THE 170 KDA GLUCOSE-REGULATED STRESS PROTEIN IS A LARGE HSP70-LIKE, HSP110-LIKE PROTEIN OF THE ENDOPLASMIC-RETICULUM

The existence of a family of unusually large and highly diverged hsp70 -like proteins (the hsp110/SSE family) has recently been described, Th e 170 kDa glucose regulated stress protein (grp170) is a retained endo plasmic reticulum glycoprotein that may be involved in immunoglobulin folding and/or assembly, We describe here the cloning of the cDNA for grp170 and show that it, like hsp110, is a large and highly diverged h sp70-like polypeptide which shares specific features with hsp70 (the d naK family) and the hsp110/SSE family, while also differing from both, Grp170 contains an ATP binding domain and binds ATP, it possesses a c arboxyl terminal NDEL sequence, and its mRNA is anoxia inducible.