Scarb1

Function

Receptor for different ligands such as phospholipids, cholesterol ester, lipoproteins, phosphatidylserine and apoptotic cells (By similarity). Both isoform 1 and isoform 2 act as receptors for HDL, mediating selective uptake of cholesteryl ether and HDL-dependent cholesterol efflux (PubMed:9254074, PubMed:9614139). Also facilitates the flux of free and esterified cholesterol between the cell surface and apoB-containing lipoproteins and modified lipoproteins, although less efficiently than HDL. May be involved in the phagocytosis of apoptotic cells, via its phosphatidylserine binding activity (By similarity).

Post-translational modifications

N-glycosylated.

The six cysteines of the extracellular domain are all involved in intramolecular disulfide bonds.

Sequence Similarities

Belongs to the CD36 family.

Tissue Specificity

Expressed primarily in liver, ovary and adrenal gland, and, at lower levels in other non-placental steroidogenic tissues, including adipose tissue, mammary gland and testis (at protein level) (PubMed:8560269, PubMed:9254074, PubMed:9614139). Isoform 2 is expressed at lower levels than isoform 1 in liver, testis and adrenal gland (PubMed:9614139). At the mRNA, but not at the protein level, isoform 2 is the predominant isoform in testis (80%) (PubMed:9254074).

Cellular localization

• Cell membrane
• Multi-pass membrane protein
• Membrane
• Caveola
• Multi-pass membrane protein
• Predominantly localized to cholesterol and sphingomyelin-enriched domains within the plasma membrane, called caveolae.
• Isoform 1
• Cell membrane
• Membrane
• Caveola
• Isoform 2
• Cell membrane
• Membrane
• Caveola

Alternative names

Srb1, Scarb1, Scavenger receptor class B member 1, SRB1, SR-BI

Database links

swissprot:Q61009 swissprot:O35114 entrezGene:20778 entrezGene:12492