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Updated: Jun 24, 2026

Spatiotemporal Control of Protein Activity through Optogenetic Allosteric Regulation
Published on: October 4, 2024
Conformational Dynamics and Allostery in the cAMP-Protein Kinase A Signalosome
Varun Venkatakrishnan1, Ganesh S Anand2,3,4
1Department of Chemistry, The Pennsylvania State University, University Park, PA, USA.
Abstract:
Protein kinase A (PKA) is a master kinase that controls numerous cellular processes via phosphorylation. PKA, or cAMP-dependent protein kinase, is regulated by the second messenger 3'5' cyclic adenosine monophosphate (cAMP) generated in response to upstream G-protein-coupled receptor stimulation. Intracellularly, PKA is organized into multiprotein complexes that bring together the regulatory and catalytic elements of PKA, termed signalosomes. cAMP-PKA signalosomes exert spatiotemporal control of PKA activity by precisely regulating activation and termination phases of PKA signaling. While cAMP binds to PKA, triggering signal activation, phosphodiesterases catalyze cAMP degradation to terminate PKA signaling. Amide-hydrogen/deuterium exchange mass spectrometry (HDXMS), a powerful biophysical technique, has captured the conformational dynamics of regulation in PKA signaling. This has revealed allosteric mechanisms of PKA regulation and identified key pathway intermediates in the activation and termination phases of PKA. This chapter describes the components that constitute the PKA signalosome and the allosteric mechanisms of PKA regulation as revealed by HDXMS.
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