A Structural View of αB-crystallin Assembly and Amyloid Aggregation

The major len protein alpha B-crystallin (alpha B) is an intracellular chaperone. It belongs to the family of small heat shock proteins (sHsps) which plays a critical role in maintaining protein homeostasis and preventing protein aggregation, especially under stress conditions. Dysfunction of alpha B is closely related to cataract, and many neurodegenerative diseases including Alzheimer's, Parkinson's, and Creutzfeldt-Jakob disease. Due to the extremely heterogeneous and polydispersed nature of alpha B, it remains unclear how alpha B self-assemblies and prevents its client proteins from aggregation. In this minireview, we summarize the structural studies of alpha B in self-assembly, chaperoning client proteins and amyloid aggregation. We also mention the recent progress in identification of small molecules preventing alpha B aggregation for potential cataract treatment. This review highlights the polymorphic structures of alpha B under different conditions and its wide-spectrum chaperone activities, and sheds light on understanding the complex relationship among alpha B, client proteins and the related diseases.