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 Sorensen

18 Citationer (Scopus)
106 Downloads (Pure)

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.

OriginalsprogEngelsk
Artikelnummere30203
TidsskrifteLife
Vol/bind6
Antal sider41
ISSN2050-084X
DOI
StatusUdgivet - 25 okt. 2017

Fingeraftryk

Dyk ned i forskningsemnerne om 'Phosphatidylinositol 4,5-bisphosphate optical uncaging potentiates exocytosis'. Sammen danner de et unikt fingeraftryk.

Citationsformater