title: Bruton's tyrosine kinase regulates B cell antigen receptor-mediated JNK1 response through Rac1 and phospholipase C-gamma2 activation.
abstract: Bruton's tyrosine kinase (Btk) is essential for B cell development and B cell antigen receptor (BCR) function. Recent studies have shown that Btk plays an important role in BCR-mediated c-Jun NH(2)-terminal kinase (JNK) 1 activation; however, the mechanism by which Btk participates in the JNK1 response remains elusive. Here we show that the BCR-mediated Rac1 activation is significantly inhibited by loss of Btk, while this Rac1 activation is not affected by loss of phospholipase C-gamma2 (PLC-gamma2). Since PLC-gamma2 is also required for BCR-mediated JNK1 response, our results suggest that Btk regulates Rac1 pathway as well as PLC-gamma2 pathway, both of which contribute to the BCR-mediated JNK1 response.
authors.affiliation: Department of Molecular Genetics, Institute for Liver Research, Kansai Medical University, Moriguchi 570-8506, Japan.
authors.forename: Kazunori
authors.initials: K
authors.lastname: Inabe
authors.forename: Toshio
authors.initials: T
authors.lastname: Miyawaki
authors.forename: Richard
authors.initials: R
authors.lastname: Longnecker
authors.forename: Hiroyoshi
authors.initials: H
authors.lastname: Matsukura
authors.forename: Satoshi
authors.initials: S
authors.lastname: Tsukada
authors.forename: Tomohiro
authors.initials: T
authors.lastname: Kurosaki
mesh_terms: D000077329:Agammaglobulinaemia Tyrosine Kinase; D000361:Agammaglobulinemia / Q000201:enzymology; D000818:Animals; D001402:B-Lymphocytes / Q000378:metabolism; D015153:Blotting, Western; D002460:Cell Line; D002645:Chickens; D004789:Enzyme Activation / Q000502:physiology; D006801:Humans; D007527:Isoenzymes / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D048055:Mitogen-Activated Protein Kinase 8; D020928:Mitogen-Activated Protein Kinases / Q000378:metabolism*; D051966:Phospholipase C gamma; D011233:Precipitin Tests; D011505:Protein-Tyrosine Kinases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D011947:Receptors, Antigen, B-Cell / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology; D014162:Transfection; D010738:Type C Phospholipases / Q000172:deficiency / Q000235:genetics / Q000378:metabolism*; D020830:rac1 GTP-Binding Protein / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D011947:Receptors, Antigen, B-Cell; D011505:Protein-Tyrosine Kinases; D000077329:Agammaglobulinaemia Tyrosine Kinase; C000625949:BTK protein, human; D048055:Mitogen-Activated Protein Kinase 8; D020928:Mitogen-Activated Protein Kinases; D010738:Type C Phospholipases; D051966:Phospholipase C gamma; D020830:rac1 GTP-Binding Protein