The HSP70 family is a set of highly conserved proteins that are induced by a variety of biological stresses, including heat stress, in every organism in which the proteins have been examined. The human HSP70 family members include: HSP70, a 70 kDa protein which is strongly inducible in all organisms but which is also constitutively expressed in primate cells; HSP72, a 72 kDa protein which is induced exclusively under stress conditions; HSC70, or cognate protein, is a 72 kDa constitutively expressed protein which is involved in uncoating clathrin-coated vesicles; GRP78, or BiP, is a glucose-regulated 78 kDa protein localized to the endoplasmic reticulum; and mitochondrial HSP70 (mtHSP70, GRP75 or mortalin) a 75 kDa protein that is found within the mitochondria.
mtHSP70 is a mitochondrial resident protein that is involved in protein translocation into the mitochondria. Preproteins cross the mitochondrial membranes in an extended conformation. This requires unfolding of preproteins before entering translocation pores in the mitochondrial outer membrane. Preprotein unfolding is thought to be mediated by mtHSP70 and other inner membrane proteins of the mitochondria.
68 kDa heat shock protein; dnaK-type molecular chaperone HSP70-1; epididymis secretory protein Li 103; Heat shock 70 kDa protein 1; heat shock 70 kDa protein 1/2; Heat shock 70 kDa protein 1A; heat shock 70 kDa protein 1A/1B; Heat shock 70 kDa protein 1B; Heat shock 70 kDa protein 2; Heat shock 70 kDa protein 3; heat shock 70kD protein 1A; heat shock 70kDa protein 1A; heat shock protein, 70 kDa 3; heat shock-induced protein; Hsp68; HSP70-1; HSP70-1/HSP70-2; HSP70-1A; HSP70-2; HSP70.1/HSP70.2; HSP70.3; HSP70I; HSP72; HSPA1; inducible heat shock protein 70