Nature's molecular sponges: Small heat shock proteins grow into their chaperone roles

摘要

Although their better-known cousins, the Hsp70, Hsp90, and Cpn60 molecular chaperone families, have been the subjects of ever more detailed mechanistic scrutiny (1, 2), the small heat shock proteins (sHSPs) have remained mysterious and relatively understudied, even though they are ubiquitous and intimately linked to protein homeostasis and survival under stress conditions (3). There are several reasons for this. First, sHSPs form large and dynamic oligomers with a technically daunting proclivity to heterogeneity in their stoichiometry of oligomerization and client binding. Second, this family of molecular chaperones does not use ATP to kick off their substrates for a new start in folding and assembly.