title: A Deafness- and Diabetes-associated tRNA Mutation Causes Deficient Pseudouridinylation at Position 55 in tRNAGlu and Mitochondrial Dysfunction.
abstract: Several mitochondrial tRNA mutations have been associated with maternally inherited diabetes and deafness. However, the pathophysiology of these tRNA mutations remains poorly understood. In this report, we identified the novel homoplasmic 14692A→G mutation in the mitochondrial tRNAGlugene among three Han Chinese families with maternally inherited diabetes and deafness. The m.14692A→G mutation affected a highly conserved uridine at position 55 of the TΨC loop of tRNAGluThe uridine is modified to pseudouridine (Ψ55), which plays an important role in the structure and function of this tRNA. Using lymphoblastoid cell lines derived from a Chinese family, we demonstrated that the m.14692A→G mutation caused loss of Ψ55 modification and increased angiogenin-mediated endonucleolytic cleavage in mutant tRNAGluThe destabilization of base-pairing (18A-Ψ55) caused by the m.14692A→G mutation perturbed the conformation and stability of tRNAGluAn approximately 65% decrease in the steady-state level of tRNAGluwas observed in mutant cells compared with control cells. A failure in tRNAGlumetabolism impaired mitochondrial translation, especially for polypeptides with a high proportion of glutamic acid codons such as ND1, ND6, and CO2 in mutant cells. An impairment of mitochondrial translation caused defective respiratory capacity, especially reducing the activities of complexes I and IV. Furthermore, marked decreases in the levels of mitochondrial ATP and membrane potential were observed in mutant cells. These mitochondrial dysfunctions caused an increasing production of reactive oxygen species in the mutant cells. Our findings may provide new insights into the pathophysiology of maternally inherited diabetes and deafness, which is primarily manifested by the deficient nucleotide modification of mitochondrial tRNAGlu.
authors: From the Division of Clinical Genetics and Genomics, Children's Hospital and the Institute of Genetics, Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 310001.
authors: Meng
authors: M
authors: Wang
authors: the Institute of Genetics, Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 310001.
authors: Hao
authors: H
authors: Liu
authors: From the Division of Clinical Genetics and Genomics, Children's Hospital and the Institute of Genetics, Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 310001.
authors: Jing
authors: J
authors: Zheng
authors: the Department of Otolaryngology, Second Affiliated Hospital, Wenzhou Medical University, Wenzhou, Zhejiang, China 325035, the Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China 325035.
authors: Bobei
authors: B
authors: Chen
authors: From the Division of Clinical Genetics and Genomics, Children's Hospital and the Institute of Genetics, Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 310001.
authors: Mi
authors: M
authors: Zhou
authors: the Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China 325035.
authors: Wenlu
authors: W
authors: Fan
authors: the Attardi Institute of Mitochondrial Biomedicine, School of Life Sciences, Wenzhou Medical University, Wenzhou, Zhejiang, China 325035.
authors: Hen
authors: H
authors: Wang
authors: From the Division of Clinical Genetics and Genomics, Children's Hospital and the Institute of Genetics, Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 310001.
authors: Xiaoyang
authors: X
authors: Liang
authors: the Institute of Biochemistry and Cell Biology, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, Shanghai, China 200031, and.
authors: Xiaolong
authors: X
authors: Zhou
authors: the Architecture et Réactivité de l'ARN, Université de Strasbourg, CNRS, Institut de Biologie Moléculaire et Cellulaire, 15 rue René Descartes, 67084 Strasbourg, France.
authors: Gilbert
authors: G
authors: Eriani
authors: From the Division of Clinical Genetics and Genomics, Children's Hospital and the Institute of Genetics, Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 310001.
authors: Pingping
authors: P
authors: Jiang
authors: From the Division of Clinical Genetics and Genomics, Children's Hospital and the Institute of Genetics, Department of Genetics, Zhejiang University School of Medicine, Hangzhou, Zhejiang, China 310001, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, and Joining Institute of Genetics and Genomic Medicine between Zhejiang University and University of Toronto, Zhejiang University, Hangzhou, Zhejiang, China 310058, gminxin88@zju.edu.cn.
authors: Min-Xin
authors: MX
authors: Guan
mesh_terms: D044466:Asian People; D020029:Base Pairing; D002460:Cell Line; D002681:China; D003638:Deafness / Q000235:genetics / Q000378:metabolism; D003920:Diabetes Mellitus / Q000235:genetics / Q000378:metabolism; D005260:Female; D006801:Humans; D008297:Male; D024101:Mitochondrial Proteins / Q000096:biosynthesis / Q000235:genetics; D017354:Point Mutation; D014176:Protein Biosynthesis / Q000235:genetics; D011560:Pseudouridine / Q000235:genetics / Q000378:metabolism; D012313:RNA / Q000235:genetics / Q000378:metabolism; D000077278:RNA, Mitochondrial; D012352:RNA, Transfer, Glu / Q000235:genetics / Q000378:metabolism
chemical_list: D024101:Mitochondrial Proteins; D000077278:RNA, Mitochondrial; D012352:RNA, Transfer, Glu; D011560:Pseudouridine; D012313:RNA
keywords: diabetes; hearing; mitochondrial disease; mtDNA; mutant; pathogenesis; posttranslational modification (PTM); tRNA