Cytochrome P450 24A1
| Cytochrome P450 24A1 | ||
|---|---|---|
| Properties of human protein | ||
| Mass / length primary structure | 479 amino acids | |
| Cofactor | Hamm | |
| Identifier | ||
| Gene names | CYP24A1 ; CP24; CYP24; MGC126273; MGC126274; P450-CC24 | |
| External IDs | ||
| Enzyme classification | ||
| EC, category | 1.14.13.- , dioxygenase | |
| Response type | Hydroxylation | |
| Substrate | Calcidiol (calcitriol) + NADPH + O 2 | |
| Products | Secalciferol (Calcitetrol) + NADP + + H 2 O | |
| Occurrence | ||
| Homology family | Cytochrome P450 | |
| Parent taxon | Creature | |
The cytochrome P450, family 24, subfamily A, polypeptide 1 (short: CYP24A1 , or alternatively according to the function: 24-hydroxylase called) belongs to the cytochrome P450 superfamily and is a mitochondrial enzyme which is instrumental in the degradation of the vitamin D - Metabolite is involved. It hydroxylates the 25 (OH) vitamin D 3 ( calcidiol ) and the 1,25 (OH) 2 vitamin D 3 ( calcitriol ) and inactivates them. It is counter - regulated to 1α-hydroxylase , which activates 25 (OH) vitamin D 3 : 1,25 (OH) 2 vitamin D 3 induces 24-hydroxylase, hypocalcemia and increased parathyroid hormone suppress this enzyme.
biosynthesis
The biosynthesis of 24-hydroxylase is mainly triggered by the presence of vitamin D , for which there are two vitamin D-responsive elements (VDRE) on the promoter of the CYP24A1 gene.
The gene is encoded on chromosome 20 (20q13.2-q13.3), the enzyme precursor has 514 amino acids and a molecular mass of 59 kDa.
function
Due to its function in the breakdown of vitamin D, 24-hydroxylase plays a role in the calcium balance.
Catalyzed reaction
24-hydroxylase is not only able to hydroxylate calcidiol once (to 1α, 24-dihydroxycholecalciferol), it can change calcitriol to 1alpha-hydroxy-23-carboxytetranorvitamin D. It also shows 23-hydroxylating activity.
More functions
In addition to the catalyzed reaction, overexpression of the enzyme could play a role in tumor development due to the resulting vitamin D deficiency.
Web links
- Jassal / reactome.org: 1,25-dihydroxyvitamin D3 is deactivated
- Jassal / reactome.org: CYP24A1 catalyzes the initial step in the deactivation of the hormonally active form of vitamin D3
- CYP24A1 on Entrez Gene
- CYP24A1 HSA - 1591 in the Kyoto Encyclopedia of Genes and Genomes
Individual evidence
- ↑ DG Albertson, B. Ylstra, R. Segraves, C. Collins, SH Dairkee, D. Kowbel, WL Kuo, JW Gray, D. Pinkel: Quantitative mapping of amplicon structure by array CGH identifies CYP24 as a candidate oncogene . In: Nature Genetics . tape 25 , no. 2 , 2000, pp. 144-146 , doi : 10.1038 / 75985 , PMID 10835626 .