title: Digestive proteolysis in the Colorado potato beetle, Leptinotarsa decemlineata: Activity-based profiling and imaging of a multipeptidase network.
abstract: The Colorado potato beetle (CPB), Leptinotarsa decemlineata, is a major pest of potato plants, and its digestive system is a promising target for development of pest control strategies. This work focuses on functional proteomic analysis of the digestive proteolytic enzymes expressed in the CPB gut. We identified a set of peptidases using imaging with specific activity-based probes and activity profiling with selective substrates and inhibitors. The secreted luminal peptidases were classified as: (i) endopeptidases of cathepsin D, cathepsin L, and trypsin types and (ii) exopeptidases with aminopeptidase (cathepsin H), carboxypeptidase (serine carboxypeptidase, prolyl carboxypeptidase), and carboxydipeptidase (cathepsin B) activities. The proteolytic arsenal also includes non-luminal peptidases with prolyl oligopeptidase and metalloaminopeptidase activities. Our results indicate that the CPB gut employs a multienzyme network of peptidases with complementary specificities to efficiently degrade ingested proteins. This proteolytic system functions in both CPB larvae and adults and is controlled mainly by cysteine and aspartic peptidases and supported by serine and metallopeptidases. The component enzymes identified here are potential targets for inhibitors with tailored specificities that could be engineered into potato plants to confer resistance to CPB.
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 166 10, Czech Republic; Department of Biochemistry, Faculty of Science, Charles University, Hlavova 8, Prague 128 40, Czech Republic.
authors.forename: Jaroslav
authors.initials: J
authors.lastname: Srp
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 166 10, Czech Republic.
authors.forename: Martina
authors.initials: M
authors.lastname: Nussbaumerová
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 166 10, Czech Republic.
authors.forename: Martin
authors.initials: M
authors.lastname: Horn
authors.affiliation: Institute of Organic Chemistry and Biochemistry, Academy of Sciences of the Czech Republic, Flemingovo nam. 2, Prague 166 10, Czech Republic. Electronic address: mares@uochb.cas.cz.
authors.forename: Michael
authors.initials: M
authors.lastname: Mareš
mesh_terms: D000824:Animal Nutritional Physiological Phenomena; D000818:Animals; D001517:Coleoptera / Q000201:enzymology / Q000235:genetics* / Q000254:growth & development / Q000378:metabolism*; D004063:Digestion; D041981:Gastrointestinal Tract / Q000201:enzymology; D019476:Insect Proteins / Q000235:genetics* / Q000378:metabolism; D007814:Larva / Q000235:genetics / Q000254:growth & development / Q000378:metabolism; D010447:Peptide Hydrolases / Q000235:genetics* / Q000378:metabolism; D010940:Plant Proteins / Q000378:metabolism*; D059748:Proteolysis; D040901:Proteomics
chemical_list: D019476:Insect Proteins; D010940:Plant Proteins; D010447:Peptide Hydrolases
keywords: Activity-based probe; Cathepsin; Colorado potato beetle; Digestive system; Multienzyme network; Peptidase