title: Two stress proteins of the endoplasmic reticulum bind denatured collagen.
abstract: A differentiation-related gelatin-binding 46 kilodalton (kDa) glycoprotein in myoblasts (GP46, colligin) shares several properties with the 78-kDa glucose-regulated protein (GRP78), including location in the endoplasmic reticulum and related C-terminal sequences. These similarities extend to stress inducibility, since we find that GP46 is a heat-shock protein; its synthesis is elevated at 42 degrees C, resulting in a two- to three-fold increase in protein level. Further, GRP78 is a gelatin-binding protein; together with GP46 it is retained on gelatin-Sepharose beads. GRP78 and GP46 do not interact; each protein can be individually eluted, GP46 at low pH and GRP78 by ATP. These results suggest that the proteins have distinct roles in the synthesis of collagen and point to a simple method for purification.
authors.affiliation: Department of Biochemistry, University of Western Ontario, London, Canada.
authors.forename: D
authors.initials: D
authors.lastname: Nandan
authors.forename: E H
authors.initials: EH
authors.lastname: Ball
authors.forename: B D
authors.initials: BD
authors.lastname: Sanwal
mesh_terms: D000818:Animals; D002352:Carrier Proteins / Q000378:metabolism; D003094:Collagen / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D000091342:Endoplasmic Reticulum Chaperone BiP; D005780:Gelatin / Q000378:metabolism; D005786:Gene Expression Regulation; D006023:Glycoproteins; D006360:Heat-Shock Proteins / Q000378:metabolism*; D006358:Hot Temperature; D018832:Molecular Chaperones; D008970:Molecular Weight; D009132:Muscles / Q000166:cytology / Q000378:metabolism; D011485:Protein Binding; D011489:Protein Denaturation; D051381:Rats
chemical_list: D002352:Carrier Proteins; D000091342:Endoplasmic Reticulum Chaperone BiP; D006023:Glycoproteins; D006360:Heat-Shock Proteins; D018832:Molecular Chaperones; C046289:colligin; D005780:Gelatin; D003094:Collagen