JNK1 in complex with inhibitor
[MK08_HUMAN] Serine/threonine-protein kinase involved in various processes such as cell proliferation, differentiation, migration, transformation and programmed cell death. Extracellular stimuli such as proinflammatory cytokines or physical stress stimulate the stress-activated protein kinase/c-Jun N-terminal kinase (SAP/JNK) signaling pathway. In this cascade, two dual specificity kinases MAP2K4/MKK4 and MAP2K7/MKK7 phosphorylate and activate MAPK8/JNK1. In turn, MAPK8/JNK1 phosphorylates a number of transcription factors, primarily components of AP-1 such as JUN, JDP2 and ATF2 and thus regulates AP-1 transcriptional activity. Phosphorylates the replication licensing factor CDT1, inhibiting the interaction between CDT1 and the histone H4 acetylase HBO1 to replication origins. Loss of this interaction abrogates the acetylation required for replication initiation. Promotes stressed cell apoptosis by phosphorylating key regulatory factors including p53/TP53 and Yes-associates protein YAP1. In T-cells, MAPK8 and MAPK9 are required for polarized differentiation of T-helper cells into Th1 cells. Contributes to the survival of erythroid cells by phosphorylating the antagonist of cell death BAD upon EPO stimulation. Mediates starvation-induced BCL2 phosphorylation, BCL2 dissociation from BECN1, and thus activation of autophagy. Phosphorylates STMN2 and hence regulates microtubule dynamics, controlling neurite elongation in cortical neurons. In the developing brain, through its cytoplasmic activity on STMN2, negatively regulates the rate of exit from multipolar stage and of radial migration from the ventricular zone. Phosphorylates several other substrates including heat shock factor protein 4 (HSF4), the deacetylase SIRT1, ELK1, or the E3 ligase ITCH.        JNK1 isoforms display different binding patterns: beta-1 preferentially binds to c-Jun, whereas alpha-1, alpha-2, and beta-2 have a similar low level of binding to both c-Jun or ATF2. However, there is no correlation between binding and phosphorylation, which is achieved at about the same efficiency by all isoforms.       
Publication Abstract from PubMed
Checkpoint kinases, CHK1 and CHK2 are activated in response to DNA damage that results in cell cycle arrest allowing sufficient time for DNA repair. Agents which lead to abrogation of such checkpoints have potential to increase the efficacy of such as chemo- and radio-therapies. Thiophene carboxamide ureas (TCUs) were identified as inhibitors of CHK1 by high throughput screening. A structure-based approach is described using crystal structures of JNK1 and CHK1 in complex with 1 and 2, and of the CHK1-3b complex. The ribose binding pocket of CHK1 was targetted to generate inhibitors with excellent cellular potency and selectivity over CDK1and IKKbeta key features lacking from the initial compounds. Optimization of 3b resulted in the identification of a regioisomeric 3-TCU lead, 12a. Optimization of 12a led to the discovery of the clinical candidate 4 (AZD7762), that strongly potentiates the efficacy of a variety of DNA-damaging agents in preclinical models.
Discovery of Checkpoint Kinase Inhibitor (S)-5-(3-fluorophenyl)-N-(piperidin-3-yl)-3-ureidothiophene-2-carboxamide (AZD7762) by Structure Based Design and Optimization of Thiophene Carboxamide Ureas.,Oza VB, Ashwell S, Almeida L, Brassil P, Breed J, Deng C, Gero T, Grondine M, Horn C, Ioannidis S, Liu D, Lyne PD, Newcombe N, Pass M, Read J, Ready S, Rowsell S, Su M, Toader D, Vasbinder M, Yu D, Yu Y, Xue Y, Zabludoff S, Janetka J J Med Chem. 2012 May 2. PMID:22551018
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine.