:metabolism*; D011498:Protein Precursors / Q000096:biosynthesis / Q000235:genetics*; D017346:Protein Serine-Threonine Kinases / Q000378:metabolism*; D011505:Protein-Tyrosine Kinases / Q000378:metabolism; D016755:Proto-Oncogene Proteins c-jun / Q000378:metabolism; D019908:Proto-Oncogene Proteins c-raf / Q000378:metabolism; D011993:Recombinant Fusion Proteins / Q000378:metabolism; D019893:Ribosomal Protein S6 Kinases / Q000378:metabolism; D015398:Signal Transduction; D012867:Skin / Q000166:cytology; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D018808:Transcription Factor AP-1 / Q000378:metabolism*; D014162:Transfection; D048051:p38 Mitogen-Activated Protein Kinases; D018631:ras Proteins / Q000378:metabolism*
chemical_list: D011498:Protein Precursors; D016755:Proto-Oncogene Proteins c-jun; D011993:Recombinant Fusion Proteins; D018808:Transcription Factor AP-1; C032253:involucrin; D008156:Luciferases; D011505:Protein-Tyrosine Kinases; D017346:Protein Serine-Threonine Kinases; D019908:Proto-Oncogene Proteins c-raf; D019893:Ribosomal Protein S6 Kinases; D011493:Protein Kinase C; D017871:Calcium-Calmodulin-Dependent Protein Kinases; D020928:Mitogen-Activated Protein Kinases; D048051:p38 Mitogen-Activated Protein Kinases; D048728:MAP Kinase Kinase Kinase 1; C482576:MAP3K1 protein, human; D048369:MAP Kinase Kinase 1; D048371:MAP Kinase Kinase 3; D048688:MAP Kinase Kinase 7; C482125:MAP2K1 protein, human; C482530:MAP2K3 protein, human; C482569:MAP2K7 protein, human; D020929:Mitogen-Activated Protein Kinase Kinases; D018631:ras Proteins; D013755:Tetradecanoylphorbol Acetate