A single form of protein kinase C is expressed in bovine adrenocortical tissue, as compared to four chromatographically resolved isozymes in rat brain.
Protein kinase C purified to apparent homogeneity from rat brain was resolved into four active moieties following chromatography over a hydroxyapatite high resolution system. By contrast, the same procedure applied to bovine adrenocortical protein kinase C revealed that a single protein kinase C isoform could be detected in this tissue, with a chromatographic behavior identical to that of one of the brain isoenzymes. Although the isolated protein kinase C isozymes were all activated to various degrees in the presence of phospholipids and calcium, quantitative differences were observed in their catalytic properties, especially with regard to their sensitivity to diacylglycerol and TPA and to their relative affinity for different protein substrates. These observations confirmed at the protein level the heterogeneity of protein kinase C predicted on the basis of cDNA cloning studies. They also suggest that the expression of a specific set of protein kinase C isoenzyme(s) in a given cell type deserves further attention, since it may reflect a functional significance with regard to the regulation of specific cellular processes.
D000302:Adrenal Cortex / Q000201:enzymology*; D000818:Animals; D001921:Brain / Q000201:enzymology*; D002118:Calcium / Q000378:metabolism; D002384:Catalysis; D002851:Chromatography, High Pressure Liquid; D004075:Diglycerides / Q000494:pharmacology; D004789:Enzyme Activation; D007527:Isoenzymes / Q000378:metabolism; D010703:Phorbol Esters / Q000494:pharmacology; D010743:Phospholipids / Q000378:metabolism; D011493:Protein Kinase C / Q000032:analysis / Q000378:metabolism*; D051381:Rats; D013379:Substrate Specificity; D014018:Tissue Distribution
D004075:Diglycerides; D007527:Isoenzymes; D010703:Phorbol Esters; D010743:Phospholipids; D011493:Protein Kinase C; D002118:Calcium