Translocation and downregulation of protein kinase C isoenzymes-alpha and -epsilon by phorbol ester and bryostatin-1 in human keratinocytes and fibroblasts.
Protein kinase C isoenzymes can be subdivided into two classes, based on their requirement for calcium. Protein kinase C-alpha, beta I, -beta II, and -gamma are calcium dependent, whereas protein kinase C-gamma, -epsilon, -zeta, -eta, and -theta are calcium independent. We have examined the expression, translocation, downregulation, and activation of calcium-dependent and -independent protein kinase C isoenzymes in human skin keratinocytes and fibroblasts. Human keratinocytes and fibroblasts expressed protein kinase C-alpha, -delta, -epsilon, and -zeta mRNA and protein, whereas protein kinase C-eta (L) was detected only in keratinocytes. Protein kinase C-beta I, -beta II, -gamma, and -theta were not detected in either cell type. The protein kinase C activators 12-0-tetradecanoylphorbol 13-acetate and bryostatin-1 (50 nM, for 5 min) induced translocation of protein kinase C-alpha and -epsilon cytosol to membrane in both keratinocytes and fibroblasts. 12-0-tetradecanoylphorbol 13-acetate and bryostatin-1, for 18 h, induced complete downregulation (i.e., loss) of protein kinase C-alpha and -epsilon in keratinocytes, but only partial downregulation was observed in fibroblasts. The subcellular distribution of protein kinase C-delta, -zeta or protein kinase C-eta, in keratinocytes or fibroblasts, did not change in response to 12-0-tetradecanoylphorbol 13-acetate or bryostatin-1. These data indicate differential expression, subcellular distribution, and regulation of protein kinase C isoenzymes in human skin cells.
Reynolds
N J
NJ
Department of Dermatology, University of Michigan, Ann Arbor 48109.
Baldassare
J J
JJ
Henderson
P A
PA
Shuler
J L
JL
Ballas
L M
LM
Burns
D J
DJ
Moomaw
C R
CR
Fisher
G J
GJ
D001483:Base Sequence; D001692:Biological Transport; D054713:Bryostatins; D002478:Cells, Cultured; D004789:Enzyme Activation; D005347:Fibroblasts / Q000378:metabolism*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D015603:Keratinocytes / Q000378:metabolism*; D007783:Lactones / Q000494:pharmacology*; D018942:Macrolides; D015335:Molecular Probes / Q000235:genetics; D008969:Molecular Sequence Data; D016133:Polymerase Chain Reaction; D011493:Protein Kinase C / Q000378:metabolism*; D013755:Tetradecanoylphorbol Acetate / Q000494:pharmacology*; D014158:Transcription, Genetic
D054713:Bryostatins; D007527:Isoenzymes; D007783:Lactones; D018942:Macrolides; D015335:Molecular Probes; C046785:bryostatin 1; D011493:Protein Kinase C; D013755:Tetradecanoylphorbol Acetate