protein_function: Acute phase-regulated receptor involved in clearance andendocytosis of hemoglobin,haptoglobin complexes by macrophages andmay thereby protect tissues from free hemoglobin-mediatedoxidative damage. May play a role in the uptake and recycling ofiron, via endocytosis of hemoglobin,haptoglobin and subsequentbreakdown of heme. Binds hemoglobin,haptoglobin complexes in acalcium-dependent and pH-dependent manner. Exhibits a higheraffinity for complexes of hemoglobin and multimeric haptoglobin ofHP*1F phenotype than for complexes of hemoglobin and dimerichaptoglobin of HP*1S phenotype. Induces a cascade of intracellularsignals that involves tyrosine kinase-dependent calciummobilization, inositol triphosphate production and secretion ofIL6 and CSF1. Isoform 3 exhibits the higher capacity for ligandendocytosis and the more pronounced surface expression whenexpressed in cells.
CD163(Cluster of Differentiation 163) is a human protein encoded by the CD163 gene. It has also been shown to mark cells of monocyte,macrophage lineage. CD163, a member of the scavenger receptor cysteine-rich(SRCR) superfamily, is exclusively expressed by monocytes and macrophages. Using FISH, somatic cell hybrid analysis, and radiation hybrid analysis, CD163 gene was mapped the to chromosome 12p13.3. CD163 is upregulated in a large range of diseases inflammatory diseases including type 2 diabetes, macrophage activation sickness, Tangier"s disease, reumatoid arthritis etc.