Optical Mapping of cAMP Signaling at the Nanometer Scale

Bock, Andreas; Annibale, Paolo; Konrad, Charlotte; Hannawacker, Annette; Anton, Selma E.; Maiellaro, Isabella; Zabel, Ulrike; Sivaramakrishnan, Sivaraj; Falcke, Martin; Lohse, Martin J.

Abstract

Cells relay a plethora of extracellular signals to specific cellular responses by using only a few second messengers, such as cAMP. To explain signaling specificity, cAMP-degrading phosphodiesterases (PDEs) have been suggested to confine cAMP to distinct cellular compartments. However, measured rates of fast cAMP diffusion and slow PDE activity render cAMP compartmentalization essentially impossible. Using fluorescence spectroscopy, we show that, contrary to earlier data, cAMP at physiological concentrations is predominantly bound to cAMP binding sites and, thus, immobile. Binding and unbinding results in largely reduced cAMP dynamics, which we term “buffered diffusion.” With a large fraction of cAMP being buffered, PDEs can create nanometer-size domains of low cAMP concentrations. Using FRET-cAMP nanorulers, we directly map cAMP gradients at the nanoscale around PDE molecules and the areas of resulting downstream activation of cAMP-dependent protein kinase (PKA). Our study reveals that spatiotemporal cAMP signaling is under precise control of nanometer-size domains shaped by PDEs that gate activation of downstream effectors.

Citation

Bock, A., Annibale, P., Konrad, C., Hannawacker, A., Anton, S. E., Maiellaro, I., Zabel, U., Sivaramakrishnan, S., Falcke, M., & Lohse, M. J. (2020). Optical Mapping of cAMP Signaling at the Nanometer Scale. Cell, 182(6), 1519-1530.e17. https://doi.org/10.1016/j.cell.2020.07.035

• Journal Article Type: Article
• Acceptance Date: Jul 25, 2020
• Online Publication Date: Aug 25, 2020
• Publication Date: Sep 17, 2020
• Deposit Date: Sep 1, 2020
• Publicly Available Date: Aug 26, 2021
• Journal: Cell
• Print ISSN: 0092-8674
• Publisher: Cell Press
• Peer Reviewed: Peer Reviewed
• Volume: 182
• Issue: 6
• Pages: 1519-1530.e17
• DOI: https://doi.org/10.1016/j.cell.2020.07.035
• Keywords: General Biochemistry, Genetics and Molecular Biology
• Public URL: https://nottingham-repository.worktribe.com/output/4869961
• Publisher URL: https://www.cell.com/cell/fulltext/S0092-8674(20)30943-0?_returnURL=https%3A%2F%2Flinkinghub.elsevier.com%2Fretrieve%2Fpii%2FS0092867420309430%3Fshowall%3Dtrue
• Related Public URLs: https://www.sciencedirect.com/science/article/abs/pii/S0092867420309430