(A) Mutation in erg-28 suppresses sluggish locomotion of slo-1(ky399gf) mutant. Average speed of animals with indicated genotypes on NGM agar plates without food. slo-1(gf) and erg-28 alleles are ky399 and cim16, respectively. +muscle #1, #2, #3: three independent lines of erg-28 slo-1(gf);cimEx[myo-3p::gfp::erg-28, ttx-3p::mRFP]. +neuron#1, #2: two independent transgenic lines of erg-28 slo-1(gf);cimEx[H20p::gfp::erg-28, ttx-3p::mRFP]. Error bars represent S.E.M. (standard error of the mean). n = 10. One way ANOVA with Tukey’s post-hoc analysis. P values are presented in comparison to slo-1(gf). (B) ERG-28 is predicted to be an endoplasmic reticulum resident protein with four transmembrane domains and KKXX ER retrieval COPI binding motif. Mutation sites of cim16, tm6168, and gk697770 alleles are indicated. (C) Suppression of egg laying defects of slo-1(ky399gf) mutant by erg-28(cim16) mutation. Number of eggs retained in the animals. Error bars represent S.E.M. n = 10. ****p<0.0001, one way ANOVA with Tukey’s post-hoc analysis. (D) Suppression of defective asymmetric str-2 gene expression in slo-1(ky399gf) mutant by erg-28(gk697770). Mutants used in this experiment: erg-28(gk697770), slo-1(ky399), unc-36(e251), and unc-43(n498n1186). (Figure 1—source data 1: This file contains raw measurement data and statistical analysis summary for Figure 1A, C and D).