Fig. 1.

Expression of nonselective ionic currents in Xenopus laevis oocytes expressing wild-type (WT) and G41R FXYD2 polypeptides. A: 2 microelectrode currents in response to voltage steps from −10 mV to voltages between −140 and +80 mV, in 20-mV increments, from 2 oocytes that had been injected with the FXYD2 WT and FXYD2 G41R cRNAs, respectively, in ND96 solutions. B: “steady-state” current and voltage relationships for the WT and G41R-induced currents. *P < 0.01, G41R compared with FXYD2 WT. C: mean inward currents at −140 mV from oocytes injected with WT and G41R cRNA or H₂O as indicated. Currents in ND96 solution were measured 1∼2 days after injection of cRNAs. Bars show means ± SE [number of oocytes (n) indicated]. D: immunoblot of membrane fractions prepared from oocytes expressing FXYD2 WT (5 ng cRNA injected/cell) or the G41R mutant (50 ng cRNA injected/cell). Membranes enriched in plasma membranes (light membranes) or intracellular membranes (heavy membranes) were immunoblotted using an anti-FXYD2 antibody.