Bruton tyrosine kinase is tyrosine phosphorylated and activated in pre-B lymphocytes and receptor-ligated B cells.
The gene encoding Bruton tyrosine kinase (Btk) is known to be mutated in human X chromosome-linked agammaglobulinemia and in the Xid mouse. This kinase was examined in B lymphocytes before and after antigen receptor ligation and also in pre-B cells. Btk was found to be catalytically activated and tyrosine phosphorylated in response to anti-IgM stimulation in B cells. This kinase is also constitutively phosphorylated on tyrosine residues in pre-B cells. These findings point to a functional role for Btk in pre-antigen and antigen receptor signaling during B-cell development and provide a biochemical explanation for the X-linked genetic syndromes already linked to this kinase.
Aoki
Y
Y
Massachusetts General Hospital Cancer Center, Boston 02129.
Isselbacher
K J
KJ
Pillai
S
S
D000077329:Agammaglobulinaemia Tyrosine Kinase; D000361:Agammaglobulinemia / Q000235:genetics / Q000276:immunology; D000818:Animals; D001402:B-Lymphocytes / Q000201:enzymology* / Q000276:immunology; D002460:Cell Line; D004789:Enzyme Activation; D006412:Hematopoietic Stem Cells / Q000201:enzymology / Q000276:immunology; D006801:Humans; D007075:Immunoglobulin M; D007700:Kinetics; D051379:Mice; D008817:Mice, Mutant Strains; D008954:Models, Biological; D009154:Mutation; D010766:Phosphorylation; D019000:Phosphotyrosine; D011505:Protein-Tyrosine Kinases / Q000302:isolation & purification / Q000378:metabolism*; D011948:Receptors, Antigen, T-Cell / Q000378:metabolism*; D015398:Signal Transduction; D014443:Tyrosine / Q000031:analogs & derivatives / Q000032:analysis; D014960:X Chromosome
D007075:Immunoglobulin M; D011948:Receptors, Antigen, T-Cell; D019000:Phosphotyrosine; D014443:Tyrosine; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; C000625949:BTK protein, human; C000625951:Btk protein, mouse