title: Protein kinase C activities with different characteristics, including substrate specificity, from two human HL-60 leukemia cell variants.
abstract: To evaluate the role of protein kinase C in the cellular maturation processes induced by phorbol diesters, we examined the biochemical activity of protein kinase C from HL-205, a cell variant from the human promyelocytic HL-60 leukemia that is susceptible to differentiation induced by phorbol 12-myristate 13-acetate, and from HL-525, an HL-60 variant that is resistant to such an induction. The activities of protein kinase C from the two cell types differed in their requirements for the cofactors Ca2+ and lipids. These enzyme activities also differed in their abilities to phosphorylate protamine and a series of four oligopeptides. We suggest that the differences in vitro in the activities of protein kinase C between HL-205 and HL-525 cells, especially in their substrate specificity, are closely related to the different phosphorylation patterns induced in vivo by phorbol 12-myristate 13-acetate in these cells. We also suggest that these differences may be responsible for the different susceptibilities of the two cell types to maturation induced by phorbol diesters.
authors.affiliation: Division of Biological, Environmental, and Medical Research, Argonne National Laboratory, Illinois 60439-4833.
authors.forename: Y
authors.initials: Y
authors.lastname: Homma
authors.forename: M A
authors.initials: MA
authors.lastname: Gemmell
authors.forename: E
authors.initials: E
authors.lastname: Huberman
mesh_terms: D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D002118:Calcium / Q000494:pharmacology; D006801:Humans; D007546:Isoquinolines / Q000494:pharmacology; D015470:Leukemia, Myeloid, Acute / Q000201:enzymology*; D008055:Lipids / Q000494:pharmacology; D010766:Phosphorylation; D010879:Piperazines / Q000494:pharmacology; D011493:Protein Kinase C / Q000032:analysis*; D011506:Proteins / Q000378:metabolism; D013379:Substrate Specificity; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology; D014407:Tumor Cells, Cultured
chemical_list: D007546:Isoquinolines; D008055:Lipids; D010879:Piperazines; D011506:Proteins; D019307:1-(5-Isoquinolinesulfonyl)-2-Methylpiperazine; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate; D002118:Calcium