Deiodinase, iodothyronine, type II
Symbols DIO2; 5DII; D2; DIOII; SelY; TXDI2
External IDs OMIM601413 MGI1338833 HomoloGene621 GeneCards: DIO2 Gene
EC number
Species Human Mouse
Entrez 1734 13371
Ensembl n/a ENSMUSG00000007682
UniProt n/a Q05A70
RefSeq (mRNA) NM_000793.5 NM_010050.2
RefSeq (protein) NP_000784.2 NP_034180.1
Location (UCSC) n/a Chr 12:
91.13 – 91.14 Mb
PubMed search [1] [2]

Type II iodothyronine deiodinase is an enzyme that in humans is encoded by the DIO2 gene.[1][2][3]

The protein encoded by this gene belongs to the iodothyronine deiodinase family. It activates thyroid hormone by converting the prohormone thyroxine (T4) by outer ring deiodination (ORD) to bioactive 3,3',5-triiodothyronine (T3). It is highly expressed in the thyroid, and may contribute significantly to the relative increase in thyroidal T3 production in patients with Graves' disease and thyroid adenomas. This protein contains selenocysteine (Sec) residues encoded by the UGA codon, which normally signals translation termination. The 3' UTR of Sec-containing genes have a common stem-loop structure, the Sec insertion sequence (SECIS), which is necessary for the recognition of UGA as a Sec codon rather than as a stop signal. Alternative splicing results in multiple transcript variants encoding different isoforms.[3]



DIO2 has been shown to interact with USP33.[4]

See also


  1. ^ Croteau W, Davey JC, Galton VA, St Germain DL (Sep 1996). "Cloning of the mammalian type II iodothyronine deiodinase. A selenoprotein differentially expressed and regulated in human and rat brain and other tissues". J Clin Invest 98 (2): 405–417. doi:10.1172/JCI118806. PMC 507444. PMID 8755651. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=507444. 
  2. ^ Araki O, Murakami M, Morimura T, Kamiya Y, Hosoi Y, Kato Y, Mori M (Jun 1999). "Assignment of type II iodothyronine deiodinase gene (DIO2) to human chromosome band 14q24.2→q24.3 by in situ hybridization". Cytogenet Cell Genet 84 (1–2): 73–74. doi:10.1159/000015218. PMID 10343107. 
  3. ^ a b "Entrez Gene: DIO2 deiodinase, iodothyronine, type II". http://www.ncbi.nlm.nih.gov/sites/entrez?Db=gene&Cmd=ShowDetailView&TermToSearch=1734. 
  4. ^ Curcio-Morelli, Cyntia; Zavacki Ann Marie, Christofollete Marcelo, Gereben Balazs, de Freitas Beatriz C G, Harney John W, Li Zaibo, Wu Guan, Bianco Antonio C (Jul. 2003). "Deubiquitination of type 2 iodothyronine deiodinase by von Hippel-Lindau protein-interacting deubiquitinating enzymes regulates thyroid hormone activation". J. Clin. Invest. (United States) 112 (2): 189–196. doi:10.1172/JCI18348. ISSN 0021-9738. PMC 164294. PMID 12865408. http://www.pubmedcentral.nih.gov/articlerender.fcgi?tool=pmcentrez&artid=164294. 

Further reading