title: Differences in phorbol-ester-induced down-regulation of protein kinase C between cell lines.
abstract: Down-regulation of protein kinase C induced by 12-O-tetradecanoylphorbol 13-acetate (TPA) was examined in Swiss 3T3, V79, MDBK and C6 cells by Western blotting. Variations in the rate of down-regulation caused by treatment with 100 nM-TPA were observed; TPA treatment for 5 h caused maximal down-regulation in V79 cells, whereas TPA treatment for 10 h or 30 h was needed for maximal down-regulation of protein kinase C in MDBK or Swiss 3T3 cells respectively. The decrease in amount of immunologically detectable protein kinase C was 30% in MDBK cells and 100% in V79 and Swiss 3T3 cells. MDBK and C6 cells could be completely depleted of protein kinase C by treatment with 250 nM-TPA. In C6 cells, after treatment with 500 nM-TPA, an 80% loss of protein kinase C was seen over 10 h. Measurement of the numbers of phorbol-ester-binding sites remaining in each cell line when protein kinase C was maximally down-regulated indicated that in MDBK and Swiss 3T3 cells loss of phorbol-ester-binding sites paralleled loss of protein kinase C, whereas in V79 and C6 cells no such correlation was observed.
authors.affiliation: Chester Beatty Research Laboratories, Institute of Cancer Research, London, U.K.
authors.forename: J C
authors.initials: JC
authors.lastname: Adams
authors.forename: W J
authors.initials: WJ
authors.lastname: Gullick
mesh_terms: D000818:Animals; D001665:Binding Sites; D002460:Cell Line; D006224:Cricetinae; D015240:Phorbol 12,13-Dibutyrate / Q000378:metabolism; D011493:Protein Kinase C / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014407:Tumor Cells, Cultured
chemical_list: D015240:Phorbol 12,13-Dibutyrate; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate