Switching Aurora-A kinase on and off at an allosteric site

Area of Science:

• Biochemistry
• Molecular Biology
• Cell Signaling

Background:

• Protein kinases regulate crucial cellular processes like the cell cycle and signaling pathways.
• Kinase activity is tightly controlled by post-translational modifications and protein interactions, leading to distinct active and inactive states.
• Studying the dynamic nature of protein kinases, such as Aurora-A, is challenging for capturing all functional states.

Purpose of the Study:

• To present novel structural insights into the active and inactive states of Aurora-A kinase.
• To elucidate the mechanism by which synthetic proteins modulate Aurora-A kinase activity.
• To demonstrate how targeting a common allosteric pocket can lead to opposing functional outcomes.

Main Methods:

• X-ray crystallography was employed to determine the structures of Aurora-A kinase.
• Aurora-A kinase was stabilized in distinct conformational states through interactions with synthetic proteins.
• A single-domain antibody and a hydrocarbon-stapled peptide were used as protein interaction partners.

Main Results:

• Two distinct structures of Aurora-A kinase were resolved, representing its active and inactive conformations.
• Both the inhibitory antibody and the activating peptide bind to the same allosteric pocket on Aurora-A kinase.
• The synthetic proteins induce opposing effects on Aurora-A kinase activity by interacting with this shared allosteric site.

Conclusions:

• The study provides high-resolution structures of Aurora-A kinase in both active and inactive states.
• These findings highlight a conserved allosteric pocket that can be targeted to control kinase activity.
• The developed synthetic proteins serve as valuable tools for investigating allosteric mechanisms in cellular contexts.