RRC ID 3577
Author Guest M, Bull K, Walker RJ, Amliwala K, O'Connor V, Harder A, Holden-Dye L, Hopper NA.
Title The calcium-activated potassium channel, SLO-1, is required for the action of the novel cyclo-octadepsipeptide anthelmintic, emodepside, in Caenorhabditis elegans.
Journal Int. J. Parasitol.
Abstract The cyclo-octadepsipeptide anthelmintic, emodepside, has pleiotropic effects on the behaviour of the model genetic animal Caenorhabditis elegans: it inhibits locomotion, feeding, egg-laying and slows development. Previous studies on pharyngeal muscle indicated a role for latrophilin-dependent signalling and therefore prompted the suggestion that this is a common effector of this drug's actions. However, whilst a C. elegans functional null mutant for latrophilin (lat-1) is less sensitive to the effect of emodepside on the pharynx it remains sensitive to the inhibitory effects of emodepside on locomotion. Here we show that this is not due to functional redundancy between two C. elegans latrophilins, as the double mutant, lat-2, lat-1, also remains sensitive to the effects of emodepside on locomotion. Therefore, emodepside has latrophilin-independent effects. To define the molecular basis for this we performed a mutagenesis screen. We recovered nine alleles of slo-1, which encodes a Ca(2+)-activated K(+) channel. These mutants were highly resistant to the inhibitory effect of emodepside on both pharyngeal and locomotor activity. The slo-1 alleles are predicted to reduce or eliminate SLO-1 signalling, suggesting that emodepside may signal through a SLO-1-dependent pathway. The observation that gain-of-function slo-1 alleles phenocopy the effects of emodepside, but are not themselves emodepside hypersensitive, favours a model whereby emodepside directly acts through a SLO-1-dependent pathway. Tissue-specific genetic rescue experiments reveal that emodepside acts through SLO-1 expressed in either body wall muscle or in neurones to inhibit locomotion. In contrast, in the pharyngeal system, emodepside acts through SLO-1 in neurones, but not muscle, to inhibit feeding. These data further inform understanding of the mode of action of emodepside and suggest that emodepside causes inhibition of feeding via a neuronal SLO-1-dependent pathway which is facilitated by LAT-1 whilst it signals through a latrophilin-independent, SLO-1-dependent pathway, in either neurones or body wall muscle, to inhibit locomotion.
Volume 37(14)
Pages 1577-88
Published 2007-12
DOI 10.1016/j.ijpara.2007.05.006
PII S0020-7519(07)00153-1
PMID 17583712
MeSH Amino Acid Sequence Animals Anthelmintics / pharmacology* Caenorhabditis elegans / drug effects* Caenorhabditis elegans / genetics Caenorhabditis elegans / physiology Caenorhabditis elegans Proteins / physiology* Depsipeptides / pharmacology* Drug Resistance Eating / drug effects Genes, Helminth Large-Conductance Calcium-Activated Potassium Channels / physiology* Locomotion / drug effects Locomotion / physiology Molecular Sequence Data Muscle, Skeletal / metabolism Mutagenesis Neurons / metabolism Pharynx / drug effects Pharynx / physiology Phenotype Receptors, Peptide / genetics
IF 3.078
Times Cited 50
C.elegans tm463