Mutations in the FAD binding domain cause stress-induced misoxidation of the endoplasmic reticulum oxidoreductase Ero1b

Dias-Gunasekara, S.; van Lith, M.; Williams, J.A.G.; Kataky, R.; Benham, A.M.

Abstract

Disulfide bond catalysis is an essential component of protein biogenesis in the secretory pathway, from yeast through to man. In the endoplasmic reticulum (ER), protein-disulfide isomerase (PDI) catalyzes the oxidation and isomerization of disulfide bonds and is re-oxidized by an endoplasmic reticulum oxidoreductase (ERO). The elucidation of ERO function was greatly aided by the genetic analysis of two ero mutants, whose impairment results from point mutations in the FAD binding domain of the Ero protein. The ero1-1 and ero1-2 yeast strains have conditional and dithiothreitol-sensitive phenotypes, but the effects of the mutations on the behavior of Ero proteins has not been reported. Here, we show that these Gly to Ser and His to Tyr mutations do not prevent the dimerization of Ero1 or the non-covalent interaction of Ero1 with PDI. However, the Gly to Ser mutation abolishes disulfide-dependent PDI-Ero1 heterodimers. Both the Gly to Ser and His to Tyr mutations make Ero1 susceptible to misoxidation and aggregation, particularly during a temperature or redox stress. We conclude that the Ero FAD binding domain is critical for conformational stability, allowing Ero proteins to withstand stress conditions that cause client proteins to misfold.

Citation

Dias-Gunasekara, S., van Lith, M., Williams, J., Kataky, R., & Benham, A. (2006). Mutations in the FAD binding domain cause stress-induced misoxidation of the endoplasmic reticulum oxidoreductase Ero1b. Journal of Biological Chemistry, 281(35), 25018-25025. https://doi.org/10.1074/jbc.m602354200

• Journal Article Type: Article
• Publication Date: Sep 1, 2006
• Deposit Date: May 14, 2007
• Journal: Journal of Biological Chemistry
• Print ISSN: 0021-9258
• Electronic ISSN: 1083-351X
• Publisher: American Society for Biochemistry and Molecular Biology
• Peer Reviewed: Peer Reviewed
• Volume: 281
• Issue: 35
• Pages: 25018-25025
• DOI: https://doi.org/10.1074/jbc.m602354200
• Public URL: https://durham-repository.worktribe.com/output/1577907