Heavy chain binding protein recognizes incompletely disulfide-bonded forms of vesicular stomatitis virus G protein.
To investigate the function of heavy chain binding protein (BiP, GRP 78) in the endoplasmic reticulum, we have characterized its interaction with a model plasma membrane glycoprotein, the G protein of vesicular stomatitis virus. We used a panel of well characterized mutant G proteins and immunoprecipitation with anti-BiP antibodies to determine if BiP interacted with newly synthesized G protein and/or mutant G proteins retained in the endoplasmic reticulum. We made three major observations: 1) BiP bound transiently to folding intermediates of wild-type G protein which were incompletely disulfide-bonded; 2) BiP did not bind stably to all mutant G proteins which remain in the endoplasmic reticulum; and 3) BiP bound stably only to mutant G proteins which do not form correct intrachain disulfide bonds.
Machamer
C E
CE
Department of Cell Biology, Yale University School of Medicine, New Haven, Connecticut 06510.
Doms
R W
RW
Bole
D G
DG
Helenius
A
A
Rose
J K
JK
D000818:Animals; D002460:Cell Line; D002872:Chromosome Deletion; D004220:Disulfides / Q000378:metabolism*; D004721:Endoplasmic Reticulum / Q000378:metabolism; D006031:Glycosylation; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D009154:Mutation; D011485:Protein Binding; D014162:Transfection; D014721:Vesicular stomatitis Indiana virus / Q000235:genetics / Q000378:metabolism*; D014759:Viral Envelope Proteins / Q000235:genetics / Q000378:metabolism*
D004220:Disulfides; C028391:G protein, vesicular stomatitis virus; D046911:Macromolecular Substances; D008562:Membrane Glycoproteins; D014759:Viral Envelope Proteins