Alpha-crystallin B chain (CRYAB) (CRYAB)

Alpha-crystallin B chain (CRYAB), also known as HSPB5, is a member of the small heat shock protein (sHSP) family that functions primarily as a molecular chaperone (UniProt P02511). It is highly expressed in the ocular lens, where it maintains transparency, as well as in cardiac and skeletal muscle and the central nervous system (NCBI Gene 1410). CRYAB prevents the irreversible aggregation of misfolded proteins under stress conditions, such as heat or oxidative stress, and plays a critical role in maintaining the integrity of the cytoskeleton (UniProt P02511). In disease contexts, mutations in CRYAB are linked to cataracts and desmin-related myopathy, while its overexpression is often observed in neurodegenerative disorders like Alzheimer's and various cancers, where it may promote cell survival (PubMed 17567853, PubMed 24508216). Therapeutic strategies targeting CRYAB include small molecule chaperones like lanosterol to restore its function in protein-aggregation diseases or inhibitors to sensitize cancer cells to treatment (PubMed 26200341).

Other names

HSPB5Alpha-B crystallinRosenthal fiber proteinRenal carcinoma antigen NY-REN-27Heat shock protein beta-5

Acts as a molecular chaperone by binding to unfolded or misfolded proteins to prevent their aggregation and maintain cellular proteostasis. It also inhibits apoptosis by interacting with pro-apoptotic factors like caspase-3 and BAX, and stabilizes the cytoskeleton by binding to intermediate filaments.