MT-TV (mitochondrial)

Last updated
mitochondrially encoded tRNA valine
Identifiers
SymbolMT-TV
Alt. symbolsMTTV
NCBI gene 4577
HGNC 7500
OMIM 590105
RefSeq NC_001807
Other data
Locus Chr. MT

Mitochondrially encoded tRNA valine also known as MT-TV is a transfer RNA which in humans is encoded by the mitochondrial MT-TV gene. [1]

Contents

Structure

The MT-TV gene is located on the p arm of the non-nuclear mitochondrial DNA at position 12 and it spans 69 base pairs. [2] The structure of a tRNA molecule is a distinctive folded structure which contains three hairpin loops and resembles a three-leafed clover. [3]

Function

MT-TV is a small 69 nucleotide RNA (human mitochondrial map position 1602-1670) that transfers the amino acid valine to a growing polypeptide chain at the ribosome site of protein synthesis during translation.

In animals, more specifically vertebrates, MT-tRNAVal performs an integral structural role for the mitoribosome by filling in the position of a missing 5S mitoribosomal RNA. [4]

Clinical significance

Mutations in MT-TV which impair oxidate phosphorylation result in mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS). MELAS is a rare mitochondrial disorder known to affect many parts of the body, especially the nervous system and the brain. Symptoms of MELAS include recurrent severe headaches, muscle weakness (myopathy), hearing loss, stroke-like episodes with a loss of consciousness, seizures, and other problems affecting the nervous system. Two specific mutations of 1642G>A and 1644G>A have been found to result in the disease. [5]

Changes in the gene have also been associated with Leigh's syndrome, a progressive brain disorder characterized by vomiting, seizures, delayed development, muscle weakness, problems with movement, heart disease, kidney problems, and difficulty breathing. Symptoms typically appear in infancy or early childhood. A 1624C>T mutation has been linked to this disease. [6]

Other clinical manifestations associated with MT-TV mutations have included recurrent migraine headaches, muscle weakness and poor coordination, hearing loss, learning disabilities, dementia, and more. It has not been found why such mutations cause symptoms of these diseases. [5] A 1606A>G mutation resulted in ataxia accompanied by progressive seizures, mental deterioration, and hearing loss. [7] Cardiomyopathy, which weakens and enlarges the heart muscle, has also been reported in a small number of affected individuals. [5]

Related Research Articles

MELAS syndrome Medical condition

Mitochondrial encephalopathy, lactic acidosis, and stroke-like episodes (MELAS) is one of the family of mitochondrial diseases, which also include MERRF syndrome, and Leber's hereditary optic neuropathy. It was first characterized under this name in 1984. A feature of these diseases is that they are caused by defects in the mitochondrial genome which is inherited purely from the female parent.

MERRF syndrome Medical condition

MERRF syndrome is a mitochondrial disease. It is extremely rare, and has varying degrees of expressivity owing to heteroplasmy. MERRF syndrome affects different parts of the body, particularly the muscles and nervous system. The signs and symptoms of this disorder appear at an early age, generally childhood or adolescence. The causes of MERRF syndrome are difficult to determine, but because it is a mitochondrial disorder, it can be caused by the mutation of nuclear DNA or mitochondrial DNA. The classification of this disease varies from patient to patient, since many individuals do not fall into one specific disease category. The primary features displayed on a person with MERRF include myoclonus, seizures, cerebellar ataxia, myopathy, and ragged red fibers (RRF) on muscle biopsy, leading to the disease's name. Secondary features include dementia, optic atrophy, bilateral deafness, peripheral neuropathy, spasticity, or multiple lipomata. Mitochondrial disorders, including MERRFS, may present at any age.

Chronic progressive external ophthalmoplegia (CPEO), is a type of eye disorder characterized by slowly progressive inability to move the eyes and eyebrows. It is often the only feature of mitochondrial disease, in which case the term CPEO may be given as the diagnosis. In other people suffering from mitochondrial disease, CPEO occurs as part of a syndrome involving more than one part of the body, such as Kearns–Sayre syndrome. Occasionally CPEO may be caused by conditions other than mitochondrial diseases.

MT-RNR1

Mitochondrially encoded 12S ribosomal RNA, also known as Mitochondrial-derived peptide MOTS-c or Mitochondrial open reading frame of the 12S rRNA-c is the SSU rRNA of the mitochondrial ribosome. In humans, 12S is encoded by the MT-RNR1 gene and is 959 nucleotides long. MT-RNR1 is one of the 37 genes contained in animal mitochondria genomes. Their 2 rRNA, 22 tRNA and 13 mRNA genes are very useful in phylogenetic studies, in particular the 12S and 16S rRNAs. The 12S rRNA is the mitochondrial homologue of the prokaryotic 16S and eukaryotic nuclear 18S ribosomal RNAs. Mutations in the MT-RNR1 gene may be associated with hearing loss.

Mitochondrially encoded tRNA leucine 1 (UUA/G) also known as MT-TL1 is a transfer RNA which in humans is encoded by the mitochondrial MT-TL1 gene.

Mitochondrially encoded tRNA histidine, also known as MT-TH, is a transfer RNA which, in humans, is encoded by the mitochondrial MT-TH gene.

Mitochondrially encoded tRNA aspartic acid also known as MT-TD is a transfer RNA which in humans is encoded by the mitochondrial MT-TD gene.

Mitochondrially encoded tRNA glutamic acid also known as MT-TE is a transfer RNA which in humans is encoded by the mitochondrial MT-TE gene. MT-TE is a small 69 nucleotide RNA that transfers the amino acid glutamic acid to a growing polypeptide chain at the ribosome site of protein synthesis during translation.

Mitochondrially encoded tRNA phenylalanine also known as MT-TF is a transfer RNA which in humans is encoded by the mitochondrial MT-TF gene.

Mitochondrially encoded tRNA glycine also known as MT-TG is a transfer RNA which in humans is encoded by the mitochondrial MT-TG gene.

Mitochondrially encoded tRNA isoleucine also known as MT-TI is a transfer RNA which in humans is encoded by the mitochondrial MT-TI gene.

Mitochondrially encoded tRNA lysine also known as MT-TK is a transfer RNA which in humans is encoded by the mitochondrial MT-TK gene.

Mitochondrially encoded tRNA leucine 2 (CUN) also known as MT-TL2 is a transfer RNA which in humans is encoded by the mitochondrial MT-TL2 gene.

Mitochondrially encoded tRNA asparagine also known as MT-TN is a transfer RNA which in humans is encoded by the mitochondrial MT-TN gene.

Mitochondrially encoded tRNA proline also known as MT-TP is a transfer RNA that in humans is encoded by the mitochondrial MT-TP gene.

Mitochondrially encoded tRNA arginine also known as MT-TR is a transfer RNA which in humans is encoded by the mitochondrial MT-TR gene.

Mitochondrially encoded tRNA threonine also known as MT-TT is a transfer RNA which in humans is encoded by the mitochondrial MT-TT gene.

Mitochondrially encoded tRNA tryptophan also known as MT-TW is a transfer RNA which in humans is encoded by the mitochondrial MT-TW gene.

Mitochondrially encoded tRNA tyrosine also known as MT-TY is a transfer RNA which in humans is encoded by the mitochondrial MT-TY gene.

Mitochondrial DNA depletion syndrome Medical condition

Mitochondrial DNA depletion syndrome, or Alper's disease, is any of a group of autosomal recessive disorders that cause a significant drop in mitochondrial DNA in affected tissues. Symptoms can be any combination of myopathic, hepatopathic, or encephalomyopathic. These syndromes affect tissue in the muscle, liver, or both the muscle and brain, respectively. The condition is typically fatal in infancy and early childhood, though some have survived to their teenage years with the myopathic variant and some have survived into adulthood with the SUCLA2 encephalomyopathic variant. There is currently no curative treatment for any form of MDDS, though some preliminary treatments have shown a reduction in symptoms.

References

  1. ↑ Anderson S, Bankier AT, Barrell BG, de Bruijn MH, Coulson AR, Drouin J, et al. (April 1981). "Sequence and organization of the human mitochondrial genome". Nature. 290 (5806): 457–65. Bibcode:1981Natur.290..457A. doi:10.1038/290457a0. PMID   7219534. S2CID   4355527.
  2. ↑ "MT-TV mitochondrially encoded tRNA valine [Homo sapiens (human)] - Gene - NCBI". www.ncbi.nlm.nih.gov.
  3. ↑ "tRNA / transfer RNA". Learn Science at Scitable.
  4. ↑ Brown A, Amunts A, Bai XC, Sugimoto Y, Edwards PC, Murshudov G, et al. (November 2014). "Structure of the large ribosomal subunit from human mitochondria". Science. 346 (6210): 718–722. Bibcode:2014Sci...346..718B. doi:10.1126/science.1258026. PMC   4246062 . PMID   25278503.
  5. 1 2 3 "MT-TH gene". Genetics Home Reference.PD-icon.svgThis article incorporates text from this source, which is in the public domain .
  6. ↑ McFarland R, Clark KM, Morris AA, Taylor RW, Macphail S, Lightowlers RN, Turnbull DM (February 2002). "Multiple neonatal deaths due to a homoplasmic mitochondrial DNA mutation". Nature Genetics. 30 (2): 145–6. doi:10.1038/ng819. PMID   11799391. S2CID   10940372.
  7. ↑ Tiranti V, D'Agruma L, Pareyson D, Mora M, Carrara F, Zelante L, et al. (January 1998). "A novel mutation in the mitochondrial tRNA(Val) gene associated with a complex neurological presentation". Annals of Neurology. 43 (1): 98–101. doi:10.1002/ana.410430116. PMID   9450773. S2CID   25775432.

This article incorporates text from the United States National Library of Medicine, which is in the public domain.

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