Bruton’s tyrosine kinase regulates B cell antigen receptor-mediated JNK1 response through Rac1 and phospholipase C-γ2 activation

• Published in: FEBS letters Vol. 514; no. 2; pp. 260 - 262
• Main Authors: Inabe, Kazunori, Miyawaki, Toshio, Longnecker, Richard, Matsukura, Hiroyoshi, Tsukada, Satoshi, Kurosaki, Tomohiro
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 13.03.2002
• Subjects: B cell antigen receptor; BCR, B cell antigen receptor; Bruton's tyrosine kinase; Btk, Bruton's tyrosine kinase; c-Jun NH 2-terminal kinase; c-Jun NH2-terminal kinase; CRIB, Cdc42/Rac interactive binding domain; JNK, c-Jun NH2-terminal kinase; Phospholipase C-γ2; PLC-γ2, phospholipase C-γ2; PTK, protein tyrosine kinase; Rac1; XLA, X-linked agammaglobulinemia; Bruton’s tyrosine kinase; c-Jun NH 2-terminal kinase; CRIB, Cdc42/Rac interactive binding domain; BCR, B cell antigen receptor; PLC-γ2, phospholipase C-γ2; JNK, c-Jun NH 2-terminal kinase; PTK, protein tyrosine kinase; Phospholipase C-γ2; Btk, Bruton’s tyrosine kinase; Rac1; B cell antigen receptor; XLA, X-linked agammaglobulinemia
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(02)02375-X

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-γ2 (PLC-γ2). Since PLC-γ2 is also required for BCR-mediated JNK1 response, our results suggest that Btk regulates Rac1 pathway as well as PLC-γ2 pathway, both of which contribute to the BCR-mediated JNK1 response.