title: Isolation and characterization of the corticotropin-releasing factor-related diuretic hormone receptor in Rhodnius prolixus.
abstract: Rhodnius prolixus, the vector of human Chagas disease, is a hemipteran insect that undergoes rapid post-feeding diuresis following ingestion of a blood meal that can be up to 10 times its initial body weight. Corticotropin-releasing factor-related diuretic hormone (Rhopr-CRF/DH) and serotonin are neurohormones that are synergistic in increasing rates of fluid secretion by Malpighian tubules during this rapid post-feeding diuresis. A Rhopr-CRF/DH receptor transcript has now been isolated and characterized from fifth instar R. prolixus. The receptor is a family B1 (secretin) G protein-coupled receptor (GPCR) and was deorphaned in a heterologous cellular system using Chinese hamster ovary (CHO) cells stably expressing a promiscuous G-protein (Gα16). This assay was also used to demonstrate the presence of Rhopr-CRF/DH in the haemolymph of R. prolixus in response to blood-gorging. Two additional cell lines were used in this heterologous assay to verify that the cyclic adenosine monophosphate (cAMP) pathway and not the inositol triphosphate (IP3) pathway was stimulated upon activation of the receptor. Lastly, quantitative PCR demonstrated strong receptor expression in digestive tissues, upper Malpighian tubules and reproductive tissues. Identification of the Rhopr-CRF/DH receptor now provides tools for a more detailed understanding into the precise coordination of diuresis and other physiological processes in R. prolixus.
authors.affiliation: Department of Biology, University of Toronto Mississauga, Mississauga, ON, L5L1C6, Canada.
authors.forename: Hae-Ri
authors.initials: HR
authors.lastname: Lee
authors.affiliation: Department of Biology, University of Toronto Mississauga, Mississauga, ON, L5L1C6, Canada.
authors.forename: Meet
authors.initials: M
authors.lastname: Zandawala
authors.affiliation: Department of Biology, University of Toronto Mississauga, Mississauga, ON, L5L1C6, Canada.
authors.forename: Angela B
authors.initials: AB
authors.lastname: Lange
authors.affiliation: Department of Biology, University of Toronto Mississauga, Mississauga, ON, L5L1C6, Canada. Electronic address: ian.orchard@utoronto.ca.
authors.forename: Ian
authors.initials: I
authors.lastname: Orchard
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D016466:CHO Cells; D006224:Cricetinae; D003412:Cricetulus; D018076:DNA, Complementary / Q000235:genetics; D005247:Feeding Behavior; D020869:Gene Expression Profiling; D057809:HEK293 Cells; D006458:Hemolymph / Q000378:metabolism; D006801:Humans; D008954:Models, Biological; D010802:Phylogeny; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D018019:Receptors, Corticotropin-Releasing Hormone / Q000737:chemistry / Q000302:isolation & purification* / Q000378:metabolism*; D012239:Rhodnius / Q000235:genetics / Q000378:metabolism*; D016415:Sequence Alignment; D020539:Sequence Analysis, Protein
chemical_list: D018076:DNA, Complementary; D012333:RNA, Messenger; D018019:Receptors, Corticotropin-Releasing Hormone
keywords: Corticotropin-releasing factor; Cyclic AMP; Disease vector; Diuresis; Diuretic hormone; G protein-coupled receptor