Deiodinase
From Wikipedia, the free encyclopedia
|
deiodinase, iodothyronine, type I
|
|
| Identifiers | |
| Symbol | DIO1 |
| Alt. Symbols | TXDI1 |
| Entrez | 1733 |
| HUGO | 2883 |
| OMIM | 147892 |
| RefSeq | NM_000792 |
| UniProt | P49895 |
| Other data | |
| EC number | 1.97.1.10 |
| Locus | Chr. 1 p32-p33 |
| Identifiers | |
| Symbol | DIO2 |
| Entrez | 1734 |
| HUGO | 2884 |
| OMIM | 601413 |
| RefSeq | NM_000793 |
| UniProt | Q92813 |
| Other data | |
| Locus | Chr. 14 q24.2-24.3 |
|
deiodinase, iodothyronine, type III
|
|
| Identifiers | |
| Symbol | DIO3 |
| Alt. Symbols | TXDI3 |
| Entrez | 1735 |
| HUGO | 2885 |
| OMIM | 601038 |
| RefSeq | NM_001362 |
| UniProt | P55073 |
| Other data | |
| Locus | Chr. 14 q32 |
|
deiodinase, iodothyronine, type III opposite strand
|
|
| Identifiers | |
| Symbol | DIO3OS |
| Alt. Symbols | C14orf134 |
| Entrez | 64150 |
| HUGO | 20348 |
| OMIM | 608523 |
| RefSeq | NM_022345 |
| UniProt | Q9HAR6 |
| Other data | |
| Locus | Chr. 14 q32.33 |
Deiodinase (EC 1.97.1.10) is an enzyme important in the action of thyroid hormones. Deiodinases are unusual in that the enzyme contains selenium, in the form of an otherwise rare amino acid selenocysteine.[1][2][3]
Contents |
[edit] Activation and inactivation
In the tissues, deiodinases can either activate or inactivate thyroid hormones:
- Activation occurs by conversion of the prohormone thyroxine (T4) to the active hormone triiodothyronine (T3) through the removal of an iodine atom on the outer ring.
- Inactivation of thyroid hormones occurs by removal of an iodine atom on the inner ring, which converts thyroxine to the inactive reverse triiodothyronine (rT3), or which converts the active triiodothyronine to the inactive diiodothyronine (T2). The major part of thyroxine deiodination occurs within the cells.
[edit] Types
In most vertebrates, there are three types of enzymes that can deiodinate thyroid hormones:
| Type | Location | Function |
| type I (DI) | is commonly found in the liver, kidney, muscle tissue and thyroid gland | DI can deiodinate both rings |
| type II deiodinase (DII) | mostly in the brain but also in the testis and thyroid | DII can only deiodinate the outer ring of the prohormone thyroxine (or the metabolically inactive reverse triiodothyronine) and is the major activating enzyme |
| type III deiodinase (DIII) | found in the fetal tissue and the placenta | DIII can only deiodinate the inner ring of thyroxine or triiodothyronine and is the major inactivating enzyme |
[edit] Reactions
[edit] References
- ^ Köhrle J (January 2000). "The selenoenzyme family of deiodinase isozymes controls local thyroid hormone availability". Rev Endocr Metab Disord 1 (1-2): 49–58. doi:. PMID 11704992.
- ^ Köhrle J (May 1999). "Local activation and inactivation of thyroid hormones: the deiodinase family". Mol. Cell. Endocrinol. 151 (1-2): 103–19. doi:. PMID 10411325.
- ^ Köhrle J (December 2000). "The deiodinase family: selenoenzymes regulating thyroid hormone availability and action". Cell. Mol. Life Sci. 57 (13-14): 1853–63. doi:. PMID 11215512.
[edit] External links
 |
This EC 1.97 enzyme-related article is a stub. You can help Wikipedia by expanding it. |
|
|||||
