title: Cathepsin L function in insect moulting: molecular cloning and functional analysis in cotton bollworm, Helicoverpa armigera.
abstract: Moulting is an essential process of insect development but little is known about cysteine proteases in the process. Here, we detail a proteolytic activity profile from fifth larval instar to new pupae of the lepidopteran Helicoverpa armigera. At fifth to sixth instar moulting, the activities were significantly higher than those in non-moulting stages, and were inhibited by the cysteine protease inhibitor, 2S, 3S-trans-epoxysuccinyl-L-leucylamido-3-methylbutane ethyl ester (E-64), or by the cathepsin L-selective inhibitor CLIK148. Further, a 1513 bp cathepsin L cDNA (Har-CL) was isolated from the H. armigera larval cuticle and epidermis layer. Har-CL gene expression, which is correlated closely with ecdysone, was higher during larval moulting. Injection of E-64 or CLIK148 resulted in delayed fifth to sixth instar moulting, suggesting an essential role for cathepsin L in larval moulting.
authors.affiliation: Department of Molecular and Cell Biology, University of Science and Technology of China, Hefei, China.
authors.forename: J
authors.initials: J
authors.lastname: Liu
authors.forename: G-P
authors.initials: GP
authors.lastname: Shi
authors.forename: W-Q
authors.initials: WQ
authors.lastname: Zhang
authors.forename: G-R
authors.initials: GR
authors.lastname: Zhang
authors.forename: W-H
authors.initials: WH
authors.lastname: Xu
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D056668:Cathepsin L; D002403:Cathepsins / Q000037:antagonists & inhibitors / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D003001:Cloning, Molecular; D003546:Cysteine Endopeptidases / Q000737:chemistry / Q000235:genetics / Q000378:metabolism*; D018076:DNA, Complementary / Q000302:isolation & purification; D004440:Ecdysone / Q000378:metabolism; D004791:Enzyme Inhibitors / Q000494:pharmacology; D004817:Epidermis / Q000187:drug effects; D020869:Gene Expression Profiling; D018507:Gene Expression Regulation, Developmental / Q000187:drug effects; D003368:Gossypium / Q000469:parasitology*; D006458:Hemolymph / Q000187:drug effects / Q000378:metabolism; D007814:Larva / Q000187:drug effects; D007915:Lepidoptera / Q000254:growth & development / Q000502:physiology*; D008018:Life Cycle Stages; D008969:Molecular Sequence Data; D018978:Molting / Q000187:drug effects / Q000502:physiology*; D011499:Protein Processing, Post-Translational / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D016415:Sequence Alignment
chemical_list: D018076:DNA, Complementary; D004791:Enzyme Inhibitors; D012333:RNA, Messenger; D004440:Ecdysone; D002403:Cathepsins; D003546:Cysteine Endopeptidases; D056668:Cathepsin L