Manipulating disulfide bond formation and protein folding in the endoplasmic reticulum.
Addition of the reducing agent dithiothreitol (DTT) to the medium of living cells prevented disulfide bond formation in newly synthesized influenza hemagglutinin (HA0) and induced the reduction of already oxidized HA0 inside the ER. The reduced HA0 did not trimerize or leave the ER. When DTT was washed out, HA0 was rapidly oxidized, correctly folded, trimerized and transported to the Golgi complex. We concluded that protein folding and the redox conditions in the ER can be readily manipulated by addition of DTT without affecting most other cellular functions, that the reduced influenza HA0 remains largely unfolded, and that folding events that normally take place on the nascent HA0 chains can be delayed and induced post-translationally without loss in efficiency.
Braakman
I
I
Department of Cell Biology, Yale University School of Medicine, New Haven, CT 06510-8002.
Helenius
J
J
Helenius
A
A
D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D004220:Disulfides / Q000378:metabolism*; D004229:Dithiothreitol / Q000494:pharmacology; D004721:Endoplasmic Reticulum / Q000378:metabolism*; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral / Q000096:biosynthesis / Q000378:metabolism*; D010084:Oxidation-Reduction; D011233:Precipitin Tests; D011487:Protein Conformation; D011499:Protein Processing, Post-Translational; D014759:Viral Envelope Proteins / Q000096:biosynthesis / Q000378:metabolism
D004220:Disulfides; D019267:Hemagglutinin Glycoproteins, Influenza Virus; D006389:Hemagglutinins, Viral; D014759:Viral Envelope Proteins; D000255:Adenosine Triphosphate; D004229:Dithiothreitol