4l7s | pdb_00004l7s
Kinase domain mutant of human Itk in complex with an aminobenzothiazole inhibitor
Structural highlights
DiseaseITK_HUMAN Defects in ITK are the cause of lymphoproliferative syndrome EBV-associated autosomal type 1 (LPSA1) [MIM:613011. LPSA1 is a rare immunodeficiency characterized by extreme susceptibility to infection with Epstein-Barr virus (EBV). Inadequate immune response to EBV can have a fatal outcome. Clinical features include splenomegaly, lymphadenopathy, anemia, thrombocytopenia, pancytopenia, recurrent infections. There is an increased risk for lymphoma.[1] FunctionITK_HUMAN Tyrosine kinase that plays an essential role in regulation of the adaptive immune response. Regulates the development, function and differentiation of conventional T-cells and nonconventional NKT-cells. When antigen presenting cells (APC) activate T-cell receptor (TCR), a series of phosphorylation lead to the recruitment of ITK to the cell membrane, in the vicinity of the stimulated TCR receptor, where it is phosphorylated by LCK. Phosphorylation leads to ITK autophosphorylation and full activation. Once activated, phosphorylates PLCG1, leading to the activation of this lipase and subsequent cleavage of its substrates. In turn, the endoplasmic reticulum releases calcium in the cytoplasm and the nuclear activator of activated T-cells (NFAT) translocates into the nucleus to perform its transcriptional duty. Phosphorylates 2 essential adapter proteins: the linker for activation of T-cells/LAT protein and LCP2. Then, a large number of signaling molecules such as VAV1 are recruited and ultimately lead to lymphokine production, T-cell proliferation and differentiation.[2] [3] [4] Publication Abstract from PubMedInhibition of Itk potentially constitutes a novel, nonsteroidal treatment for asthma and other T-cell mediated diseases. In-house kinase cross-screening resulted in the identification of an aminopyrazole-based series of Itk inhibitors. Initial work on this series highlighted selectivity issues with several other kinases, particularly AurA and AurB. A template-hopping strategy was used to identify a series of aminobenzothiazole Itk inhibitors, which utilized an inherently more selective hinge binding motif. Crystallography and modeling were used to rationalize the observed selectivity. Initial exploration of the SAR around this series identified potent Itk inhibitors in both enzyme and cellular assays. Identification of a Novel and Selective Series of Itk Inhibitors via a Template-Hopping Strategy.,Alder CM, Ambler M, Campbell AJ, Champigny AC, Deakin AM, Harling JD, Harris CA, Longstaff T, Lynn S, Maxwell AC, Mooney CJ, Scullion C, Singh OM, Smith IE, Somers DO, Tame CJ, Wayne G, Wilson C, Woolven JM ACS Med Chem Lett. 2013 Aug 12;4(10):948-52. doi: 10.1021/ml400206q. eCollection , 2013 Oct 10. PMID:24900590[5] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See AlsoReferences
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