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Phosphatidylinositol 4,5-bisphosphate optical uncaging potentiates exocytosis

Publikation: Forskning - peer reviewTidsskriftartikel

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 Sorensen

Phosphatidylinositol-4,5-bisphosphate [PI(4,5)P2] is essential for exocytosis. Classical ways of manipulating PI(4,5)P2 levels are slower than 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 Ca(2+) 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 bypasses 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.

OriginalsprogEngelsk
TidsskrifteLife
Vol/bind6
ISSN2050-084X
DOI
StatusE-pub ahead of print - 25 okt. 2017

ID: 185030190