Abstract
Mitsugumin 23 (MG23) is a transmembrane protein expressed in the nuclear membrane and endo/sarcoplasmic reticulum (ER/SR) of various tissues, including skeletal and cardiac muscle. MG23 is a non-selective cation channel that has been implicated in the leakage of calcium ions (Ca(2+)) under diverse pathophysiological conditions. SR Ca(2+) leak is considered to be a contributing factor of skeletal muscle weakness and is also implicated in the progression of heart failure. The absence of MG23 has been reported to alleviate negative outcomes associated with SR Ca(2+) leak. Targeting MG23 could represent a new therapeutic strategy against muscle disorders. This review discusses the potential role of MG23 in skeletal and cardiac muscle, and highlights MG23 as both a regulator of basal SR Ca(2+)-handling and a mediator of pathophysiological remodelling in muscle.