Physical and Functional Cross Talk Between Endo-Sarcoplasmic Reticulum and Mitochondria in Skeletal Muscle

Recent Advances: An extensive close proximity of these two organelles is a late developmental event, which suggests that it does not have an essential function. Critical Issues: The intimate association of SR/mitochondria develops during murine postnatal differentiation and the recovery of denervated atrophic muscle, which suggests that this is a highly regulated process with a specific function. Analyses of mouse models for muscle diseases suggest that impaired ER/SR-mitochondrial contacts may be due to ER stress and lead to defective bioenergetics and insulin signaling. Future Directions: Future studies are necessary to identify the molecular determinants weakening insulin signaling upon impairment of ER/mitochondrial contacts in skeletal muscles as well as to analyze the distance between SR/ER and mitochondria in muscle diseases associated with ER stress.