Multifunctional Roles of αB-Crystallin in Skeletal and Cardiac Muscle Homeostasis and Disease

αB-Crystallin, or HspB5, is a small molecular-weight heat shock protein expressed highly in cardiac and skeletal muscle with multifaceted cellular roles including, chaperone function towards essential myofibrillar components. Insights into protective roles played by αB-crystallin, as well as mutations in the gene encoding αB-crystallin, CRYAB, which resulted in human pathologies, have highlighted the critical functions of αB-crystallin in both skeletal and cardiac muscle, inter alia. Various human mutations in CRYAB appear to have tissue-specific effects, with loss of αB-crystallin only impacting skeletal muscle under basal conditions. This review aims to highlight the roles of αB-crystallin in skeletal and cardiac muscle homeostasis as well as under conditions of stress and disease, drawing insights from human pathologies resulting from CRYAB mutations, and to discuss the potential of using induced pluripotent stem cells to model αB-crystallin-opathies in vitro.