Modulation of cytosolic protein kinase C activity by ferricyanide: priming event seems transmembrane redox signalling: A study on transformed C3H/10T1/2 cells in culture

Transformed 3T3/10T1/2 cultured cells incubated with ferricyanide caused a decrease of 2 mM EDTA extractable cytosolic protein kinase C activity in 2 min, whereas 5 or 20 min ferricyanide treatment reverted the enzyme activity to that observed without ferricyanide. The ferricyanide effect in 2 min was abolished by amiloride and sustained by ouabain. Thus, deactivation-activation of cytosolic protein kinase C is attributed to an unknown signal generation during H + accumulation coupled with the Na +/H + exchange phase. In this mechanism the priming event concerns the transmembrane redox process shedding H + into the cell interior while impermeant ferricyanide acts as a unique electron acceptor.