Breakage of the oligomeric CaMKII hub by the regulatory segment of the kinase
- Howard Hughes Medical Institute, University of California, Berkeley, United States
- University of California, Berkeley, United States
- San Diego State University, United States
Abstract
Ca2+/calmodulin dependent protein kinase II (CaMKII) is an oligomeric enzyme with crucial roles in neuronal signaling and cardiac function. Previously, we showed that activation of CaMKII triggers the exchange of subunits between holoenzymes, potentially increasing the spread of the active state (Stratton et al. 2014; Bhattacharyya et al. 2016). Using mass spectrometry, we show now that unphosphorylated and phosphorylated peptides derived from the CaMKII-α regulatory segment bind to the CaMKII-α hub and break it into smaller oligomers. Molecular dynamics simulations show that the regulatory segments dock spontaneously at the interface between hub subunits, trapping large fluctuations in hub structure. Single-molecule fluorescence intensity analysis of CaMKII-α expressed in mammalian cells shows that activation of CaMKII-α results in the destabilization of the holoenzyme. Our results suggest that release of the regulatory segment by activation and phosphorylation allows it to destabilize the hub, producing smaller assemblies that might reassemble to form new holoenzymes.
Data availability
Molecular dynamics simulation trajectories are available at Pittsburg Supercomputing Center's data storage facility and are accessible at the following link: https://psc.edu/anton-project-summaries?id=3071&pid=35. Mass spectrometry data (Figure 2-4) is available via the MassIVE database under identifier MSV000086103
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Breakage of the Oligomeric CaMKII Hub by the Regulatory Segment of the KinasePittsburg Supercomputing Center.
Article and author information
Author details
Moitrayee Bhattacharyya
Funding
National Institute of General Medical Sciences (K99 GM 126145)
- Moitrayee Bhattacharyya
National Science Foundation (CHE-1609866)
- Zijie Xia
National Science Foundation (CHE-1609866)
- Evan R Williams
Howard Hughes Medical Institute
- John Kuriyan
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2020, Karandur et al.
This article is distributed under the terms of the Creative Commons Attribution License permitting unrestricted use and redistribution provided that the original author and source are credited.
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Breakage of the oligomeric CaMKII hub by the regulatory segment of the kinase
eLife 9:e57784.
https://doi.org/10.7554/eLife.57784
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