Binding of Bacillus thuringiensis toxin Cry1Ac to multiple sites of cadherin in pink bollworm

J. A. Fabrick, B. E. Tabashnik

Research output: Contribution to journalArticlepeer-review

60 Scopus citations


Toxins from Bacillus thuringiensis (Bt) are widely used for pest control. In particular, Bt toxin Cry1Ac produced by transgenic cotton kills some key lepidopteran pests. We found that Cry1Ac binds to recombinant peptides corresponding to extracellular regions of a cadherin protein (BtR) in a major cotton pest, pink bollworm (Pectinophora gossypiella) (PBW). In conjunction with previous results showing that PBW resistance to Cry1Ac is linked with mutations in the BtR gene, the results reported here support the hypothesis that BtR is a receptor for Cry1Ac in PBW. Similar to other lepidopteran cadherins that bind Bt toxins, BtR has at least two Cry1Ac-binding domains in cadherin-repeat regions 10 and 11, which are immediately adjacent to the membrane proximal region. However, unlike cadherins from Manduca sexta and Bombyx mori, toxin binding was not seen in regions more distal from the membrane proximal region. We also found that both the protoxin and activated toxin forms of Cry1Ac bound to recombinant BtR fragments, suggesting that Cry1Ac activation may occur either before or after receptor binding.

Original languageEnglish (US)
Pages (from-to)97-106
Number of pages10
JournalInsect Biochemistry and Molecular Biology
Issue number2
StatePublished - Feb 2007


  • Bacillus thuringiensis (Bt)
  • BtR
  • Cadherin
  • Cry1Ac receptor
  • Pectinophora gossypiella
  • Pink bollworm

ASJC Scopus subject areas

  • Biochemistry
  • Molecular Biology
  • Insect Science


Dive into the research topics of 'Binding of Bacillus thuringiensis toxin Cry1Ac to multiple sites of cadherin in pink bollworm'. Together they form a unique fingerprint.

Cite this