title: Copper-Induced Membrane Depolarizations Involve the Induction of Mosaic TRP Channels, Which Activate VDCC Leading to Calcium Increases in Ulva compressa.
abstract: The marine macroalga Ulva compressa (Chlorophyceae) is a cosmopolitan species, tolerant to heavy metals, in particular to copper. U. compressa was cultivated with 10 μM copper for 12 h and membrane depolarization events were detected. First, seven depolarization events occurred at 4, 8, 12-13, 80, and 86 min, and at 5 and 9 h of copper exposure. Second, bathocuproine sulphonate, a specific copper-chelating compound, was added before incorporating copper to the culture medium. Copper-induced depolarizations were inhibited by bathocuproine at 4, 8, 12-13, 80, and 86 min, but not at 5 and 9 h, indicating that initial events are due to copper ions entry. Third, specific inhibitors of human TRPA1, C4, C5, M8, and V1corresponding to HC030031, ML204, SKF96363, M8B, and capsazepin, respectively, were used to analyze whether copper-induced depolarizations were due to activation of transient receptor potentials (TRPs). Inhibitor effects indicate that the seven depolarizations involved the activation of functional mosaic TRPs that displayed properties similar to human TRPA, C, M, and/or V. Finally, inhibition of copper-induced depolarizations using specific TRP inhibitors suppressed calcium increases at 2, 3, and 12 h due to activation of voltage-dependent calcium channels (VDCCs). Thus, copper induces seven depolarization events that involve activation of mosaic TRPs which, in turn, activates VDCC leading to calcium increases at 2, 3, and 12 h in U. compressa.
authors.affiliation: Laboratory of Marine Biotechnology, Faculty of Chemistry and Biology, University of Santiago of Chile Santiago, Chile.
authors.forename: Melissa
authors.initials: M
authors.lastname: Gómez
authors.affiliation: Laboratory of Marine Biotechnology, Faculty of Chemistry and Biology, University of Santiago of Chile Santiago, Chile.
authors.forename: Alberto
authors.initials: A
authors.lastname: González
authors.affiliation: Laboratory of Coastal Toxicology, Center of Advanced Studies, University of Playa Ancha Viña del Mar, Chile.
authors.forename: Claudio A
authors.initials: CA
authors.lastname: Sáez
authors.affiliation: Laboratory of Marine Biotechnology, Faculty of Chemistry and Biology, University of Santiago of Chile Santiago, Chile.
authors.forename: Alejandra
authors.initials: A
authors.lastname: Moenne
keywords: TRP channels; Ulva compressa; calcium; copper; marine alga; voltage-dependent calcium channels