Thyroxine 5-deiodinase

DIO3
Available structures
PDB	Ortholog search: PDBe RCSB
List of PDB id codes
	4TR3, 4TR4
Identifiers
Aliases	DIO3, 5DIII, D3, DIOIII, TXDI3, deiodinase, iodothyronine, type III, iodothyronine deiodinase 3, Dio3 Gene
External IDs	OMIM: 601038; MGI: 1306782; HomoloGene: 1044; GeneCards: DIO3; OMA:DIO3 - orthologs
Gene location (Human)
Chr.	Chromosome 14 (human)
End	101,563,452 bp
Gene location (Mouse)
Chr.	Chromosome 12 (mouse)
End	110,247,531 bp
RNA expression pattern
	Top expressed in
	canal of the cervix; ; tendon of biceps brachii; ; right ovary; ; left ovary; ; ectocervix; ; cartilage tissue; ; left uterine tube; ; tibial arteries; ; vagina; ; body of uterus;
	Top expressed in
	placenta; ; yolk sac; ; stria vascularis; ; lip; ; embryo; ; morula; ; embryo; ; lens; ; ligament; ; auditory system;
	More reference expression data
	n/a
Gene ontology
Molecular function	oxidoreductase activity; thyroxine 5-deiodinase activity; thyroxine 5'-deiodinase activity;
Cellular component	integral component of membrane; endosome; plasma membrane; endosome membrane; membrane;
Biological process	thyroid hormone generation; thyroid hormone catabolic process; hormone biosynthetic process; positive regulation of multicellular organism growth; apoptotic process; retinal cone cell development; biological process; negative regulation of eye photoreceptor cell development; retinal cone cell apoptotic process; thyroid hormone metabolic process; macromolecule metabolic process;
	Sources:Amigo / QuickGO
Orthologs
	1735
	107585
	ENSG00000197406
	ENSMUSG00000075707
	P55073
	Q91ZI8
	NM_001362
	NM_172119
	NP_001353
	NP_742117
	Wikidata
View/Edit Human	View/Edit Mouse

Thyroxine 5-deiodinase also known as type III iodothyronine deiodinase (EC number 1.21.99.3) is an enzyme that in humans is encoded by the DIO3 gene. This enzyme catalyses the following chemical reaction

3,3',5'-triiodo-L-thyronine + iodide + A + H⁺

\rightleftharpoons

L-thyroxine + AH₂

The protein encoded by this intronless gene belongs to the iodothyronine deiodinase family. It catalyzes the inactivation of thyroid hormone by inner ring deiodination of the prohormone thyroxine (T₄) and the bioactive hormone 3,3',5-triiodothyronine (T₃) to inactive metabolites, 3,3',5'-triiodothyronine (RT₃) and 3,3'-diiodothyronine (T₂), respectively. This enzyme is highly expressed in the pregnant uterus, placenta, fetal and neonatal tissues, suggesting that it plays an essential role in the regulation of thyroid hormone inactivation during embryological development.