Molecular basis of the remarkable species selectivity of an insecticidal sodium channel toxin from the African spider Augacephalus ezendami

Herzig, Volker, Ikonomopoulou, Maria, Smith, Jennifer J., Dziemborowicz, Slawomir, Gilchrist, John, Kuhn-Nentwig, Lucia, Rezende, Fernanda Oliveira, Moreira, Luciano Andrade, Nicholson, Graham M., Bosmans, Frank and King, Glenn F. (2016) Molecular basis of the remarkable species selectivity of an insecticidal sodium channel toxin from the African spider Augacephalus ezendami. Scientific Reports, 6 . doi:10.1038/srep29538


Author Herzig, Volker
Ikonomopoulou, Maria
Smith, Jennifer J.
Dziemborowicz, Slawomir
Gilchrist, John
Kuhn-Nentwig, Lucia
Rezende, Fernanda Oliveira
Moreira, Luciano Andrade
Nicholson, Graham M.
Bosmans, Frank
King, Glenn F.
Title Molecular basis of the remarkable species selectivity of an insecticidal sodium channel toxin from the African spider Augacephalus ezendami
Formatted title
Molecular basis of the remarkable species selectivity of an insecticidal sodium channel toxin from the African spider Augacephalus ezendami
Journal name Scientific Reports   Check publisher's open access policy
ISSN 2045-2322
Publication date 2016-07-07
Year available 2016
Sub-type Article (original research)
DOI 10.1038/srep29538
Open Access Status DOI
Volume 6
Total pages 11
Place of publication London, United Kingdom
Publisher Nature Publishing Group
Collection year 2017
Language eng
Formatted abstract
The inexorable decline in the armament of registered chemical insecticides has stimulated research into environmentally-friendly alternatives. Insecticidal spider-venom peptides are promising candidates for bioinsecticide development but it is challenging to find peptides that are specific for targeted pests. In the present study, we isolated an insecticidal peptide (Ae1a) from venom of the African spider Augacephalus ezendami (family Theraphosidae). Injection of Ae1a into sheep blowflies (Lucilia cuprina) induced rapid but reversible paralysis. In striking contrast, Ae1a was lethal to closely related fruit flies (Drosophila melanogaster) but induced no adverse effects in the recalcitrant lepidopteran pest Helicoverpa armigera. Electrophysiological experiments revealed that Ae1a potently inhibits the voltage-gated sodium channel BgNaV1 from the German cockroach Blattella germanica by shifting the threshold for channel activation to more depolarized potentials. In contrast, Ae1a failed to significantly affect sodium currents in dorsal unpaired median neurons from the American cockroach Periplaneta americana. We show that Ae1a interacts with the domain II voltage sensor and that sensitivity to the toxin is conferred by natural sequence variations in the S1-S2 loop of domain II. The phyletic specificity of Ae1a provides crucial information for development of sodium channel insecticides that target key insect pests without harming beneficial species.
Keyword Insecticides
Environmentally-friendly alternatives
Insecticidal spider-venom peptides
Sodium channel toxin
Augacephalus ezendami
Q-Index Code C1
Q-Index Status Provisional Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: HERDC Pre-Audit
Institute for Molecular Bioscience - Publications
 
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