Article open access publication

Phosphatidylinositol 4,5-bisphosphate optical uncaging potentiates exocytosis

eLife, eLife, ISSN 2050-084X

Volume 6, 2017

DOI:10.7554/elife.30203, Dimensions: pub.1092342415, PMC: PMC5711374, PMID: 29068313,

Affiliations

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  1. (1) University of Copenhagen, grid.5254.6, KU
  2. (2) Leibniz-Forschungsinstitut für Molekulare Pharmakologie, grid.418832.4
  3. (3) European Molecular Biology Laboratory, grid.4709.a
  4. (4) Max Planck Institute of Molecular Cell Biology and Genetics, grid.419537.d
  5. (5) AstraZeneca (United Kingdom), grid.417815.e
  6. (6) University of Washington, grid.34477.33
  7. (7) Saarland University, grid.11749.3a

Description

Phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2] is essential for exocytosis. Classical ways of manipulating PI(4,5)P2 levels are slower than its metabolism, making it difficult to distinguish effects of PI(4,5)P2 from those of its metabolites. We developed a membrane-permeant, photoactivatable PI(4,5)P2, which is loaded into cells in an inactive form and activated by light, allowing sub-second increases in PI(4,5)P2 levels. By combining this compound with electrophysiological measurements in mouse adrenal chromaffin cells, we show that PI(4,5)P2 uncaging potentiates exocytosis and identify synaptotagmin-1 (the Ca2+ sensor for exocytosis) and Munc13-2 (a vesicle priming protein) as the relevant effector proteins. PI(4,5)P2 activation of exocytosis did not depend on the PI(4,5)P2-binding CAPS-proteins, suggesting that PI(4,5)P2 uncaging may bypass CAPS-function. Finally, PI(4,5)P2 uncaging triggered the rapid fusion of a subset of readily-releasable vesicles, revealing a rapid role of PI(4,5)P2 in fusion triggering. Thus, optical uncaging of signaling lipids can uncover their rapid effects on cellular processes and identify lipid effectors.

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Times Cited: 12

Field Citation Ratio (FCR): 2.44

Relative Citation ratio (RCR): 0.95

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