MT-TT

Last updated
MT-TT
Identifiers
Aliases MT-TT, TRNT, RF00005
External IDs OMIM: 590090 MGI: 102473 GeneCards: MT-TT
Orthologs
SpeciesHumanMouse
Entrez
Ensembl
UniProt
RefSeq (mRNA)

n/a

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RefSeq (protein)

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Location (UCSC)n/an/a
PubMed search [1] [2]
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Mitochondrially encoded tRNA threonine also known as MT-TT is a transfer RNA which in humans is encoded by the mitochondrial MT-TT gene. [3]

Contents

Structure

The MT-TT gene is located on the p arm of the non-nuclear mitochondrial DNA at position 12 and it spans 66 base pairs. [4] The structure of a tRNA molecule is a distinctive folded structure which contains three hairpin loops and resembles a three-leafed clover. [5]

Function

MT-TT is a small 66 nucleotide RNA (human mitochondrial map position 15888-15953) that transfers the amino acid threonine to a growing polypeptide chain at the ribosome site of protein synthesis during translation.

Clinical significance

Myoclonic epilepsy with ragged-red fibers (MERRF)

Mutations in MT-TT have been associated with myoclonic epilepsy with ragged-red fibers (MERRF), and cause mitochondrial energy deficiencies and reduced proliferation leading to oxidative phosphorylation. Myoclonic epilepsy with ragged-red fibers (MERRF) is a rare mitochondrial disorder that affects many parts of the body, particularly the muscles and nervous system. In most cases, the signs and symptoms of this disorder appear during childhood or adolescence. The features of MERRF vary widely among affected individuals, even among members of the same family. Common clinical manifestations include myoclonus, myopathy, spasticity, epilepsy, peripheral neuropathy, dementia, ataxia, atrophy and more. [6] [7] In addition, mutations have also been linked to lethal infantile mitochondrial myopathy, Parkinson's disease associated with a 15950G>A mutation, [8] and a 15923A>G mutation found to result in an unconfirmed heart disease. [9] [10]

Cytochrome c oxidase deficiency

MT-TT mutations result in complex IV deficiency of the mitochondrial respiratory chain, also known as the cytochrome c oxidase deficiency. Cytochrome c oxidase deficiency is a rare genetic condition that can affect multiple parts of the body, including skeletal muscles, the heart, the brain, or the liver. Common clinical manifestations include myopathy, hypotonia, and encephalomyopathy, lactic acidosis, and hypertrophic cardiomyopathy. [11] A 15915G>A mutation was found in a patient with cytochrome c oxidase deficiency with accompany symptoms of seizures, progressive hearing loss and muscle weakness. [12]

Related Research Articles

<span class="mw-page-title-main">Mitochondrial myopathy</span> Medical condition

Mitochondrial myopathies are types of myopathies associated with mitochondrial disease. On biopsy, the muscle tissue of patients with these diseases usually demonstrate "ragged red" muscle fibers. These ragged-red fibers contain mild accumulations of glycogen and neutral lipids, and may show an increased reactivity for succinate dehydrogenase and a decreased reactivity for cytochrome c oxidase. Inheritance was believed to be maternal. It is now known that certain nuclear DNA deletions can also cause mitochondrial myopathy such as the OPA1 gene deletion. There are several subcategories of mitochondrial myopathies.

<span class="mw-page-title-main">MELAS syndrome</span> 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.

<span class="mw-page-title-main">MERRF syndrome</span> 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.

<span class="mw-page-title-main">MT-RNR1</span> SSU rRNA of the mitochondrial ribosome

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.

<span class="mw-page-title-main">Cytochrome c oxidase subunit 2</span> Enzyme of the respiratory chain encoded by the mitochondrial genome

Cytochrome c oxidase subunit 2, also known as cytochrome c oxidase polypeptide II, is a protein that in humans is encoded by the MT-CO2 gene. Cytochrome c oxidase subunit II, abbreviated COXII, COX2, COII, or MT-CO2, is the second subunit of cytochrome c oxidase. It is also one of the three mitochondrial DNA (mtDNA) encoded subunits of respiratory complex IV.

<span class="mw-page-title-main">Cytochrome c oxidase subunit III</span> Enzyme of the respiratory chain encoded by the mitochondrial genome

Cytochrome c oxidase subunit III (COX3) is an enzyme that in humans is encoded by the MT-CO3 gene. It is one of main transmembrane subunits of cytochrome c oxidase. It is also one of the three mitochondrial DNA (mtDNA) encoded subunits of respiratory complex IV. Variants of it have been associated with isolated myopathy, severe encephalomyopathy, Leber hereditary optic neuropathy, mitochondrial complex IV deficiency, and recurrent myoglobinuria.

<span class="mw-page-title-main">COX6B1</span> Protein-coding gene in the species Homo sapiens

Cytochrome c oxidase subunit 6B1 is an enzyme that in humans is encoded by the COX6B1 gene. Cytochrome c oxidase 6B1 is a subunit of the cytochrome c oxidase complex, also known as Complex IV, the last enzyme in the mitochondrial electron transport chain. Mutations of the COX6B1 gene are associated with severe infantile encephalomyopathy and mitochondrial complex IV deficiency (MT-C4D).

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

References

  1. "Human PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  2. "Mouse PubMed Reference:". National Center for Biotechnology Information, U.S. National Library of Medicine.
  3. Anderson S, Bankier AT, Barrell BG, de Bruijn MH, Coulson AR, Drouin J, Eperon IC, Nierlich DP, Roe BA, Sanger F, Schreier PH, Smith AJ, Staden R, Young IG (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.
  4. "MT-TT mitochondrially encoded tRNA threonine [Homo sapiens (human)] - Gene - NCBI". www.ncbi.nlm.nih.gov.
  5. "tRNA / transfer RNA". Learn Science at Scitable.
  6. "Myoclonic epilepsy with ragged-red fibers". Genetics Home Reference. U.S. National Library of Medicine.
  7. Graham BH, Waymire KG, Cottrell B, Trounce IA, MacGregor GR, Wallace DC (July 1997). "A mouse model for mitochondrial myopathy and cardiomyopathy resulting from a deficiency in the heart/muscle isoform of the adenine nucleotide translocator". Nature Genetics. 16 (3): 226–34. doi:10.1038/ng0797-226. PMID   9207786. S2CID   7285265.
  8. Grasbon-Frodl EM, Kösel S, Sprinzl M, von Eitzen U, Mehraein P, Graeber MB (April 1999). "Two novel point mutations of mitochondrial tRNA genes in histologically confirmed Parkinson disease". Neurogenetics. 2 (2): 121–7. doi:10.1007/s100480050063. PMID   10369889. S2CID   13031885.
  9. Yoon KL, Aprille JR, Ernst SG (May 1991). "Mitochondrial tRNA(thr) mutation in fatal infantile respiratory enzyme deficiency". Biochemical and Biophysical Research Communications. 176 (3): 1112–5. doi:10.1016/0006-291X(91)90399-R. PMID   1645537.
  10. Reference, Genetics Home. "MT-TT gene". Genetics Home Reference.
  11. Reference, Genetics Home. "Cytochrome c oxidase deficiency". Genetics Home Reference.PD-icon.svg This article incorporates text from this source, which is in the public domain .
  12. Nishino I, Seki A, Maegaki Y, Takeshita K, Horai S, Nonaka I, Goto Y (August 1996). "A novel mutation in the mitochondrial tRNA(Thr) gene associated with a mitochondrial encephalomyopathy". Biochemical and Biophysical Research Communications. 225 (1): 180–5. doi:10.1006/bbrc.1996.1150. PMID   8769114.

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