Two phases of disulfide bond formation have differing requirements for oxygen

Marianne Koritzinsky*, Fiana Levitin, Twan van den Beucken, Ryan A. Rumantir, Nicholas J. Harding, Kenneth C. Chu, Paul C. Boutros, Ineke Braakman, Bradly G. Wouters

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


Most proteins destined for the extracellular space require disulfide bonds for folding and stability. Disulfide bonds are introduced co- and post-translationally in endoplasmic reticulum (ER) cargo in a redox relay that requires a terminal electron acceptor. Oxygen can serve as the electron acceptor in vitro, but its role in vivo remains unknown. Hypoxia causes ER stress, suggesting a role for oxygen in protein folding. Here we demonstrate the existence of two phases of disulfide bond formation in living mammalian cells, with differential requirements for oxygen. Disulfide. bonds introduced rapidly during protein synthesis can occur without oxygen, whereas those introduced during post-translational folding or isomerization are oxygen dependent. Other protein maturation processes in the secretory pathway, including ER-localized N-linked glycosylation, glycan trimming, Golgi-localized complex glycosylation, and protein transport, occur independently of oxygen availability. These results suggest that an alternative electron acceptor is available transiently during an initial phase of disulfide bond formation and that post-translational oxygen-dependent disulfide bond formation causes hypoxia-induced ER stress.
Original languageEnglish
Pages (from-to)615-627
JournalJournal of Cell Biology
Issue number4
Publication statusPublished - 25 Nov 2013

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