Jawad S. Khalil
Protein Kinase A Regulates Platelet Phosphodiesterase 3A through an A-Kinase Anchoring Protein Dependent Manner
Khalil, Jawad S.; Law, Robert; Raslan, Zaher; Cheah, Lih T.; Hindle, Matthew S.; Aburima, Ahmed A.; Kearney, Mark T.; Naseem, Khalid M.
Authors
Robert Law
Zaher Raslan
Lih T. Cheah
Matthew S. Hindle
Ahmed A. Aburima
Mark T. Kearney
Khalid M. Naseem
Abstract
Platelet activation is critical for haemostasis, but if unregulated can lead to pathological thrombosis. Endogenous platelet inhibitory mechanisms are mediated by prostacyclin (PGI2)-stimulated cAMP signalling, which is regulated by phosphodiesterase 3A (PDE3A). However, spatiotemporal regulation of PDE3A activity in platelets is unknown. Here, we report that platelets possess multiple PDE3A isoforms with seemingly identical molecular weights (100 kDa). One isoform contained a unique N-terminal sequence that corresponded to PDE3A1 in nucleated cells but with negligible contribution to overall PDE3A activity. The predominant cytosolic PDE3A isoform did not possess the unique N-terminal sequence and accounted for >99% of basal PDE3A activity. PGI2 treatment induced a dose and time-dependent increase in PDE3A phosphorylation which was PKA-dependent and associated with an increase in phosphodiesterase enzymatic activity. The effects of PGI2 on PDE3A were modulated by A-kinase anchoring protein (AKAP) disruptor peptides, suggesting an AKAP-mediated PDE3A signalosome. We identified AKAP7, AKAP9, AKAP12, AKAP13, and moesin expressed in platelets but focussed on AKAP7 as a potential PDE3A binding partner. Using a combination of immunoprecipitation, proximity ligation techniques, and activity assays, we identified a novel PDE3A/PKA RII/AKAP7 signalosome in platelets that integrates propagation and termination of cAMP signalling through coupling of PKA and PDE3A.
Citation
Khalil, J. S., Law, R., Raslan, Z., Cheah, L. T., Hindle, M. S., Aburima, A. A., Kearney, M. T., & Naseem, K. M. (2024). Protein Kinase A Regulates Platelet Phosphodiesterase 3A through an A-Kinase Anchoring Protein Dependent Manner. Cells, 13(13), Article 1104. https://doi.org/10.3390/cells13131104
| Journal Article Type | Article |
|---|---|
| Acceptance Date | Jun 21, 2024 |
| Online Publication Date | Jun 26, 2024 |
| Publication Date | Jul 1, 2024 |
| Deposit Date | Aug 28, 2024 |
| Publicly Available Date | Aug 28, 2024 |
| Journal | Cells |
| Electronic ISSN | 2073-4409 |
| Publisher | MDPI |
| Peer Reviewed | Peer Reviewed |
| Volume | 13 |
| Issue | 13 |
| Article Number | 1104 |
| DOI | https://doi.org/10.3390/cells13131104 |
| Keywords | Platelets; Phosphodiesterase 3A; AKAP7 |
| Public URL | https://hull-repository.worktribe.com/output/4792021 |
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Copyright Statement
© 2024 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license (https://creativecommons.org/licenses/by/4.0/).