Insect sodium channels and insecticide resistance

Dong, Ke

doi:10.1007/s10158-006-0036-9

Cited by 316 publications

(316 citation statements)

References 125 publications

(111 reference statements)

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“…The differential sensitivities of BgNa v sodium channel splice variants from B. germanica have been valuable in elucidating the channel regions involved in channel function and resistance to pyrethroid insecticides (4,5). Here, we examined the sensitivity of 10 BgNa v channel variants to the insect-selective scorpion depressant ␤-toxin Lqh-dprIT 3 .…”

Section: Discussionmentioning

confidence: 99%

Substitutions in the Domain III Voltage-sensing Module Enhance the Sensitivity of an Insect Sodium Channel to a Scorpion β-Toxin

Song

Liu

et al. 2011

Journal of Biological Chemistry

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Scorpion ␤-toxins bind to the extracellular regions of the voltage-sensing module of domain II and to the pore module of domain III in voltage-gated sodium channels and enhance channel activation by trapping and stabilizing the voltage sensor of domain II in its activated state. We investigated the interaction of a highly potent insect-selective scorpion depressant ␤-toxin, Lqh-dprIT 3 , from Leiurus quinquestriatus hebraeus with insect sodium channels from Blattella germanica (BgNa v ). Like other scorpion ␤-toxins, Lqh-dprIT 3 shifts the voltage dependence of activation of BgNa v channels expressed in Xenopus oocytes to more negative membrane potentials but only after strong depolarizing prepulses. Notably, among 10 BgNa v splice variants tested for their sensitivity to the toxin, only BgNa v 1-1 was hypersensitive due to an L1285P substitution in IIIS1 resulting from a U-to-C RNA-editing event. Furthermore, charge reversal of a negatively charged residue (E1290K) at the extracellular end of IIIS1 and the two innermost positively charged residues (R4E and R5E) in IIIS4 also increased the channel sensitivity to Lqh-dprIT 3 . Besides enhancement of toxin sensitivity, the R4E substitution caused an additional 20-mV negative shift in the voltage dependence of activation of toxin-modified channels, inducing a unique toxin-modified state. Our findings provide the first direct evidence for the involvement of the domain III voltage-sensing module in the action of scorpion ␤-toxins. This hypersensitivity most likely reflects an increase in IIS4 trapping via allosteric mechanisms, suggesting coupling between the voltage sensors in neighboring domains during channel activation.

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Section: Discussionmentioning

confidence: 99%

Substitutions in the Domain III Voltage-sensing Module Enhance the Sensitivity of an Insect Sodium Channel to a Scorpion β-Toxin

Song

Liu

et al. 2011

Journal of Biological Chemistry

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“…Recent characterization of the German cockroach BgNa V sodium channel gene suggests that alternative splicing and RNA editing are two major mechanisms by which cockroaches produce functionally diverse sodium channels (Tan et al, 2002;Liu et al, 2004;Song et al, 2004;Dong, 2007). To determine whether alternative splicing-and RNA editing-mediated generation of diverse sodium channel gating properties is a common phenomenon in insects, we conducted a large-scale functional characterization of alternative splicing and RNA editing variants of the D. melanogaster DmNa V gene.…”

Section: Introductionmentioning

confidence: 99%

Molecular and functional characterization of voltage-gated sodium channel variants from Drosophila melanogaster

Olson

Liu

Nomura

et al. 2008

Insect Biochemistry and Molecular Biology

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Extensive alternative splicing and RNA editing have been documented for the transcript of DmNa V (formerly para), the sole sodium channel gene in Drosophila melanogaster. However, the functional consequences of these post-transcriptional modifications are not well understood. In this study we isolated 64 full-length DmNa V cDNA clones from D. melanogaster adults. Based on the usage of 11 alternative exons, 64 clones could be grouped into 29 splice types. When expressed in Xenopus oocytes, 33 DmNa V variants generated sodium currents large enough for functional characterization. Among these variants, DmNa V 5-1 and DmNa V 7-1 channels activated at the most hyperpolarizing potentials, whereas DmNa V 1-6 and DmNa V 19 channels activated at the most depolarizing membrane potentials. We identified an A-to-I editing event in DmNa V 5-1 that is responsible for its uniquely low-voltage-dependent activation. The wide range of voltage dependence of gating properties exhibited by DmNa V variants represents a rich resource for future studies to determine the role of DmNa V in regulating sodium channel gating, pharmacology, and neuronal excitability in insects.

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“…Note that at present nine isoforms of ␣-subunit have been well characterized in humans (Na v 1.1-1.9), and just one appears to function in insects (e.g. the Para protein in Drosophila) (4,5). To date, a host of substances has been described affecting Na v s through binding to different parts of the channels, so-called receptor sites (6).…”

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confidence: 99%

Modular Organization of α-Toxins from Scorpion Venom Mirrors Domain Structure of Their Targets, Sodium Channels

Chugunov

Koromyslova

Berkut

et al. 2013

Journal of Biological Chemistry

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Background: Scorpion ␣-toxins affect voltage-gated sodium channels in both mammals and insects. Results: We perform thorough computational analyses of ␣-toxin molecular architecture and structure-function relationship. Conclusion: Taxon specificity of "orphan" toxins can be predicted from a structural perspective. Significance: The proposed surface mapping technique is a new tool to analyze protein-protein complexes.

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Insect sodium channels and insecticide resistance

Cited by 316 publications

References 125 publications

Substitutions in the Domain III Voltage-sensing Module Enhance the Sensitivity of an Insect Sodium Channel to a Scorpion β-Toxin

Substitutions in the Domain III Voltage-sensing Module Enhance the Sensitivity of an Insect Sodium Channel to a Scorpion β-Toxin

Molecular and functional characterization of voltage-gated sodium channel variants from Drosophila melanogaster

Modular Organization of α-Toxins from Scorpion Venom Mirrors Domain Structure of Their Targets, Sodium Channels

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