CD22 Mediates B-cell B-cell interactions. May be involved in the localization of B-cells in lymphoid tissues. Binds sialylated glycoproteins; one of which is CD45. Preferentially binds to alpha-2,6-linked sialic acid. The sialic acid recognition site can be masked by cis interactions with sialic acids on the same cell surface. Upon ligand induced tyrosine phosphorylation in the immune response seems to be involved in regulation of B-cell antigen receptor signaling. Plays a role in positive regulation through interaction with Src family tyrosine kinases and may also act as an inhibitory receptor by recruiting cytoplasmic phosphatases via their SH2 domains that block signal transduction through dephosphorylation of signaling molecules. Belongs to the immunoglobulin superfamily. SIGLEC (sialic acid binding Ig-like lectin) family. B-lymphocytes. 5 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
Protein type: Cell surface; Membrane protein, integral
Chromosomal Location of human Ortholog: 19q13.12
Cellular Component:  cell surface; cytoplasm; early endosome; integral component of membrane; neuronal cell body membrane; plasma membrane; recycling endosome
Molecular Function:  carbohydrate binding; CD4 receptor binding; IgM binding; protein binding; protein phosphatase binding; sialic acid binding; signaling receptor binding
Biological Process:  B cell activation; cell adhesion; negative regulation of B cell receptor signaling pathway; negative regulation of calcium-mediated signaling; negative regulation of immunoglobulin secretion; regulation of B cell proliferation; regulation of endocytosis; regulation of immune response
Reference #:  P20273 (UniProtKB)
Alt. Names/Synonyms: B-cell receptor CD22; B-lymphocyte cell adhesion molecule; BL-CAM; CD22; CD22 antigen; CD22 molecule; FLJ22814; MGC130020; sialic acid binding Ig-like lectin 2; Sialic acid-binding Ig-like lectin 2; Siglec-2; SIGLEC2; T-cell surface antigen Leu-14
Gene Symbols: CD22
Molecular weight: 95,348 Da
Basal Isoelectric point: 6.21  Predict pI for various phosphorylation states
Protein-Specific Antibodies, siRNAs or Recombinant Proteins from Cell Signaling Technology® Total Proteins
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Protein Structure Not Found.

Cross-references to other databases:  AlphaFold  |  STRING  |  cBioPortal  |  Wikipedia  |  neXtProt  |  Protein Atlas  |  BioGPS  |  Pfam  |  RCSB PDB  |  Phospho.ELM  |  NetworKIN  |  GeneCards  |  UniProtKB  |  Entrez-Gene  |  GenPept  |  Ensembl Gene  |  Ensembl Protein