Fig. 4.

JPH-1 and SHN-1 binding to EGL-19/CaV1’s C-terminal PBD are required for VICR mediated SLO-2 activation. Ik_hiCl currents were recorded from adult body wall muscles at holding potentials of −60 to +60 mV in the presence and absence of external calcium. Representative Ik_hiCl traces are shown (A and B). The ratio of Ik_hiCl current density at +30 mV recorded in the absence of external calcium to the mean current density recorded in 5 mM Ca²⁺ [Ik_hiCl (0/5Ca²⁺)] is plotted for each genotype (C). The Ik_hiCl (0/5Ca²⁺) ratio was significantly decreased in jph-1(muscle KO), egl-19(ΔVTTL), shn-1(null), and shn-1(GAGA) mutants. These results suggest that VICR-mediated SLO-2 activation is decreased in these mutants. Nonnormalized Ik_hiCl IV curves are shown in SI Appendix, Fig. S2. Values that differ significantly are indicated (***P < 0.001; ****P < 0.0001). Error bars indicate SEM.