ryanodine and chlorantranilipole

Diamide insecticides have emerged as one of the most promising new classes of insecticide chemistry owing to their excellent insecticidal efficacy and high margins of mammalian safety. Chlorantraniliprole and flubendiamide, the first two insecticides from this class, demonstrate exceptional activity across a broad range of pests in the order Lepidoptera. This chemistry has been confirmed to control insects via activation of ryanodine receptors which leads to uncontrolled calcium release in muscle. The high levels of mammalian safety are attributed to a strong selectivity for insect over mammalian receptors.

Topics: Animals; Benzamides; Insect Control; Insecticides; Lepidoptera; ortho-Aminobenzoates; Ryanodine; Ryanodine Receptor Calcium Release Channel; Sulfones

The detailed molecular mechanism of wilforine, a novel botanical insecticidal component, remains unclear, except for the knowledge that it affects the calcium signaling pathway. The aim of the current study was to examine the underlying molecular mechanism of wilforine in Mythimna separata (Walker) by transcriptome and RNA interference (RNAi), with chlorantraniliprole as control. RNA sequencing showed that the relative expression of genes related to the calcium signaling pathway and muscle contraction in M. separata treated with wilforine significantly changed and was further validated by qRT-PCR. Interestingly, the expression level of the ryanodine receptor (MsRyR) gene was downregulated by wilforine at relatively high concentrations and long treatment time, contrary to that observed using chlorantraniliprole. Furthermore, a putative MsRyR was cloned using a 16,258-bp contiguous sequence containing a 308-bp 5'-untranslated region and 578-bp 3'-untranslated region by RT-PCR and RACE. The results of the RNAi experiment showed that injection of dsMsRyR significantly reduced MsRyR mRNA levels, and growth and development were inhibited. Importantly, silencing of the MsRyR gene resulted in decreased susceptibility to both wilforine and chlorantraniliprole. Together with the results of our previous studies on toxic symptoms and muscle tissue lesions between wilforine and chlorantraniliprole, we propose that RyR Ca

Topics: Animals; Calcium Signaling; Insecticides; Lactones; Larva; Moths; ortho-Aminobenzoates; Pyridines; RNA, Messenger; Ryanodine; Ryanodine Receptor Calcium Release Channel; Transcriptome

Very recently, the diamide insecticide chlorantraniliprole was shown to induce Ca2+-release from sarcoplasmic reticulum (SR) vesicles isolated from mammalian skeletal muscle through the activation of the SR Ca2+ channel ryanodine receptor. As this result raises severe concerns about the safety of this chemical, we aimed to learn more about its action. To this end, single-channel analysis was performed, which showed that chlorantraniliprole induced high-activity bursts of channel opening that accounts for the Ca2+-releasing action described before.

Topics: Animals; Calcium; Diamide; Insecticides; Muscle, Skeletal; ortho-Aminobenzoates; Ryanodine; Ryanodine Receptor Calcium Release Channel; Sarcoplasmic Reticulum

Diamides, such as flubendiamide and chlorantraniliprole, belong to a new chemical class of insecticides that act as conformation-sensitive activators of insect ryanodine receptors (RyRs). Both compounds are registered for use against lepidopteran species such as the diamondback moth, Plutella xylostella, a notorious global pest of cruciferous crops. Recently acquired resistance to diamide insecticides in this species is thought to be due to a target-site mutation conferring an amino acid substitution (G4946E), located within the trans-membrane domain of the RyR, though the exact role of this mutation has not yet been fully determined. To address this we have cloned a full-length cDNA encoding the P. xylostella RyR and established clonal Sf9 cell lines stably expressing either the wildtype RyR or the G4946E variant, in order to test the sensitivity to flubendiamide and chlorantraniliprole on the recombinant receptor. We report that the efficacy of both diamides was dramatically reduced in clonal Sf9 cells stably expressing the G4946E modified RyR, providing clear functional evidence that the G4946E RyR mutation impairs diamide insecticide binding.

Topics: Animals; Benzamides; Caffeine; Calcium Signaling; Cloning, Molecular; Drug Tolerance; Gene Expression; Insect Proteins; Insecticides; Mutation, Missense; ortho-Aminobenzoates; Protein Binding; Ryanodine; Ryanodine Receptor Calcium Release Channel; Sf9 Cells; Spodoptera; Sulfones

Radiolabeled anthranilic diamide insecticide [N-C(3)H(3)]chlorantraniliprole was synthesized at high specific activity. It was compared with phthalic diamide insecticide flubendiamide and [(3)H]ryanodine in radioligand binding studies with house fly muscle membranes to provide the first direct evidence with a native insect ryanodine receptor that the major anthranilic and phthalic diamide insecticides bind at different allosterically coupled sites, i.e., there are three distinct Ca(2+)-release channel targets for insecticide action.

Topics: Animals; Benzamides; Binding Sites; Calcium; Carbon; Insect Proteins; Insecta; Insecticides; Nitrogen; ortho-Aminobenzoates; Protein Binding; Ryanodine; Ryanodine Receptor Calcium Release Channel; Sulfones; Tritium