FIGURE 7.
Cx50tr290 and full-length Cx50 have identical single-channel properties. Junctional currents were recorded from single channels composed of Cx50tr290 at three different transjunctional voltages. Cx50tr290 channels were primarily open at -25 mV (A) but transitioned to lower conductance states at -50 mV (B) and showed a unitary conductance of 210 pS. During extended recording of a single Cx50tr290 channel at -30 mV (C), the truncated channels remained in the fully open state, with only brief transitions into lower conducting states. An expanded portion of the record (D) shows only two brief transitions (asterisk) to substates. Full-length Cx50 single-channel currents recorded at -40 mV had a peak at 8.4 pA, corresponding to a unitary conductance of 210 pS (E). All-point histograms are plotted on the right.