AKAP79 enables calcineurin to directly suppress protein kinase A activity
- University College London, United Kingdom
- KTH Royal Institute of Technology, Sweden
Abstract
Interplay between the second messengers cAMP and Ca2+ is a hallmark of dynamic cellular processes. A common motif is the opposition of the Ca2+-sensitive phosphatase calcineurin and the major cAMP receptor, protein kinase A (PKA). Calcineurin dephosphorylates sites primed by PKA to bring about changes including synaptic long-term depression (LTD). AKAP79 supports signaling of this type by anchoring PKA and calcineurin in tandem. In this study, we discovered that AKAP79 increases the rate of calcineurin dephosphorylation of type II PKA regulatory subunits by an order of magnitude. Fluorescent PKA activity reporter assays, supported by kinetic modeling, show how AKAP79-enhanced calcineurin activity enables suppression of PKA without altering cAMP levels by increasing PKA catalytic subunit capture rate. Experiments with hippocampal neurons indicate that this mechanism contributes towards LTD. This non-canonical mode of PKA regulation may underlie many other cellular processes.
Data availability
Source data files have been provided for figures 1-6, figure 1-supplement 2, figure 1-supplement 3, figure 3-supplement 1, and figure 3-supplement 2.Original images an uncrossed images for Coomassie-stained gels and immunoblots presented in the manuscript are shown in the zipped folder provided as an additional file.A code repository for this study may be accessed at https://github.com/jdgas/AKAP79_PKA. It contains the R code for the ABC method as well as MATLAB code for reproducing figures. The R code has to be run on a computer cluster. The repository also contains the models with a few example parameter sets, the full parameter sample as described above, and supplementary figures with simulations and experimental data for all 0, 0.2, 1 and 2 M cAMP levels with either WT S98A, or S98E RII𝛼 in the reaction mix.
Article and author information
Author details
Jeanette Hellgren Kotaleski
Funding
Wellcome Trust and Royal Society (104194/Z/14/A)
- Matthew G Gold
BBSRC (BB/N015274/1)
- Matthew G Gold
Swedish Research Council (VR-M-2017-02806)
- Matthew G Gold
European Union/Horizon 2020 (945539 Human Brain Project SGA3)
- Matthew G Gold
Erasmus Scholarship
- João Antunes
Wellcome Trust (217199/Z/19/Z)
- Saad Hannan
- Trevor G Smart
Swedish Research Council (VR-M-2020-01652)
- Matthew G Gold
The funders had no role in study design, data collection and interpretation, or the decision to submit the work for publication.
Ethics
Animal experimentation: Experiments involving rats were done in accordance with the United Kingdom Animals Act, 1986 and within University College London Animal Research guidelines overseen by the UCL Animal Welfare and Ethical Review Body under project code 14058.
Copyright
© 2021, Church 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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AKAP79 enables calcineurin to directly suppress protein kinase A activity
eLife 10:e68164.
https://doi.org/10.7554/eLife.68164
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