Identification and characterization of a novel SH3-domain binding protein, Sab, which preferentially associates with Bruton's tyrosine kinase (BtK).
Matsushita M,
Yamadori T,
Kato S,
Takemoto Y,
Inazawa J,
Baba Y,
Hashimoto S,
Sekine S,
Arai S,
Kunikata T,
Kurimoto M,
Kishimoto T,
Tsukada S.
Department of Medicine III, Osaka University Medical School, Japan.
Protein interaction cloning method was used to identify a novel molecule, Sab, which binds to the SH3 domain of Bruton's tyrosine kinase (Btk), the deficient cytoplasmic tyrosine kinase in human X-linked agammaglobulinemia and murine X-linked immunodeficiency. Immunoprecipitation using the anti-Sab antibody identified the protein product of the gene as a 70 kDa molecule. While Sab does not have a proline-rich sequence, it was shown to bind to Btk through the commonly conserved structure among SH3 domains. Remarkably, Sab exhibited a high preference for binding to Btk rather than to other cytoplasmic tyrosine kinases, which suggests a unique role of Sab in the Btk signal transduction pathway.
PMID: 9571151 [PubMed - indexed for MEDLINE]