Carausius morosus'ta PISCF-allatostatin reseptörü'nün farmakolojik olarak nitelenmesi

Allatostatins (ASTs) are multifunctional insect neuropeptides that suppress juvenile hormone (JH) synthesis and feeding behavior. Three different classes of ASTs in insects are known as FGLa/ASTs (A-type), MIP/ASTs (B-type) and PISCF/ASTs (C-type). Each type of ASTs exert its activity through binding to its cognate G protein coupled receptor families, called as Allatostatin receptors (AstRs). Very little is known on how JH synthesis is regulated and how AST/AstR system regulates this process. AstRs are also potential targets for pesticide development, since their activation negatively modulates insect growth and feeding-related processes. A transcript from an invasive African pest, Carausius morosus, which shows high sequence similarity to other insect PISCF/AST receptors was previously identified by our group. In this study, we characterized the pharmacological properties and early signaling events of this PISCF/AST receptor (CamAstRC) by means of FRET using a heterologous expression system. A dose-dependent activation of Gαi1 and Gαo were detected upon stimulation of CamAstR-C. Receptor coupling with Gβγ subunits was observed only in the presence of Gαi1 or Gαo, but not other Gα subunits. A partial inhibition of adenylyl cyclase 5-mediated cAMP production upon receptor activation with PISCF/AST and a dose-dependent interaction between β-arrestin2 and the receptor was detected. In summary, a PISCF/AST receptor from Carausius morosus has been functionally characterized, activated by Drosophila PISCF/AST, but not Drosophila FGLa/ASTs.