title: C1orf163/RESA1 is a novel mitochondrial intermembrane space protein connected to respiratory chain assembly.
abstract: Oxidative phosphorylation (OXPHOS) in mitochondria takes place at the inner membrane, which folds into numerous cristae. The stability of cristae depends, among other things, on the mitochondrial intermembrane space bridging complex. Its components include inner mitochondrial membrane protein mitofilin and outer membrane protein Sam50. We identified a conserved, uncharacterized protein, C1orf163 [SEL1 repeat containing 1 protein (SELRC1)], as one of the proteins significantly reduced after the knockdown of Sam50 and mitofilin. We show that C1orf163 is a mitochondrial soluble intermembrane space protein. Sam50 depletion affects moderately the import and assembly of C1orf163 into two protein complexes of approximately 60kDa and 150kDa. We observe that the knockdown of C1orf163 leads to reduction of levels of proteins belonging to the OXPHOS complexes. The activity of complexes I and IV is reduced in C1orf163-depleted cells, and we observe the strongest defects in the assembly of complex IV. Therefore, we propose C1orf163 to be a novel factor important for the assembly of respiratory chain complexes in human mitochondria and suggest to name it RESA1 (for RESpiratory chain Assembly 1).
authors: Department of Microbiology, Biocenter, University of Würzburg, 97074 Würzburg, Germany. Electronic address: Vera.Kozjak@uni-wuerzburg.de.
authors: Vera
authors: V
authors: Kozjak-Pavlovic
authors: Department of Microbiology, Biocenter, University of Würzburg, 97074 Würzburg, Germany.
authors: Florian
authors: F
authors: Prell
authors: The Biotechnology Center of Oslo, University of Oslo, Gaustadallen 21, 0349 Oslo, Norway.
authors: Bernd
authors: B
authors: Thiede
authors: Department of Microbiology, Biocenter, University of Würzburg, 97074 Würzburg, Germany.
authors: Monika
authors: M
authors: Götz
authors: Department of Microbiology, Biocenter, University of Würzburg, 97074 Würzburg, Germany.
authors: Dominik
authors: D
authors: Wosiek
authors: Department of Microbiology, Biocenter, University of Würzburg, 97074 Würzburg, Germany.
authors: Christine
authors: C
authors: Ott
authors: Department of Microbiology, Biocenter, University of Würzburg, 97074 Würzburg, Germany.
authors: Thomas
authors: T
authors: Rudel
mesh_terms: D000595:Amino Acid Sequence; D003576:Electron Transport Complex IV / Q000378:metabolism; D055785:Gene Knockdown Techniques; D006367:HeLa Cells; D006801:Humans; D008565:Membrane Proteins / Q000235:genetics / Q000378:metabolism; D051336:Mitochondrial Membranes / Q000378:metabolism*; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins / Q000235:genetics / Q000378:metabolism*; D008969:Molecular Sequence Data; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism; D010085:Oxidative Phosphorylation; D021381:Protein Transport; D012995:Solubility
chemical_list: C000588697:COA7 protein, human; C088548:IMMT protein, human; D008565:Membrane Proteins; D000090622:Mitochondrial Precursor Protein Import Complex Proteins; D024101:Mitochondrial Proteins; D009124:Muscle Proteins; C522815:SAMM50 protein, human; D003576:Electron Transport Complex IV
keywords: CPOX; IMM; IMS; MIB; MINOS; OMM; OXPHOS; SEL1 repeat containing 1 protein; SEL1-like repeat; SELRC1; SILAC; SLR; Sam50; TOM; coproporphyrinogen oxidase; cristae; inner mitochondrial membrane; intermembrane space; mitochondria; mitochondrial inner membrane organizing system; mitochondrial intermembrane space bridging; outer mitochondrial membrane; oxidative phosphorylation; shRNA; short hairpin RNA; stable isotope labeling with amino acids in cell culture; translocase of the outer membrane