title: A chymotrypsin-like serine protease interacts with the chitin synthase from the midgut of the tobacco hornworm.
abstract: The chitin portion of the peritrophic matrix in the midgut of the tobacco hornworm, Manduca sexta, is produced by chitin synthase 2 (CHS2), a transmembrane family II glycosyltransferase, located at the apical tips of brush border microvilli. To look for proteins that potentially interact with CHS2, we performed yeast two-hybrid screening, identifying a novel chymotrypsin-like protease (CTLP1) that binds to the extracellular carboxyterminal domain of CHS2. The occurrence of this interaction in vivo is supported by co-localization and co-immunoprecipitation data. Based on our findings we propose that chitin synthesis is controlled by an intestinal proteolytic signalling cascade linking chitin synthase activity to the nutritional state of the larvae.
authors.affiliation: Department of Biology/Chemistry, University of Osnabrück, D-49069 Osnabrück, Germany.
authors.forename: Gunnar
authors.initials: G
authors.lastname: Broehan
authors.forename: Lars
authors.initials: L
authors.lastname: Zimoch
authors.forename: Anton
authors.initials: A
authors.lastname: Wessels
authors.forename: Beyhan
authors.initials: B
authors.lastname: Ertas
authors.forename: Hans
authors.initials: H
authors.lastname: Merzendorfer
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D002686:Chitin / Q000096:biosynthesis; D002687:Chitin Synthase / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D053818:Chymases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000235:genetics / Q000302:isolation & purification; D004064:Digestive System / Q000166:cytology / Q000201:enzymology*; D015971:Gene Expression Regulation, Enzymologic; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D018402:Manduca / Q000166:cytology / Q000201:enzymology* / Q000235:genetics; D008969:Molecular Sequence Data; D011485:Protein Binding; D017434:Protein Structure, Tertiary; D021381:Protein Transport; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D017422:Sequence Analysis, DNA; D020798:Two-Hybrid System Techniques
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D002686:Chitin; D002687:Chitin Synthase; C400821:chitin synthase 2; D053818:Chymases