title: Cloning, Expression, and Characterization of Prophenoloxidases from Asian Corn Borer,Ostrinia furnacalis(Gunée).
abstract: Insect phenoloxidase (PO) belongs to the type 3 copper protein family and possesses oxidoreductase activities. PO is typically synthesized as a zymogen called prophenoloxidase (PPO) and requires the proteolytic activation to function. We here cloned full-length cDNA for 3 previously unidentified PPOs, which we named OfPPO1a, OfPPO1b, and OfPPO3, from Asian corn borer,Ostrinia furnacalis(Gunée), in addition to the previously known OfPPO2. These conceptual PPOs and OfPPO2 all contain two common copper-binding regions, two potential proteolytic activation sites, a plausible thiol-ester site, and a conserved C-terminal region but lack a secretion signal peptide sequence at the N-terminus.O. furnacalisPPOs were highly similar to other insect PPOs (42% to 79% identity) and clustered well with other lepidopteran PPOs. RT-PCR assay showed the transcripts of the 4 OfPPOs were all detected at the highest level in hemocytes and at the increased amounts after exposure to infection by bacteria and fungi. Additionally, we established anEscherichia coli(E. coli) expression system to produce recombinantO. furnacalisPPO proteins for future use in investigating their functions. These insights could provide valuable information for better understanding the activation and functioning mechanisms ofO. furnacalisPPOs.
authors.affiliation: Department of Entomology, China Agricultural University, Beijing 100193, China.
authors.forename: Shasha
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Entomology, China Agricultural University, Beijing 100193, China.
authors.forename: Fang
authors.initials: F
authors.lastname: Hong
authors.affiliation: Department of Entomology, China Agricultural University, Beijing 100193, China.
authors.forename: He
authors.initials: H
authors.lastname: Song
authors.affiliation: Department of Entomology, China Agricultural University, Beijing 100193, China.
authors.forename: Lei
authors.initials: L
authors.lastname: Wang
authors.affiliation: Department of Entomology, China Agricultural University, Beijing 100193, China.
authors.forename: Qizhi
authors.initials: Q
authors.lastname: Liu
authors.affiliation: Department of Entomology, China Agricultural University, Beijing 100193, China.
authors.forename: Chunju
authors.identifier: 0000-0001-7925-5353
authors.initials: C
authors.lastname: An
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D004156:Catechol Oxidase / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D003001:Cloning, Molecular; D004792:Enzyme Precursors / Q000737:chemistry* / Q000235:genetics* / Q000378:metabolism; D004926:Escherichia coli / Q000235:genetics; D006434:Hemocytes / Q000382:microbiology / Q000821:virology; D007814:Larva / Q000201:enzymology; D009036:Moths / Q000201:enzymology* / Q000235:genetics; D010571:Pest Control; D021382:Protein Sorting Signals / Q000235:genetics; D011994:Recombinant Proteins / Q000737:chemistry / Q000378:metabolism; D016415:Sequence Alignment; D003313:Zea mays
chemical_list: D004792:Enzyme Precursors; D021382:Protein Sorting Signals; D011994:Recombinant Proteins; C038451:pro-phenoloxidase; D004156:Catechol Oxidase