Anti-CD21 antibody [SP199],Abcam,AB227668

Target data Serves as a receptor for various ligands including complement component CD3d, HNRNPU OR IFNA1 (PubMed : 1849076, PubMed : 21527715, PubMed : 7753047). When C3d is bound to antigens, attaches to C3d on B-cell surface and thereby facilitates the recognition and uptake of antigens by B-cells (PubMed : 21527715). This interaction enhances B-cell activation and subsequent immune responses. Forms a complex with several partners on the surface of B-cells including CD19, FCRL5 and CD81, to form the B-cell coreceptor complex that plays a crucial role in B-cell activation and signaling (PubMed : 1383329, PubMed : 30107486). Induces also specific intracellular signaling separately from the BCR and CD19 by activating the tyrosine kinase SRC, which then phosphorylates nucleolin/NCL and triggers AKT and GSK3 kinase activities in a SYK/CD19-independent manner (PubMed : 12938232). Acts as a ligand for CD23 (FcepsilonRII), a low-affinity receptor for IgE, which is expressed on B-cells and other immune cells, and thus participates in the regulation of IgE production (PubMed : 1386409).. (Microbial infection) Acts as a receptor for Epstein-Barr virus. See full target information CR2