Bioenergetics Interplay Between Cardiac Mitochondria and Other Subcellular Compartments

Abstract

Several important mechanisms are involved in the mitochondrial response to varying cellular energy demands. In cardiomyocyte, a short-term adjustment can be made through cytosolic processes including metabolic signaling and signal transmission. The former one is achieved by changing cytosolic ADP and Pi concentrations (ATP hydrolysis in the cytosol increases ADP and Pi fluxes to mitochondria, and the amount of substrates available for ATP production increases). Metabolic signaling adjustments are made via phosphotransfer networks and compartmentalized energy transfer systems. The mitochondrial adenine nucleotide translocator plays a central role in the ATP transfer from mitochondria to the cytosol. Impairment of this essential transport system is implicated in several neuromuscular diseases. In addition, direct functional interplay exists in cardiomyocytes between mitochondria and other subcellular compartments that makes it possible direct energy and signal channeling between organelles.