G Protein-Coupled Receptors in Anopheles gambiae

Abstract

We used bioinformatic approaches to identify a total of 276 G protein-coupled receptors (GPCRs) from the Anopheles gambiae genome. These include GPCRs that are likely to play roles in pathways affecting almost every aspect of the mosquito's life cycle. Seventy-nine candidate odorant receptors were characterized for tissue expression and, along with 76 putative gustatory receptors, for their molecular evolution relative to Drosophila melanogaster. Examples of lineage-specific gene expansions were observed as well as a single instance of unusually high sequence conservation.

Olfactory regulation of mosquito–host interactions

“…gambiae (Holt et al, 2002) has facilitated the use of bioinformatics and molecular approaches to describe the entire GPCR gene family in this vector insect (AgGPCRs) (Hill et al, 2002). Within the over 275 putative AgGPCRs cataloged, an additional 74 candidate AgORs have been described resulting in a total of 79 AgOR family members.…”

Genes encoding candidate pheromone receptors in a moth ( Heliothis virescens )

“…To find new genes encoding candidate chemoreceptors, we extended the strategy that was used successfully to detect the first candidate olfactory receptors in H. virescens (12) by using the sequences of Heliothis receptor 1-9 (HR1-HR9) and of newly identified HRs, as well as the sequences of candidate olfactory receptors from Drosophila melanogaster (4)(5)(6)(7)(8) and Anopheles gambiae (9)(10)(11) in BLAST analyses (22,23) of the nonpublic Heliothis genomic database.…”

“…These specialized cells generate electrical signals upon interaction with appropriate chemical compounds. Experimental evidence indicating that the underlying chemoelectrical transduction process is mediated by means of odor-activated G protein-secondmessenger cascades, a mechanism used by most chemosensory cells (3), supports the notion that receptors for odorous compounds in insects should be members of the G protein-coupled receptor superfamily; however, it was only with the aid of sequenced genomes that genes encoding candidate odorant receptors from insects were identified recently in fly (4)(5)(6)(7)(8), mosquito (9)(10)(11), and moth (12) models. Despite the progress in identification and characterization of insect olfactory receptors, receptors for insect pheromones are still elusive.…”

“…One could imagine some identifying features that might distinguish pheromone receptors among general olfactory receptors. A characteristic trait of insect olfactory receptor types is the extreme diversity of their sequences (9,12,19). Because pheromone detection is probably under different kinds of selective pressure than detection of food odors or host odors, one might speculate whether receptors for pheromones are more conserved than other olfactory receptor types.…”

Preface: Cellular actions of biogenic amines

“…In recent years, however, considerable progress has been made toward an understanding of the functional properties of these receptors (and of amine transporters) at the cellular and molecular level. The availability of completely sequenced insect genomes (i.e., Drosophila melanogaster, Anopheles gambiae, and Apis mellifera) provides excellent tools to unravel the various families of insect biogenic amine receptors in detail (Brody and Cravchik, 2000;Vanden Broeck, 2001;Hill et al, 2002). Pioneering work on Drosophila receptors is now being followed by molecular studies in other species of insects that are well suited for physiological and behavioral experiments.…”