SR-AI/MSR: ProductsThe scavenger receptor (SR) family is a group of membrane receptors that share the common ability to bind and internalize modified forms of low-density lipoproteins (mLDL). The three SR-A alternatively spliced isoforms (I, II, and III) and a structurally similar protein, MARCO, make up the A class of homotrimeric, type II membrane proteins. SR-AI has an N-terminal cytoplasmic domain, transmembrane domain, spacer domain, a-helical coiled coil domain, collagen-like domain, and C-terminal cysteine-rich domain. SR-As are expressed by most tissue macrophages and dendritic cells. SR-As bind a broad range of polyanionic ligands and therefore have been implicated in many physiological and pathophysiological functions.