Type II iodothyronine deiodinase (iodothyronine 5'-deiodinase, iodothyronine 5'-monodeiodinase) is an enzyme that in humans is encoded by the DIO2 gene. 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.

Western

Western blot analysis of DIO2 in lysates of MCF7,PC-3,SH-SY5Y and A549 using DIO2 antibody.

Immunohistochemistry

Immunohistochemistry analysis of paraffin-embedded Human thyroid cancer using DIO2 antibody.High pressure and temperature Tris/EDTA (PH 9.0) used for antigen retrieval.The brown color represents the positive signal observed with DIO2 antibody.