Phosphorylation of NADPH-cytochrome c reductase in guinea pig peritoneal macrophages stimulated with phorbol myristate acetate.

The plasma membrane-bound NADPH-cytochrome c reductase of guinea pig macrophages (M phi) was found to be phosphorylated when [32P]phosphate-labeled cells were stimulated with 12-phorbol 13-myristate acetate (PMA). The time course of phosphorylation was parallel to that of O2- -generating activity elicited. These results suggest that the reductase participates as a flavoprotein in activation of the respiratory burst NADPH oxidase, when phosphorylated.