The Structural Determinants of PH Domain-Mediated Regulation of Akt Revealed by Segmental Labeling
- Harvard Medical School, Brigham and Women's Hospital, United States
- Harvard Medical School, Dana-Farber Cancer Institute, United States
- Harvard Medical School, United States
Abstract
Akt is a critical protein kinase that governs cancer cell growth and metabolism. Akt appears to be autoinhibited by an intramolecular interaction between its N-terminal pleckstrin homology (PH) domain and kinase domain, which is relieved by C-tail phosphorylation, but the precise molecular mechanisms remain elusive. Here we use a combination of protein semisynthesis, NMR, and enzymological analysis to characterize structural features of the PH domain in its autoinhibited and activated states. We find that Akt autoinhibition depends on the length/flexibility of the PH-kinase linker. We identify a role for a dynamic short segment in the PH domain that appears to regulate autoinhibition and PDK1-catalyzed phosphorylation of Thr308 in the activation loop. We determine that Akt allosteric inhibitor MK2206 drives distinct PH domain structural changes compared to baseline autoinhibited Akt. These results highlight how the conformational plasticity of Akt governs the delicate control of its catalytic properties.
Data availability
Source data: Enzyme kinetics, fluorescence binding data, western blots, SDSPAGE gels have been deposited in Dryad: http://dx.doi:10.5061/dryad.0p2ngf1xg
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The Structural Determinants of PH Domain-Mediated Regulation of Akt Revealed by Segmental LabelingDryad Digital Repository, doi:10.5061/dryad.0p2ngf1xg.
Article and author information
Author details
Funding
National Cancer Institute (CA74305)
- Philip A Cole
Claudia Adams Barr Program in Innovative Cancer Research
- Haribabu Arthanari
Austrian Science Fund (Schroedinger Fellowship)
- Andras Boeszoermenyi
American Heart Association (19POST34380800)
- Andras Boeszoermenyi
National Institutes of Health (EB002026)
- Haribabu Arthanari
Kwanjeong Educational Foundation (pre-doctoral fellowship)
- Hwan Bae
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2020, Chu 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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The Structural Determinants of PH Domain-Mediated Regulation of Akt Revealed by Segmental Labeling
eLife 9:e59151.
https://doi.org/10.7554/eLife.59151
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