title: A cathepsin L-like proteinase is involved in moulting and metamorphosis in Helicoverpa armigera.
abstract: Holometabolous insects undergo larval moulting and metamorphosis within their life cycle. A cDNA encoding the cathepsin L-like proteinase Ha-cathL has been cloned from Helicoverpa armigera. It has a sequence of 1826 bp and encodes a 550-residue protein with a molecular mass of 63 kDa. Northern blot analysis indicated that Ha-cathL is specifically expressed in haemocytes, with increased expression during larval moulting and metamorphosis. In vivo experimentation revealed that Ha-cathL is up-regulated by 20-hydroxyecdysone. Meanwhile, in situ hybridization and immunocytochemistry revealed that Ha-cathL mRNA is mainly expressed in granulocytes and plasmatocytes. Knock down of cathepsin L by RNA interference results in larvae death before pupation or the formation of a chimeric pupa containing a larval head and thorax, abnormal wings and the pupal abdomen. The reason for this is that the affected haemocytes cannot become granulated, and therefore cannot participate in fat body remodelling and wing development. These facts suggest that Ha-cathL is involved in larval moulting and metamorphosis by participating in the functioning of haemocytes.
authors.affiliation: School of Life Sciences, the Key Laboratory of Plant Cell Engineering and Germplasm Innovation, Ministry of Education, Shandong University, Jinan, Shandong, China.
authors.forename: L-F
authors.initials: LF
authors.lastname: Wang
authors.forename: L-Q
authors.initials: LQ
authors.lastname: Chai
authors.forename: H-J
authors.initials: HJ
authors.lastname: He
authors.forename: Q
authors.initials: Q
authors.lastname: Wang
authors.forename: J-X
authors.initials: JX
authors.lastname: Wang
authors.forename: X-F
authors.initials: XF
authors.lastname: Zhao
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D000906:Antibodies / Q000378:metabolism; D001483:Base Sequence; D056668:Cathepsin L; D003001:Cloning, Molecular; D018076:DNA, Complementary / Q000737:chemistry; D018507:Gene Expression Regulation, Developmental; D006434:Hemocytes / Q000201:enzymology; D019476:Insect Proteins / Q000378:metabolism*; D007814:Larva / Q000201:enzymology; D008969:Molecular Sequence Data; D018978:Molting; D009036:Moths / Q000201:enzymology* / Q000254:growth & development; D009928:Organ Specificity; D010447:Peptide Hydrolases / Q000276:immunology / Q000378:metabolism*; D034622:RNA Interference; D011994:Recombinant Proteins / Q000378:metabolism
chemical_list: D000906:Antibodies; D018076:DNA, Complementary; D019476:Insect Proteins; D011994:Recombinant Proteins; D010447:Peptide Hydrolases; D056668:Cathepsin L