UNC-13 domains required for rescue of isoflurane sensitivity. (A) unc-13 constructs used to transform unc-13(s69) and the resultant protein products. mdIs3 is an integrated array of a genomic fragment encoding the entire unc-13 L + R coding sequence 15 the predicted locations of the Rab3a-interacting molecule (RIM) 16, calmodulin (CAM) 17, and syntaxin (Stx) 9 binding sites are indicated. nuIs46 is an integrated array encoding the M + R shortened form of UNC-13 – UNC-13S – that partially rescues locomotion and transmitter release 18. oxIs78 is an integrated array otherwise identical to nuIs46 except with a 51-nucleotide insertion at the 5’ end of the unc-13S coding sequence that encodes the N-terminal myristoylation sequence of the C. elegans Goα protein 19. (B) Suppression of isoflurane antagonism of truncated syntaxin by overexpression of UNC-13. Isoflurane EC50s measured by the body bend assay. mdIs3[unc-13(+)] is an integrant of the mdEx43 array 15 that overexpresses wild type UNC-13. * - p < 0.01 vs N2; † - p < 0.01 vs corresponding truncated syntaxin strain alone. (C) A null mutant of unc-10 RIM is not isoflurane resistant. The full genotype is unc-64(js115null); unc-10(md1117null); oxIs34[unc-64(L166A/E167A);Pmyo-2::GFP] 20. The isoflurane sensitivity of unc-64(js115 null);oxIs34 is shown for comparison. EC50s (vol%): N2 – 0.82 ± 0.09, js115;md1117;oxIs34 – 0.25 ± 0.03, js115;oxIs34 – 0.85 ± 0.16 (D) UNC-13S restores isoflurane sensitivity to unc-13(s69). EC50s: N2 = 0.72 ± 0.13, s69;nuIs46 = 0.77 ± 0.15 (E) animals expressing myr-UNC-13S are isoflurane resistant. EC50s: s69;nuIs46 = 0.77 ± 0.15, s69;oxIs78 = 3.40 ± 0.32. (F) Summary of isoflurane EC50's ± SE of the fit of the curves in D, E, and the body bend data for unc-13(s69);mdIs3. * - p < 0.01 vs N2. (G) myr-UNC-13s has wild-type sensitivity to aldicarb. The fraction of animals moving after various incubation times on agar plates containing 0.35 mM aldicarb. Each point represents the mean ± sem of triplicate measurements of at least 30 animals/measurement.