Phospho-Btk (Ser180) (3D3) Mouse mAb detects transfected levels of Btk protein when phosphorylated at Ser180. For Western immunoblotting, CST recommends using immunoprecipitated Btk first.
Source / Purification
Monoclonal antibody is produced by immunizing animals with a synthetic phosphopeptide corresponding to residues around Ser180 of human Btk.
Background
Bruton's tyrosine kinase (Btk) is a member of the Btk/Tec family of cytoplasmic tyrosine kinases. Like other Btk family members, it contains a pleckstrin homology (PH) domain, and Src homology SH3 and SH2 domains. Btk plays an important role in B cell development (1,2). Activation of B cells by various ligands is accompanied by Btk membrane translocation mediated by its PH domain binding to phosphatidylinositol-3,4,5-trisphosphate (3-5). The membrane-located Btk is active and associated with transient phosphorylation of two tyrosine residues, Tyr551 and Tyr223. Tyr551 in the activation loop is transphosphorylated by the Src family tyrosine kinase, leading to autophosphorylation at Tyr223 within the SH3 domain, which is necessary for full activation (6,7). The activation of Btk is negatively regulated by PKCβ through phosphorylation of Btk at Ser180, which results in reduced membrane recruitment, transphosphorylation and subsequent activation (8). The PKC inhibitory signal is likely to be a key determinant of the B-cell receptor signaling threshold to maintain optimal Btk activity (8).
Storage:Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA, 50% glycerol and less than 0.02% sodium azide. Store at –20°C. Do not aliquot the antibody.