[Protein kinase C and its role in normal and transformed cells]

Data are reviewed on protein kinase C (PK-C) and its function in phosphorylation and regulation of different cellular proteins--enzymes, receptors, contractile and cytoskeletal proteins, as well as expression of cellular oncogenes. Besides, interactions between PK-C and cAMP-dependent PK are discussed. The evidence provided suggests that PK-C-phosphorylation may be one of the mechanisms of transformation of extracellular transmembrane signals (hormones, neuromediators, growth factors) into responsive biochemical cell reactions.