A water-mediated allosteric network governs activation of Aurora kinase A.
The catalytic activity of many protein kinases is controlled by conformational changes of a conserved Asp-Phe-Gly (DFG) motif. We used an infrared probe to track the DFG motif of the mitotic kinase Aurora A (AurA) and found that allosteric activation by the spindle-associated protein Tpx2 involves an equilibrium shift toward the active DFG-in state. Förster resonance energy transfer experiments show that the activation loop undergoes a nanometer-scale movement that is tightly coupled to the DFG equilibrium. Tpx2 further activates AurA by stabilizing a water-mediated allosteric network that links the C-helix to the active site through an unusual polar residue in the regulatory spine. The polar spine residue and water network of AurA are essential for phosphorylation-driven activation, but an alternative form of the water network found in related kinases can support Tpx2-driven activation, suggesting that variations in the water-mediated hydrogen bond network mediate regulatory diversification in protein kinases.
Department of Pharmacology, University of Minnesota, Twin Cities, Minneapolis, Minnesota, USA.
Soreen
S
Cyphers
Department of Pharmacology, University of Minnesota, Twin Cities, Minneapolis, Minnesota, USA.
Emily F
EF
Ruff
Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York, USA.|Tri-Institutional Program in Computational Biology and Medicine, Weill Cornell Medical College, New York, New York, USA.
Julie M
JM
Behr
Computational and Systems Biology Program, Sloan Kettering Institute, Memorial Sloan Kettering Cancer Center, New York, New York, USA.
John D
0000-0003-0542-119X
JD
Chodera
Department of Pharmacology, University of Minnesota, Twin Cities, Minneapolis, Minnesota, USA.
Nicholas M
NM
Levinson
D000494:Allosteric Regulation; D064096:Aurora Kinase A / Q000378:metabolism*; D004789:Enzyme Activation; D006801:Humans; D008958:Models, Molecular; D014867:Water / Q000737:chemistry / Q000378:metabolism*
D014867:Water; C576917:AURKA protein, human; D064096:Aurora Kinase A