Tyrosine phosphorylation of CD22 during B cell activation.
Ligation of the antigen receptor on B cells induces the rapid phosphorylation of tyrosine on a number of cellular proteins. A monoclonal antibody that recognized a tyrosine-phosphorylated cell surface protein that was present in activated B cells was generated. Amino acid sequence analysis showed that this 140-kilodalton protein was CD22, a B cell-specific cell surface glycoprotein and putative extracellular ligand of the protein tyrosine phosphatase CD45. Tyrosine phosphorylation of CD22 may be important in B cell signal transduction, possibly through regulation of the adhesiveness of activated B cells.
D015703:Antigens, CD / Q000378:metabolism*; D000944:Antigens, Differentiation, B-Lymphocyte / Q000378:metabolism*; D001402:B-Lymphocytes / Q000276:immunology*; D002051:Burkitt Lymphoma; D015815:Cell Adhesion Molecules; D002918:Chymotrypsin / Q000378:metabolism; D006801:Humans; D015151:Immunoblotting; D007163:Immunosorbent Techniques; D037102:Lectins; D008213:Lymphocyte Activation; D010449:Peptide Mapping; D010766:Phosphorylation; D019000:Phosphotyrosine; D051918:Sialic Acid Binding Ig-like Lectin 2; D015398:Signal Transduction / Q000502:physiology; D014407:Tumor Cells, Cultured; D014443:Tyrosine / Q000031:analogs & derivatives* / Q000378:metabolism
D015703:Antigens, CD; D000944:Antigens, Differentiation, B-Lymphocyte; C497867:CD22 protein, human; D015815:Cell Adhesion Molecules; D037102:Lectins; D051918:Sialic Acid Binding Ig-like Lectin 2; D019000:Phosphotyrosine; D014443:Tyrosine; D002918:Chymotrypsin