8ejb

Bruton's tyrosine kinase in complex with 3-{[4-(1-acetylpiperidin-4-yl)phenyl]amino}-5-[(3R)-3-(3-methyl-2-oxoimidazolidin-1-yl)piperidin-1-yl]pyrazine-2-carboxamide

spinqualitylabelsall models 8ejb, resolution 1.58Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 8ejb is a 1 chain structure with sequence from Homo sapiens. Full crystallographic information is available from OCA. For a guided tour on the structure components use FirstGlance. Method: X-ray diffraction, Resolution 1.58Å Ligands: CL, EDO, PD, WKC Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Disease BTK_HUMAN Defects in BTK are the cause of X-linked agammaglobulinemia (XLA) [MIM:300755; also known as X-linked agammaglobulinemia type 1 (AGMX1) or immunodeficiency type 1 (IMD1). XLA is a humoral immunodeficiency disease which results in developmental defects in the maturation pathway of B-cells. Affected boys have normal levels of pre-B-cells in their bone marrow but virtually no circulating mature B-lymphocytes. This results in a lack of immunoglobulins of all classes and leads to recurrent bacterial infections like otitis, conjunctivitis, dermatitis, sinusitis in the first few years of life, or even some patients present overwhelming sepsis or meningitis, resulting in death in a few hours. Treatment in most cases is by infusion of intravenous immunoglobulin. Defects in BTK may be the cause of X-linked hypogammaglobulinemia and isolated growth hormone deficiency (XLA-IGHD) [MIM:307200; also known as agammaglobulinemia and isolated growth hormone deficiency or Fleisher syndrome or isolated growth hormone deficiency type 3 (IGHD3). In rare cases XLA is inherited together with isolated growth hormone deficiency (IGHD). Function BTK_HUMAN Non-receptor tyrosine kinase indispensable for B lymphocyte development, differentiation and signaling. Binding of antigen to the B-cell antigen receptor (BCR) triggers signaling that ultimately leads to B-cell activation. After BCR engagement and activation at the plasma membrane, phosphorylates PLCG2 at several sites, igniting the downstream signaling pathway through calcium mobilization, followed by activation of the protein kinase C (PKC) family members. PLCG2 phosphorylation is performed in close cooperation with the adapter protein B-cell linker protein BLNK. BTK acts as a platform to bring together a diverse array of signaling proteins and is implicated in cytokine receptor signaling pathways. Plays an important role in the function of immune cells of innate as well as adaptive immunity, as a component of the Toll-like receptors (TLR) pathway. The TLR pathway acts as a primary surveillance system for the detection of pathogens and are crucial to the activation of host defense. Especially, is a critical molecule in regulating TLR9 activation in splenic B-cells. Within the TLR pathway, induces tyrosine phosphorylation of TIRAP which leads to TIRAP degradation. BTK plays also a critical role in transcription regulation. Induces the activity of NF-kappa-B, which is involved in regulating the expression of hundreds of genes. BTK is involved on the signaling pathway linking TLR8 and TLR9 to NF-kappa-B. Transiently phosphorylates transcription factor GTF2I on tyrosine residues in response to BCR. GTF2I then translocates to the nucleus to bind regulatory enhancer elements to modulate gene expression. ARID3A and NFAT are other transcriptional target of BTK. BTK is required for the formation of functional ARID3A DNA-binding complexes. There is however no evidence that BTK itself binds directly to DNA. BTK has a dual role in the regulation of apoptosis. Publication Abstract from PubMed Bruton tyrosine kinase (BTK) is essential for B-cell receptor (BCR) signaling, a driver of chronic lymphocytic leukemia (CLL). Covalent inhibitors bind C481 in the active site of BTK and have become a preferred CLL therapy. Disease progression on covalent BTK inhibitors is commonly associated with C481 mutations. Here, we investigated a targeted protein degrader, NRX-0492, that links a noncovalent BTK-binding domain to cereblon, an adaptor protein of the E3 ubiquitin ligase complex. NRX-0492 selectively catalyzes ubiquitylation and proteasomal degradation of BTK. In primary CLL cells, NRX-0492 induced rapid and sustained degradation of both wild-type and C481 mutant BTK at half maximal degradation concentration (DC50) of </=0.2 nM and DC90 of </=0.5 nM, respectively. Sustained degrader activity was maintained for at least 24 hours after washout and was equally observed in high-risk (deletion 17p) and standard-risk (deletion 13q only) CLL subtypes. In in vitro testing against treatment-naive CLL samples, NRX-0492 was as effective as ibrutinib at inhibiting BCR-mediated signaling, transcriptional programs, and chemokine secretion. In patient-derived xenografts, orally administered NRX-0492 induced BTK degradation and inhibited activation and proliferation of CLL cells in blood and spleen and remained efficacious against primary C481S mutant CLL cells collected from a patient progressing on ibrutinib. Oral bioavailability, >90% degradation of BTK at subnanomolar concentrations, and sustained pharmacodynamic effects after drug clearance make this class of targeted protein degraders uniquely suitable for clinical translation, in particular as a strategy to overcome BTK inhibitor resistance. Clinical studies testing this approach have been initiated (NCT04830137, NCT05131022). NRX-0492 degrades wild-type and C481 mutant BTK and demonstrates in vivo activity in CLL patient-derived xenografts.,Zhang D, Harris HM, Chen J, Judy J, James G, Kelly A, McIntosh J, Tenn-McClellan A, Ambing E, Tan YS, Lu H, Gajewski S, Clifton MC, Yung S, Robbins DW, Pirooznia M, Skanland SS, Gaglione E, Mhibik M, Underbayev C, Ahn IE, Sun C, Herman SEM, Noviski M, Wiestner A Blood. 2023 Mar 30;141(13):1584-1596. doi: 10.1182/blood.2022016934. PMID:36375120 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Tyrosine kinase 3D structures

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