Phosphatidylinositol 4,5-bisphosphate optical uncaging potentiates exocytosis

Alexander M. Walter, Rainer Müller, Bassam Tawfik, Keimpe Db Wierda, Paulo S. Pinheiro, André Nadler, Anthony W. McCarthy, Iwona Ziomkiewicz, Martin Kruse, Gregor Reither, Jens Rettig, Martin Lehmann, Volker Haucke, Bertil Hille, Carsten Schultz, Jakob Balslev Sørensen

Research output: Contribution to journalArticle

13 Scopus citations

Abstract

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.

Original languageEnglish (US)
Article numbere30203
JournaleLife
Volume6
DOIs
StatePublished - Oct 25 2017

Keywords

  • Munc13
  • adrenal chromaffin cell
  • cell biology
  • exocytosis
  • mouse
  • neuroscience
  • optical uncaging
  • phosphatidylinositols
  • synaptotagmin

ASJC Scopus subject areas

  • Neuroscience(all)
  • Immunology and Microbiology(all)
  • Biochemistry, Genetics and Molecular Biology(all)

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    Walter, A. M., Müller, R., Tawfik, B., Wierda, K. D., Pinheiro, P. S., Nadler, A., McCarthy, A. W., Ziomkiewicz, I., Kruse, M., Reither, G., Rettig, J., Lehmann, M., Haucke, V., Hille, B., Schultz, C., & Sørensen, J. B. (2017). Phosphatidylinositol 4,5-bisphosphate optical uncaging potentiates exocytosis. eLife, 6, [e30203]. https://doi.org/10.7554/eLife.30203