C11orf83, a Mitochondrial Cardiolipin-Binding Protein Involved in bc<sub>1</sub> Complex Assembly and Supercomplex Stabilization

Article Article scientifique Article C11orf83, a Mitochondrial Cardiolipin-Binding Protein Involved in bc<sub>1</sub> Complex Assembly and Supercomplex Stabilization eng 2015 author Desmurs-Rousseau Marjorie 740175 author Foti Michelangelo 0000-0001-7199-4135 28033 author Raemy Etienne 632231 author Vaz Frédéric Maxime author Martinou Jean-Claude 27293 author Bairoch Amos Marc 0000-0003-2826-6444 21964 author Lane Lydie 0000-0002-9818-3030 639317 1139-1156 10.1128/MCB.01047-14 25605331 0270-7306 http://mcb.asm.org/content/35/7/1139.full Mammalian mitochondria may contain up to 1,500 different proteins, and many of them have neither been confidently identified nor characterized. In this study, we demonstrated that C11orf83, which was lacking experimental characterization, is a mitochondrial inner membrane protein facing the intermembrane space. This protein is specifically associated with the bc1 complex of the electron transport chain and involved in the early stages of its assembly by stabilizing the bc1 core complex. C11orf83 displays some overlapping functions with Cbp4p, a yeast bc1 complex assembly factor. Therefore, we suggest that C11orf83, now called UQCC3, is the functional human equivalent of Cbp4p. In addition, C11orf83 depletion in HeLa cells caused abnormal crista morphology, higher sensitivity to apoptosis, a decreased ATP level due to impaired respiration and subtle, but significant, changes in cardiolipin composition. We showed that C11orf83 binds to cardiolipin by its α-helices 2 and 3 and is involved in the stabilization of bc1 complex-containing supercomplexes, especially the III2/IV supercomplex. We also demonstrated that the OMA1 metalloprotease cleaves C11orf83 in response to mitochondrial depolarization, suggesting a role in the selection of cells with damaged mitochondria for their subsequent elimination by apoptosis, as previously described for OPA1. Dewey 570 Dewey 576 Dewey 612 46 Département de biologie cellulaire 165 134 Département de physiologie cellulaire et métabolisme 21C 136 Département de biologie structurale et bioinformatique 21E false 405b9ec3-ed88-49e8-9c17-4f861cf66d82 Swiss Institute of Bioinformatics (SIB) 57 Calipho 80 472 Obésité et syndrome métabolique 803 Molecular and cellular biology 35 7 21f1b6ec-374b-474c-b03c-3dc1ae790010 Article (Published version) Public pub_193_25605331.pdf 3794288 application/pdf openAccess Faculté des sciences / Section de biologie / Département de biologie cellulaire Faculté de médecine / Section de médecine fondamentale / Département de physiologie cellulaire et métabolisme Faculté de médecine / Section de médecine fondamentale / Département de biologie structurale et bioinformatique

Title	Published in	Year	Views	Downloads

C11orf83, a mitochondrial cardiolipin-binding protein involved in bc1 complex assembly and supercomplex stabilization		2015	765	480
C11orf83, a Mitochondrial Cardiolipin-Binding Protein Involved in bc₁ Complex Assembly and Supercomplex Stabilization	Molecular and cellular biology	2015	737	266

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Desmurs-Rousseau, Marjorie