FIGURE 2.

TREK-1 and TREK-2 subunits form functional heterodimers in Xenopus oocytes. A, Xenopus oocytes were injected with TREK-1 (circles), TREK-2 (triangles), or TREK-2/TREK-1 tandem (diamonds) cRNA. TREK currents were measured as described in Fig. 1. The sensitivity of the currents to extracellular acidification and RR application was plotted against each other. Averages of the three groups (empty diamonds) are shown with error bars representing S.E. The straight line connects the averages of the groups expressing TREK-1 or TREK-2 homodimers, respectively. B, Xenopus oocytes were injected with different ratios of TREK-1 and TREK-2 cRNA (squares). The pH and RR sensitivity of the expressed TREK currents were measured as in Fig. 1 and plotted as in A. The averages (with error bars) of the three groups and the straight line from A are also displayed.