Stress-induced cardioadaptation reveals a code linking hormone receptors and spatial redistribution of PKC isoforms

Extracellular agents, including growth factors, cytokines and hormones, transmit their information into cells utilizing a balanced mosaic of intracellular phosphatases and kinases. How do these agonists select the correct substrates and modify them in order to produce defined physiological responses? Our studies have centered on the mechanisms of stress-induced cardioprotection (preconditioning) against postischemic dysfunction. In several species, the ischemia-reperfusion resistant phenotype appears to be induced by metabotropic-receptor pathways linked to PKC. Our results on the isolated rat heart show that each protective stimulus involves a characteristic mosaic of PKC isoforms, translocating into distinct cellular compartments. The distinct receptor-stimulated PKC isoform profile engaged by each extracellular metabotropic agent could allow the heart several overlapping modes of phenotypic adaptation to ischemia.