HEAT-SHOCK-PROTEIN-70 KDA - MOLECULAR-BIOLOGY, BIOCHEMISTRY, AND PHYSIOLOGY

Heat shock proteins (HSPs) are detected in all cells, prokaryotic and eukaryotic, In vivo and in vitro studies have shown that various stres sors transiently increase production of HSPs as protection against har mful insults. Increased levels of HSPs occur after environmental stres ses, infection, normal physiological processes, and gene transfer. Alt hough the mechanisms by which HSPs protect cells are not clearly under stood, their expression can be modulated by cell signal transducers, s uch as changes in intracellular pH, cyclic AMP, Ca2+, Na+, inositol tr isphosphate, protein kinase C, and protein phosphatases, Most of the H SPs interact with other proteins in cells and alter their function. Th ese and other protein-protein interactions may mediate the little unde rstood effects of HSPs on various cell functions. In this review, we f ocus on the structure of the HSP-70 family (HSP-70s), regulation of HS P-70 gene expression, their cytoprotective effects, and the possibilit y of regulating HSP-70 expression through modulation of signal transdu ction pathways. The clinical importance and therapeutic potential of H SPs are discussed. (C) 1998 Elsevier Science Inc.