TY - JOUR
T1 - Biallelic mutations in MRPS34 lead to instability of the small mitoribosomal subunit and Leigh Syndrome
AU - Lake, Nicole J.
AU - Webb, Bryn D.
AU - Stroud, David A.
AU - Richman, Tara R.
AU - Ruzzenente, Benedetta
AU - Compton, Alison G.
AU - Mountford, Hayley S.
AU - Pulman, Juliette
AU - Zangarelli, Coralie
AU - Rio, Marlene
AU - Boddaert, Nathalie
AU - Assouline, Zahra
AU - Sherpa, Mingma D.
AU - Schadt, Eric E.
AU - Houten, Sander M.
AU - Byrnes, James
AU - McCormick, Elizabeth M.
AU - Zolkipli-Cunningham, Zarazuela
AU - Haude, Katrina
AU - Zhang, Zhancheng
AU - Retterer, Kyle
AU - Bai, Renkui
AU - Calvo, Sarah E.
AU - Mootha, Vamsi K.
AU - Christodoulou, John
AU - Rötig, Agnes
AU - Filipovska, Aleksandra
AU - Cristian, Ingrid
AU - Falk, Marni J.
AU - Metodiev, Metodi D.
AU - Thorburn, David R.
N1 - Funding: This project was supported by Australian National Health and Medical Research Council (NHMRC) fellowships and project grants to D.R.T., A.G.C., A.F., and D.A.S. (1022896, 1068409, 1068056, 1058442, 1078273, 1125390, 1107094, 1070916), the Australian Research Council (DP170103000 to A.F.), the Jaxson Flynt Research Fund (M.J.F. and J.B.), the Joseph and Pat Holveck Research Fund (M.J.F. and Z.Z.-C.), an Australian Postgraduate Award (N.J.L.), a NHMRC scholarship (1017174 to H.S.M.), Australian Mitochondrial Disease Foundation scholarship (N.J.L. and H.S.M.), the Victorian Government's Operational Infrastructure Support Program (D.R.T. and A.G.C.), the Icahn Institute for Genomics and Multiscale Biology, NIH National Institute of Child Health and Human Development (NICHD) (grant K08HD086827 to B.D.W.), the NIH (R01GM077465 and 1R35GM122455 to V.K.M.), the French Muscular Dystrophy Association (AFM grant #19876 to M.D.M.), and Genomit (01GML1207 to A.R.). We acknowledge the use of bioresources of the Necker Imagine DNA biobank (BB-033-00065). We thank the subjects, families, and multi-disciplinary clinical care providers for their involvement. The authors acknowledge the GeneMatcher tool, which enabled the identification of two of the families described in this study, and the Monash Biomedical Proteomics Facility, Monash University, for the provision of instrumentation, training, and technical support. We thank Associate Professor Susan Donath for her expert advice on appropriate statistical analyses. The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies.
PY - 2017/8/3
Y1 - 2017/8/3
N2 - The synthesis of all 13 mitochondrial DNA (mtDNA)-encoded protein subunits of the human oxidative phosphorylation (OXPHOS) system is carried out by mitochondrial ribosomes (mitoribosomes). Defects in the stability of mitoribosomal proteins or mitoribosome assembly impair mitochondrial protein translation, causing combined OXPHOS enzyme deficiency and clinical disease. Here we report four autosomal-recessive pathogenic mutations in the gene encoding the small mitoribosomal subunit protein, MRPS34, in six subjects from four unrelated families with Leigh syndrome and combined OXPHOS defects. Whole-exome sequencing was used to independently identify all variants. Two splice-site mutations were identified, including homozygous c.321+1G>T in a subject of Italian ancestry and homozygous c.322−10G>A in affected sibling pairs from two unrelated families of Puerto Rican descent. In addition, compound heterozygous MRPS34 mutations were identified in a proband of French ancestry; a missense (c.37G>A [p.Glu13Lys]) and a nonsense (c.94C>T [p.Gln32∗]) variant. We demonstrated that these mutations reduce MRPS34 protein levels and the synthesis of OXPHOS subunits encoded by mtDNA. Examination of the mitoribosome profile and quantitative proteomics showed that the mitochondrial translation defect was caused by destabilization of the small mitoribosomal subunit and impaired monosome assembly. Lentiviral-mediated expression of wild-type MRPS34 rescued the defect in mitochondrial translation observed in skin fibroblasts from affected subjects, confirming the pathogenicity of MRPS34 mutations. Our data establish that MRPS34 is required for normal function of the mitoribosome in humans and furthermore demonstrate the power of quantitative proteomic analysis to identify signatures of defects in specific cellular pathways in fibroblasts from subjects with inherited disease.
AB - The synthesis of all 13 mitochondrial DNA (mtDNA)-encoded protein subunits of the human oxidative phosphorylation (OXPHOS) system is carried out by mitochondrial ribosomes (mitoribosomes). Defects in the stability of mitoribosomal proteins or mitoribosome assembly impair mitochondrial protein translation, causing combined OXPHOS enzyme deficiency and clinical disease. Here we report four autosomal-recessive pathogenic mutations in the gene encoding the small mitoribosomal subunit protein, MRPS34, in six subjects from four unrelated families with Leigh syndrome and combined OXPHOS defects. Whole-exome sequencing was used to independently identify all variants. Two splice-site mutations were identified, including homozygous c.321+1G>T in a subject of Italian ancestry and homozygous c.322−10G>A in affected sibling pairs from two unrelated families of Puerto Rican descent. In addition, compound heterozygous MRPS34 mutations were identified in a proband of French ancestry; a missense (c.37G>A [p.Glu13Lys]) and a nonsense (c.94C>T [p.Gln32∗]) variant. We demonstrated that these mutations reduce MRPS34 protein levels and the synthesis of OXPHOS subunits encoded by mtDNA. Examination of the mitoribosome profile and quantitative proteomics showed that the mitochondrial translation defect was caused by destabilization of the small mitoribosomal subunit and impaired monosome assembly. Lentiviral-mediated expression of wild-type MRPS34 rescued the defect in mitochondrial translation observed in skin fibroblasts from affected subjects, confirming the pathogenicity of MRPS34 mutations. Our data establish that MRPS34 is required for normal function of the mitoribosome in humans and furthermore demonstrate the power of quantitative proteomic analysis to identify signatures of defects in specific cellular pathways in fibroblasts from subjects with inherited disease.
KW - Leigh syndrome
KW - mitochondrial diseases
KW - mitochondrial ribosome
KW - mitochondrial translation
KW - MRPS34
KW - quantitative proteomics
KW - respiratory chain
KW - ribosome profiling
KW - whole-exome sequencing
UR - https://doi.org/10.1016/j.ajhg.2018.03.015
U2 - 10.1016/j.ajhg.2017.07.005
DO - 10.1016/j.ajhg.2017.07.005
M3 - Article
C2 - 28777931
AN - SCOPUS:85026528870
SN - 0002-9297
VL - 101
SP - 239
EP - 254
JO - American Journal of Human Genetics
JF - American Journal of Human Genetics
IS - 2
ER -