4rvm

CHK1 kinase domain with diazacarbazole compound 19

spinqualitylabelsall models 4rvm, resolution 1.86Å Show:Asymmetric Unit Biological Assembly Drag the structure with the mouse to rotate   Export Animated Image   Print3D Structural highlights 4rvm 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 1.86Å Ligands: 3X7 Resources: FirstGlance, OCA, PDBe, RCSB, PDBsum, ProSAT Function CHK1_HUMAN Serine/threonine-protein kinase which is required for checkpoint-mediated cell cycle arrest and activation of DNA repair in response to the presence of DNA damage or unreplicated DNA. May also negatively regulate cell cycle progression during unperturbed cell cycles. This regulation is achieved by a number of mechanisms that together help to preserve the integrity of the genome. Recognizes the substrate consensus sequence [R-X-X-S/T]. Binds to and phosphorylates CDC25A, CDC25B and CDC25C. Phosphorylation of CDC25A at 'Ser-178' and 'Thr-507' and phosphorylation of CDC25C at 'Ser-216' creates binding sites for 14-3-3 proteins which inhibit CDC25A and CDC25C. Phosphorylation of CDC25A at 'Ser-76', 'Ser-124', 'Ser-178', 'Ser-279' and 'Ser-293' promotes proteolysis of CDC25A. Phosphorylation of CDC25A at 'Ser-76' primes the protein for subsequent phosphorylation at 'Ser-79', 'Ser-82' and 'Ser-88' by NEK11, which is required for polyubiquitination and degradation of CDCD25A. Inhibition of CDC25 leads to increased inhibitory tyrosine phosphorylation of CDK-cyclin complexes and blocks cell cycle progression. Also phosphorylates NEK6. Binds to and phosphorylates RAD51 at 'Thr-309', which promotes the release of RAD51 from BRCA2 and enhances the association of RAD51 with chromatin, thereby promoting DNA repair by homologous recombination. Phosphorylates multiple sites within the C-terminus of TP53, which promotes activation of TP53 by acetylation and promotes cell cycle arrest and suppression of cellular proliferation. Also promotes repair of DNA cross-links through phosphorylation of FANCE. Binds to and phosphorylates TLK1 at 'Ser-743', which prevents the TLK1-dependent phosphorylation of the chromatin assembly factor ASF1A. This may enhance chromatin assembly both in the presence or absence of DNA damage. May also play a role in replication fork maintenance through regulation of PCNA. May regulate the transcription of genes that regulate cell-cycle progression through the phosphorylation of histones. Phosphorylates histone H3.1 (to form H3T11ph), which leads to epigenetic inhibition of a subset of genes. May also phosphorylate RB1 to promote its interaction with the E2F family of transcription factors and subsequent cell cycle arrest. Isoform 2: Endogenous repressor of isoform 1, interacts with, and antagonizes CHK1 to promote the S to G2/M phase transition. Publication Abstract from PubMed Checkpoint kinsase 1 (ChK1) plays a key role in the DNA damage response, facilitating cell-cycle arrest to provide sufficient time for lesion repair. This leads to the hypothesis that inhibition of ChK1 might enhance the effectiveness of DNA-damaging therapies in the treatment of cancer. Lead compound 1 (GNE-783), the prototype of the 1,7-diazacarbazole class of ChK1 inhibitors, was found to be a highly potent inhibitor of acetylcholine esterase (AChE) and unsuitable for development. A campaign of analog synthesis established SAR delineating ChK1 and AChE activities, and allowing identification of new leads with improved profiles. In silico docking using a model of AChE permitted rationalization of the observed SAR. Compound 19 (GNE-900) and compound 30 (GNE-145) were identified as selective, orally bioavailable ChK1 inhibitors offering excellent in vitro potency with significantly reduced AChE activity. In combination with gemcitabine, these compounds demonstrate an in vivo pharmacodynamic effect and are efficacious in a mouse p53-mutant xenograft model. Mitigation of Acetylcholine Esterase Activity in the 1,7-Diazacarbazole Series of Inhibitors of Checkpoint Kinase 1.,Gazzard L, Williams K, Chen H, Axford L, Blackwood E, Burton B, Chapman K, Crackett P, Drobnick J, Ellwood C, Epler J, Flagella M, Gancia E, Gill M, Goodacre S, Halladay J, Hewitt J, Hunt H, Kintz S, Lyssikatos J, Macleod C, Major S, Medard G, Narukulla R, Ramiscal J, Schmidt S, Seward E, Wiesmann C, Wu P, Yee S, Yen I, Malek S J Med Chem. 2015 May 19. PMID:25988399 From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. See Also Serine/threonine protein kinase 3D structures

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