International Immunology, Vol. 12, No. 10, 1397-1408,
October 2000
© 2000 Japanese Society for Immunology
Identification and characterization of a molecule, BAM11, that associates with the pleckstrin homology domain of mouse Btk
1 Department of Immunology, Institute of Medical Science, University of Tokyo, 4-6-1 Shirokanedai, Minato-ku, Tokyo 108-8639, Japan
2 Laboratory of Molecular Immunology, Center for Basic Research, Kitasato Institute, 5-9-1 Shirokane, Minato-ku, Tokyo 108-8642, Japan
3 Department of Pathology, Aichi Cancer Center, Chikusa-ku, Nagoya 464-8681, Japan
Correspondence to: K. Takatsu,
Bruton's tyrosine kinase (Btk) is required for normal B cell development and signal transduction through cell surface molecules, and its defects lead to X-linked immune deficiency in mice and X-linked agammaglobulinemia in humans. In this report, we will describe the identification and characterization of a molecule, BAM11, which binds to the pleckstrin homology domain of Btk. A sequence homology search revealed that BAM11 has 89% homology, at the amino acid level, to human LTG19/ENL, that was originally identified as one of the fusion partners involved in chromosomal translocations of 11q23, MLL/ALL-1/HRX, in leukemia cells. Deletion mutants demonstrated that the region of BAM11 required for binding to Btk was localized between amino acid residues 240 and 256. Forced expression of a truncated form of BAM11 (amino acids 246–368) inhibited IL-5-induced proliferation by 50%, whereas forced expression of full-length BAM11 in Y16 cells did not affect the IL-5 responsiveness. We have also shown that BAM11 (amino acids 246–368) inhibited the kinase activity of Btk. These results suggest that the binding of BAM11 to Btk plays a regulatory role in the Btk signal transduction pathway. A cell fractionation study and analysis using EGFP-fused Btk protein demonstrated that a proportion of Btk is present within the nucleus.
Keywords: IL-5, LTG19, ENL, signal transduction
The first two authors contributed equally to this work
Transmitting editor: D. Kitamura
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  J. Rajaiya, J. C. Nixon, N. Ayers, Z. P. Desgranges, A. L. Roy, and C. F. Webb Induction of Immunoglobulin Heavy-Chain Transcription through the Transcription Factor Bright Requires TFII-I Mol. Cell. Biol., June 15, 2006; 26(12): 4758 - 4768. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
J. Rajaiya, M. Hatfield, J. C. Nixon, D. J. Rawlings, and C. F. Webb Bruton's Tyrosine Kinase Regulates Immunoglobulin Promoter Activation in Association with the Transcription Factor Bright Mol. Cell. Biol., March 15, 2005; 25(6): 2073 - 2084. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 B.-g. Moon, S. Takaki, K. Miyake, and K. Takatsu The Role of IL-5 for Mature B-1 Cells in Homeostatic Proliferation, Cell Survival, and Ig Production J. Immunol., May 15, 2004; 172(10): 6020 - 6029. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. Hirano, Y. Kikuchi, S. Nisitani, A. Yamaguchi, A. Satoh, T. Ito, H. Iba, and K. Takatsu Bruton's tyrosine kinase (Btk) enhances transcriptional co-activation activity of BAM11, a Btk-associated molecule of a subunit of SWI/SNF complexes Int. Immunol., May 1, 2004; 16(5): 747 - 757. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 A. Takesono, L. D. Finkelstein, and P. L. Schwartzberg Beyond calcium: new signaling pathways for Tec family kinases J. Cell Sci., January 8, 2002; 115(15): 3039 - 3048. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
K. Horikawa, H. Kaku, H. Nakajima, H. W. Davey, L. Henninghausen, I. Iwamoto, T. Yasue, A. Kariyone, and K. Takatsu Essential Role of Stat5 for IL-5-Dependent IgH Switch Recombination in Mouse B Cells J. Immunol., November 1, 2001; 167(9): 5018 - 5026. [Abstract] [Full Text] [PDF]
|
|