Differential recruitment of PKC isoforms in HeLa cells during redox stress.

The protein kinase C (PKC) family is a major transducer of several intracellular pathways. In confirmation of this important role, PKCs exhibit high molecular heterogeneity, because they occur in at least 10 different isoforms differing in biochemical properties and sensitivity to activators. In this report we focused on the ability of different redox agents to induce modification of intracellular distribution of specific PKC isoforms in HeLa cells. To this end we utilized a panel of green fluorescent protein (GFP) chimeras and a high-speed digital imaging system. We observed a remarkable complexity of PKC signalling patterns occurring during redox stress with marked differences among PKC isoforms also belonging to the same subgroup. Moreover our results suggest that modifications of the intracellular redox state can modulate the responsiveness of specific PKC isoforms and, in turn, change the sensitivity of the different isoforms to cell stimulation.