Many insect species exert a negative impact on human health through serving as disease propagation vectors or through causing agricultural damage. Chemosensory receptors, odorant receptors (ORs) and taste receptors, are critical to the ability of insects to function in these roles. Insect chemosensory receptors are an entirely novel receptor class, having no genetic or structural relationship to any known receptor family (including mammalian chemosensory receptors). Thus, these receptors are appealing targets for the development of new compounds for insect control. Realizing this goal requires development of a detailed understanding of insect chemosensory receptor structure and function. However, one of the most notable characteristics of these receptors is how little we know about their structure. In this project, we will identify structural features of insect ORs that are important in odorant binding and recognition. We have established a robust functional assay for insect odorant receptors using the Xenopus oocyte expression system and robotic electrophysiology. Using this assay, we are proposing a project that will determine the structural basis for odorant recognition by insect ORs.
In Aim 1, we will express and screen a large panel of Drosophila melanogaster odorant receptors (DmORs) using our assay.
In Aim 2, we will identify regions of interest on the odorant binding subunits of DmOrs by screening the receptor panel with cysteine-reactive methanethiosulfonate reagents. This screen will take advantage of the natural distribution of cysteine residues across the DmOR family.
In Aim 3, we will use the Substituted Cysteine Accessibility Method (SCAM) to explore critical functional regions (identified in Aim 2) of the odorant binding subunits of insect ORs.
In Aim 4, we will use site-directed mutagenesis and functional analysis to reveal the structural basis for odorant recognition by insect odorant receptors. This project will provide an understanding of odorant ligand recognition by insect ORs at the molecular level. This project is important to human health because insect ORs are a novel target for the development of compounds to control deleterious insect species.

Public Health Relevance

Insects can have a negative impact on human health through serving as disease propagation vectors or through causing agricultural damage. Odorant receptors (ORs) are critical to the ability of insects to function in these roles. Insect ORs are an entirely novel receptor class, having no genetic or structural relationship to any known receptor family. In fact, insect ORs are not related to any proteins in humans and other mammals, making these receptors appealing targets for the development of compounds with higher selectivity and lower environmental toxicity than currently available insecticides. However, we currently know essentially nothing about the structure of these receptors. In this project, we will identify structural features of insect ORs that are important in odorant binding and recognition. This work will aid in the development of new compounds to control deleterious insect species.

Agency
National Institute of Health (NIH)
Institute
National Institute on Deafness and Other Communication Disorders (NIDCD)
Type
Research Project (R01)
Project #
5R01DC011091-04
Application #
8461225
Study Section
Somatosensory and Chemosensory Systems Study Section (SCS)
Program Officer
Sullivan, Susan L
Project Start
2010-06-01
Project End
2015-05-31
Budget Start
2013-06-01
Budget End
2014-05-31
Support Year
4
Fiscal Year
2013
Total Cost
$296,533
Indirect Cost
$101,118
Name
University of Miami School of Medicine
Department
Pharmacology
Type
Schools of Medicine
DUNS #
052780918
City
Coral Gables
State
FL
Country
United States
Zip Code
33146
Rahman, Suhaila; Luetje, Charles W (2017) Mutant cycle analysis identifies a ligand interaction site in an odorant receptor of the malaria vector Anopheles gambiae. J Biol Chem 292:18916-18923
Hughes, David T; Pelletier, Julien; Rahman, Suhaila et al. (2017) Functional and Nonfunctional Forms of CquiOR91, an Odorant Selectivity Subunit of Culex quinquefasciatus. Chem Senses 42:333-341
Price, Daniel R G; Wilson, Alex C C; Luetje, Charles W (2015) Proton-dependent glutamine uptake by aphid bacteriocyte amino acid transporter ApGLNT1. Biochim Biophys Acta 1848:2085-91
Price, Daniel R G; Feng, Honglin; Baker, James D et al. (2014) Aphid amino acid transporter regulates glutamine supply to intracellular bacterial symbionts. Proc Natl Acad Sci U S A 111:320-5
Hughes, David T; Wang, Guirong; Zwiebel, Laurence J et al. (2014) A determinant of odorant specificity is located at the extracellular loop 2-transmembrane domain 4 interface of an Anopheles gambiae odorant receptor subunit. Chem Senses 39:761-9
Xu, Pingxi; Choo, Young-Moo; Pelletier, Julien et al. (2013) Silent, generic and plant kairomone sensitive odorant receptors from the Southern house mosquito. J Insect Physiol 59:961-6
Chen, Sisi; Luetje, Charles W (2013) Phenylthiophenecarboxamide antagonists of the olfactory receptor co-receptor subunit from a mosquito. PLoS One 8:e84575
Chen, Sisi; Luetje, Charles W (2012) Identification of new agonists and antagonists of the insect odorant receptor co-receptor subunit. PLoS One 7:e36784
Mitchell, Robert F; Hughes, David T; Luetje, Charles W et al. (2012) Sequencing and characterizing odorant receptors of the cerambycid beetle Megacyllene caryae. Insect Biochem Mol Biol 42:499-505
Nichols, Andrew S; Chen, Sisi; Luetje, Charles W (2011) Subunit contributions to insect olfactory receptor function: channel block and odorant recognition. Chem Senses 36:781-90

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