DIO2

The protein encoded by this gene belongs to the iodothyronine deiodinase family. It catalyzes the conversion of prohormone thyroxine (3,5,3',5'-tetraiodothyronine, T4) to the bioactive thyroid hormone (3,5,3'-triiodothyronine, T3) by outer ring 5'-deiodination. This gene is widely expressed, including in thyroid and brain. It is thought to be responsible for the 'local' production of T3, and thus important in influencing thyroid hormone action in these tissues. It has also been reported to be highly expressed in thyroids of patients with Graves disease, and in follicular adenomas. The intrathyroidal T4 to T3 conversion by this enzyme may contribute significantly to the relative increase in thyroidal T3 production in these patients. This protein is a selenoprotein containing the non-standard amino acid, selenocysteine (Sec), which is encoded by the UGA codon that normally signals translation termination. The 3' UTRs of selenoprotein mRNAs contain a conserved stem-loop structure, designated the Sec insertion sequence (SECIS) element, that is necessary for the recognition of UGA as a Sec codon, rather than as a stop signal. Unlike the other two members (DIO1 and DIO3) of this enzyme family, the mRNA for this gene contains an additional in-frame UGA codon that has been reported (in human) to function either as a Sec or a stop codon, which can result in two isoforms with one or two Sec residues; however, only the upstream Sec (conserved with the single Sec residue found at the active site in DIO1 and DIO3) was shown to be essential for enzyme activity (PMID:10403186). Alternatively spliced transcript variants have been described for this gene. [provided by RefSeq, Oct 2018]

Description

Iodothyronine deiodinase 2

Tissue specificity

Tissue enhanced (cervix, thyroid gland)

Subcell location

Nucleoplasm, Vesicles, Plasma membrane

Predicted location

Intracellular, Membrane

Protein family

Enzymes
Mapped to neXtProt
Mapped to UniProt SWISS-PROT
Metabolic proteins
Predicted intracellular proteins
Predicted membrane proteins

Chromosome

14 (80197526 - 80387757)

Ensembl ID

ENSG00000211448  (ver. 103.38)

Orthologs

Mouse Dio2: ENSMUSG00000007682

UniProt

Q92813

neXtProt

NX_Q92813

Human splice variants
Mouse splice variants

Protein structure