Thymidine kinase 2, mitochondrial

"TK2" redirects here. For the video game, see Tekken 2.

Thymidine kinase 2, mitochondrial is a protein that in humans is encoded by the TK2 gene.^[5]

TK2
Identifiers
Aliases	TK2, MTDPS2, MTTK, SCA31, thymidine kinase 2, mitochondrial, PEOB3, thymidine kinase 2, TK2-EXT
External IDs	OMIM: 188250; MGI: 1913266; HomoloGene: 3392; GeneCards: TK2; OMA:TK2 - orthologs
Gene location (Human) Chr. Chromosome 16 (human)[1] Band 16q21 Start 66,508,003 bp[1] End 66,552,544 bp[1]
Gene location (Mouse) Chr. Chromosome 8 (mouse)[2] Band 8|8 D3 Start 104,953,317 bp[2] End 104,975,190 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in Achilles tendon sural nerve monocyte epithelium of colon left testis right testis adipose tissue right adrenal gland subcutaneous adipose tissue stromal cell of endometrium Top expressed in granulocyte superior surface of tongue gallbladder stroma of bone marrow adrenal gland transitional epithelium of urinary bladder spleen neural layer of retina superior frontal gyrus spermatocyte More reference expression data BioGPS n/a
Gene ontology Molecular function transferase activity nucleotide binding deoxycytidine kinase activity ATP binding kinase activity nucleoside kinase activity thymidine kinase deoxynucleoside kinase activity thymidine kinase activity Cellular component mitochondrial matrix mitochondrion cytoplasm Biological process pyrimidine nucleoside salvage thymidine metabolic process deoxyribonucleoside monophosphate biosynthetic process nucleotide biosynthetic process DNA biosynthetic process nucleobase-containing compound metabolic process deoxycytidine metabolic process phosphorylation Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 7084 57813 Ensembl ENSG00000166548 ENSMUSG00000035824 UniProt O00142 Q9R088 RefSeq (mRNA) NM_001172643 NM_001172644 NM_001172645 NM_001271934 NM_001271935 NM_001272050 NM_004614 NM_021028 RefSeq (protein) NP_001166114 NP_001166115 NP_001166116 NP_001258863 NP_001258864 NP_001258979 NP_004605 n/a Location (UCSC) Chr 16: 66.51 – 66.55 Mb Chr 8: 104.95 – 104.98 Mb PubMed search [3] [4]
Wikidata
View/Edit Human View/Edit Mouse

Function

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.

This kinase is not present in yeast.^[6]