Positive selection of digestive Cys proteases in herbivorous Coleoptera

Vorster, Juan, Rasoolizadeh, Asieh, Goulet, Marie-Claire, Cloutier, Conrad, Sainsbury, Frank and Michaud, Dominique (2015) Positive selection of digestive Cys proteases in herbivorous Coleoptera. Insect Biochemistry and Molecular Biology, 65 10-19. doi:10.1016/j.ibmb.2015.07.017

Attached Files (Some files may be inaccessible until you login with your UQ eSpace credentials)
Name Description MIMEType Size Downloads

Author Vorster, Juan
Rasoolizadeh, Asieh
Goulet, Marie-Claire
Cloutier, Conrad
Sainsbury, Frank
Michaud, Dominique
Title Positive selection of digestive Cys proteases in herbivorous Coleoptera
Journal name Insect Biochemistry and Molecular Biology   Check publisher's open access policy
ISSN 1879-0240
Publication date 2015-10
Year available 2015
Sub-type Article (original research)
DOI 10.1016/j.ibmb.2015.07.017
Open Access Status File (Author Post-print)
Volume 65
Start page 10
End page 19
Total pages 10
Place of publication Oxford, United Kingdom
Publisher Elsevier
Collection year 2016
Language eng
Formatted abstract
Positive selection is thought to contribute to the functional diversification of insect-inducible protease inhibitors in plants in response to selective pressures exerted by the digestive proteases of their herbivorous enemies. Here we assessed whether a reciprocal evolutionary process takes place on the insect side, and whether ingestion of a positively selected plant inhibitor may translate into a measurable rebalancing of midgut proteases in vivo. Midgut Cys proteases of herbivorous Coleoptera, including the major pest Colorado potato beetle (Leptinotarsa decemlineata), were first compared using a codon-based evolutionary model to look for the occurrence of hypervariable, positively selected amino acid sites among the tested sequences. Hypervariable sites were found, distributed within –or close to– amino acid regions interacting with Cys-type inhibitors of the plant cystatin protein family. A close examination of L. decemlineata sequences indicated a link between their assignment to protease functional families and amino acid identity at positively selected sites. A function-diversifying role for positive selection was further suggested empirically by in vitro protease assays and a shotgun proteomic analysis of L. decemlineata Cys proteases showing a differential rebalancing of protease functional family complements in larvae fed single variants of a model cystatin mutated at positively selected amino acid sites. These data confirm overall the occurrence of hypervariable, positively selected amino acid sites in herbivorous Coleoptera digestive Cys proteases. They also support the idea of an adaptive role for positive selection, useful to generate functionally diverse proteases in insect herbivores ingesting functionally diverse, rapidly evolving dietary cystatins.
Keyword Positive selectionCoevolutionary arms race
Herbivorous Coleoptera
Digestive cysteine proteases
Plant cystatins
Plant-insect interactions
Leptinotarsa decemlineata Say
Q-Index Code C1
Q-Index Status Confirmed Code
Institutional Status UQ

Document type: Journal Article
Sub-type: Article (original research)
Collections: Official 2016 Collection
Australian Institute for Bioengineering and Nanotechnology Publications
Version Filter Type
Citation counts: TR Web of Science Citation Count  Cited 2 times in Thomson Reuters Web of Science Article | Citations
Scopus Citation Count Cited 4 times in Scopus Article | Citations
Google Scholar Search Google Scholar
Created: Tue, 01 Sep 2015, 00:14:00 EST by System User on behalf of Scholarly Communication and Digitisation Service