Protein kinase activity associated with a phorbol ester receptor purified from mouse brain

Protein kinase activity copurified with the receptor for 12-O-[3H]tetradecanoylphorbol-13-acetate during its purification from mouse brain particulate protein. All attempts to resolve the protein kinase activity from the receptor were unsuccessful. The isolated receptor required phospholipid and divalent calcium for maximal protein kinase activity. The protein kinase was not activated by cyclic nucleotides or calmodulin. There are striking similarities between the receptor-associated protein kinase activity and the calcium- and phospholipid-dependent protein kinase, which has been suspected of mediating the effects of biological stimuli associated with increased phosphatidylinositol turnover.