SCARB1 (Scavenger Receptor Class B Member 1)
A key regulator of cholesterol transport, HDL metabolism, and steroidogenesis, implicated in cardiovascular and metabolic diseases.
Gene Information Card
| Symbol | SCARB1 |
|---|---|
| Full Name | Scavenger Receptor Class B Member 1 |
| Gene Type | protein-coding |
| Chromosomal Location | 12q24.31 |
| NCBI Gene ID | 949 ncbi.nlm.nih.gov/gene/949 |
| Ensembl ID | ENSG00000073060 |
| UniProt ID | Q8WTV0 |
| OMIM ID | 601040 |
| HGNC ID | 1664 |
| Aliases | SR-BI, CD36L1, CLA-1, SRB1 |
Description
The SCARB1 gene encodes scavenger receptor class B member 1 (SR-BI), a cell surface glycoprotein that mediates selective uptake of high-density lipoprotein (HDL) cholesteryl esters. It plays a critical role in reverse cholesterol transport, steroidogenesis, and lipid metabolism. SR-BI is expressed in various tissues, including liver, adrenal glands, and gonads, and is involved in the regulation of plasma HDL cholesterol levels. Mutations in SCARB1 have been associated with altered HDL levels and increased risk of cardiovascular disease.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Cardiovascular disease | Altered HDL cholesterol metabolism due to SCARB1 variants, affecting cholesterol efflux and hepatic uptake. | ClinVar, PubMed |
| Hypercholesterolemia | Loss-of-function mutations impair HDL cholesterol uptake, leading to elevated plasma HDL levels but increased atherosclerosis risk. | ClinVar, PubMed |
| Adrenal insufficiency | Impaired cholesterol uptake in adrenal glands reduces steroid hormone synthesis. | PubMed |
| Infertility | Defective SR-BI in gonads affects cholesterol supply for steroidogenesis, impacting reproductive function. | PubMed |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Liver | High | High expression in hepatocytes for HDL cholesterol uptake |
| Adrenal gland | High | High expression for steroid hormone production |
| Ovary | High | High expression in theca and granulosa cells for steroidogenesis |
| Testis | Medium | Expression in Leydig cells for testosterone synthesis |
| Small intestine | Medium | Involved in dietary cholesterol absorption |
| Kidney | Low | Low expression |
| Brain | Low | Low expression |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| HepG2 | High | Hepatocyte carcinoma cell line, used for HDL uptake studies |
| H295R | High | Adrenocortical carcinoma cell line, steroidogenic |
| KGN | Medium | Granulosa cell tumor cell line, steroidogenic |
| MCF-7 | Low | Breast cancer cell line, low expression |
| A549 | Low | Lung carcinoma cell line, low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1050C>T (p.Arg350Cys) | Missense | Rare | Reduced HDL cholesterol uptake, associated with elevated HDL levels and increased cardiovascular risk |
| c.754C>T (p.Arg252Trp) | Missense | Rare | Impaired SR-BI function, linked to adrenal insufficiency |
| c.1118A>G (p.Asn373Ser) | Missense | Rare | Altered HDL binding, potential impact on cholesterol efflux |
| c.1120G>A (p.Gly374Ser) | Missense | Rare | Reduced cell surface expression, affecting HDL uptake |
Mutation functional classification
Loss of Function (LOF)
Mutations that reduce or abolish SR-BI-mediated HDL cholesterol uptake, leading to elevated plasma HDL but impaired reverse cholesterol transport.
Gain of Function (GOF)
No clear gain-of-function mutations reported; overexpression studies suggest increased HDL uptake but clinical relevance is unclear.
Dominant Negative (DN)
Some missense mutations may exert dominant-negative effects by forming non-functional oligomers, but evidence is limited.
View complete mutation data：
Gene Ontology (GO)
| • GO:0005044 - scavenger receptor activity | • GO:0008022 - protein C-terminus binding |
| • GO:0008289 - lipid binding | • GO:0015485 - cholesterol binding |
| • GO:0030169 - low-density lipoprotein particle binding | • GO:0034185 - apolipoprotein binding |
| • GO:0042802 - identical protein binding | • GO:0046982 - protein heterodimerization activity |
| • GO:0005886 - plasma membrane | • GO:0005887 - integral component of plasma membrane |
| • GO:0005768 - endosome | • GO:0005769 - early endosome |
| • GO:0005770 - late endosome | • GO:0005794 - Golgi apparatus |
| • GO:0005901 - caveola | • GO:0016020 - membrane |
| • GO:0030139 - endocytic vesicle | • GO:0043235 - receptor complex |
| • GO:0001525 - angiogenesis | • GO:0006641 - triglyceride metabolic process |
| • GO:0006869 - lipid transport | • GO:0008203 - cholesterol metabolic process |
| • GO:0008209 - androgen metabolic process | • GO:0008207 - C21-steroid hormone metabolic process |
| • GO:0006694 - steroid biosynthetic process | • GO:0010873 - positive regulation of cholesterol esterification |
| • GO:0010888 - negative regulation of lipid storage | • GO:0015909 - long-chain fatty acid transport |
| • GO:0030301 - cholesterol transport | • GO:0033344 - cholesterol efflux |
| • GO:0034375 - high-density lipoprotein particle remodeling | • GO:0042632 - cholesterol homeostasis |
| • GO:0043691 - reverse cholesterol transport | • GO:0055096 - low-density lipoprotein particle mediated signaling |
| • GO:0060742 - epithelial cell differentiation involved in prostate gland development | • GO:0070325 - lipoprotein particle binding |
| • GO:0070326 - lipoprotein particle receptor activity | • GO:0070328 - triglyceride homeostasis |
| • GO:0097009 - hepatocyte differentiation | • GO:1902993 - positive regulation of cholesterol transport |
Pathways
• HDL-mediated lipid transport
• Reverse cholesterol transport
• Steroid hormone biosynthesis
• Lipoprotein metabolism
Protein Summary
SR-BI is a 509-amino acid transmembrane protein with a large extracellular loop and two transmembrane domains. It binds HDL particles and mediates selective uptake of cholesteryl esters without endocytosis of the entire particle. SR-BI is crucial for maintaining plasma HDL cholesterol levels and providing cholesterol for steroid hormone synthesis in endocrine tissues. Its expression is regulated by various factors including hormones and dietary cholesterol.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| SCARB1 Knockout HEK293 Cell Line | EDJ-KQ2450 | Human | 949 | Details Get a Quote |
| SCARB1 Knockout A-549 Cell Line | EDJ-KQ22977 | Human | 949 | Details Get a Quote |
| SCARB1 Knockout HCT 116 Cell Line | EDJ-KQ22978 | Human | 949 | Details Get a Quote |
| SCARB1 Knockout HeLa Cell Line | EDJ-KQ22979 | Human | 949 | Details Get a Quote |
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