A dynamic mechanism for allosteric activation of Aurora kinase A by activation loop phosphorylation

• Published in: eLife Vol. 7
• Main Authors: Ruff, Emily F, Muretta, Joseph M, Thompson, Andrew R, Lake, Eric W, Cyphers, Soreen, Albanese, Steven K, Hanson, Sonya M, Behr, Julie M, Thomas, David D, Chodera, John D, Levinson, Nicholas M
• Format: Journal Article
• Language: English
• Published: England eLife Sciences Publications Ltd 21.02.2018; eLife Sciences Publications, Ltd
• Subjects: Allosteric properties; Aurora kinase; Biology; Cancer; Computational and Systems Biology; Kinases; Peptides; Phosphorylation; Post-translation; protein dynamics; protein kinase; Proteins; Signal transduction; Simulation; Structural Biology and Molecular Biophysics; New York; United States > US; computational biology; systems biology; protein dynamics; structural biology; molecular biophysics; human; phosphorylation; protein kinase
• ISSN: 2050-084X; 2050-084X
• DOI: 10.7554/elife.32766

Many eukaryotic protein kinases are activated by phosphorylation on a specific conserved residue in the regulatory activation loop, a post-translational modification thought to stabilize the active DFG-In state of the catalytic domain. Here we use a battery of spectroscopic methods that track different catalytic elements of the kinase domain to show that the ~100 fold activation of the mitotic kinase Aurora A (AurA) by phosphorylation occurs without a population shift from the DFG-Out to the DFG-In state, and that the activation loop of the activated kinase remains highly dynamic. Instead, molecular dynamics simulations and electron paramagnetic resonance experiments show that phosphorylation triggers a switch within the DFG-In subpopulation from an autoinhibited DFG-In substate to an active DFG-In substate, leading to catalytic activation. This mechanism raises new questions about the functional role of the DFG-Out state in protein kinases.