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J Biol Chem
2012 Jan 06;2872:1150-7. doi: 10.1074/jbc.M111.312090.
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Activation of Aurora-A kinase by protein partner binding and phosphorylation are independent and synergistic.
Dodson CA
,
Bayliss R
.
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Protein kinases are activated by phosphorylation and by the binding of activator proteins. The interplay of these two factors is incompletely understood. We applied energetic analysis to this question and characterized the activation process of the serine/threonine kinase Aurora-A by phosphorylation and by its protein partner, targeting protein for Xenopus kinesin-like protein 2 (TPX2). We discovered that these two activators act synergistically and without a predefined order: each can individually increase the activity of Aurora-A, and the effect of both bound together is the exact sum of their individual contributions to catalysis. Unexpectedly, the unphosphorylated enzyme has catalytic activity that is increased 15-fold by the binding of TPX2 alone. The energetic contribution of phosphorylation to catalysis is 2-fold greater than that of TPX2 binding, which is independent of the phosphorylation state of the enzyme. Based on this analysis, we propose a revised, fluid model of Aurora-A activation in which the first step is a reduction in the mobility of the activation loop by either TPX2 binding or phosphorylation. Furthermore, our results suggest that unphosphorylated Aurora-A bound to the mitotic spindle by TPX2 is catalytically active and that the phosphorylation state of Aurora-A is an inaccurate surrogate for its activity. Extending this form of analysis will allow us to compare quantitatively the effects of the whole network of kinase-activating partners. Comparison with other kinases showed that kinetic characterization detects those kinases whose activation loops undergo a rearrangement upon phosphorylation and thus whose unphosphorylated state offers a distinct target for the development of Type II inhibitors.
Adams,
Phosphorylation modulates catalytic function and regulation in the cAMP-dependent protein kinase.
1995, Pubmed
Adams,
Phosphorylation modulates catalytic function and regulation in the cAMP-dependent protein kinase.
1995,
Pubmed
Adams,
Energetic limits of phosphotransfer in the catalytic subunit of cAMP-dependent protein kinase as measured by viscosity experiments.
1992,
Pubmed
Anderson,
Binding of TPX2 to Aurora A alters substrate and inhibitor interactions.
2007,
Pubmed
Barr,
Aurora-A: the maker and breaker of spindle poles.
2007,
Pubmed
Bayliss,
Structural basis of Aurora-A activation by TPX2 at the mitotic spindle.
2003,
Pubmed
,
Xenbase
Dodson,
Crystal structure of an Aurora-A mutant that mimics Aurora-B bound to MLN8054: insights into selectivity and drug design.
2010,
Pubmed
Eyers,
A novel mechanism for activation of the protein kinase Aurora A.
2003,
Pubmed
,
Xenbase
Hagopian,
Kinetic basis for activation of CDK2/cyclin A by phosphorylation.
2001,
Pubmed
Huse,
The conformational plasticity of protein kinases.
2002,
Pubmed
Johnson,
Active and inactive protein kinases: structural basis for regulation.
1996,
Pubmed
Lew,
MAP kinases and CDKs: kinetic basis for catalytic activation.
2003,
Pubmed
Littlepage,
Identification of phosphorylated residues that affect the activity of the mitotic kinase Aurora-A.
2002,
Pubmed
,
Xenbase
Liu,
Rational design of inhibitors that bind to inactive kinase conformations.
2006,
Pubmed
Pollard,
Discovery and development of aurora kinase inhibitors as anticancer agents.
2009,
Pubmed
Saylor,
Mutations in the activation loop tyrosine of the oncoprotein v-Fps.
1998,
Pubmed
Scutt,
Discovery and exploitation of inhibitor-resistant aurora and polo kinase mutants for the analysis of mitotic networks.
2009,
Pubmed
Sloane,
Drug-resistant aurora A mutants for cellular target validation of the small molecule kinase inhibitors MLN8054 and MLN8237.
2010,
Pubmed
,
Xenbase
Stevenson,
Activation mechanism of CDK2: role of cyclin binding versus phosphorylation.
2002,
Pubmed
Toya,
A kinase-independent role for Aurora A in the assembly of mitotic spindle microtubules in Caenorhabditis elegans embryos.
2011,
Pubmed
Tyler,
VX-680 inhibits Aurora A and Aurora B kinase activity in human cells.
2007,
Pubmed
Tyson,
Sniffers, buzzers, toggles and blinkers: dynamics of regulatory and signaling pathways in the cell.
2003,
Pubmed
Welburn,
How tyrosine 15 phosphorylation inhibits the activity of cyclin-dependent kinase 2-cyclin A.
2007,
Pubmed
Wilkinson,
Site-directed mutagenesis as a probe of enzyme structure and catalysis: tyrosyl-tRNA synthetase cysteine-35 to glycine-35 mutation.
1983,
Pubmed
Zeng,
Protein phosphatase 6 regulates mitotic spindle formation by controlling the T-loop phosphorylation state of Aurora A bound to its activator TPX2.
2010,
Pubmed
Zhang,
Enzymatic activity and substrate specificity of mitogen-activated protein kinase p38alpha in different phosphorylation states.
2008,
Pubmed
