protein_function: Acts as an endocytic receptor mediating clathrindependent endocytosis. Macrophage-restricted adhesion moleculethat mediates sialic-acid dependent binding to lymphocytes,including granulocytes, monocytes, natural killer cells, B-cellsand CD8 T-cells (By similarity). Preferentially binds to alpha-2,3-linked sialic acid. Binds to SPN,CD43 on T-cells. May play arole in hematopoiesis. May act as a counter-receptor for CLEC10Ain lymph node..
SIGLEC-1, also known as Sialoadhesin or CD169, is a cell adhesion molecule found on the surface of certain cells of the immune system called macrophages. This gene is mapped to 20p13. It belongs to the immunoglobulin superfamily(IgSF). Since sialoadhesin binds sialic acids with its N-terminal IgV-domain, it is also a member of the SIGLEC family. The localization and expression of SIGLEC-1 in humans has altered coincident with the evolutionary loss of Neu5Gc. SIGLEC-1-positive macrophages have a dual physiologic function. They act as innate "flypaper" by preventing the systemic spread of lymph-borne pathogens and as critical gatekeepers at the lymph-tissue interface that facilitate the recognition of particulate antigens by B cells and initiate humoral immune responses.
