MT-TY explained

mitochondrially encoded tRNA tyrosine
Hgncid:	7502
Symbol:	MT-TY
Altsymbols:	MTTY
Entrezgene:	4579
Refseq:	NC_001807
Chromosome:	MT

Mitochondrially encoded tRNA tyrosine, also known as MT-TY, is a transfer RNA which in humans is encoded by the mitochondrial MT-TY gene.^[1]

Structure

The MT-TY gene is located on the p arm of the non-nuclear mitochondrial DNA at position 12 and it spans 66 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-TY is a small 66 nucleotide RNA (human mitochondrial map position 5826-5891) that transfers the amino acid tyrosine to a growing polypeptide chain at the ribosome site of protein synthesis during translation.

Clinical significance

Mutations in MT-TY have been associated with mitochondrial complex III deficiency, a genetic condition that can affect several parts of the body, including the brain, kidneys, liver, heart, and the skeletal muscles. Common clinical manifestations include muscle weakness (myopathy) and extreme tiredness (fatigue), particularly during exercise (exercise intolerance). Additional symptoms may also arise depending on the severity of the condition.^[4] A patient with a mutation of the gene exhibited complex III deficiency, characterized by high levels of cytochrome c oxidase–deficient fibers with symptoms of weakness and fatigue.^[5] A 5874A-G mutation was also found in a patient with the condition.^[6]

Changes in MT-TY may also result in progressive external ophthalmoplegia. Progressive external ophthalmoplegia is characterized by weakness of the eye muscles. Common symptoms of the disorder include hearing loss, loss of sensation in the limbs, ataxia, and neuropathy.^[7] A 5885T deletion^[8] and 5877G-A substitution^[9] have been associated with the disease.

Notes and References

1. 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 . Sequence and organization of the human mitochondrial genome . Nature . 290 . 5806 . 457–65 . April 1981 . 7219534 . 10.1038/290457a0 . 1981Natur.290..457A . 4355527 .
2. Web site: MT-TY mitochondrially encoded tRNA tyrosine [Homo sapiens (human)] - Gene - NCBI ]. www.ncbi.nlm.nih.gov . en.
3. Web site: tRNA / transfer RNA . Learn Science at Scitable .
4. Reference . Genetics Home . Mitochondrial complex III deficiency . Genetics Home Reference . en.
5. Meulemans A, De Paepe B, De Bleecker J, Smet J, Lissens W, Van Coster R, De Meirleir L, Seneca S . Two novel mitochondrial DNA mutations in muscle tissue of a patient with limb-girdle myopathy . Archives of Neurology . 64 . 9 . 1339–43 . September 2007 . 17846276 . 10.1001/archneur.64.9.1339 .
6. Pulkes T, Siddiqui A, Morgan-Hughes JA, Hanna MG . A novel mutation in the mitochondrial tRNA(TYr) gene associated with exercise intolerance . Neurology . 55 . 8 . 1210–2 . October 2000 . 11071502 . 10.1212/wnl.55.8.1210. 28303519 .
7. Web site: Reference . Genetics Home . Progressive external ophthalmoplegia . Genetics Home Reference . en.
8. Raffelsberger T, Rossmanith W, Thaller-Antlanger H, Bittner RE . CPEO associated with a single nucleotide deletion in the mitochondrial tRNA(Tyr) gene . Neurology . 57 . 12 . 2298–301 . December 2001 . 11756614 . 10.1212/wnl.57.12.2298. 35762588 .
9. Sahashi K, Yoneda M, Ohno K, Tanaka M, Ibi T, Sahashi K . Functional characterisation of mitochondrial tRNA(Tyr) mutation (5877-->GA) associated with familial chronic progressive external ophthalmoplegia . Journal of Medical Genetics . 38 . 10 . 703–5 . October 2001 . 11594340 . 10.1136/jmg.38.10.703. 1734734 .