Multi-state recognition pathway of the intrinsically disordered protein kinase inhibitor by protein kinase A
- University of Minnesota, United States
- Shenzhen Bay Laboratory, China
- Vanderbilt University, United States
- UT Southwestern Medical Center, United States
- Medical College of Wisconsin, United States
- Bethel University, United States
- University of Tuscia, Italy
- Beijing University Graduate School, China
- University of Utah, United States
- University of California, San Diego, United States
Abstract
In the nucleus, the spatiotemporal regulation of the catalytic subunit of cAMP-dependent protein kinase A (PKA-C) is orchestrated by an intrinsically disordered protein kinase inhibitor, PKI, which recruits the CRM1/RanGTP nuclear exporting complex. How the PKA-C/PKI complex assembles and recognizes CRM1/RanGTP is not well understood. Using NMR, SAXS, fluorescence, metadynamics, and Markov model analysis, we determined the multi-state recognition pathway for PKI. After a fast binding step in which PKA-C selects PKI's most competent conformations, PKI folds upon binding through a slow conformational rearrangement within the enzyme's binding pocket. The high-affinity and pseudo-substrate regions of PKI become more structured and the transient interactions with the kinase augment the helical content of the nuclear export sequence, which is then poised to recruit the CRM1/RanGTP complex for nuclear translocation. The multistate binding mechanism featured by PKA-C/PKI complex represents a paradigm on how disordered, ancillary proteins (or protein domains) are able to operate multiple functions such as inhibiting the kinase while recruiting other regulatory proteins for nuclear export.
Data availability
All NMR data will be deposited as NMR-Star File in the BMRB. Fluorescence data from Figures 5 and S5 will be deposited to the University of Minnesota repository site: https://conservancy.umn.edu/
Article and author information
Author details
Funding
National Institute of General Medical Sciences (GM 100310)
- Gianluigi Veglia
National Institute of General Medical Sciences (GM 46736)
- Jiali Gao
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Copyright
© 2020, Olivieri 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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Multi-state recognition pathway of the intrinsically disordered protein kinase inhibitor by protein kinase A
eLife 9:e55607.
https://doi.org/10.7554/eLife.55607
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