Mitochondrial inner membrane protein essential for mitochondrial homeostasis, structural integrity, and cellular metabolism. Regulates mitochondrial translation by modulating protein synthesis of mitochondrial DNA-encoded genes. Plays a critical role in skeletal muscle mass and strength by regulating mitochondrial density, function, and protein synthesis. In brown adipose tissue, regulates mitochondrial cristae remodeling in response to cold stress by interacting with mitochondrial protease YME1L1 and enhancing its proteolytic activity, promoting OMA1 degradation and regulating OPA1 processing. Required for cardiac mitochondrial homeostasis and normal cardiomyocyte contractile function. In skeletal muscle, positively regulates myoblast differentiation by enhancing expression of myogenic factors. . This is the function of MIMS1 (mitochondrial inner membrane scaffold 1, Ensembl gene identifier ENSG00000177150).