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Clip domain prophenoloxidase activating protease is required for Ostrinia furnacalis Guenée to defend against bacterial infection.
Feng, Congjing; Zhao, Ya; Chen, Kangkang; Zhai, Huifeng; Wang, Zhenying; Jiang, Haobo; Wang, Yingjuan; Wang, Libao; Zhang, Yiqiang; Tang, Tai.
Affiliation
  • Feng C; Department of Plant Protection, College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu 225009, China. Electronic address: fengcj@yzu.edu.cn.
  • Zhao Y; Department of Plant Protection, College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu 225009, China.
  • Chen K; Department of Plant Protection, College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu 225009, China.
  • Zhai H; Department of Plant Protection, College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu 225009, China.
  • Wang Z; State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
  • Jiang H; Department of Entomology and Plant Pathology, Oklahoma State University, Stillwater, OK 74078, USA.
  • Wang Y; Department of Plant Protection, College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu 225009, China.
  • Wang L; Department of Plant Protection, College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu 225009, China.
  • Zhang Y; Department of Plant Protection, College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu 225009, China.
  • Tang T; Department of Plant Protection, College of Horticulture and Plant Protection, Yangzhou University, Yangzhou, Jiangsu 225009, China.
Dev Comp Immunol ; 87: 204-215, 2018 10.
Article in En | MEDLINE | ID: mdl-30017863
ABSTRACT
The prophenoloxidase (PPO) activating system in insects plays an important role in defense against microbial invasion. In this paper, we identified a PPO activating protease (designated OfPAP) containing a 1203 bp open reading frame encoding a 400-residue protein composed of two clip domains and a C-terminal serine protease domain from Ostrinia furnacalis. SignalP analysis revealed a putative signal peptide of 18 residues. The mature OfPAP was predicted to be 382 residues long with a calculated Mr of 44.8 kDa and pI of 6.66. Multiple sequence alignment and phylogenetic analysis indicated that OfPAP was orthologous to the PAPs in the other lepidopterans. A large increase of the transcript levels was observed in hemocytes at 4 h post injection (hpi) of killed Bacillus subtilis, whereas its level in integument increased continuously from 4 to 12 hpi in the challenged larvae and began to decline at 24 hpi. After OfPAP expression had been silenced, the median lethal time (LT50) of Escherichia coli-infected larvae (1.0 day) became significantly lower than that of E. coli-infected wild-type (3.0 days, p < 0.01). A 3.5-fold increase in E. coli colony forming units occurred in larval hemolymph of the OfPAP knockdown larvae, as compared with that of the control larvae not injected with dsRNA. There were notable decreases in PO and IEARase activities in hemolymph of the OfPAP knockdown larvae. In summary, we have demonstrated that OfPAP is a component of the PPO activation system, likely by functioning as a PPO activating protease in O. furnacalis larvae.
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Full text: 1 Collection: 01-internacional Database: MEDLINE Main subject: Catechol Oxidase / Insect Proteins / Enzyme Precursors / Escherichia coli / Moths Limits: Animals Language: En Journal: Dev Comp Immunol Year: 2018 Document type: Article

Full text: 1 Collection: 01-internacional Database: MEDLINE Main subject: Catechol Oxidase / Insect Proteins / Enzyme Precursors / Escherichia coli / Moths Limits: Animals Language: En Journal: Dev Comp Immunol Year: 2018 Document type: Article
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