Molecular strategies for the dominant inhibition of protein kinase C.
The regulatory (R) domain of PKC alpha fused to glutathione-S-transferase (GST-R alpha) competitively inhibited PKC activity associated with extracts of Y1 mouse adrenocortical tumor cells and the activities of several specific PKC isozymes. GST-R alpha did not inhibit the activities of cAMP-dependent protein kinase, cGMP-dependent protein kinase or calmodulin-dependent myosin light chain kinase. GST-R alpha inhibited PKC activities 20 times more potently than did a synthetic peptide corresponding to the pseudosubstrate sequence of PKC alpha. In intact yeast cells, the R domain prevented PKC beta-1-induced inhibition of growth and cytokinesis. These results indicate that the R domain of PKC alpha acts as a specific, dominant inhibitor of PKC activity, and suggest that the PKC alpha R domain may provide a useful genetic tool to assess the roles of PKC in various signal transduction processes.
Parissenti
A M
AM
Department of Research, Northeastern Ontario Regional Cancer Centre, Sudbury, Ontario, Canada.
Kirwan
A F
AF
Kim
S A
SA
Colantonio
C M
CM
Schimmer
B P
BP
D000306:Adrenal Cortex Neoplasms; D000818:Animals; D001667:Binding, Competitive; D004791:Enzyme Inhibitors / Q000494:pharmacology; D018014:Gene Transfer Techniques; D005982:Glutathione Transferase / Q000235:genetics; D006801:Humans; D051379:Mice; D011493:Protein Kinase C / Q000037:antagonists & inhibitors* / Q000737:chemistry / Q000235:genetics; D011993:Recombinant Fusion Proteins / Q000494:pharmacology; D012045:Regulatory Sequences, Nucleic Acid; D012441:Saccharomyces cerevisiae / Q000235:genetics; D014407:Tumor Cells, Cultured
D004791:Enzyme Inhibitors; D011993:Recombinant Fusion Proteins; D005982:Glutathione Transferase; D011493:Protein Kinase C