Receptor-mediated endocytosis of hexamerin in the blowfly Calliphora vicina: Functional dissection of the receptor and its ligands.
Project management at the University of Würzburg:
As insects do not feed during metamorphosis, they depend on nutrients, that have accumulated previously in the larval period. In the blowfly, Calliphora vicina, as in all other holometabolous insects investigated so far, amino acids and energy are supplied by proteins that have been selectively taken up by the fat body from the haemolymph by receptor-mediated endocytosis before pupariation. Most of the incorporated proteins belong to the family of hexamerins.To identify the binding domains of the hexamerins and their common receptor we applied the "yeast-two-hybrid-system". The binding domains of the hexamerin as well as of the receptor exhibit no similarity to any functional domains known to date and, therefore, represent new species of interaction-domains.
Basing on the two-hybrid-system we developed a high throuput screening assay (HTS) which allows a robot to test more than 15,000 substances per day on its ability to interfere with the binding domains and thus preventing resorption of hexamerin and consequently the development of the insect. We have gained a patent for this method. Furthermore, the knowledge about the quarternary structure of the binding domains permits to design drugs that binds with a very high affinity and which therefore constitute highly specific insecticides.
Projekt period: from 01.1997 to 01.2002
Wirtschaftsunternehmen ( Bayer AG )
DFG Sche 195/13-1und 13-2