Figure 4: TaALMT1 currents are activated by external malate at pH 7.5 and are regulated by GABA, muscimol and bicuculline.

All results from X. laevis oocytes injected with TaALMT1 cRNA bathed at pH 7.5 and measured using two-electrode voltage-clamp electrophysiology. (a) Representative current traces at −120 mV; M=10 mM malate; Mus=10 μm muscimol; G=100 μm GABA; Bic=100 μm bicuculline from n=5 biological replicates for top and middle traces, n=3 for the bottom trace. Response of water-injected control oocytes are shown in Supplementary Fig. 6. (b,c) Current–voltage relationship of malate-activated current as regulated by muscimol and GABA as indicated applied and recorded 30 s after each solution change. Control-subtracted currents were normalized to the largest mean outward current at +60 mV (n=5 independent oocytes for each treatment). (d) Concentration dependence of GABA- and muscimol-regulated inward current at −140 mV taken from b and c (n=5 for b, and 9 for c). All data are water-control subtracted except in a. All error bars are ±s.e.m. Experiments repeated with oocytes from at least two different frogs.