CYP26A1:Cytochrome P450 26A1

Gene Name
Cytochrome P450 26A1
Protein ID
Chromosome ID
HPP Status
Protein Name
Cytochrome P450 26A1

Retinoic acid 4-hydroxylase

retinoic acid-metabolizing cytochrome


cytochrome P450RAI


P450, retinoic acid-inactivating, 1



cytochrome P450 26A1

Retinoic acid-metabolizing cytochrome

Cytochrome P450RAI

cytochrome P450 retinoic acid-inactivating 1

cytochrome P450, subfamily XXVIA, polypeptide 1


retinoic acid 4-hydroxylase

Cytochrome P450 retinoic acid-inactivating 1

cytochrome P450, family 26, subfamily A, polypeptide 1

EC 1.14.-.-

[Reference: ]
Chromosomal Position
10q23.33 | Start:93073475 End:93073475

Entrez Gene Summary for CYP26A1
This gene encodes a member of the cytochrome P450 superfamily of enzymes. The cytochrome P450 proteins are monooxygenases which catalyze many reactions involved in drug metabolism and synthesis of cholesterol, steroids and other lipids. This endoplasmic reticulum protein acts on retinoids, including all-trans-retinoic acid (RA), with both 4-hydroxylation and 18-hydroxylation activities. This enzyme regulates the cellular level of retinoic acid which is involved in regulation of gene expression in both embryonic and adult tissues. Two alternatively spliced transcript variants of this gene, which encode the distinct isoforms, have been reported. (provided by RefSeq, Jul 2008)

UniProtKB Summary for CYP26A1
Function: Plays a key role in retinoic acid metabolism. Acts on retinoids, including all-trans-retinoic acid (RA) and its stereoisomer 9-cis-RA. Capable of both 4-hydroxylation and 18-hydroxylation. Responsible for generation of several hydroxylated forms of RA, including 4-OH-RA, 4-oxo-RA and 18-OH-RA

Tocris Summary for CYP26A1
Cytochrome P450 (CYP450) enzymes are a diverse group of catalysts that contains 57 members in humans. CYPs are usually membrane-bound and are localized to the inner mitochondrial or endoplasmic reticular membrane. CYPs have oxygenase activity and commonly catalyze redox reactions, involving the oxidation of the substrate and reduction of water. This group of enzymes contain a heme ion within the active site, which is essential for catalytic activity. CYPs have been found in all organisms tested and are ubiquitously expressed. They are found at high levels in the liver, where they have an important role in metabolism of drugs and endogenous toxic compounds (for example bilirubin). Most CYPs can metabolize numerous substrates and this accounts for their major role in drug interactions. CYPs also have functions in steroid hormone synthesis, cholesterol synthesis and vitamin D metabolism.

[Reference: ]
External IDs
Hgnc ID: 2603 EntrezGene ID: 1592 Ensembl ID: ENSG00000095596
[Reference: ]
Reference Source

Gene Reference Into Function (GeneRIF)

PubMed IDGeneRIF TextLast Update
15281009increased CYP26-mediated catabolism of retinoic by CRABP-I transfection might decrease the amount of retinoic acid that is accessible to the nuclear receptors2010-01-21
16053444The identification of a functional retinoic acid response element located 2.0 kb upstream of the Cyp26A1 transcriptional start site is reported.2010-01-21
16194896induction and regulation of CYP26A1 expression in human intestinal (Caco-2), liver (HepG2), endothelial (HUVEC), and APL (NB4) cell lines2010-01-21
16463413Observational study of gene-disease association. (HuGE Navigator)2008-03-13
16463413Variants in CYP26A1 are unlikely to be a major risk factor for caudal regression syndrome; further study with a larger number of genotyped subjects is required.2010-01-21
16778795Constitutive expression of CYP26AI in vivo and in organotypic culture was found to be restricted to basal epidermal keratinocytes, as well as eccrine sweat glands and sebaceous glands.2010-01-21
16933217Observational study of gene-disease association. (HuGE Navigator)2008-03-13
16933217g.3116delT mutation is of particular interest because it was identified in a patient with spina bifida and likely encodes a truncated protein with no enzymatic activity, as demonstrated by preliminary in vitro data.2010-01-21
17059167analysis of CYP26A1 active site architecture and ligand binding2010-01-21
17218384Low CYP26A1 expression may explain high risk of resistance installation, by increase retinoid pressure.2010-01-21
17460545Three new alleles termed as CYP26A1*2, CYP26A1*3, and CYP26A1*4, are potentially defective in all-trans retinoic acid metabolism.2010-01-21
18059332Overexpression of CYP26A1 causes intracellular retinoic acid depletion and drives the cell into a highly proliferative and invasive state with induction of other known oncogenes2010-01-21
18992717Results provide a biochemical framework for CYP26A1 function and offer insight into the role of CYP26A1 as a drug target as well as in fetal development and cell cycle regulation2010-01-21
19519282cytochrome P450 family 26 (CYP26) enzymes have a role in determining the cellular exposure to retinoic acid by inactivating retinoic acid in cells that do not need retinoic acid--REVIEW2010-01-21
19553612Observational study of gene-disease association. (HuGE Navigator)2009-08-12
19703508Observational study of gene-disease association and gene-gene interaction. (HuGE Navigator)2009-09-16
20167577Observational study of gene-disease association. (HuGE Navigator)2010-04-07
20375987Observational study of gene-disease association and gene-gene interaction. (HuGE Navigator)2010-06-30
20513361CYP26A1 is expressed in human liver microsomes; its expression correlates with retinoic acid hydroxylation.2010-08-16
20682464the functioning of multiple RAREs may account for the strong inducibility of CYP26A1 in liver, which, in turn, may be important physiologically for restoring retinoid homeostasis when the concentration of RA rises.2010-08-30
20693622Observational study of gene-disease association and gene-gene interaction. (HuGE Navigator)2010-09-15
21521770Primary metabolites of all-trans-retinoic acid formed by CYP26A1 are identified and the ligand selectivity and ligand interactions of CYP26A1 are characterized.2011-09-17
21850183CYP26A1 and CYP26C1 play a pivotal role in the pathogenesis of nonsyndromic bilateral and unilateral optic nerve aplasia.2011-12-10
21975512The promoter region of CYP26A1 is significantly hypermethylated in allergic asthmatic subjects.2012-10-06
22020119CYP26A1 and CYP26B1 are qualitatively similar retinoic acid hydroxylases with overlapping expression profiles; CYP26A1 has higher catalytic activity than CYP26B1.2012-01-21
22179182Our observation suggests an involvement of enhanced CYP26A1 expression causing a functional vitamin A deficieny state in skin that can potentially lead to neoplastic transformation of keratinocytes in an early phase during skin carcinogenesis2012-04-14
24043786CYP26 is able to inactivate retinoids in serum, preventing retinoic acid signaling and thus bone-marrow hematopoietic stem cell differentiation.2013-12-07
24819304HNF4alpha coordinates with retinoic acid receptors in a retinoic acid-dependent manner to strongly induce CYP26A1 gene expression in the liver, which may explain the high level of response to retinoic acid observed in vivo.2015-05-16
25294402data suggested that CYP26A1 overexpression might contribute to the development and progression of cervical malignancies and squamous neoplasia of the head and neck2015-06-06
25492813In liver microsomes, CYP26A1 plays a role in clearing bioactive retinoids.2015-03-21
25541526Molecular recognition of CYP26A1 binding pockets and structure-activity relationship studies for design of potent and selective retinoic acid metabolism blocking agents has been described.2015-10-03
26058854CYP26A1-mediated oncogenic characteristics may be partially responsible for the elevated expression of fascin.2016-03-26


Relevant citations within the PubMed literature


Putative/known Functions


Homologues, Orthologues, Paralogues and Family

Sequence Similarity and Functional Annotation

Post Translational Modifications

Protein Protein Interactions

Best Available Mass Spectra without FDR

Showing 1-3 of 3 items.


Peptide SequenceEvidence LevelLog ENumber Of ObservationSpectraAccession IDProteotypicityAnnotation
Evidence File
Fenyö, David; Beavis, Ronald C. (2015). "The GPMDB REST interface". Bioinformatics 31 (12): 2056–2058. doi:10.1093/bioinformatics/btv107. ISSN 1367-4803. ">Global Proteome Machine Database - THE GPM


Peptide SequenceScoresPride IDSpectrum IDAnnotation
No results found.
Evidence File
Vizcaino JA, et al. 2016 update of the PRIDE database and related tools. Nucleic Acids Res. 2016 Jan 1;44(D1):D447-D456. ">PRIDE Archive

Showing 1-2 of 2 items.

Proteomics DB

Peptide SequenceSearch EngineScoreThreshold ScoreIdentification IDExperiment IDAnnotation
Evidence File
Wilhelm, M et al. (2014) Mass-spectrometry-based draft of the human proteome. Nature. 509:582-7. ">Proteomics DB