CD22 Mouse Monoclonal Antibody [A2G6] (EM1902-13)

UNIPROT #

P20273

PROTEIN NAME

CD22

SYNONYMS

B cell receptor CD22 precursor antibody;B lymphocyte cell adhesion molecule antibody;B-cell receptor CD22 antibody;B-lymphocyte cell adhesion molecule antibody;BL CAM antibody;BL-CAM antibody;BLCAM antibody;CD 22 antibody;CD22 antibody;CD22 antigen antibody;CD22 molecule antibody;CD22 protein antibody;CD22_HUMAN antibody;Lectin 2 antibody;Leu14 antibody;Lyb8 antibody;MGC130020 antibody;sialic acid binding Ig like lectin 2 antibody;Sialic acid binding immunoglobulin like lectin 2 antibody;Sialic acid-binding Ig-like lectin 2 antibody;SIGLEC 2 antibody;Siglec-2 antibody;SIGLEC2 antibody;T cell surface antigen Leu 14 antibody;T-cell surface antigen Leu-14 antibody

SEQUENCE SIMILARITIES

Belongs to the immunoglobulin superfamily. SIGLEC (sialic acid binding Ig-like lectin) family.

TISSUE SPECIFICITY

B-lymphocytes.

POST-TRANSLATIONAL MODIFICATION

Phosphorylation of Tyr-762, Tyr-807 and Tyr-822 are involved in binding to SYK, GRB2 and SYK, respectively. Phosphorylation of Tyr-842 is involved in binding to SYK, PLCG2 and PIK3R1/PIK3R2.; Phosphorylated on tyrosine residues by LYN.

SUBCELLULAR LOCATION

Cell membrane.

FUNCTION

CD22, or cluster of differentiation-22, is a molecule belonging to the SIGLEC family of lectins. It is found on the surface of mature B cells and to a lesser extent on some immature B cells. Generally speaking, CD22 is a regulatory molecule that prevents the overactivation of the immune system and the development of autoimmune diseases. CD22 is a sugar binding transmembrane protein, which specifically binds sialic acid with an immunoglobulin (Ig) domain located at its N-terminus. The presence of Ig domains makes CD22 a member of the immunoglobulin superfamily. CD22 functions as an inhibitory receptor for B cell receptor (BCR) signaling. 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.