Figure 1. SHN-1 promotes EGL-19/Ca_v1 channel function.

(A) The protein domains found in SHN-1 and rat Shank3A are compared. SHN-1 lacks an SH3 domain but contains all other domains found in mammalian Shank proteins. Homology between the worm and mammalian protein is shown for each domain. (B–F) Voltage-activated Ca⁺² currents were recorded from adult body wall muscles of the indicated genotypes at holding potentials of −60 to +40 mV. Averaged traces (B), mean current density as a function of holding potential (C), normalized conductance as a function of holding potential (D), mean current density at 10 mV (E), and mean deactivation time constants (F) are shown. shn-1 mutants had significantly decreased Ca⁺² current-density and this defect was rescued by a single copy transgene expressing SHN-1 in body muscles (nuSi26) (D). No significant differences were observed for voltage-dependence of current activation and de-activation kinetics. The number of animals analyzed is indicated for each genotype. Values that differ significantly from wild type controls are indicated (***p<0.001). Error bars indicate SEM. Mean, standard errors, sample sizes, and p values for this figure are shown in Supplementary file 1.

DOI: http://dx.doi.org/10.7554/eLife.18931.002

Figure 1—figure supplement 1. Supplemental data related to Figure 1.

(A–B) The SHN-1 PDZ domain binds to the EGL-19/Ca_v1 c-terminus in yeast two-hybrid (A) and GST-pull down (B) assays. (C) Potassium current density and voltage-dependence of activation were unaltered in shn-1 mutants. Voltage-activated K⁺ currents were recorded from adult body wall muscles at holding potentials of −60 to +40 mV. Averaged traces, mean current density (pA/pF) as a function of holding potential, and normalized conductance (G/G_max) as a function of holding potential are shown. No significant differences were observed. (D) Representation of protein domains found in SHN-1 and the predicted protein products made in the shn-1(tm488) and shn-1(ok1241) mutants. Numbers report amino acid residues for each domain and extent of deletions in the mutants. Error bars indicate SEM. Mean, standard errors, sample sizes, and p values for this figure are shown in Supplementary file 1.

DOI: http://dx.doi.org/10.7554/eLife.18931.003