title: Identification of the Mamestra configurata (Lepidoptera: Noctuidae) peritrophic matrix proteins and enzymes involved in peritrophic matrix chitin metabolism.
abstract: The peritrophic matrix (PM) is essential for insect digestive system physiology as it protects the midgut epithelium from damage by food particles, pathogens, and toxins. The PM is also an attractive target for development of new pest control strategies due to its per os accessibility. To understand how the PM performs these functions, the molecular architecture of the PM was examined using genomic and proteomic approaches in Mamestra configurata (Lepidoptera: Noctuidae), a major pest of cruciferous oilseed crops in North America. Liquid chromatography-tandem mass spectrometry analyses of the PM identified 82 proteins classified as: (i) peritrophins, including a new class with a CBDIII domain; (ii) enzymes involved in chitin modification (chitin deacetylases), digestion (serine proteases, aminopeptidases, carboxypeptidases, lipases and α-amylase) or other reactions (β-1,3-glucanase, alkaline phosphatase, dsRNase, astacin, pantetheinase); (iii) a heterogenous group consisting of polycalin, REPATs, serpin, C-Type lectin and Lsti99/Lsti201 and 3 novel proteins without known orthologs. The genes encoding PM proteins were expressed predominantly in the midgut. cDNAs encoding chitin synthase-2 (McCHS-2), chitinase (McCHI), and β-N-acetylglucosaminidase (McNAG) enzymes, involved in PM chitin metabolism, were also identified. McCHS-2 expression was specific to the midgut indicating that it is responsible for chitin synthesis in the PM, the only chitinous material in the midgut. In contrast, the genes encoding the chitinolytic enzymes were expressed in multiple tissues. McCHS-2, McCHI, and McNAG were expressed in the midgut of feeding larvae, and NAG activity was present in the PM. This information was used to generate an updated model of the lepidopteran PM architecture.
authors.affiliation: Agriculture and Agri-Food Canada, Saskatoon, SK, Canada.|Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada.|Department of Plant Protection, Faculty of Agriculture, University of Ankara, Ankara, Turkey.
authors.forename: Umut
authors.initials: U
authors.lastname: Toprak
authors.affiliation: Agriculture and Agri-Food Canada, Saskatoon, SK, Canada.|Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada.
authors.forename: Martin
authors.initials: M
authors.lastname: Erlandson
authors.affiliation: Agriculture and Agri-Food Canada, Saskatoon, SK, Canada.
authors.forename: Doug
authors.initials: D
authors.lastname: Baldwin
authors.affiliation: Agriculture and Agri-Food Canada, Saskatoon, SK, Canada.
authors.forename: Steve
authors.initials: S
authors.lastname: Karcz
authors.affiliation: Plant Biotechnology Institute, National Research Council of Canada, Saskatoon, SK, Canada.
authors.forename: Lianglu
authors.initials: L
authors.lastname: Wan
authors.affiliation: Agriculture and Agri-Food Canada, Saskatoon, SK, Canada.
authors.forename: Cathy
authors.initials: C
authors.lastname: Coutu
authors.affiliation: Department of Biology, University of Saskatchewan, Saskatoon, SK, Canada.
authors.forename: Cedric
authors.initials: C
authors.lastname: Gillott
authors.affiliation: Agriculture and Agri-Food Canada, Saskatoon, SK, Canada. Dwayne.Hegedus@agr.gc.ca.|Department of Food and Bioproduct Sciences, University of Saskatchewan, Saskatoon, SK, Canada. Dwayne.Hegedus@agr.gc.ca.
authors.forename: Dwayne D
authors.initials: DD
authors.lastname: Hegedus
mesh_terms: D000818:Animals; D002686:Chitin / Q000235:genetics / Q000378:metabolism*; D020224:Expressed Sequence Tags; D041981:Gastrointestinal Tract / Q000201:enzymology / Q000378:metabolism; D049750:Genome, Insect; D019476:Insect Proteins / Q000378:metabolism*; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D009036:Moths / Q000235:genetics / Q000254:growth & development / Q000378:metabolism*
chemical_list: D019476:Insect Proteins; D002686:Chitin
keywords: Mamestra configurata; chitin; peritrophic matrix; protein