Annual Main Meeting of the Society of Experimental Biology location:Marseille, France date:6th - 10th July 2008
Membrane receptor guanylate cyclases (rGCs) are homodimeric, ligand-binding transmembrane proteins which catalyse the formation cGMP. The Drosophila genome encodes at least seven receptor and receptor-like GCs including Gyc76C.
In the adult fly, expression of Gyc76c is highest in epithelial tissues, including Malpighian (renal) tubules and in ovary (flyatlas.org). In-situ hybridisation studies in intact tubules reveal that Gyc76c is expressed in principal cells of main segment.
Ablation of Gyc76c via RNAi in tubule principal cells results in lethality of adult flies two days post-eclosion. By contrast, ablation of Gyc76c in either tubule stellate cells or in the CNS does not result in adult lethality. No ligand has yet been identified for any member of the rGC family in Drosophila, nor in insects. Here we describe a screen for peptide modulators of Gyc76c function; and indicate a novel peptide ligand for Gyc76C, which impacts on Malpighian tubule function.