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A hypertension-associated mitochondrial DNA mutation introduces an m1G37 modification into tRNAMet, altering its structure and function
- Source :
- Journal of Biological Chemistry. 293:1425-1438
- Publication Year :
- 2018
- Publisher :
- Elsevier BV, 2018.
-
Abstract
- Defective nucleotide modifications of mitochondrial tRNAs have been associated with several human diseases, but their pathophysiology remains poorly understood. In this report, we investigated the pathogenic molecular mechanism underlying a hypertension-associated 4435A→G mutation in mitochondrial tRNAMet. The m.4435A→G mutation affected a highly conserved adenosine at position 37, 3′ adjacent to the tRNA's anticodon, which is important for the fidelity of codon recognition and stabilization. We hypothesized that the m.4435A→G mutation introduced an m1G37 modification of tRNAMet, altering its structure and function. Primer extension and methylation activity assays indeed confirmed that the m.4435A→G mutation created a tRNA methyltransferase 5 (TRMT5)–catalyzed m1G37 modification of tRNAMet. We found that this mutation altered the tRNAMet structure, indicated by an increased melting temperature and electrophoretic mobility of the mutated tRNA compared with the wildtype molecule. We demonstrated that cybrid cell lines carrying the m.4435A→G mutation exhibited significantly decreased efficiency in aminoacylation and steady-state levels of tRNAMet, as compared with those of control cybrids. The aberrant tRNAMet metabolism resulted in variable decreases in mitochondrial DNA (mtDNA)-encoded polypeptides in the mutant cybrids. Furthermore, we found that the m.4435A→G mutation caused respiratory deficiency, markedly diminished mitochondrial ATP levels and membrane potential, and increased the production of reactive oxygen species in mutant cybrids. These results demonstrated that an aberrant m1G37 modification of mitochondrial tRNAMet affected the structure and function of its tRNA and consequently altered mitochondrial function. Our findings provide critical insights into the pathophysiology of maternally inherited hypertension, which is manifested by the deficient tRNA nucleotide modification.
- Subjects :
- 0301 basic medicine
Mitochondrial DNA
RNA, Transfer, Met
RNA, Mitochondrial
Mutant
medicine.disease_cause
DNA, Mitochondrial
Biochemistry
Structure-Activity Relationship
03 medical and health sciences
0302 clinical medicine
medicine
Humans
Point Mutation
Molecular Biology
Cell Line, Transformed
Mutation
Chemistry
Wild type
TRNA Methyltransferase
Molecular Bases of Disease
Translation (biology)
Cell Biology
Methylation
Cell biology
030104 developmental biology
Hypertension
Transfer RNA
Nucleic Acid Conformation
RNA
030217 neurology & neurosurgery
Subjects
Details
- ISSN :
- 00219258
- Volume :
- 293
- Database :
- OpenAIRE
- Journal :
- Journal of Biological Chemistry
- Accession number :
- edsair.doi.dedup.....0f3bd47922c4bf6e399e93ace88631d4