Structure and Function of Small Heat Shock Proteins

Small heat shock proteins (sHSPs) have been found in almost all known organisms. The key structure of sHSPs consists of a conserved α-crystallin domain, approximately 90 amino acid residues, which binds to various N-terminal extensions that modulates the oligomerization, subunit dynamics and substrate binding. sHSPs associate with cellular proteins, nuclei, cytoskeletons and lipid membranes to maintain the stability of a cell. A common characteristic of sHSPs family members is the phosphorylation at specific serine residues. The phosphorylation of sHSPs leads to drastic consequences within stressed cells, including regulates the oligomerization of sHSPs through a cascade involved MAPKAP kinase 2/3 and p38,which. is closely related to the biological functions of sHSPs. In this review, we focus on the structural characteristics of sHSPs and their substrates in cells. The sHSPs phosphorylation modifiede by different protein kinases and their effect on sHSPs oligomerization for chaperone activities would also be discussed.