MSR1/CD204

MSR1, known as CD204 or macrophage scavenger receptor class A, is a trimeric receptor built from collagen-like and scavenger receptor cysteine-rich domains. It binds a broad array of polyanionic ligands, most prominently acetylated and oxidized low-density lipoprotein, and mediates their internalization without the cholesterol-mediated feedback regulation that constrains foam cell formation. The receptor is expressed on macrophages and dendritic cell subsets and also contributes to host defense by binding bacterial endotoxins and lipoteichoic acid. MSR1 participates in lipid deposition during atherogenesis, and polymorphisms in the gene have been associated with Alzheimer disease susceptibility, keeping the receptor relevant to both cardiovascular and neurodegeneration research.