PxAPN5 serves as a functional receptor of Cry2Ab in Plutella xylostella (L.) and its binding domain analysis

Int J Biol Macromol. 2017 Dec;105(Pt 1):516-521. doi: 10.1016/j.ijbiomac.2017.07.070. Epub 2017 Jul 16.

Abstract

Lepidopteran midgut aminopeptidases N (APNs) are widely studied for their potential roles as one of the receptors for Bacillus thuringiensis (Bt) crystal toxins. In the present study, a loss of function analyses by RNAi (RNA interference) silencing of the Plutella xylostella APN5 (PxAPN5), a binding protein of Bt crystal toxin Cry2Ab, were performed. The knocking down of PxAPN5 in P. xylostella larvae greatly reduced their susceptibility to Cry2Ab and led to a decrease of Cry2Ab binding to P. xylostella midgut. Four truncated fragments of PxAPN5 were further constructed and expressed in Escherichia coli (E.coli) to find the binding region of PxAPN5 to Cry2Ab. The ligand blot result indicated that D1 domain (residues 1-262) and D3 domain (residues 510-620) of PxAPN5 could specially bind to Cry2Ab.

Keywords: AminopeptidaseN 5; Bacillus thuringiensis; Binding region; Cry2Ab; Plutella xylostella.

MeSH terms

  • Animals
  • Bacillus thuringiensis Toxins
  • Bacterial Proteins / metabolism*
  • Endotoxins / metabolism*
  • Hemolysin Proteins / metabolism*
  • Insect Proteins / chemistry*
  • Insect Proteins / deficiency
  • Insect Proteins / genetics
  • Insect Proteins / metabolism*
  • Lepidoptera / metabolism*
  • Models, Molecular
  • Protein Binding
  • Protein Domains
  • RNA Interference

Substances

  • Bacillus thuringiensis Toxins
  • Bacterial Proteins
  • Endotoxins
  • Hemolysin Proteins
  • Insect Proteins
  • insecticidal crystal protein, Bacillus Thuringiensis