STRESS PROTEINS AND GLYCOPROTEINS (REVIEW)

Proteins represent both structural and functional elements of biologic al organisms, however, their structural and catalytic function is dire ctly linked to the acquisition and maintenance of a complex three-dime nsional conformation. A molecular machinery to accomplish protein fold ing and maintenance in vivo is provided by a variety of molecular chap erones that include both 'classical' heat shock proteins (Hsps), gluco se-regulated proteins (Grps), and a separate class of stress glycoprot eins (S-Gps). Different chaperones associate to form functional comple xes (chaperone 'machines') and work coordinately to accomplish specifi c functions during the folding of particular proteins. In this review, we will summarize recently acquired new insights into the complexitie s of chaperones, the current state of S-Gps and their interactions wit h Hsps, and of specific chaperones that appear to be designed for the folding of cellular glycoproteins. Finally, we discuss the physiologic al role of chaperones by examining their function in specific cellular processes, namely tumor/host interactions and diseases associated wit h aberrant prion protein folding.