Ablation of Mto1 in zebrafish exhibited hypertrophic cardiomyopathy manifested by mitochondrion RNA maturation deficiency. Issue 8 (9th April 2021)

• Record Type: Journal Article
• Authors: Zhang, Qinghai; He, Xiao; Yao, Shihao; Lin, Tianxiang; Zhang, Luwen; Chen, Danni; Chen, Chao; Yang, Qingxian; Li, Feng; Zhu, Yi-Min; Guan, Min-Xin
• Is Part Of: Nucleic acids research. Volume 49:Issue 8(2021)
• Page Start: 4689
• Page End: 4704
• Publication Date: 2021-04-09
• Subjects: Nucleic acids -- Periodicals; Molecular biology -- Periodicals; 572.805
• DOI: 10.1093/nar/gkab228
• Languages: English
• ISSNs: 0305-1048

Abstract

Abstract: Deficient maturations of mitochondrial transcripts are linked to clinical abnormalities but their pathophysiology remains elusive. Previous investigations showed that pathogenic variants in MTO1 for the biosynthesis of τm 5 U of tRNA Glu, tRNA Gln, tRNA Lys, tRNA Trp and tRNA Leu(UUR) were associated with hypertrophic cardiomyopathy (HCM). Using mto1 knock-out(KO) zebrafish generated by CRISPR/Cas9 system, we demonstrated the pleiotropic effects of Mto1 deficiency on mitochondrial RNA maturations. The perturbed structure and stability of tRNAs caused by mto1 deletion were evidenced by conformation changes and sensitivity to S1-mediated digestion of tRNA Gln, tRNA Lys, tRNA Trp and tRNA Leu(UUR) . Notably, mto1 KO zebrafish exhibited the global decreases in the aminoacylation of mitochondrial tRNAs with the taurine modification. Strikingly, ablated mto1 mediated the expression of MTPAP and caused the altered polyadenylation of cox1, cox3, and nd1 mRNAs. Immunoprecipitation assay indicated the interaction of MTO1 with MTPAP related to mRNA polyadenylation. These alterations impaired mitochondrial translation and reduced activities of oxidative phosphorylation complexes. These mitochondria dysfunctions caused heart development defects and hypertrophy of cardiomyocytes and myocardial fiber disarray in ventricles. These cardiac defects in the mto1 KO zebrafish recapitulated the clinical phenotypes in HCM patients carrying the MTO1 mutation(s). Our findings highlighted the critical role of MTO1 in mitochondrial transcript maturation and their pathological consequences in hypertrophic cardiomyopathy.