title: Modulation of the transient receptor potential channel TRPA1 by phosphatidylinositol 4,5-biphosphate manipulators.
abstract: The transient receptor potential channel of the ankyrin-binding repeat subfamily, TRPA1, is a Ca(2+)-permeable non-selective cation channel that depolarizes the plasma membrane and causes Ca(2+) influx. A typical feature of TRPA1 is its rapid desensitization following activation by agonists such as mustard oil (MO), cinnamaldehyde, and a high intracellular Ca(2+) concentration. In whole-cell recordings on Chinese hamster ovary (CHO) cells expressing TRPA1, desensitization was delayed when phosphatidylinositol 4,5-biphosphate (PIP(2)) was supplemented via the patch pipette, whereas the PIP(2) scavenger neomycin accelerated desensitization. Preincubation with the PI-4 kinase inhibitor wortmannin reduced both constitutive TRPA1 channels activity and the response to MO. Run down was also accelerated by high intracellular Mg(2+) concentrations, whereas chelating intracellular Mg(2+) with 10 mM ethylenedinitrilotetraacetic acid (EDTA) increased the basal channel activity. In inside-out patches, we observed a rapid run down of TRPA1 activity, which could be prevented by application of diC8-PIP(2) or 2 mM Mg-ATP but not Na(2)-ATP to the cytosolic side of the excised patches. In isolated trigeminal ganglion neurons, preincubation with wortmannin resulted in inhibition of endogenous TRPA1 activation by MO. Taken together, our data indicate that PIP(2) modulates TRPA1, albeit to a lesser extent than other known PIP(2)-dependent TRP channels, and that tools modifying the plasma membrane PIP(2) content often have direct effects on this channel.
authors.affiliation: KU Leuven Department of Mol. Cell Biology, Lab Ion Channel Research, Campus Gasthuisberg, Herestraat 49, bus 802, B-3000, Leuven, Belgium.
authors.forename: Yuji
authors.initials: Y
authors.lastname: Karashima
authors.forename: Jean
authors.initials: J
authors.lastname: Prenen
authors.forename: Victor
authors.initials: V
authors.lastname: Meseguer
authors.forename: Grzegorz
authors.initials: G
authors.lastname: Owsianik
authors.forename: Thomas
authors.initials: T
authors.lastname: Voets
authors.forename: Bernd
authors.initials: B
authors.lastname: Nilius
mesh_terms: D000818:Animals; D001152:Arsenicals / Q000494:pharmacology; D016466:CHO Cells; D015220:Calcium Channels / Q000187:drug effects*; D006224:Cricetinae; D003412:Cricetulus; D003627:Data Interpretation, Statistical; D004594:Electrophysiology; D004963:Estrenes / Q000494:pharmacology; D009149:Mustard Plant; D019255:NADPH Oxidases / Q000037:antagonists & inhibitors; D009355:Neomycin / Q000494:pharmacology; D009419:Nerve Tissue Proteins / Q000819:agonists / Q000187:drug effects*; D009474:Neurons / Q000502:physiology; D018408:Patch-Clamp Techniques; D019269:Phosphatidylinositol 4,5-Diphosphate / Q000037:antagonists & inhibitors / Q000378:metabolism*; D010938:Plant Oils / Q000494:pharmacology; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D011760:Pyrrolidinones / Q000494:pharmacology; D012996:Solutions; D000074025:TRPA1 Cation Channel; D050051:Transient Receptor Potential Channels / Q000819:agonists / Q000187:drug effects*
chemical_list: D001152:Arsenicals; D015220:Calcium Channels; D004963:Estrenes; D009419:Nerve Tissue Proteins; D019269:Phosphatidylinositol 4,5-Diphosphate; D010938:Plant Oils; D011500:Protein Synthesis Inhibitors; D011760:Pyrrolidinones; D012996:Solutions; D000074025:TRPA1 Cation Channel; C473350:TRPA1 protein, human; D050051:Transient Receptor Potential Channels; C029341:oxophenylarsine; C074854:U 73343; D019255:NADPH Oxidases; D009355:Neomycin; C027793:mustard oil