Fig. 8.

The Cx50 double mutant, Cx50R33E,E162R, induces gain of hemichannel function. Membrane currents were elicited and recorded from oocytes under two-electrode voltage clamp in response to 10-s depolarizing voltage steps from − 80 mV to + 40 mV in 20-mV increments from a holding potential of − 80 mV. A‒E Representative families of macroscopic current traces recorded from oocytes injected with no cRNA (A), or with equal amounts of wild-type Cx50 (B), Cx50R33E (C), Cx50E162R (D) or Cx50R33E,E162R (E) cRNAs. F Graph shows the steady-state current–voltage relationships of the macroscopic hemichannel tail currents for wild-type and mutant Cx50 obtained after returning the voltage from each depolarizing step to the holding potential of − 80 mV. G Graph shows the instantaneous tail currents (I_max) for wild-type and mutant Cx50 hemichannels obtained after the + 40 mV depolarizing step. Data are presented as mean ± S.E.M. (n = 10 oocytes for each construct). *p < 0.05 and **p < 0.01 indicate significant differences vs. Cx50 cRNA-injected oocytes. Oocytes were obtained from at least three frog donors