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Adenosine turnover C

Unless otherwise stated all data on this page refer to the human proteins. Gene information is provided for human (Hs), mouse (Mm) and rat (Rn).


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A multifunctional, ubiquitous molecule, adenosine acts at cell-surface G protein-coupled receptors, as well as numerous enzymes, including protein kinases and adenylyl cyclase. Extracellular adenosine is thought to be produced either by export or by metabolism, predominantly through ecto-5’-nucleotidase activity (also producing inorganic phosphate). It is inactivated either by extracellular metabolism via adenosine deaminase (also producing ammonia) or, following uptake by nucleoside transporters, via adenosine deaminase or adenosine kinase (requiring ATP as co-substrate). Intracellular adenosine may be produced by cytosolic 5’-nucleotidases or through S-adenosylhomocysteine hydrolase (also producing L-homocysteine).


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ADA (Adenosine deaminase) C Show summary » More detailed page go icon to follow link

ADK (Adenosine kinase) C Show summary »

Target Id 1231
Nomenclature Adenosine kinase
Common abbreviation ADK
Previous and unofficial names AK | adenosine 5'-phosphotransferase | ATP:adenosine 5'-phosphotransferase
Genes ADK (Hs), Adk (Mm), Adk (Rn)
Ensembl ID ENSG00000156110 (Hs), ENSMUSG00000039197 (Mm), ENSRNOG00000012325 (Rn)
UniProtKB AC P55263 (Hs), P55264 (Mm), Q64640 (Rn)
EC number
Rank order of affinity adenosine
adenosine 5'-monophosphate
Selective inhibitors
A134974 pIC50 10.2 [10]
ABT702 pIC50 8.8 [7]
Comment The enzyme exists in two isoforms derived from alternative splicing of a single gene product: a short isoform, ADK-S, located in the cytoplasm is responsible for the regulation of intra- and extracellular levels of adenosine and hence adenosine receptor activation; a long isoform, ADK-L, located in the nucleus contributes to the regulation of DNA methylation [2,12].

NT5E (Ecto-5'-Nucleotidase / CD73) C Show summary » More detailed page go icon to follow link

SAHH (S-Adenosylhomocysteine hydrolase) C Show summary »

5'-nucleotidase IA Show summary »

5'-nucleotidase IB Show summary »

5'-nucleotidase II Show summary »

5'-nucleotidase III Show summary »

5'(3')-nucleotidase Show summary »

Mitochondrial 5'-nucleotidase Show summary »


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NC-IUPHAR subcommittee and family contributors

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How to cite this family page

Database page citation (select format):

Concise Guide to PHARMACOLOGY citation:

Alexander SPH, Fabbro D, Kelly E, Mathie AA, Peters JA, Veale EL, Armstrong JF, Faccenda E, Harding SD, Davies JA et al. (2023) The Concise Guide to PHARMACOLOGY 2023/24: Enzymes. Br J Pharmacol. 180 Suppl 2:S289-373.