AK2

Adenylate kinase 2
PDB rendering based on 1ak2.
Available structures PDB Ortholog search: PDBe, RCSB List of PDB id codes 2C9Y​
Identifiers
Symbols	AK2 ; ADK2; AK 2
External IDs	OMIM: 103020 MGI: 87978 HomoloGene: 1227 ChEMBL: 4938 GeneCards: AK2 Gene
EC number	2.7.4.3
Gene ontology Molecular function • adenylate kinase activity • ATP binding Cellular component • mitochondrial inner membrane • mitochondrial intermembrane space • extracellular exosome • sperm mitochondrial sheath Biological process • ADP biosynthetic process • nucleobase-containing small molecule interconversion • small molecule metabolic process • AMP metabolic process • ATP metabolic process • nucleotide phosphorylation • nucleobase-containing small molecule metabolic process Sources: Amigo / QuickGO
RNA expression pattern
More reference expression data
Orthologs
Species	Human	Mouse
Entrez	204	11637
Ensembl	ENSG00000004455	ENSMUSG00000028792
UniProt	P54819	Q9WTP6
RefSeq (mRNA)	NM_001199199	NM_001033966
RefSeq (protein)	NP_001186128	NP_001029138
Location (UCSC)	Chr 1: 33.01 – 33.08 Mb	Chr 4: 128.99 – 129.01 Mb
PubMed search

Adenylate kinase 2 is an enzyme is encoded in humans by the AK2 gene.^[1][2][3] The AK2 protein is found in the intermembrane space of the mitochondrion.^[4][5]

Function

Adenylate kinases are involved in regulating the adenine nucleotide composition within a cell by catalyzing the reversible transfer of phosphate groups among adenine nucleotides. Three isozymes of adenylate kinase, namely 1, 2, and 3, have been identified in vertebrates; this gene encodes isozyme 2. Expression of these isozymes is tissue-specific and developmentally regulated. Isozyme 2 is localized in the mitochondrial intermembrane space and may play a role in apoptosis. Two transcript variants encoding distinct isoforms have been identified for this gene.^[3]

AK2 deficiency

Adenylate Kinase 2 (AK2) deficiency in humans causes hematopoietic defects associated with sensorineural deafness.^{[6] [7]} Recticular dysgenesis is an autosomal recessive form of human combined immunodeficiency. It is also characterized by an impaired lymphoid maturation and early differentiation arrest in the myeloid lineage. AK2 deficiency results in absent or a large decrease in the expression of proteins. AK2 is specifically expressed in the stria vascularis of the inner ear which indicates why individuals with an AK2 deficiency will have sensorineural deafness.^[7]

References

1. Lee Y, Kim JW, Lee IA, Kang HB, Choe YK, Lee HG, Lim JS, Kim HJ, Park C, Choe IS (Feb 1997). "Cloning and characterization of cDNA for human adenylate kinase 2A". Biochem Mol Biol Int 39 (4): 833–42. PMID 8843353.
2. Carritt B, King J, Welch HM (Mar 1983). "Gene order and localization of enzyme loci on the short arm of chromosome 1". Ann Hum Genet 46 (Pt 4): 329–35. doi:10.1111/j.1469-1809.1982.tb01583.x. PMID 6961883.
3. "Entrez Gene: AK2 adenylate kinase 2".
4. Bruns GA, Regina VM (1977). "Adenylate kinase 2, a mitochondrial enzyme". Biochem. Genet. 15 (5–6): 477–86. doi:10.1007/BF00520192. PMID 195572.
5. Köhler C, Gahm A, Noma T; et al. (1999). "Release of adenylate kinase 2 from the mitochondrial intermembrane space during apoptosis". FEBS Lett. 447 (1): 10–2. doi:10.1016/S0014-5793(99)00251-3. PMID 10218571.
6. Pannicke U, Hönig M, Hess I; et al. (January 2009). "Reticular dysgenesis (aleukocytosis) is caused by mutations in the gene encoding mitochondrial adenylate kinase 2". Nat. Genet. 41 (1): 101–105. doi:10.1038/ng.265. PMID 19043417.
7. Lagresle-Peyrou C, Six EM, Picard C; et al. (January 2009). "Human adenylate kinase 2 deficiency causes a profound haematopoietic defect associated with sensorineural deafness". Nat. Genet. 41 (1): 106–11. doi:10.1038/ng.278. PMC 2612090. PMID 19043416.

Further reading

• Lee Y, Kim JW, Lee SM; et al. (1998). "Cloning and expression of human adenylate kinase 2 isozymes: differential expression of adenylate kinase 1 and 2 in human muscle tissues". J. Biochem. 123 (1): 47–54. doi:10.1093/oxfordjournals.jbchem.a021915. PMID 9504408.
• Noma T, Song S, Yoon YS; et al. (1998). "cDNA cloning and tissue-specific expression of the gene encoding human adenylate kinase isozyme 2". Biochim. Biophys. Acta 1395 (1): 34–9. doi:10.1016/s0167-4781(97)00193-0. PMID 9434148.
• Hamada M, Sumida M, Okuda H; et al. (1982). "Adenosine triphosphate-adenosine-5'-monophosphate phosphotransferase from normal human liver mitochondria. Isolation, chemical properties, and immunochemical comparison with Duchenne dystrophic serum aberrant adenylate kinase". J. Biol. Chem. 257 (21): 13120–8. PMID 6182143.