The full-length Cry1Ac protoxin without proteolytic activation exhibits toxicity against insect cell line CF-203

J Invertebr Pathol. 2018 Feb:152:25-29. doi: 10.1016/j.jip.2018.01.004. Epub 2018 Feb 3.

Abstract

The new dual model for Bacillus thuringiensis insecticidal mechanism proposed that Cry1A protoxins without proteolytic activation could bind to insect midgut receptors to exert toxicity. To evaluate insecticidal potency of Cry1Ac protoxin at precluding interference of midgut proteases, the cytotoxicity of Cry1Ac protoxin against midgut cell line CF-203 derived from Choristoneura fumiferana was analyzed. It was revealed that Cry1Ac protoxin was toxic to CF-203 cells and there existed certain differences in the cytological changes when treated with protoxin and toxin. Our cell-based study provided direct evidence for the proposed dual model and shed light on exploring the difference between two toxic pathways elicited by intact protoxin and activated toxin.

Keywords: Bacillus thuringiensis; Cry1Ac protoxin; Cytotoxicity; Insect cell line.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Bacillus thuringiensis
  • Bacillus thuringiensis Toxins
  • Bacterial Proteins / chemistry
  • Bacterial Proteins / toxicity*
  • Cell Line
  • Endotoxins / chemistry
  • Endotoxins / toxicity*
  • Hemolysin Proteins / chemistry
  • Hemolysin Proteins / toxicity*
  • Insecta / cytology
  • Insecta / drug effects*
  • Proteolysis

Substances

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