Entry
Name
cholesterol 24-hydroxylase;
cholesterol 24-monooxygenase;
CYP46;
CYP46A1;
cholesterol 24S-hydroxylase;
cytochrome P450 46A1
Class
Oxidoreductases;
Acting on paired donors, with incorporation or reduction of molecular oxygen;
With reduced flavin or flavoprotein as one donor, and incorporation of one atom of oxygen into the other donor
BRITE hierarchy
Sysname
cholesterol,NADPH---hemoprotein reductase:oxygen oxidoreductase (24-hydroxylating)
Reaction(IUBMB)
cholesterol + [reduced NADPH---hemoprotein reductase] + O2 = (24S)-cholest-5-ene-3beta,24-diol + [oxidized NADPH---hemoprotein reductase] + H2O [RN:
R07207 ]
Reaction(KEGG)
Substrate
cholesterol [CPD:
C00187 ];
[reduced NADPH---hemoprotein reductase] [CPD:
C03024 ];
O2 [CPD:
C00007 ]
Product
(24S)-cholest-5-ene-3beta,24-diol [CPD:
C13550 ];
[oxidized NADPH---hemoprotein reductase] [CPD:
C03161 ];
H2O [CPD:
C00001 ]
Comment
A P-450 heme-thiolate protein. The enzyme can also produce 25-hydroxycholesterol. In addition, it can further hydroxylate the product to 24,25-dihydroxycholesterol and 24,27-dihydroxycholesterol [2]. This reaction is the first step in the enzymic degradation of cholesterol in the brain as hydroxycholesterol can pass the blood---brain barrier whereas cholesterol cannot [3]. The direct electron donor to the enzyme is EC
1.6.2.4 , NADPH---hemoprotein reductase [3].
History
EC 1.14.14.25 created 2005 as EC 1.14.13.98, transferred 2016 to EC 1.14.14.25
Pathway
ec00120 Primary bile acid biosynthesis
Orthology
K07440 cholesterol 24-hydroxylase
Genes
ASAO : 132761810 132762545
SUND : 121919235 121919747
PMUA : 114585569 114585577 114588390
PRAF : 128407201 128407211 128407225
EMC : 129324065 129324066 129324802 129324893 129324895 129324896 129324924
XLA : 100126648(cyp46a1.3.L) 108704878(cyp46a1.1.L) 379470(cyp46a1.2.L)
XTR : 100145328 100498621 613109(cyp46a1.3) 613111(cyp46a1.1) 780005(cyp46a1.2)
NPR : 108790745 108795063 108795064 108795072
RTEM : 120920042 120920174 120920768 120920898
BBUF : 120982153 120982331 120982402 120982403 120982405 120982407 120982408 120982409 120982490
BGAR : 122921922 122921989 122922124 122922206
DRE : 393433(cyp46a1.2) 393451(cyp46a1.4) 553543(cyp46a1.1) 641477(cyp46a1.5) 692332(cyp46a1.3)
SANH : 107678664 107678670 107679679
CCAR : 109113289 109113290
CAUA : 113121257 113121258
PTET : 122324318 122324319 122324561 122325035
MASI : 127410433 127415828
TROS : 130565740 130566380
TDW : 130434024 130434519 130434833
CHAR : 105889656 105901399 105910686
PLEP : 121955336 121955367
SLUC : 116041942 116041943 116041944
PFLV : 114573150 114573151 114573152 114573153
MSAM : 119908603 119908604
SCHU : 122863503 122863505
CUD : 121510023 121521266 121521471
MZE : 101466901 101484290 101484552 106676579 111500322
ONL : 100692681 100703511 100704054 102076821 102077122
OAU : 116315530 116315535 116315536 116332193 116332210 120433299
CSAI : 133464385 133464386 133464538
PRET : 103457823 103457824
PFOR : 103147687 103147688
PLAI : 106956892 106956894
PMEI : 106916229 106916230
PPRL : 129368916 129368917
CTUL : 119784179 119784180 119784181
GMU : 124882165 124882166 124882576
KMR : 108231774 108231837 108231838 112450290
ALIM : 106525137 106525457 106525458
NWH : 119418059 119418455 119418456 119418457 119418458
BPEC : 110161286 110173902 110173912
MALB : 109962169 109962173 109962186 109962187
BSPL : 114849186 114849188
SJO : 128377315 128377316 128377317 128377319
SASA : 106571109 106571110 106571111 106608238
STRU : 115157569 115175113 115175114 115175200
OTW : 112235780 112249824 112249887 112249888
OMY : 110522567 110529322 110529323 110529324 110529326 118965490
OKI : 109866694 109900502 109900504 109900505 109901317 109901319
SALP : 111954047 111972528
SNH : 120019174 120024159 120024160
CCLU : 121548510 121552816 121552818
ELS : 105020476 105020477 105020478 106024908 109614563
SFM : 114910933 114912327 114912328 114912329
AANG : 118230143 118230144 118230145 118230146 118230147
ARUT : 117420692 117422588
LPIC : 129260635 129261079 129265168 129265494 129269742 129270038 129270403 129279633
ARUN : 117287882 117288430 117289895 117295713 117295909 117298510 117300170 117300325 117300896 117304390 117304391 117304585 117306872 117306975
PMAX : 117323274 117323275 117323276 117323277 117323279 117323755 117324632 117327808
MCAF : 127698395 127698497
LLON : 135485055 135500571
ATEN : 116288258 116291041 116301076 116301543 116301544 116302235
XEN : 124434130 124434667 124434668 124434669 124434670 124434671 124435711 124445703
» show all
Taxonomy
Reference
Authors
Lund EG, Guileyardo JM, Russell DW
Title
cDNA cloning of cholesterol 24-hydroxylase, a mediator of cholesterol homeostasis in the brain.
Journal
Sequence
Reference
Authors
Bogdanovic N, Bretillon L, Lund EG, Diczfalusy U, Lannfelt L, Winblad B, Russell DW, Bjorkhem I.
Title
On the turnover of brain cholesterol in patients with Alzheimer's disease. Abnormal induction of the cholesterol-catabolic enzyme CYP46 in glial cells.
Journal
Sequence
Reference
Authors
Mast N, Norcross R, Andersson U, Shou M, Nakayama K, Bjorkhem I, Pikuleva IA
Title
Broad substrate specificity of human cytochrome P450 46A1 which initiates cholesterol degradation in the brain.
Journal
Sequence
Reference
Authors
Lund EG, Xie C, Kotti T, Turley SD, Dietschy JM, Russell DW.
Title
Knockout of the cholesterol 24-hydroxylase gene in mice reveals a brain-specific mechanism of cholesterol turnover.
Journal
Reference
Authors
Russell DW
Title
The enzymes, regulation, and genetics of bile acid synthesis.
Journal
Other DBs
CAS: 50812-30-1 213327-78-7
LinkDB
All DBs