5ekn | pdb_00005ekn
Crystal structure of MAPK13 complex with inhibitor
Structural highlights
Function[MK13_HUMAN] Serine/threonine kinase which acts as an essential component of the MAP kinase signal transduction pathway. MAPK13 is one of the four p38 MAPKs which play an important role in the cascades of cellular responses evoked by extracellular stimuli such as proinflammatory cytokines or physical stress leading to direct activation of transcription factors such as ELK1 and ATF2. Accordingly, p38 MAPKs phosphorylate a broad range of proteins and it has been estimated that they may have approximately 200 to 300 substrates each. MAPK13 is one of the less studied p38 MAPK isoforms. Some of the targets are downstream kinases such as MAPKAPK2, which are activated through phosphorylation and further phosphorylate additional targets. Plays a role in the regulation of protein translation by phosphorylating and inactivating EEF2K. Involved in cytoskeletal remodeling through phosphorylation of MAPT and STMN1. Mediates UV irradiation induced up-regulation of the gene expression of CXCL14. Plays an important role in the regulation of epidermal keratinocyte differentiation, apoptosis and skin tumor development. Phosphorylates the transcriptional activator MYB in response to stress which leads to rapid MYB degradation via a proteasome-dependent pathway. MAPK13 also phosphorylates and down-regulates PRKD1 during regulation of insulin secretion in pancreatic beta cells.[1] [2] [3] [4] [5] [6] [7] [8] Publication Abstract from PubMedBACKGROUND: P38 MAP kinases are centrally involved in mediating extracellular signaling in various diseases. While much attention has previously been focused on the ubiquitously expressed family member MAPK14 (p38alpha), recent studies indicate that family members such as MAPK13 (p38delta) display a more selective cellular and tissue expression and might therefore represent a specific kinase to target in certain diseases. METHODS: To facilitate the design of potent and specific inhibitors, we present here the structural, biophysical, and functional characterization of two new MAPK13-inhibitor complexes, as well as the first comprehensive structural, biophysical, and functional analysis of MAPK13 complexes with four different inhibitor compounds of greatly varying potency. RESULTS: These inhibitors display IC50 values either in the nanomolar range or micromolar range (>800-fold range). The nanomolar inhibitors exhibit much longer ligand-enzyme complex half-lives compared to the micromolar inhibitors as measured by biolayer interferometry. Crystal structures of the MAPK13 inhibitor complexes reveal that the nanomolar inhibitors engage MAPK13 in the DFG-out binding mode, while the micromolar inhibitors are in the DFG-in mode. Detailed structural and computational docking analyses suggest that this difference in binding mode engagement is driven by conformational restraints imposed by the chemical structure of the inhibitors, and may be fortified by an additional hydrogen bond to MAPK13 in the nanomolar inhibitors. CONCLUSIONS: These studies provide a structural basis for understanding the differences in potency exhibited by these inhibitors. GENERAL SIGNIFICANCE: They also provide the groundwork for future studies to improve specificity, potency, pharmacodynamics, and pharmacokinetic properties. First comprehensive structural and biophysical analysis of MAPK13 inhibitors targeting DFG-in and DFG-out binding modes.,Yurtsever Z, Patel DA, Kober DL, Su A, Miller CA, Romero AG, Holtzman MJ, Brett TJ Biochim Biophys Acta. 2016 Jun 29. pii: S0304-4165(16)30228-8. doi:, 10.1016/j.bbagen.2016.06.023. PMID:27369736[9] From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine. References
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