ND3 Cys39 in complex I is exposed during mitochondrial respiration

Burger, N. et al. (2022) ND3 Cys39 in complex I is exposed during mitochondrial respiration. Cell Chemical Biology, 29(4), 636-649.e14. (doi: 10.1016/j.chembiol.2021.10.010) (PMID:34739852)

Abstract

Mammalian complex I can adopt catalytically active (A-) or deactive (D-) states. A defining feature of the reversible transition between these two defined states is thought to be exposure of the ND3 subunit Cys39 residue in the D-state and its occlusion in the A-state. As the catalytic A/D transition is important in health and disease, we set out to quantify it by measuring Cys39 exposure using isotopic labeling and mass spectrometry, in parallel with complex I NADH/CoQ oxidoreductase activity. To our surprise, we found significant Cys39 exposure during NADH/CoQ oxidoreductase activity. Furthermore, this activity was unaffected if Cys39 alkylation occurred during complex I-linked respiration. In contrast, alkylation of catalytically inactive complex I irreversibly blocked the reactivation of NADH/CoQ oxidoreductase activity by NADH. Thus, Cys39 of ND3 is exposed in complex I during mitochondrial respiration, with significant implications for our understanding of the A/D transition and the mechanism of complex I.

• Item Type: Articles
• Additional Information: This research was funded by the Medical Research Council (MC_U105663142 [M.P.M.], MC_UU_00015/7 [M.P.M], and MR/P000320/1 [T.K.]) and by the Wellcome Trust (WT110158/Z/15/Z, 110159/Z/15/Z, RG88195, 202905/Z/16/Z, and 206171/Z/17/Z). A.M. is supported by the Swedish Research Council (2018-00623). A.A.I.N is supported by the University of Glasgow.
• Status: Published
• Refereed: Yes
• Glasgow Author(s) Enlighten ID: Hartley, Professor Richard and Norman, Miss Abigail
• Authors: Burger, N., James, A. M., Mulvey, J. F., Hoogewijs, K., Ding, S., Fearnley, I. M., Loureiro-López, M., Norman, A. A.I., Arndt, S., Mottahedin, A., Sauchanka, O., Hartley, R. C., Krieg, T., and Murphy, M. P.
• College/School: College of Medical Veterinary and Life Sciences > School of Medicine, Dentistry & Nursing
• Journal Name: Cell Chemical Biology
• Publisher: Elsevier (Cell Press)
• ISSN: 2451-9456
• ISSN (Online): 2451-9448
• Published Online: 04 November 2021
• Copyright Holders: Copyright © 2021 The Authors
• First Published: First published in Cell Chemical Biology 29(4): 636-649.e14
• Publisher Policy: Reproduced under a Creative Commons License
• Data DOI: 10.5525/gla.researchdata.1143

Project Code	Award No	Project Name	Principal Investigator	Funder's Name	Funder Ref	Lead Dept
172617		Exploring mitochondrial metabolism in health and disease using targeted biological chemistry	Richard Hartley	Wellcome Trust (WELLCOTR)	110158/Z/15/Z	Chemistry