Science China Life Sciences

, Volume 59, Issue 8, pp 802–810 | Cite as

Optopharmacological control of TRPC channels by coumarin-caged lipids is associated with a phototoxic membrane effect

  • Oleksandra Tiapko
  • Bernadett BacsaEmail author
  • Gema Guedes de la Cruz
  • Toma Glasnov
  • Klaus GroschnerEmail author
Open Access
Research Paper


Photouncaging of second messengers has been successfully employed to gain mechanistic insight of cellular signaling pathways. One of the most enigmatic processes of ion channel regulation is lipid recognition and lipid-gating of TRPC channels, which represents pivotal mechanisms of cellular Ca2+ homeostasis. Recently, optopharmacological tools including caged lipid mediators became available, enabling an unprecedented level of temporal and spatial control of the activating lipid species within a cellular environment. Here we tested a commonly used caged ligand approach for suitability to investigate TRPC signaling at the level of membrane conductance and cellular Ca2+ handling. We report a specific photouncaging artifact that is triggered by the cage structure coumarin at UV illumination. Electrophysiological characterization identified a light-dependent membrane effect of coumarin. UV light (340 nm) as used for photouncaging, initiated a membrane conductance specifically in the presence of coumarin as low as 30 μmol L-1 concentrations. This conductance masked the TRPC3 conductance evoked by photouncaging, while TRPC-mediated cellular Ca2+ responses were largely preserved. The observed light-induced membrane effects of the released caging moiety may well interfere with certain cellular functions, and prompt caution in using coumarin-caged second messengers in cellular studies.


caged diacylglycerols TRPC channels Ca2+ signaling optopharmacology 


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© The Author(s) 2016

Open AccessThis article is distributed under the terms of the Creative Commons Attribution 4.0 International License (, which permits use, duplication, adaptation, distribution, and reproduction in any medium or format, as long as you give appropriate credit to the original author(s) and the source, provide a link to the Creative Commons license, and indicate if changes were made.

Authors and Affiliations

  1. 1.Institute of BiophysicsMedical University of Graz, BioTechMed-GrazGrazAustria
  2. 2.Institute of ChemistryUniversity of Graz, NAWI Graz, BioTechMed-GrazGrazAustria

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