TK2 siRNA – Thymidine Kinase 2 Isoform 2 (Human)

This gene encodes a deoxyribonucleoside kinase that specifically phosphorylates thymidine, deoxycytidine, and deoxyuridine. The encoded enzyme localizes to the mitochondria and is required for mitochondrial DNA synthesis. Mutations in this gene are associated with a myopathic form of mitochondrial DNA depletion syndrome. Alternate splicing results in multiple transcript variants encoding distinct isoforms, some of which lack transit peptide, so are not localized to mitochondria. [provided by RefSeq, Dec 2012]

TK2: Deoxyribonucleoside kinase that phosphorylates thymidine, deoxycytidine, and deoxyuridine. Also phosphorylates anti-viral and anti-cancer nucleoside analogs. Defects in TK2 are a cause of mitochondrial DNA depletion syndrome type 2 (MTDPS2). A disorder characterized primarily by childhood onset of muscle weakness associated with depletion of mtDNA in skeletal muscle. There is wide clinical variability; some patients have onset in infancy and show a rapidly progressive course with early death due to respiratory failure, whereas others have later onset of a slowly progressive myopathy. Belongs to the DCK/DGK family. 3 isoforms of the human protein are produced by alternative splicing.

Protein type: EC 2.7.1.21; Nucleotide Metabolism - pyrimidine; Xenobiotic Metabolism - drug metabolism - other enzymes; Kinase, other; Mitochondrial

Chromosomal Location of Human Ortholog: 16q22-q23.1

Cellular Component: mitochondrial matrix; mitochondrial inner membrane

Molecular Function: deoxycytidine kinase activity; thymidine kinase activity; ATP binding

Biological Process: deoxycytidine metabolic process; pyrimidine base metabolic process; nucleobase, nucleoside and nucleotide metabolic process; nucleotide biosynthetic process; nucleobase, nucleoside, nucleotide and nucleic acid metabolic process; pyrimidine nucleoside salvage; deoxyribonucleotide metabolic process; thymidine metabolic process; mitochondrial DNA replication; phosphorylation; deoxyribonucleoside monophosphate biosynthetic process

Disease: Mitochondrial Dna Depletion Syndrome 2 (myopathic Type)