title: Exclusive photorelease of signalling lipids at the plasma membrane.
abstract: Photoactivation of caged biomolecules has become a powerful approach to study cellular signalling events. Here we report a method for anchoring and uncaging biomolecules exclusively at the outer leaflet of the plasma membrane by employing a photocleavable, sulfonated coumarin derivative. The novel caging group allows quantifying the reaction progress and efficiency of uncaging reactions in a live-cell microscopy setup, thereby greatly improving the control of uncaging experiments. We synthesized arachidonic acid derivatives bearing the new negatively charged or a neutral, membrane-permeant coumarin caging group to locally induce signalling either at the plasma membrane or on internal membranes in β-cells and brain slices derived from C57B1/6 mice. Uncaging at the plasma membrane triggers a strong enhancement of calcium oscillations in β-cells and a pronounced potentiation of synaptic transmission while uncaging inside cells blocks calcium oscillations in β-cells and causes a more transient effect on neuronal transmission, respectively. The precise subcellular site of arachidonic acid release is therefore crucial for signalling outcome in two independent systems.
authors.affiliation: European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany.|Max Planck Institute of Molecular Cell Biology and Genetics, Pfotenhauerstraße 108, 01307 Dresden, Germany.
authors.forename: André
authors.initials: A
authors.lastname: Nadler
authors.affiliation: European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany.|Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo náměstí 2, 16610 Prague 6, Czech Republic.
authors.forename: Dmytro A
authors.initials: DA
authors.lastname: Yushchenko
authors.affiliation: European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany.
authors.forename: Rainer
authors.initials: R
authors.lastname: Müller
authors.affiliation: European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany.
authors.forename: Frank
authors.initials: F
authors.lastname: Stein
authors.affiliation: European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany.
authors.forename: Suihan
authors.initials: S
authors.lastname: Feng
authors.affiliation: Institut Interdisciplinaire de Neurosciences, CNRS UMR 5297 Université Bordeaux 2, 146, rue Léo-Saignat, 33077 Bordeaux, France.
authors.forename: Christophe
authors.initials: C
authors.lastname: Mulle
authors.affiliation: Institut Interdisciplinaire de Neurosciences, CNRS UMR 5297 Université Bordeaux 2, 146, rue Léo-Saignat, 33077 Bordeaux, France.
authors.forename: Mario
authors.initials: M
authors.lastname: Carta
authors.affiliation: European Molecular Biology Laboratory, Cell Biology and Biophysics Unit, Meyerhofstraße 1, 69117 Heidelberg, Germany.
authors.forename: Carsten
authors.initials: C
authors.lastname: Schultz
mesh_terms: D000818:Animals; D016718:Arachidonic Acid / Q000737:chemistry / Q000378:metabolism*; D002118:Calcium / Q000378:metabolism; D020013:Calcium Signaling / Q000528:radiation effects; D002462:Cell Membrane / Q000378:metabolism* / Q000528:radiation effects; D003374:Coumarins / Q000737:chemistry / Q000378:metabolism; D006367:HeLa Cells; D006801:Humans; D050417:Insulin-Secreting Cells / Q000378:metabolism / Q000528:radiation effects; D008027:Light; D051379:Mice; D008810:Mice, Inbred C57BL; D009474:Neurons / Q000378:metabolism / Q000528:radiation effects
chemical_list: D003374:Coumarins; D016718:Arachidonic Acid; C030123:coumarin; D002118:Calcium