Roles of cytosolic Hsp70 and Hsp40 molecular chaperones in post-translational translocation of presecretory proteins into the endoplasmic reticulum.

Hsp70 molecular chaperones and their co-chaperones work together in various cellular compartments to guide the folding of proteins and to aid the translocation of proteins across membranes. Hsp70s stimulate protein folding by binding exposed hydrophobic sequences thereby preventing irreversible aggregation. Hsp40s stimulate the ATPase activity of Hsp70s and target unfolded proteins to Hsp70s.