Architecture of the MKK6-p38α complex defines the basis of MAPK specificity and activation

• DOI: 10.1126/science.add7859
• Publication Date: 2023-09-14T17:58:58Z
• Authors: Pauline Juyoux; Ioannis Galdadas; Dorothea Gobbo; Jill von Velsen; Martin Pelosse; Mark Tully; Oscar Vadas; Francesco Luigi G...; Erika Pellegrini; Matthew W. Bowler
• Keywords: 0303 health sciences; Protein Conformation; Cryoelectron Microscopy; MAP Kinase Kinase 2; MAP Kinase Kinase 6; Mitogen activated protein kinase; Substrate Specificity; Enzyme Activation; Mitogen-Activated Protein Kinase 14; 03 medical and health sciences; Protein phosphorylation; info:eu-repo/classification/ddc/615; Phosphorylation

The mitogen-activated protein kinase (MAPK) p38α is a central component of signaling in inflammation and the immune response is, therefore, an important drug target. Little known about molecular mechanism its activation by double phosphorylation from MAPK kinases (MAP2Ks), because challenge trapping transient dynamic heterokinase complex. We applied multidisciplinary approach to generate structural model complex with MAP2K, MKK6, understand mechanism. Integrating cryo-electron microscopy dynamics simulations, hydrogen-deuterium exchange mass spectrometry, experiments cells, we demonstrate dynamic, multistep mechanism, identify catalytically relevant interactions, show that MAP2K-disordered amino termini determine pathway specificity. Our work captures fundamental step cell signaling: phosphorylating downstream target kinase.