Crystal structure of activated MAPKAPK2 kinase reveals a C-lobe allosteric pocket for furan-2-carboxamide inhibitors
- 1Evotec
Abstract
MAPK-activated protein kinase 2 (MAPKAPK2, MK2) is a downstream substrate of p38 MAPK that regulates inflammatory signaling and cytokine synthesis, making it an attractive therapeutic target. Although several crystal structures of MAPKAPK2 with ATP-competitive inhibitors have supported drug discovery, structural elucidation of selective non-ATP-competitive inhibitors has remained challenging. MK-25 is a non-ATP-competitive furan-2-carboxamide MAPKAPK2 inhibitor developed at Merck to overcome the selectivity and cellular-efficacy limitations of ATP-competitive chemotypes. Here, we show through isothermal titration calorimetry that MK-25 binds the activated MAPKAPK2, consistent with state-dependent allosteric binding. To determine the binding mode of MK-25, we solved a 2.8 A resolution crystal structure of an activated MAPKAPK2 construct in ternary complex with the ATP-site inhibitor PF-3644022 and a bromo-analogue of MK-25. The ligand occupies a pocket in the C-lobe overlapping the protein-substrate recognition region and formed through rearrangements of D and G helices and the activation segment. These interactions are consistent with the structure-activity relationships reported for the furan-2-carboxamide chemotype and identify a ligandable allosteric pocket that may facilitate future structure-guided design of selective, non-ATP-competitive MAPKAPK2 inhibitors.
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BibTeX
@misc{beaumont2026crystal,
title = {{Crystal structure of activated MAPKAPK2 kinase reveals a C-lobe allosteric pocket for furan-2-carboxamide inhibitors}},
author = {E. J. Beaumont and S. Duclos and S. Thieffine and r. Yadav and j. Barker},
howpublished = {bioRxiv},
year = {2026},
month = oct,
doi = {10.64898/2026.10.01.755332},
url = {https://www.biorxiv.org/content/10.64898/2026.10.01.755332v1},
note = {CC BY-ND},
}
RIS
TY - UNPB
TI - Crystal structure of activated MAPKAPK2 kinase reveals a C-lobe allosteric pocket for furan-2-carboxamide inhibitors
AU - E. J. Beaumont
AU - S. Duclos
AU - S. Thieffine
AU - r. Yadav
AU - j. Barker
PY - 2026
DA - 2026/10/01
PB - bioRxiv
DO - 10.64898/2026.10.01.755332
UR - https://www.biorxiv.org/content/10.64898/2026.10.01.755332v1
AB - MAPK-activated protein kinase 2 (MAPKAPK2, MK2) is a downstream substrate of p38 MAPK that regulates inflammatory signaling and cytokine synthesis, making it an attractive therapeutic target. Although several crystal structures of MAPKAPK2 with ATP-competitive inhibitors have supported drug discovery, structural elucidation of selective non-ATP-competitive inhibitors has remained challenging. MK-25 is a non-ATP-competitive furan-2-carboxamide MAPKAPK2 inhibitor developed at Merck to overcome the selectivity and cellular-efficacy limitations of ATP-competitive chemotypes. Here, we show through isothermal titration calorimetry that MK-25 binds the activated MAPKAPK2, consistent with state-dependent allosteric binding. To determine the binding mode of MK-25, we solved a 2.8 A resolution crystal structure of an activated MAPKAPK2 construct in ternary complex with the ATP-site inhibitor PF-3644022 and a bromo-analogue of MK-25. The ligand occupies a pocket in the C-lobe overlapping the protein-substrate recognition region and formed through rearrangements of D and G helices and the activation segment. These interactions are consistent with the structure-activity relationships reported for the furan-2-carboxamide chemotype and identify a ligandable allosteric pocket that may facilitate future structure-guided design of selective, non-ATP-competitive MAPKAPK2 inhibitors.
ER -