SR-BI

The ABCA1 molecule is a primary gatekeeper for regulating the intracellular transport of cholesterol. It belongs to a larger related multifamily of cAMP-dependent anion transporter cell membrane molecules. These key proteins are responsible for trafficking the reverse efflux of cholesterol from cells into peripheral tissues using the apolipoprotein A-1 (apo) carrier. In particular, the ABCA1 molecule exhibits a diverse expression profile and is found most highly expressed in macrophages.

The ATP-binding cassette transporter A1 (ABCA1) protein is a key gatekeeper for regulating intracellular cholesterol transport. It is one member of a large family of genes comprised of cAMP-dependent anion transporter cell membrane proteins. These important proteins regulate reverse cholesterol efflux from cells into the peripheral tissues via apolipoprotein A-1 (apo). ABCA1 in particular has a diverse expression profile and is most highly expressed in macrophages.

SR-B1 belongs to the CD36 scavenger receptor family and serves as a receptor for several ligands including phospholipids, cholesterol ester, lipoproteins, phosphatidylserine, and caveolae localized HDL. It is expressed in endothelial cells, macrophages, and dendritic cells. It facilitates the flux of both free and esterified cholesterol between the cell surface and extracellular donors and acceptors (HDL and to a lesser extent, apoB-containing lipoproteins and modified lipoproteins).