Identification and Characterization of Receptors for Insecticidal Toxins from Bacillus thuringiensis

Abstract

Bacillus thuringiensis (Bt) Cry toxins have been widely used in the control of insect pests either as spray products or expressed in transgenic crops. Due to their benign environmental properties and absence of any harmful effects on humans, Cry toxins are increasingly employed in pest management programs instead of synthetic pesticides. An important step of intoxication involves binding of Cry toxins to specific cellular receptors. For several Cry toxins, at least four different protein receptors have been characterized: a CADP (cadherin-like protein), a GPI (glycosylphosphatidyl-inositol)-anchored APN (aminopeptidase-N), a GPI-anchored ALP (alkaline phosphatase), and a 270-kDa glycoconjugate. In this chapter we will discuss about the different methodologies used to identify and to study different insect gut proteins that have been shown to bind Cry toxins and that may be involved in Cry toxin action.