Release-dependent feedback inhibition by a presynaptically localized ligand-gated anion channel
- University of California, San Diego, United States
Figures
Figure 1 with 1 supplement
LGIC LGC-46 localizes to presynaptic terminals.
(A) Alignment of TM2 of LGC-46 with other anion channels. * marks Met314, which is mutated to Ile in LGC-46(ju825). § marks PAR motif, a signature of ionotropic anion channels. (B–F) LGC-46::GFP …
Figure 1—figure supplement 1
lgc-46 is expressed in the nervous system including cholinergic motor neurons.
(A) Gene and protein structure of lgc-46. The positions of the deletion alleles and the M314I mutation described in the text are noted. ok2900 removes TM2 and TM3 and generates a premature stop …
Figure 2 with 1 supplement
LGC-46 regulates the decay phase of eEPSCs to modulate the late phase of SV release.
(A and B) Average traces (A) and normalized average traces (B) of eEPSCs. (C) Mean amplitude of eEPSCs. (D) Rise tau and decay tau of eEPSCs. (E) Average traces of cumulative charges of eEPSCs, and …
Figure 2—figure supplement 1
Morphology of cholinergic synapses as well as the amplitude and kinetics of endogenous EPSCs are normal in lgc-46(0).
(A) Representative images of mCherry::RAB-3 puncta in the dorsal nerve cord from each genotype. Scale bar: 5 μm. (B) Quantification of the puncta density and width show no significant differences …
Figure 3 with 1 supplement
A. gain-of-function mutation LGC-46(M314I) affects excitation and inhibition imbalance in locomotor circuit.
(A) Quantification of convulsion frequencies. lgc-46(ju825), but not lgc-46(0), suppresses acr-2(gf) convulsions. Overexpression of LGC-46(M314I) under its own promoter also strongly suppresses …
Figure 3—figure supplement 1
Pharmacological assays of aldicarb and levamisole.
(A) lgc-46(ok2900) is hypersensitive to aldicarb hypersensitivity, which is suppressed by cholinergic motor neuron-specific expression of functional LGC-46::GFP. (B) lgc-46(0) alleles do not affect …
Figure 4 with 1 supplement
LGC-46(M314I) limits synaptic transmission by shortening the decay phase of evoked release.
(A and B) Average traces (A) and normalized average traces (B) of eEPSCs. (C) Mean amplitude of eEPSCs. (D) Rise tau and decay tau of eEPSCs. (E) Average traces of cumulative charges of eEPSCs, and …
Figure 4—figure supplement 1
LGC-46(M314I) shows a presynaptic punctate localization pattern similar to LGC-46(WT), and amplitude and kinetics of endogenous EPSCs are normal in lgc-46(gf).
(A-D) Confocal images of animals expressing LGC-46(M314I)::GFP in cholinergic motor neurons. (A) (Left panel) Schematic of a cholinergic motor neuron in L1 animals. (Right panel) LGC-46(M314I)::GFP …
Figure 5 with 1 supplement
ACC-4 is required for the function of LGC-46(M314I), and localizes presynaptically.
(A) Frequency of convulsion in animals of indicated genotypes. Loss of function in acc-4 reverses the suppression effect by lgc-46(ju825) on acr-2(gf). The expression of acc-4(+) under the …
Figure 5—figure supplement 1
ACC-4 is required for the function of LGC-46(M314I).
(A) Locomotion observed in double mutants of lgc-46(ju825gf) and acc group genes. (B) Gene and protein structure of acc-4. Arrows indicate the position of the primers used to amplify cDNA. In …
Additional files
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Supplementary file 1
List of strains used in the study.
- https://doi.org/10.7554/eLife.21734.012
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Supplementary file 2
List of constructs used in the study.
- https://doi.org/10.7554/eLife.21734.013
