Plant-derived pharmacological agents have been used extensively to dissect the structure-function relationships of mammalian GABA receptors and ion channels. Picrotoxin is a non-competitive antagonist of mammalian GABA receptors. Here, we report that picrotoxin inhibits the anion (malate) efflux mediated by wheat () ALMT1 but has no effect on GABA transport. The EC for inhibition was 0.14 nM and 0.18 nM when the ALMTs were expressed in tobacco BY2 cells and in oocytes, respectively. Patch clamping of the oocyte plasma membrane expressing wheat ALMT1 showed that picrotoxin inhibited malate currents from both sides of the membrane. These results demonstrate that picrotoxin inhibits anion efflux effectively and can be used as a new inhibitor to study the ion fluxes mediated by ALMT proteins that allow either GABA or anion transport.
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http://www.ncbi.nlm.nih.gov/pmc/articles/PMC9405015 | PMC |
http://dx.doi.org/10.3390/biology11081162 | DOI Listing |
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