Thompson 2018 EMBO Mol Med
|Thompson K, Mai N, Oláhová M, Scialó F, Formosa LE, Stroud DA, Garrett M, Lax NZ, Robertson FM, Jou C, Nascimento A, Ortez C, Jimenez-Mallebrera C, Hardy SA, He L, Brown GK, Marttinen P, McFarland R, Sanz A, Battersby BJ, Bonnen PE, Ryan MT, Chrzanowska-Lightowlers ZM, Lightowlers RN, Taylor RW (2018) OXA1L mutations cause mitochondrial encephalopathy and a combined oxidative phosphorylation defect. EMBO Mol Med 10:e9060.|
Thompson K, Mai N, Olahova M, Scialo F, Formosa LE, Stroud DA, Garrett M, Lax NZ, Robertson FM, Jou C, Nascimento A, Ortez C, Jimenez-Mallebrera C, Hardy SA, He L, Brown GK, Marttinen P, McFarland R, Sanz A, Battersby BJ, Bonnen PE, Ryan MT, Chrzanowska-Lightowlers ZM, Lightowlers RN, Taylor RW (2018) EMBO Mol Med
Abstract: OXA1, the mitochondrial member of the YidC/Alb3/Oxa1 membrane protein insertase family, is required for the assembly of oxidative phosphorylation complexes IV and V in yeast. However, depletion of human OXA1 (OXA1L) was previously reported to impair assembly of complexes I and V only. We report a patient presenting with severe encephalopathy, hypotonia and developmental delay who died at 5 years showing complex IV deficiency in skeletal muscle. Whole exome sequencing identified biallelic OXA1L variants (c.500_507dup, p.(Ser170Glnfs*18) and c.620G>T, p.(Cys207Phe)) that segregated with disease. Patient muscle and fibroblasts showed decreased OXA1L and subunits of complexes IV and V. Crucially, expression of wild-type human OXA1L in patient fibroblasts rescued the complex IV and V defects. Targeted depletion of OXA1L in human cells or Drosophila melanogaster caused defects in the assembly of complexes I, IV and V, consistent with patient data. Immunoprecipitation of OXA1L revealed the enrichment of mtDNA-encoded subunits of complexes I, IV and V. Our data verify the pathogenicity of these OXA1L variants and demonstrate that OXA1L is required for the assembly of multiple respiratory chain complexes.
Labels: MiParea: Respiration, nDNA;cell genetics
Preparation: Homogenate Enzyme: Complex I, Complex II;succinate dehydrogenase, Complex III, Complex IV;cytochrome c oxidase, Complex V;ATP synthase
Coupling state: LEAK, OXPHOS Pathway: N, Gp, CIV, Other combinations, ROX HRR: Oxygraph-2k