Sarcoplasmic Reticulum-Mitochondrial Symbiosis: Bidirectional Signaling in Skeletal Muscle

In mammalian skeletal muscle, an intimate association between the sarcoplasmic reticulum (SR) and mitochondria results in a symbiotic and privileged bidirectional communication between these organelles. Orthograde signaling reflects SR calcium (Ca2+) release stimulating mitochondrial adenosine triphosphate production via excitation-metabolism coupling. Retrograde signaling involves mitochondrial inhibition of local SR Ca2+ release by controlling the redox environment of the Ca2+ release unit