Discovery and Characterization of Guanylate Cyclase Receptors in Manduca sexta

Abstract

Natriuretic peptide receptors are very important in mammals for controlling water homeostasis in the body. It is possible that during evolution, these receptors played a key role in the process, by which animals moved from the sea to the land. Until now, there has been little information on most natriuretic peptide receptors in insects. We use Manduca sexta as our research model. We have now found five guanylate cyclase receptors in this organism similar to the ANP receptor, which are found in different tissues of Manduca. We have complete four mRNA sequences for these large (>1,000 AA) proteins. The one incomplete receptor is very rare in most tissues. An ELISA for human ANP revealed a cross reacting material with hydrophobicity appropriate for ANP in Manduca sexta larvae. We are now pursuing the identity of the hormones which target these receptors.