CYP7B1
Cytochrome P450 Family 7 Subfamily B Member 1
Gene Information Card
| Symbol | CYP7B1 |
|---|---|
| Full Name | Cytochrome P450 Family 7 Subfamily B Member 1 |
| Gene Type | Protein coding |
| Chromosomal Location | 8q12.3 |
| NCBI Gene ID | 9420 ncbi.nlm.nih.gov/gene/9420 |
| Ensembl ID | ENSG00000172817 |
| UniProt ID | O75881 |
| OMIM ID | 603711 |
| HGNC ID | 2652 |
| Aliases | CP7B, SPG5A, oxysterol 7-alpha-hydroxylase |
Description
CYP7B1 encodes a member of the cytochrome P450 superfamily of enzymes, specifically oxysterol 7α-hydroxylase. This enzyme catalyzes the 7α-hydroxylation of oxysterols, including 25-hydroxycholesterol and 27-hydroxycholesterol, playing a critical role in the alternative (acidic) pathway of bile acid synthesis. It is also involved in neurosteroid metabolism, particularly in the brain. Mutations in CYP7B1 cause hereditary spastic paraplegia type 5A (SPG5A), a neurodegenerative disorder characterized by progressive lower limb spasticity and weakness.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Hereditary spastic paraplegia 5A (SPG5A) | Loss-of-function mutations impair oxysterol 7α-hydroxylase activity, leading to accumulation of neurotoxic oxysterols (e.g., 27-hydroxycholesterol) in the central nervous system, causing axonal degeneration. | ClinVar, OMIM |
| Bile acid synthesis defect, congenital, 3 | Deficient enzyme activity disrupts the alternative bile acid synthesis pathway, resulting in accumulation of atypical bile acids and cholestatic liver disease. | OMIM, NCBI Gene |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | 12.5 | Medium |
| Brain | 8.3 | Medium |
| Adrenal gland | 6.1 | Low |
| Kidney | 4.7 | Low |
| Testis | 3.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | 15.0 | Hepatocellular carcinoma cell line |
| SH-SY5Y | 9.8 | Neuroblastoma cell line |
| HEK293 | 5.2 | Embryonic kidney cell line |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.889A>G (p.Thr297Ala) | Missense | Rare | Reduced enzyme activity; associated with SPG5A |
| c.145C>T (p.Arg49*) | Nonsense | Rare | Premature stop codon; loss of function; SPG5A |
| c.1075C>T (p.Arg359*) | Nonsense | Rare | Loss of function; SPG5A |
| c.169G>A (p.Gly57Arg) | Missense | Rare | Impaired catalytic activity; SPG5A |
Mutation functional classification
Loss of Function (LOF)
Most CYP7B1 mutations are loss-of-function, leading to reduced or absent oxysterol 7α-hydroxylase activity, causing accumulation of oxysterols and bile acid intermediates.
Gain of Function (GOF)
No gain-of-function mutations have been reported for CYP7B1.
Dominant Negative (DN)
No dominant-negative effects have been described for CYP7B1 mutations; inheritance is autosomal recessive.
View complete mutation data：
Gene Ontology (GO)
| • oxysterol 7-alpha-hydroxylase activity | • iron ion binding |
| • heme binding | • oxidoreductase activity |
| • acting on paired donors | • with incorporation or reduction of molecular oxygen |
| • steroid hydroxylase activity | • endoplasmic reticulum membrane |
Pathways
• Alternative pathway of bile acid synthesis
• Neurosteroid metabolism
• Cholesterol metabolism
Protein Summary
CYP7B1 is a 506-amino acid microsomal cytochrome P450 enzyme localized to the endoplasmic reticulum. It catalyzes the 7α-hydroxylation of oxysterols such as 25-hydroxycholesterol and 27-hydroxycholesterol, initiating the acidic pathway of bile acid synthesis. The enzyme is highly expressed in liver and brain, where it also metabolizes neurosteroids. Deficiency due to biallelic mutations leads to accumulation of toxic oxysterols, causing hereditary spastic paraplegia type 5A and, in some cases, congenital bile acid synthesis defects.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CYP7B1 Knockout HEK293 Cell Line | EDJ-KQ2899 | Human | 9420 | Details Get a Quote |
| CYP7B1 Knockout HeLa Cell Line | EDJ-KQ55159 | Human | 9420 | Details Get a Quote |
| CYP7B1 Knockout A-549 Cell Line | EDJ-KQ63639 | Human | 9420 | Details Get a Quote |
| CYP7B1 Knockout HCT 116 Cell Line | EDJ-KQ72101 | Human | 9420 | Details Get a Quote |
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