Recombinant Human BTK Kinase Domain (aa 216-659) is a high-purity protein fragment encompassing the SH2 and Protein Kinase functional domains of Bruton's Tyrosine Kinase. This product serves as an essential tool for investigating B-cell receptor signaling, kinase activity, and immune pathway regulation in life science research.

Tyrosine-protein kinase BTK is a non-receptor tyrosine kinase crucial for B lymphocyte development, differentiation, and signaling. Following B-cell antigen receptor engagement, BTK phosphorylates PLCG2 in cooperation with BLNK adapter protein, initiating downstream signaling through calcium mobilization and PKC activation. BTK functions as a signaling platform in cytokine receptor pathways and Toll-like receptor pathways, particularly regulating TLR9 activation in splenic B-cells. It induces NF-kappa-B activity and is involved in TLR8/TLR9 to NF-kappa-B signaling pathways. BTK also activates NLRP3 inflammasome assembly through NLRP3 phosphorylation and plays a role in STING1-mediated type I interferon response by phosphorylating DDX41. The protein exhibits dual roles in apoptosis regulation and transiently phosphorylates transcription factors including GTF2I, ARID3A, and NFAT. BTK localizes predominantly in the cytoplasm under steady-state conditions, translocates to the plasma membrane following BCR engagement via its PH domain, and shuttles between the nucleus and cytoplasm with nuclear export mediated by CRM1.