SPLTRAK Abstract Submission
Characterization of Drosophila Delta glutathione transferases involved in isothiocyanate detoxification and perception
Elodie Gonis, Stéphane Fraichard, Evelyne Chavanne, Jean-François Ferveur, Loïc Briand, Fabrice Neiers
CSGA, INRA, CNRS, Université de Bourgogne Franche Comté, DIJON, France

A variety of enzymes are found within Drosophila olfactory and taste hairs. These enzymes include cytochrome P450, esterases and glutathione transferases (GSTs). GSTs are ubiquitously found in animals. They catalyse the conjugation of glutathione to various compounds leading to their elimination. GSTs have been proposed to play a dual role in the protection of the chemosensory organs but more surprisingly in the chemosensory perception. Indeed when they modify odorant or tastant molecules, GST can also contribute to the sensory signal termination. GSTs include numerous families among which two insect specific families: GSTs Delta and Epsilon. The number of genes coding for both enzyme families has expanded during evolution in relation with the chemical diversity of environment. We propose to study the link between GSTs Delta and isothiocyanate molecules. Isothiocyanates are insecticidal compounds naturally present in plants and they are perceived by animals including Drosophila. Each GSTs of the Delta family was tested for its ability to conjugate six isothiocyanate molecules. The expression of the GST Delta was also quantified using PCR in the chemosensory organs before and after isothiocyanate exposure. The X-ray structure of a GST Delta involved in the chemoresistance toward isothiocyanate molecules was solved. We discuss the link of this GST family with it putative role in chemosensory perception.