| Tissue Specificity | Mature B-lymphocytes, T-lymphocytes, pharyngeal epithelial cells, astrocytes and follicular dendritic cells of the spleen. |
| Function | Serves as a receptor for various ligands including complement component CD3d, HNRNPU OR IFNA1. 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. 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. 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. 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. (Microbial infection) Acts as a receptor for Epstein-Barr virus. |
| Peptide Name | Complement Receptor Type 2Cr2Complement C3d ReceptorEpstein-Barr Virus ReceptorEbv ReceptorCd Antigen Cd21 |
| Database Links | Reactome: R-HSA-977606 |
| Cellular Localisation | Cell MembraneSingle-Pass Type I Membrane Protein |
| Alternative Peptide Names | Complement Receptor Type 2 proteinCr2 proteinComplement C3d Receptor proteinEpstein-Barr Virus Receptor proteinEbv Receptor proteinCd Antigen Cd21 proteinCR2 proteinC3DR protein |
Information sourced from Uniprot.org
