Scavenger Receptor Class B Membrane 1, also known as SR-BI plays an important role in lipid metabolism. Its main function is to mediate transfer of cholesterol between the cell surface and high density lipoprotein (HDL). HDL acts as an extracellular donor and acceptor of free and esterified Cholesterol. SR-BI also acts as a receptor for other ligands including lipoproteins, apoptotic cells and phospholipids. SR-BI is widely expressed and exists in high abundance in caveolae, which is highly enriched with cholesterol. SR-BI expression has been shown to increase cholesterol influx and efflux from HDL.
Four isoforms have been described to be produced by alternative splicing of SR-BI. This protein also functions a receptor for Hepatitis C virus glycoprotein E2. Barth, H., et al. may have found a significant contribution to the design of Hepatitis C virus vaccines [PMID: 18216094]. Using SR-BI antibodies to identify the function of the protein they demonstrated that SR-BI antibodies inhibit the uptake of hepatitis C virus. They therefore identified SR-BI as a key factor required for the uptake of the virus. SR-BI has been found to be highly expressed on the cell surface of human dendritic cells. Using antibodies to bind to the protein on the cell surface the researchers found that cross-presentation by human dendritic cells was inhibited therefore demonstrating the need for SR-BI in this role.
Novus Biologicals offers SR-BI reagents for your research needs including:
