Molecular Chaperones

All organisms have a protein quality-control system that includes an array of proteins, referred to as molecular chaperones. The major functions of molecular chaperones include facilitating the folding of unfolded and misfolded polypeptides, preventing the formation of irreversible protein aggregates, reactivating inactive proteins, disassembling proteins from aggregates, and partnering with proteases to degrade proteins. Molecular chaperones assist in maintaining activity and solubility of proteins in the cell during normal growth and under stress conditions. Presented here is an overview of five major chaperone families involved in protein remodeling reactions. These families include chaperonin/Hsp60, Hsp70/DnaK, Hsp90, Clp/Hsp100, and sHsp.