DIO2
Description
The DIO2 (iodothyronine deiodinase 2) is a protein-coding gene located on chromosome 14.
Type II iodothyronine deiodinase (iodothyronine 5'-deiodinase, iodothyronine 5'-monodeiodinase) is an enzyme encoded by the DIO2 gene in humans. It belongs to the iodothyronine deiodinase family and activates thyroid hormone by converting the prohormone thyroxine (T4) to bioactive 3,3',5-triiodothyronine (T3) through outer ring deiodination (ORD). This enzyme is highly expressed in the thyroid and may contribute significantly to the increased thyroidal T3 production in patients with Graves' disease and thyroid adenomas. The DIO2 protein contains selenocysteine (Sec) residues encoded by the UGA codon, which usually signals translation termination. However, the 3' UTR of Sec-containing genes has a common stem-loop structure, the Sec insertion sequence (SECIS), that allows the UGA codon to be recognized as a Sec codon instead of a stop signal. Alternative splicing leads to multiple transcript variants encoding different isoforms. DIO2 has been shown to interact with USP33.
DIO2 is also known as 5DII, D2, DIOII, SELENOY, SelY, TXDI2.
