TK2
TK2 (thymidine kinase 2, also listed under the alias SCA31) is a mitochondrial deoxyribonucleoside kinase that phosphorylates thymidine, deoxycytidine and deoxyuridine in the mitochondrial matrix. It is required for mitochondrial DNA synthesis. Browse Assay Genie's current range of TK2 research reagents below, or read on for the biology behind the target.
TK2 is a deoxyribonucleoside kinase that specifically phosphorylates thymidine, deoxycytidine and deoxyuridine within the mitochondrial matrix. These phosphorylation steps supply nucleotides for mitochondrial DNA (mtDNA) synthesis. In non-replicating cells, where cytosolic dNTP synthesis is down-regulated, mtDNA synthesis depends solely on TK2 and DGUOK, which makes the enzyme central to mitochondrial genome maintenance in those cells.
The TK2 gene encodes a protein of the DCK/DGK family, classed by HGNC in the deoxyribonucleoside kinase gene group and assigned EC 2.7.1.21. The mature enzyme localises to the mitochondrion. Alternate splicing gives multiple transcript variants encoding distinct isoforms, and some of these lack the transit peptide, so they are not localised to mitochondria. Researchers working with the TK2 protein or TK2 gene should therefore consider which isoform is relevant to their question. The mouse ortholog is Tk2.
Mutations in TK2 are associated with a myopathic form of mitochondrial DNA depletion syndrome, which ties the enzyme directly to mitochondrial disease research. The enzyme is also widely used as a target of antiviral and chemotherapeutic agents, because it phosphorylates nucleoside analogues as well as its natural substrates. The gene appears in HGNC under the previous name thymidine kinase 2, mitochondrial, and under the alias SCA31.
TK2 is required for mtDNA synthesis and, with DGUOK, sustains it in non-replicating cells where cytosolic dNTP synthesis is down-regulated.
Mutations in TK2 are associated with a myopathic form of mitochondrial DNA depletion syndrome.
TK2 is widely used as a target of antiviral and chemotherapeutic agents, making it relevant to drug action studies.
TK2 phosphorylates thymidine, deoxycytidine and deoxyuridine in the mitochondrial matrix, placing it within deoxyribonucleoside salvage.
TK2 phosphorylates thymidine, deoxycytidine and deoxyuridine in the mitochondrial matrix. This supports mitochondrial DNA synthesis. In non-replicating cells, where cytosolic dNTP synthesis is down-regulated, mtDNA synthesis depends solely on TK2 and DGUOK.
TK2 is the HGNC symbol for thymidine kinase 2, with the UniProt name thymidine kinase 2, mitochondrial, and the alias SCA31. Alternate splicing produces multiple transcript variants and distinct isoforms, and some lack the transit peptide, so are not localised to mitochondria.
Mutations in TK2 are associated with a myopathic form of mitochondrial DNA depletion syndrome. The mouse ortholog is Tk2. Check the datasheet of any product for its validated reactivity before use in a given species.
Thymidine kinase relatives and other targets with similar names that have products at Assay Genie.
Gene and protein annotations from HGNC, NCBI Gene and UniProt O00142; product specifications from Assay Genie datasheets.