1
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Guo J, Kang SG, Huang K, Tong T. Targeting Odorant Receptors in Adipose Tissue with Food-Derived Odorants: A Novel Approach to Obesity Treatment. Foods 2024; 13:3938. [PMID: 39683011 DOI: 10.3390/foods13233938] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2024] [Revised: 11/22/2024] [Accepted: 12/03/2024] [Indexed: 12/18/2024] Open
Abstract
Odorant receptors (ORs) have long been thought to serve as chemosensors located on the cilia of olfactory sensory neurons (OSNs) in the olfactory epithelium, where they recognize odorant molecules and comprise the largest family of seven transmembrane-domain G protein-coupled receptors (GPCRs). Over the last three decades, accumulating evidence has suggested that ORs are distributed in a variety of peripheral tissues beyond their supposed typical tissue expression in the olfactory epithelium. These ectopic ORs play a role in regulating various cellular, physiological, and pathophysiological phenomena in the body, such as regulation of hypertension, hepatic glucose production, cancer development, and chronic skin disease. Adipose tissue, the key organ in regulating obesity and energy metabolism, has been reported to take advantage of ectopic OR-mediated signaling. In this review, we summarize and provide an in-depth analysis of the current research on the key biological functions of adipose tissue ORs in response to food-derived odorants, as well as the molecular mechanisms underlying their activity.
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Affiliation(s)
- Jingya Guo
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
| | - Seong-Gook Kang
- Department of Food Engineering and Solar Salt Research Center, Mokpo National University, Muangun 58554, Republic of Korea
| | - Kunlun Huang
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
- Key Laboratory of Safety Assessment of Genetically Modified Organism (Food Safety), Ministry of Agriculture, Beijing 100083, China
- Beijing Laboratory for Food Quality and Safety, Beijing 100083, China
| | - Tao Tong
- College of Food Science and Nutritional Engineering, China Agricultural University, Beijing 100083, China
- Key Laboratory of Safety Assessment of Genetically Modified Organism (Food Safety), Ministry of Agriculture, Beijing 100083, China
- Beijing Laboratory for Food Quality and Safety, Beijing 100083, China
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2
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Ryu SE, Bae J, Shim T, Kim WC, Kim K, Moon C. Conserved pattern-based classification of human odorant receptor multigene family. Sci Rep 2024; 14:27271. [PMID: 39516664 PMCID: PMC11549229 DOI: 10.1038/s41598-024-79183-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2024] [Accepted: 11/06/2024] [Indexed: 11/16/2024] Open
Abstract
Conserved protein-coding sequences are critical for maintaining protein function across species. Odorant receptors (ORs), a large poorly understood multigene family responsible for odor detection, lack comprehensive classification methods that reflect their functional diversity. In this study, we propose a new approach called conserved motif-based classification (CMC) for classifying ORs based on amino acid sequence similarities within conserved motifs. Specifically, we focused on three well-conserved motifs: MAYDRYVAIC in TM3, KAFSTCASH in TM6, and PMLNPFIY in TM7. Using an unsupervised clustering technique, we classified human ORs (hORs) into two main clusters with six sub-clusters. CMC partly reflects previously identified subfamilies, revealing altered residue positions among the sub-clusters. These altered positions interacted with specific residues within or adjacent to the transmembrane domain, suggesting functional implications. Furthermore, we found that the CMC correlated with both ligand responses and ectopic expression patterns, highlighting its relevance to OR function. This conserved motif-based classification will help in understanding the functions and features that are not understood by classification based solely on entire amino acid sequence similarity.
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Affiliation(s)
- Sang Eun Ryu
- Department of Brain Sciences, Graduate School, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
- Korea Brain Research Institute (KBRI), 61 Choemdan-Ro, Dong-Gu, Daegu, 41062, Republic of Korea
| | - Jisub Bae
- Department of Brain Sciences, Graduate School, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
- Center for Cognition and Sociality, Institute for Basic Science (IBS), 55 Expo-Ro, Yuseong-Gu, Daejeon, 34126, Republic of Korea
| | - Tammy Shim
- Department of Brain Sciences, Graduate School, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Won-Cheol Kim
- Department of Brain Sciences, Graduate School, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Kwangsu Kim
- Department of Brain Sciences, Graduate School, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Cheil Moon
- Department of Brain Sciences, Graduate School, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea.
- Convergence Research Advanced Centre for Olfaction, Daegu Gyeungbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea.
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3
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Fryer E, Guha S, Rogel-Hernandez LE, Logan-Garbisch T, Farah H, Rezaei E, Mollhoff IN, Nekimken AL, Xu A, Selin Seyahi L, Fechner S, Druckmann S, Clandinin TR, Rhee SY, Goodman MB. An efficient behavioral screening platform classifies natural products and other chemical cues according to their chemosensory valence in C. elegans. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.06.02.542933. [PMID: 37333363 PMCID: PMC10274637 DOI: 10.1101/2023.06.02.542933] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/20/2023]
Abstract
Throughout history, humans have relied on plants as a source of medication, flavoring, and food. Plants synthesize large chemical libraries and release many of these compounds into the rhizosphere and atmosphere where they affect animal and microbe behavior. To survive, nematodes must have evolved the sensory capacity to distinguish plant-made small molecules (SMs) that are harmful and must be avoided from those that are beneficial and should be sought. This ability to classify chemical cues as a function of their value is fundamental to olfaction, and represents a capacity shared by many animals, including humans. Here, we present an efficient platform based on multi-well plates, liquid handling instrumentation, inexpensive optical scanners, and bespoke software that can efficiently determine the valence (attraction or repulsion) of single SMs in the model nematode, Caenorhabditis elegans. Using this integrated hardware-wetware-software platform, we screened 90 plant SMs and identified 37 that attracted or repelled wild-type animals, but had no effect on mutants defective in chemosensory transduction. Genetic dissection indicates that for at least 10 of these SMs, response valence emerges from the integration of opposing signals, arguing that olfactory valence is often determined by integrating chemosensory signals over multiple lines of information. This study establishes that C. elegans is an effective discovery engine for determining chemotaxis valence and for identifying natural products detected by the chemosensory nervous system.
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Affiliation(s)
- Emily Fryer
- Department of Plant Biology, Carnegie Institution for Science
- Department of Molecular and Cellular Physiology, Stanford University
| | - Sujay Guha
- Department of Molecular and Cellular Physiology, Stanford University
| | | | - Theresa Logan-Garbisch
- Department of Molecular and Cellular Physiology, Stanford University
- Neurosciences Graduate Program, Stanford University
| | - Hodan Farah
- Department of Plant Biology, Carnegie Institution for Science
- Department of Molecular and Cellular Physiology, Stanford University
| | - Ehsan Rezaei
- Department of Molecular and Cellular Physiology, Stanford University
| | - Iris N. Mollhoff
- Department of Plant Biology, Carnegie Institution for Science
- Department of Molecular and Cellular Physiology, Stanford University
- Department of Biology, Stanford University
| | - Adam L. Nekimken
- Department of Molecular and Cellular Physiology, Stanford University
- Department of Mechanical Engineering, Stanford University
| | - Angela Xu
- Department of Plant Biology, Carnegie Institution for Science
| | - Lara Selin Seyahi
- Department of Plant Biology, Carnegie Institution for Science
- Department of Molecular and Cellular Physiology, Stanford University
| | - Sylvia Fechner
- Department of Molecular and Cellular Physiology, Stanford University
| | | | | | - Seung Y. Rhee
- Department of Plant Biology, Carnegie Institution for Science
| | - Miriam B. Goodman
- Department of Molecular and Cellular Physiology, Stanford University
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4
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Sharma A, Kumar R, Varadwaj P. Developing human olfactory network and exploring olfactory receptor-odorant interaction. J Biomol Struct Dyn 2023; 41:8941-8960. [PMID: 36310099 DOI: 10.1080/07391102.2022.2138976] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2022] [Accepted: 10/17/2022] [Indexed: 06/16/2023]
Abstract
The Olfactory receptor (OR)-odorant interactions are perplexed. ORs can bind to structurally diverse odorants associated with one or more odor percepts. Various attempts have been made to understand the intricacies of OR-odorant interaction. In this study, experimentally documented OR-odorant interactions are investigated comprehensively to; (a) suggest potential odor percepts for ORs based on the OR-OR network; (b) determine how odorants interacting with specific ORs differ in terms of inherent pharmacophoric features and molecular properties, (c) identify molecular interactions that explained OR-odorant interactions of selective ORs; and (d) predict the probable role of ORs other than olfaction. Human olfactory receptor network (hORnet) is developed to study possible odor percepts for ORs. We identified six molecular properties which showed variation and significant patterns to differentiate odorants binding with five ORs. The pharmacophore analysis revealed that odorants subset of five ORs follow similar pharmacophore hypothesis, (one hydrogen acceptor and two hydrophobic regions) but differ in terms of distance and orientation of pharmacophoric features. To ascertain the binding site residues and key interactions between the selected ORs and their interacting odorants, 3D-structure modelling, docking and molecular dynamics studies were carried out. Lastly, the potential role of ORs beyond olfaction is explored. A human OR-OR network was developed to suggest possible odor percepts for ORs using empirically proven OR-odorant interactions. We sought to find out significant characteristics, molecular properties, and molecular interactions that could explain OR-odorant interactions and add to the understanding of the complex issue of odor perception.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Anju Sharma
- Department of Applied Sciences, Indian Institute of Information Technology, Allahabad, Uttar Pradesh, India
| | - Rajnish Kumar
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow, Uttar Pradesh, India
| | - Pritish Varadwaj
- Department of Applied Sciences, Indian Institute of Information Technology, Allahabad, Uttar Pradesh, India
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5
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Cho S, Park TH. Advances in the Production of Olfactory Receptors for Industrial Use. Adv Biol (Weinh) 2023; 7:e2200251. [PMID: 36593488 DOI: 10.1002/adbi.202200251] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/14/2022] [Revised: 12/11/2022] [Indexed: 01/04/2023]
Abstract
In biological olfactory systems, olfactory receptors (ORs) can recognize and discriminate between thousands of volatile organic compounds with very high sensitivity and specificity. The superior properties of ORs have led to the development of OR-based biosensors that have shown promising potential in many applications over the past two decades. In particular, newly designed technologies in gene synthesis, protein expression, solubilization, purification, and membrane mimetics for membrane proteins have greatly opened up the previously inaccessible industrial potential of ORs. In this review, gene design, expression and solubilization strategies, and purification and reconstitution methods available for modern industrial applications are examined, with a focus on ORs. The limitations of current OR production technology are also estimated, and future directions for further progress are suggested.
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Affiliation(s)
- Seongyeon Cho
- School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
| | - Tai Hyun Park
- School of Chemical and Biological Engineering, Institute of Chemical Processes, Seoul National University, 1 Gwanak-ro, Gwanak-gu, Seoul, 08826, Republic of Korea
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6
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Sharma A, Saha BK, Kumar R, Varadwaj PK. OlfactionBase: a repository to explore odors, odorants, olfactory receptors and odorant-receptor interactions. Nucleic Acids Res 2021; 50:D678-D686. [PMID: 34469532 PMCID: PMC8728123 DOI: 10.1093/nar/gkab763] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 08/13/2021] [Accepted: 08/28/2021] [Indexed: 12/04/2022] Open
Abstract
Olfaction is a multi-stage process that initiates with the odorants entering the nose and terminates with the brain recognizing the odor associated with the odorant. In a very intricate way, the process incorporates various components functioning together and in synchronization. OlfactionBase is a free, open-access web server that aims to bring together knowledge about many aspects of the olfaction mechanism in one place. OlfactionBase contains detailed information of components like odors, odorants, and odorless compounds with physicochemical and ADMET properties, olfactory receptors (ORs), odorant- and pheromone binding proteins, OR-odorant interactions in Human and Mus musculus. The dynamic, user-friendly interface of the resource facilitates exploration of different entities: finding chemical compounds having desired odor, finding odorants associated with OR, associating chemical features with odor and OR, finding sequence information of ORs and related proteins. Finally, the data in OlfactionBase on odors, odorants, olfactory receptors, human and mouse OR-odorant pairs, and other associated proteins could aid in the inference and improved understanding of odor perception, which might provide new insights into the mechanism underlying olfaction. The OlfactionBase is available at https://bioserver.iiita.ac.in/olfactionbase/.
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Affiliation(s)
- Anju Sharma
- Department of Applied Science, Indian Institute of Information Technology, Allahabad, Uttar Pradesh 211015, India
| | | | - Rajnish Kumar
- Amity Institute of Biotechnology, Amity University Uttar Pradesh, Lucknow Campus, Uttar Pradesh 226028, India
| | - Pritish Kumar Varadwaj
- Department of Applied Science, Indian Institute of Information Technology, Allahabad, Uttar Pradesh 211015, India
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7
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Ectopic Odorant Receptor Responding to Flavor Compounds: Versatile Roles in Health and Disease. Pharmaceutics 2021; 13:pharmaceutics13081314. [PMID: 34452275 PMCID: PMC8402194 DOI: 10.3390/pharmaceutics13081314] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Revised: 08/11/2021] [Accepted: 08/17/2021] [Indexed: 12/23/2022] Open
Abstract
Prompted by the ground-breaking discovery of the rodent odorant receptor (OR) gene family within the olfactory epithelium nearly 30 years ago, followed by that of OR genes in cells of the mammalian germ line, and potentiated by the identification of ORs throughout the body, our appreciation for ORs as general chemoreceptors responding to odorant compounds in the regulation of physiological or pathophysiological processes continues to expand. Ectopic ORs are now activated by a diversity of flavor compounds and are involved in diverse physiological phenomena varying from adipogenesis to myogenesis to hepatic lipid accumulation to serotonin secretion. In this review, we outline the key biological functions of the ectopic ORs responding to flavor compounds and the underlying molecular mechanisms. We also discuss research opportunities for utilizing ectopic ORs as therapeutic strategies in the treatment of human disease as well as challenges to be overcome in the future. The recognition of the potent function, signaling pathway, and pharmacology of ectopic ORs in diverse tissues and cell types, coupled with the fact that they belong to G protein-coupled receptors, a highly druggable protein family, unequivocally highlight the potential of ectopic ORs responding to flavor compounds, especially food-derived odorant compounds, as a promising therapeutic strategy for various diseases.
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8
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Sollai G, Melis M, Mastinu M, Paduano D, Chicco F, Magri S, Usai P, Hummel T, Barbarossa IT, Crnjar R. Olfactory Function in Patients with Inflammatory Bowel Disease (IBD) Is Associated with Their Body Mass Index and Polymorphism in the Odor Binding-Protein (OBPIIa) Gene. Nutrients 2021; 13:nu13020703. [PMID: 33671721 PMCID: PMC7926749 DOI: 10.3390/nu13020703] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2021] [Revised: 02/09/2021] [Accepted: 02/19/2021] [Indexed: 02/06/2023] Open
Abstract
Smell strongly contributes to food choice and intake, influencing energy balance and body weight; its reduction or loss has been related to malnutrition problems. Some patients with inflammatory bowel disease (IBD), mainly Crohn’s disease (CD) and ulcerative colitis (UC), are underweight, while others are overweight. Some studies suggest that changes in eating habits could be linked to specific disorders of the olfactory functions. We assessed the olfactory performance in 199 subjects (healthy control (HC) n = 99, IBD n = 100), based on the olfactory Threshold, Discrimination and Identification score (TDI score), measured with the “Sniffin’ Sticks” test. Subjects were genotyped for the rs2590498 polymorphism of the OBPIIa gene. IBD patients showed both a slightly, but significantly, lower olfactory function and a higher BMI compared to HC subjects. Threshold (in both population) and Discrimination (in IBD patients) olfactory score were affected by the OBPIIa genotype. BMI was influenced by both health status and OBPIIa genotype. A lower olfactory function may delay the satiety sensation and thus increase meal duration and body weight in IBD patients. However, the AA genotype of the OBPIIa seems to “protect” IBD patients from more severe olfactory dysfunction.
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Affiliation(s)
- Giorgia Sollai
- Department of Biomedical Sciences, University of Cagliari, Monserrato, 09042 Cagliari, Italy; (M.M.); (M.M.); (I.T.B.); (R.C.)
- Correspondence: ; Tel.: +39-070-6754160
| | - Melania Melis
- Department of Biomedical Sciences, University of Cagliari, Monserrato, 09042 Cagliari, Italy; (M.M.); (M.M.); (I.T.B.); (R.C.)
| | - Mariano Mastinu
- Department of Biomedical Sciences, University of Cagliari, Monserrato, 09042 Cagliari, Italy; (M.M.); (M.M.); (I.T.B.); (R.C.)
| | - Danilo Paduano
- Department of Medical Sciences and Public Health, University of Cagliari, Presidio Policlinico of Monserrato, 09042 Cagliari, Italy; (D.P.); (F.C.); (S.M.); (P.U.)
| | - Fabio Chicco
- Department of Medical Sciences and Public Health, University of Cagliari, Presidio Policlinico of Monserrato, 09042 Cagliari, Italy; (D.P.); (F.C.); (S.M.); (P.U.)
| | - Salvatore Magri
- Department of Medical Sciences and Public Health, University of Cagliari, Presidio Policlinico of Monserrato, 09042 Cagliari, Italy; (D.P.); (F.C.); (S.M.); (P.U.)
| | - Paolo Usai
- Department of Medical Sciences and Public Health, University of Cagliari, Presidio Policlinico of Monserrato, 09042 Cagliari, Italy; (D.P.); (F.C.); (S.M.); (P.U.)
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, 01067 Dresden, Germany;
| | - Iole Tomassini Barbarossa
- Department of Biomedical Sciences, University of Cagliari, Monserrato, 09042 Cagliari, Italy; (M.M.); (M.M.); (I.T.B.); (R.C.)
| | - Roberto Crnjar
- Department of Biomedical Sciences, University of Cagliari, Monserrato, 09042 Cagliari, Italy; (M.M.); (M.M.); (I.T.B.); (R.C.)
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9
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Melis M, Tomassini Barbarossa I, Hummel T, Crnjar R, Sollai G. Effect of the rs2890498 polymorphism of the OBPIIa gene on the human ability to smell single molecules. Behav Brain Res 2021; 402:113127. [PMID: 33422593 DOI: 10.1016/j.bbr.2021.113127] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2020] [Revised: 12/27/2020] [Accepted: 01/04/2021] [Indexed: 01/20/2023]
Abstract
Most odors of foods and drinks are mixtures of molecules. By means of the coupled Gas Chromatography-Olfactometry (GC-O) technique, single components of flavor mixtures can be separated, identified and verbally evaluated by subjects. The number of single molecules smelled by subjects during GC-O analysis (i.e., the number of odor-active compounds) was previously found to be linearly correlated with odor Threshold (T) score. Using the "Sniffin' Sticks" test, the same subjects were classified as normosmic or hyposmic. Hydrophobic odorants are captured and transported through the mucus layer by the odorant binding proteins (OBPs), particularly expressed in the olfactory cleft and associated with the olfactory function. In this study, subjects were genotyped for the rs2590498 (A/G) polymorphism of the OBPIIa gene, whose major allele A is associated with a higher olfactory sensitivity as compared to the minor allele G. One-way ANOVA showed a significant effect of the genotype of the OBPIIa locus on the: a) T score; b) number of odor-active compounds smelled; c) intensity perceived when sniffing the complex odor of banana. In conclusion, the threshold olfactory performance, but also the individual ability to smell single molecules, can be attributed, partly at least, to the rs2590498 polymorphism of the OBPIIa gene.
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Affiliation(s)
- Melania Melis
- Department of Biomedical Sciences, University of Cagliari, Monserrato, CA, 09042, Italy
| | | | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | - Roberto Crnjar
- Department of Biomedical Sciences, University of Cagliari, Monserrato, CA, 09042, Italy.
| | - Giorgia Sollai
- Department of Biomedical Sciences, University of Cagliari, Monserrato, CA, 09042, Italy.
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10
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Kowalewski J, Ray A. Predicting Human Olfactory Perception from Activities of Odorant Receptors. iScience 2020; 23:101361. [PMID: 32731170 PMCID: PMC7393469 DOI: 10.1016/j.isci.2020.101361] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2020] [Revised: 05/31/2020] [Accepted: 07/09/2020] [Indexed: 11/30/2022] Open
Abstract
Odor perception in humans is initiated by activation of odorant receptors (ORs) in the nose. However, the ORs linked to specific olfactory percepts are unknown, unlike in vision or taste where receptors are linked to perception of different colors and tastes. The large family of ORs (~400) and multiple receptors activated by an odorant present serious challenges. Here, we first use machine learning to screen ~0.5 million compounds for new ligands and identify enriched structural motifs for ligands of 34 human ORs. We next demonstrate that the activity of ORs successfully predicts many of the 146 different perceptual qualities of chemicals. Although chemical features have been used to model odor percepts, we show that biologically relevant OR activity is often superior. Interestingly, each odor percept could be predicted with very few ORs, implying they contribute more to each olfactory percept. A similar model is observed in Drosophila where comprehensive OR-neuron data are available. Machine learning predicted activity of 34 human ORs for ~0.5 million chemicals Activities of human ORs could predict odor character using machine learning Few OR activities were needed to optimize predictions of each odor percept Behavior predictions in Drosophila also need few olfactory receptor activities
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Affiliation(s)
- Joel Kowalewski
- Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, USA
| | - Anandasankar Ray
- Interdepartmental Neuroscience Program, University of California, Riverside, CA 92521, USA; Department of Molecular, Cell and Systems Biology, University of California, 3401 Watkins Drive, Riverside, CA 92521, USA.
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11
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Makeyeva Y, Nicol C, Ledger WL, Ryugo DK. Immunocytochemical Localization of Olfactory-signaling Molecules in Human and Rat Spermatozoa. J Histochem Cytochem 2020; 68:491-513. [PMID: 32603211 DOI: 10.1369/0022155420939833] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
Expression of olfactory receptors (ORs) in non-olfactory tissues has been widely reported over the last 20 years. Olfactory marker protein (OMP) is highly expressed in mature olfactory sensory neurons (mOSNs) of the olfactory epithelium. It is involved in the olfactory signal transduction pathway, which is mediated by well-conserved components, including ORs, olfactory G protein (Golf), and adenylyl cyclase 3 (AC3). OMP is widely expressed in non-olfactory tissues with an apparent preference for motile cells. We hypothesized that OMP is expressed in compartment-specific locations and co-localize with an OR, Golf, and AC3 in rat epididymal and human-ejaculated spermatozoa. We used immunocytochemistry to examine the expression patterns of OMP and OR6B2 (human OR, served as positive olfactory control) in experimentally induced modes of activation and determine whether there are any observable differences in proteins expression during the post-ejaculatory stages of spermatozoal functional maturation. We found that OMP was expressed in compartment-specific locations in human and rat spermatozoa. OMP was co-expressed with Golf and AC3 in rat spermatozoa and with OR6B2 in all three modes of activation (control, activated, and hyperactivated), and the mode of activation changed the co-expression pattern in acrosomal-reacted human spermatozoa. These observations suggest that OMP expression is a reliable indicator of OR-mediated chemoreception, may be used to identify ectopically expressed ORs, and could participate in second messenger signaling cascades that mediate fertility.
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Affiliation(s)
- Yuliya Makeyeva
- Garvan Institute of Medical Research, Royal Hospital for Women, Sydney, NSW, Australia.,Westfield Research Laboratories, School of Women's and Children's Health, Royal Hospital for Women, Sydney, NSW, Australia
| | - Christopher Nicol
- UNSW Sydney, Sydney, NSW, Australia, and Andrology Laboratory, NSW Health Pathology, Royal Hospital for Women, Sydney, NSW, Australia
| | - William L Ledger
- Fertility & Research Centre, Royal Hospital for Women, Sydney, NSW, Australia
| | - David K Ryugo
- Garvan Institute of Medical Research, Royal Hospital for Women, Sydney, NSW, Australia.,School of Medical Sciences, UNSW, Royal Hospital for Women, Sydney, NSW, Australia.,Department of Otolaryngology, Head, Neck & Skull Base Surgery, St. Vincent's Hospital, Royal Hospital for Women, Sydney, NSW, Australia
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12
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Sollai G, Melis M, Magri S, Usai P, Hummel T, Tomassini Barbarossa I, Crnjar R. Association between the rs2590498 polymorphism of Odorant Binding Protein (OBPIIa) gene and olfactory performance in healthy subjects. Behav Brain Res 2019; 372:112030. [PMID: 31195037 DOI: 10.1016/j.bbr.2019.112030] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Revised: 05/06/2019] [Accepted: 06/08/2019] [Indexed: 01/08/2023]
Abstract
Olfactory function varies by several orders of magnitude among healthy individuals, who may exhibit a reduced sensitivity (hyposmia), a high sensitivity (hyperosmia), or an olfactory blindness (anosmia). Environmental and genetic factors seem to account for this variability. Most of odorant molecules are hydrophobic and it has been suggested that odorants are transported to the olfactory receptors by means of odorant binding proteins (OBPs). Aim of this study was to evaluate the presence of a relationship between the olfactory performance of healthy subjects and the polymorphism in the odor binding-protein (OBPIIa) gene, the only OBP found in the olfactory epithelium of humans. Using the "Sniffin' Sticks" Extended Test we assessed the olfactory performance in 69 subjects, who were genotyped for the rs2590498 polymorphism of the OBPIIa gene, whose major allele A has been associated with a higher retronasal perception as compared to the minor allele G. We found that subjects homozygous for the A-allele exhibited threshold scores higher than subjects homozous for the G-allele or heterozygous. In addition, subjects classified as normosmic and hyposmic differed on the basis of genotype distribution and allelic frequencies. In fact, a normosmic condition was associated with genotype AA and allele A and a hyposmic condition was associated with genotype GG and allele G. In conclusion, our results show that a relationship exists between the physiological variations of olfactory performance and the OBPIIa gene polymorphism.
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Affiliation(s)
- Giorgia Sollai
- Department of Biomedical Sciences, Sect. of Physiology, University of Cagliari, Italy.
| | - Melania Melis
- Department of Biomedical Sciences, Sect. of Physiology, University of Cagliari, Italy
| | - Salvatore Magri
- Department of Medical Sciences and Public Health, University of Cagliari, Presidio Policlinico of Monserrato, Cagliari, Italy
| | - Paolo Usai
- Department of Medical Sciences and Public Health, University of Cagliari, Presidio Policlinico of Monserrato, Cagliari, Italy
| | - Thomas Hummel
- Smell and Taste Clinic, Department of Otorhinolaryngology, TU Dresden, Dresden, Germany
| | | | - Roberto Crnjar
- Department of Biomedical Sciences, Sect. of Physiology, University of Cagliari, Italy
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13
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Maßberg D, Hatt H. Human Olfactory Receptors: Novel Cellular Functions Outside of the Nose. Physiol Rev 2018; 98:1739-1763. [PMID: 29897292 DOI: 10.1152/physrev.00013.2017] [Citation(s) in RCA: 137] [Impact Index Per Article: 22.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Olfactory receptors (ORs) are not exclusively expressed in the olfactory sensory neurons; they are also observed outside of the olfactory system in all other human tissues tested to date, including the testis, lung, intestine, skin, heart, and blood. Within these tissues, certain ORs have been determined to be exclusively expressed in only one tissue, whereas other ORs are more widely distributed in many different tissues throughout the human body. For most of the ectopically expressed ORs, limited data are available for their functional roles. They have been shown to be involved in the modulation of cell-cell recognition, migration, proliferation, the apoptotic cycle, exocytosis, and pathfinding processes. Additionally, there is a growing body of evidence that they have the potential to serve as diagnostic and therapeutic tools, as ORs are highly expressed in different cancer tissues. Interestingly, in addition to the canonical signaling pathways activated by ORs in olfactory sensory neurons, alternative pathways have been demonstrated in nonolfactory tissues. In this review, the existing data concerning the expression, as well as the physiological and pathophysiological functions, of ORs outside of the nose are highlighted to provide insights into future lines of research.
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Affiliation(s)
- Désirée Maßberg
- Ruhr-University Bochum, Department of Cell Physiology , Bochum , Germany
| | - Hanns Hatt
- Ruhr-University Bochum, Department of Cell Physiology , Bochum , Germany
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14
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Cave JW, Wickiser JK, Mitropoulos AN. Progress in the development of olfactory-based bioelectronic chemosensors. Biosens Bioelectron 2018; 123:211-222. [PMID: 30201333 DOI: 10.1016/j.bios.2018.08.063] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Revised: 08/18/2018] [Accepted: 08/25/2018] [Indexed: 12/13/2022]
Abstract
Artificial chemosensory devices have a wide range of applications in industry, security, and medicine. The development of these devices has been inspired by the speed, sensitivity, and selectivity by which the olfactory system in animals can probe the chemical nature of the environment. In this review, we examine how molecular and cellular components of natural olfactory systems have been incorporated into artificial chemosensors, or bioelectronic sensors. We focus on the biological material that has been combined with signal transduction systems to develop artificial chemosensory devices. The strengths and limitations of different biological chemosensory material at the heart of these devices, as well as the reported overall effectiveness of the different bioelectronic sensor designs, is examined. This review also discusses future directions and challenges for continuing to advance development of bioelectronic sensors.
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Affiliation(s)
- John W Cave
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY, United States; Burke Neurological Institute, White Plains, NY, United States; Feil Family Brain and Mind Research Institute, Weill Cornell Medicine, New York, NY, United States
| | - J Kenneth Wickiser
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY, United States
| | - Alexander N Mitropoulos
- Department of Chemistry and Life Science, United States Military Academy, West Point, NY, United States; Department of Mathematical Sciences, United States Military Academy, West Point, NY, United States.
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15
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Zhang X, Cheng J, Wu L, Mei Y, Jaffrezic-Renault N, Guo Z. An overview of an artificial nose system. Talanta 2018; 184:93-102. [PMID: 29674088 DOI: 10.1016/j.talanta.2018.02.113] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2017] [Revised: 01/31/2018] [Accepted: 02/28/2018] [Indexed: 12/22/2022]
Abstract
The present review describes recent advances in the development of an artificial nose system based on olfactory receptors and various sensing platforms. The kind of artificial nose, the production of olfactory receptors, the sensor platform for signal conversion and the application of the artificial nose system based on olfactory receptors and various sensing platforms are presented. The associated transduction modes are also discussed. The paper presents a review of the latest achievements and a critical evaluation of the state of the art in the field of artificial nose systems.
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Affiliation(s)
- Xiu Zhang
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Medical College, Wuhan University of Science and Technology, Wuhan 430065, PR China
| | - Jing Cheng
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Medical College, Wuhan University of Science and Technology, Wuhan 430065, PR China
| | - Lei Wu
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Medical College, Wuhan University of Science and Technology, Wuhan 430065, PR China
| | - Yong Mei
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Medical College, Wuhan University of Science and Technology, Wuhan 430065, PR China.
| | - Nicole Jaffrezic-Renault
- Institute of Analytical Sciences, UMR-CNRS 5280, University of Lyon, 5, La Doua Street, Villeurbanne 69100, France.
| | - Zhenzhong Guo
- Hubei Province Key Laboratory of Occupational Hazard Identification and Control, Medical College, Wuhan University of Science and Technology, Wuhan 430065, PR China.
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16
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Wasilewski T, Gębicki J, Kamysz W. Bioelectronic nose: Current status and perspectives. Biosens Bioelectron 2016; 87:480-494. [PMID: 27592240 DOI: 10.1016/j.bios.2016.08.080] [Citation(s) in RCA: 69] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Revised: 08/23/2016] [Accepted: 08/24/2016] [Indexed: 11/30/2022]
Abstract
A characteristic feature of human and animal organs of smell is the ability to identify hundreds of thousands of odours. It is accompanied by particular smell sensations, which are a basic source of information about odour mixture. The main structural elements of biological smell systems are the olfactory receptors. Small differences in a structure of odorous molecules (odorants) can lead to significant change of odour, which is due to the fact that each of the olfactory receptors is coded with different gene and usually corresponds to different type of odour. Discovery and characterisation of the gene family coding the olfactory receptors contributed to the elaboration and development of the electronic smell systems, the so-called bioelectronic noses. The olfactory receptors are employed as a biological element in this type of instruments. An electronic system includes a converter part, which allows measurement and processing of generated signals. A suitable data analysis system is also required to visualise the results. Application potentialities of the bioelectronic noses are focused on the fields of economy and science where highly selective and sensitive analysis of odorous substances is required. The paper presents a review of the latest achievements and critical evaluation of the state of art in the field of bioelectronic noses.
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Affiliation(s)
- Tomasz Wasilewski
- Medical University of Gdansk, Department of Inorganic Chemistry, Faculty of Pharmacy, Medical University of Gdansk, Poland, Al. Hallera 107, Gdansk 80-416, Poland.
| | - Jacek Gębicki
- Gdańsk University of Technology, Department of Chemical and Process Engineering, Chemical Faculty, Gdańsk University of Technology, Gabriela Narutowicza 11/12 Str., Gdańsk 80-233, Poland
| | - Wojciech Kamysz
- Medical University of Gdansk, Department of Inorganic Chemistry, Faculty of Pharmacy, Medical University of Gdansk, Poland, Al. Hallera 107, Gdansk 80-416, Poland
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17
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Gonzalez F, Witzgall P, Walker WB. Protocol for Heterologous Expression of Insect Odourant Receptors in Drosophila. Front Ecol Evol 2016. [DOI: 10.3389/fevo.2016.00024] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
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18
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Silva Teixeira CS, Cerqueira NMFSA, Silva Ferreira AC. Unravelling the Olfactory Sense: From the Gene to Odor Perception. Chem Senses 2015; 41:105-21. [PMID: 26688501 DOI: 10.1093/chemse/bjv075] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Although neglected by science for a long time, the olfactory sense is now the focus of a panoply of studies that bring new insights and raises interesting questions regarding its functioning. The importance in the clarification of this process is of interest for science, but also motivated by the food and perfume industries boosted by a consumer society with increasingly demands for higher quality standards. In this review, a general overview of the state of art of science regarding the olfactory sense is presented with the main focus on the peripheral olfactory system. Special emphasis will be given to the deorphanization of the olfactory receptors (ORs), a critical issue because the specificity and functional properties of about 90% of human ORs remain unknown mainly due to the difficulties associated with the functional expression of ORs in high yields.
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Affiliation(s)
- Carla S Silva Teixeira
- Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto, Portugal
| | - Nuno M F S A Cerqueira
- UCIBIO@Requimte/Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre s/n, 4169-007 Porto, Portugal and
| | - António C Silva Ferreira
- Escola Superior de Biotecnologia, Universidade Católica Portuguesa, Rua Arquiteto Lobão Vital, Apartado 2511, 4202-401 Porto, Portugal, Department of Viticulture and Oenology, Institute for Wine Biotechnology, University of Stellenbosch, Private Bag XI, Matieland 7602, South Africa
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19
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Affiliation(s)
- Anne Tromelin
- CNRS; UMR6265 Centre des Sciences du Goût et de l'Alimentation; F-21000 Dijon France
- INRA; UMR1324 Centre des Sciences du Goût et de l'Alimentation; F-21000 Dijon France
- Université de Bourgogne; UMR Centre des Sciences du Goût et de l'Alimentation; F-21000 Dijon France
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20
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von der Weid B, Rossier D, Lindup M, Tuberosa J, Widmer A, Col JD, Kan C, Carleton A, Rodriguez I. Large-scale transcriptional profiling of chemosensory neurons identifies receptor-ligand pairs in vivo. Nat Neurosci 2015; 18:1455-63. [PMID: 26322926 DOI: 10.1038/nn.4100] [Citation(s) in RCA: 83] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2015] [Accepted: 08/04/2015] [Indexed: 12/11/2022]
Abstract
In mammals, olfactory perception is based on the combinatorial activation of G protein-coupled receptors. Identifying the full repertoire of receptors activated by a given odorant in vivo, a quest that has been hampered for over 20 years by technical difficulties, would represent an important step in deciphering the rules governing chemoperception. We found that odorants induced a fast and reversible concentration-dependent decrease in the transcription of genes corresponding to activated receptors in intact mice. On the basis of this finding, we developed a large-scale transcriptomic approach to uncover receptor-ligand pairs in vivo. We identified the mouse and rat odorant receptor signatures corresponding to specific odorants. Finally, we found that this approach, which can be used for species for which no genomic sequence is available, is also applicable to non-vertebrate species such as Drosophila.
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Affiliation(s)
- Benoît von der Weid
- Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.,Geneva Neuroscience Center, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics of Geneva, University of Geneva, Geneva, Switzerland
| | - Daniel Rossier
- Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.,Geneva Neuroscience Center, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics of Geneva, University of Geneva, Geneva, Switzerland
| | - Matti Lindup
- Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.,Geneva Neuroscience Center, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics of Geneva, University of Geneva, Geneva, Switzerland
| | - Joël Tuberosa
- Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.,Geneva Neuroscience Center, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics of Geneva, University of Geneva, Geneva, Switzerland
| | - Alexandre Widmer
- Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.,Geneva Neuroscience Center, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics of Geneva, University of Geneva, Geneva, Switzerland
| | - Julien Dal Col
- Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.,Geneva Neuroscience Center, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics of Geneva, University of Geneva, Geneva, Switzerland
| | - Chenda Kan
- Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.,Geneva Neuroscience Center, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics of Geneva, University of Geneva, Geneva, Switzerland
| | - Alan Carleton
- Geneva Neuroscience Center, University of Geneva, Geneva, Switzerland.,Department of Basic Neurosciences, School of Medicine, University of Geneva, Geneva, Switzerland
| | - Ivan Rodriguez
- Department of Genetics and Evolution, University of Geneva, Geneva, Switzerland.,Geneva Neuroscience Center, University of Geneva, Geneva, Switzerland.,Institute of Genetics and Genomics of Geneva, University of Geneva, Geneva, Switzerland
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21
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de March CA, Ryu S, Sicard G, Moon C, Golebiowski J. Structure-odour relationships reviewed in the postgenomic era. FLAVOUR FRAG J 2015. [DOI: 10.1002/ffj.3249] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Affiliation(s)
- Claire A. de March
- Institut de Chimie de Nice; Université Nice Sophia Antipolis; UMR CNRS 7272, parc Valrose 06108 Nice cedex 02 France
| | - SangEun Ryu
- Laboratory of Chemical Senses, Department of Brain and Cognitive Science; DGIST (Daegu Gyeongbuk Institute of Science & Technology); 50-1 Sang-Ri, Hyeonpung-Myeon, Dalseong-Gun Daegu 711-873 Korea
| | - Gilles Sicard
- Neurobiology of Cellular Interactions and Neurophysiopathology; Aix-Marseille Université; UMR CNRS 7259 13331 Marseille cedex 03 France
| | - Cheil Moon
- Laboratory of Chemical Senses, Department of Brain and Cognitive Science; DGIST (Daegu Gyeongbuk Institute of Science & Technology); 50-1 Sang-Ri, Hyeonpung-Myeon, Dalseong-Gun Daegu 711-873 Korea
| | - Jérôme Golebiowski
- Institut de Chimie de Nice; Université Nice Sophia Antipolis; UMR CNRS 7272, parc Valrose 06108 Nice cedex 02 France
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22
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Lobasso S, Vitale R, Lopalco P, Corcelli A. Haloferax volcanii, as a Novel Tool for Producing Mammalian Olfactory Receptors Embedded in Archaeal Lipid Bilayer. Life (Basel) 2015; 5:770-82. [PMID: 25761264 PMCID: PMC4390878 DOI: 10.3390/life5010770] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/14/2015] [Revised: 02/17/2015] [Accepted: 03/02/2015] [Indexed: 11/16/2022] Open
Abstract
The aim of this study was to explore the possibility of using an archaeal microorganism as a host system for expressing mammalian olfactory receptors (ORs). We have selected the archaeon Haloferax volcanii as a cell host system and one of the most extensively investigated OR, namely I7-OR, whose preferred ligands are short-chain aldehydes, such as octanal, heptanal, nonanal. A novel plasmid has been constructed to express the rat I7-OR, fused with a hexahistidine-tag for protein immunodetection. The presence of the recombinant receptor at a membrane level was demonstrated by immunoblot of the membranes isolated from the transgenic archaeal strain. In addition, the lipid composition of archaeonanosomes containing ORs has been characterized in detail by High-Performance Thin-Layer Chromatography (HPTLC) in combination with Matrix-Assisted Laser Desorption Ionization-Time-Of-Flight/Mass Spectrometry (MALDI-TOF/MS) analysis.
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Affiliation(s)
- Simona Lobasso
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari "Aldo Moro", Piazza Giulio Cesare 11, I-70124 Bari, Italy.
| | - Rita Vitale
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari "Aldo Moro", Piazza Giulio Cesare 11, I-70124 Bari, Italy.
| | - Patrizia Lopalco
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari "Aldo Moro", Piazza Giulio Cesare 11, I-70124 Bari, Italy.
| | - Angela Corcelli
- Department of Basic Medical Sciences, Neurosciences and Sensory Organs, University of Bari "Aldo Moro", Piazza Giulio Cesare 11, I-70124 Bari, Italy.
- Institute for Chemical-Physical Processes, National Research Council (IPCF-CNR), Bari Unit, via Orabona 4, I-70126 Bari, Italy.
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23
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Gonzalez-Kristeller DC, do Nascimento JBP, Galante PAF, Malnic B. Identification of agonists for a group of human odorant receptors. Front Pharmacol 2015; 6:35. [PMID: 25784876 PMCID: PMC4347425 DOI: 10.3389/fphar.2015.00035] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 02/11/2015] [Indexed: 11/13/2022] Open
Abstract
Olfaction plays a critical role in several aspects of the human life. Odorants are detected by hundreds of odorant receptors (ORs) which belong to the superfamily of G protein-coupled receptors. These receptors are expressed in the olfactory sensory neurons of the nose. The information provided by the activation of different combinations of ORs in the nose is transmitted to the brain, leading to odorant perception and emotional and behavioral responses. There are ~400 intact human ORs, and to date only a small percentage of these receptors (~10%) have known agonists. The determination of the specificity of the human ORs will contribute to a better understanding of how odorants are discriminated by the olfactory system. In this work, we aimed to identify human specific ORs, that is, ORs that are present in humans but absent from other species, and their corresponding agonists. To do this, we first selected 22 OR gene sequences from the human genome with no counterparts in the mouse, rat or dog genomes. Then we used a heterologous expression system to screen a subset of these human ORs against a panel of odorants of biological relevance, including foodborne aroma volatiles. We found that different types of odorants are able to activate some of these previously uncharacterized human ORs.
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Affiliation(s)
| | - João B P do Nascimento
- Department of Biochemistry, Institute of Chemistry, University of São Paulo São Paulo, Brazil
| | - Pedro A F Galante
- Centro de Oncologia Molecular, Hospital Sírio-Libanês São Paulo, Brazil
| | - Bettina Malnic
- Department of Biochemistry, Institute of Chemistry, University of São Paulo São Paulo, Brazil
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24
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Abstract
Although the human olfactory system is capable of discriminating a vast number of odors, we do not currently understand what chemical features are encoded by olfactory receptors. In large part this is due to a paucity of data in a search space covering the interactions of hundreds of receptors with billions of odorous molecules. Of the approximately 400 intact human odorant receptors, only 10% have a published ligand. Here we used a heterologous luciferase assay to screen 73 odorants against a clone library of 511 human olfactory receptors. This dataset will allow other researchers to interrogate the combinatorial nature of olfactory coding.
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25
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Dörrich S, Gelis L, Wolf S, Sunderkötter A, Mahler C, Guschina E, Tacke R, Hatt H, Kraft P. Comparative Analysis of the Olfactory Properties of Silicon/Germanium/Tin Analogues of the Lily-of-the-Valley Odorants Lilial and Bourgeonal. Chempluschem 2014. [DOI: 10.1002/cplu.201402160] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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26
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27
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A computational microscope focused on the sense of smell. Biochimie 2014; 107 Pt A:3-10. [PMID: 24952349 DOI: 10.1016/j.biochi.2014.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 06/07/2014] [Indexed: 11/24/2022]
Abstract
In this article, we review studies of the protagonists of the perception of smell focusing on Odorant-Binding Proteins and Olfactory Receptors. We notably put forward studies performed by means of molecular modeling, generally combined with experimental data. Those works clearly emphasize that computational approaches are now a force to reckon with. In the future, they will certainly be more and more used, notably in the framework of a computational microscope meant to observe how the laws of physics govern the biomolecular systems originating our sense of smell.
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28
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Trimmer C, Snyder LL, Mainland JD. High-throughput analysis of mammalian olfactory receptors: measurement of receptor activation via luciferase activity. J Vis Exp 2014. [PMID: 24961834 DOI: 10.3791/51640] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Odorants create unique and overlapping patterns of olfactory receptor activation, allowing a family of approximately 1,000 murine and 400 human receptors to recognize thousands of odorants. Odorant ligands have been published for fewer than 6% of human receptors(1-11). This lack of data is due in part to difficulties functionally expressing these receptors in heterologous systems. Here, we describe a method for expressing the majority of the olfactory receptor family in Hana3A cells, followed by high-throughput assessment of olfactory receptor activation using a luciferase reporter assay. This assay can be used to (1) screen panels of odorants against panels of olfactory receptors; (2) confirm odorant/receptor interaction via dose response curves; and (3) compare receptor activation levels among receptor variants. In our sample data, 328 olfactory receptors were screened against 26 odorants. Odorant/receptor pairs with varying response scores were selected and tested in dose response. These data indicate that a screen is an effective method to enrich for odorant/receptor pairs that will pass a dose response experiment, i.e. receptors that have a bona fide response to an odorant. Therefore, this high-throughput luciferase assay is an effective method to characterize olfactory receptors-an essential step toward a model of odor coding in the mammalian olfactory system.
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29
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Verbeurgt C, Wilkin F, Tarabichi M, Gregoire F, Dumont JE, Chatelain P. Profiling of olfactory receptor gene expression in whole human olfactory mucosa. PLoS One 2014; 9:e96333. [PMID: 24800820 PMCID: PMC4011832 DOI: 10.1371/journal.pone.0096333] [Citation(s) in RCA: 89] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2014] [Accepted: 04/07/2014] [Indexed: 11/19/2022] Open
Abstract
Olfactory perception is mediated by a large array of olfactory receptor genes. The human genome contains 851 olfactory receptor gene loci. More than 50% of the loci are annotated as nonfunctional due to frame-disrupting mutations. Furthermore haplotypic missense alleles can be nonfunctional resulting from substitution of key amino acids governing protein folding or interactions with signal transduction components. Beyond their role in odor recognition, functional olfactory receptors are also required for a proper targeting of olfactory neuron axons to their corresponding glomeruli in the olfactory bulb. Therefore, we anticipate that profiling of olfactory receptor gene expression in whole human olfactory mucosa and analysis in the human population of their expression should provide an opportunity to select the frequently expressed and potentially functional olfactory receptors in view of a systematic deorphanization. To address this issue, we designed a TaqMan Low Density Array (Applied Biosystems), containing probes for 356 predicted human olfactory receptor loci to investigate their expression in whole human olfactory mucosa tissues from 26 individuals (13 women, 13 men; aged from 39 to 81 years, with an average of 67±11 years for women and 63±12 years for men). Total RNA isolation, DNase treatment, RNA integrity evaluation and reverse transcription were performed for these 26 samples. Then 384 targeted genes (including endogenous control genes and reference genes specifically expressed in olfactory epithelium for normalization purpose) were analyzed using the same real-time reverse transcription PCR platform. On average, the expression of 273 human olfactory receptor genes was observed in the 26 selected whole human olfactory mucosa analyzed, of which 90 were expressed in all 26 individuals. Most of the olfactory receptors deorphanized to date on the basis of sensitivity to known odorant molecules, which are described in the literature, were found in the expressed olfactory receptors gene set.
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Affiliation(s)
- Christophe Verbeurgt
- Department of Otorhinolaryngology, Erasme University Hospital, Brussels, Belgium
| | | | - Maxime Tarabichi
- Institute of Interdisciplinary Research in human and molecular Biology, Free University of Brussels, Brussels, Belgium
| | - Françoise Gregoire
- Laboratory of Pathophysiological and Nutritional Biochemistry, Department of Biochemistry, Free University of Brussels, Brussels, Belgium
| | - Jacques E. Dumont
- Institute of Interdisciplinary Research in human and molecular Biology, Free University of Brussels, Brussels, Belgium
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30
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Peterlin Z, Firestein S, Rogers ME. The state of the art of odorant receptor deorphanization: a report from the orphanage. ACTA ACUST UNITED AC 2014; 143:527-42. [PMID: 24733839 PMCID: PMC4003190 DOI: 10.1085/jgp.201311151] [Citation(s) in RCA: 67] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
The odorant receptors (ORs) provide our main gateway to sensing the world of volatile chemicals. This involves a complex encoding process in which multiple ORs, each of which detects its own set of odorants, work as an ensemble to produce a distributed activation code that is presumably unique to each odorant. One marked challenge to decoding the olfactory code is OR deorphanization, the identification of a set of activating odorants for a particular receptor. Here, we survey various methods used to try to express defined ORs of interest. We also suggest strategies for selecting odorants for test panels to evaluate the functional expression of an OR. Integrating these tools, while retaining awareness of their idiosyncratic limitations, can provide a multi-tiered approach to OR deorphanization, spanning the initial discovery of a ligand to vetting that ligand in a physiologically relevant setting.
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Affiliation(s)
- Zita Peterlin
- Corporate Research and Development, Firmenich Incorporated, Plainsboro, NJ 08536
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31
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Laska M. Olfactory Sensitivity and Odor Structure-Activity Relationships for Aliphatic Ketones in CD-1 Mice. Chem Senses 2014; 39:415-24. [DOI: 10.1093/chemse/bju011] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
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32
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Lai PC, Guida B, Shi J, Crasto CJ. Preferential binding of an odor within olfactory receptors: a precursor to receptor activation. Chem Senses 2014; 39:107-23. [PMID: 24398973 PMCID: PMC3894857 DOI: 10.1093/chemse/bjt060] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Using computational methods, which allow mechanistic insights at a molecular level, we explored the olfactory receptor (OR)-odor interactions for 2 mouse ORs, S79 and S86. Both ORs have been previously experimentally, functionally characterized. The odors used were mostly carboxylic acids, which differed in chain length, substituents on the primary carbon atom-chain and degree of unsaturation. These odors elicited varied activation responses from both ORs. Our studies revealed that both receptors have 2 distinct binding sites. Preferential binding in 1 of the 2 sites is correlated with OR activation. The activating odorants: nonanedioic acid, heptanoic acid, and octanoic acid for OR S79 and nonanoic acid for OR S86 preferentially bind in the region bound by transmembranes (TMs [helical domains]) III, IV, V, and VI. The non excitatory odorants heptanol for S79 and heptanoic acid for S86 showed a greater likelihood of binding in the region bound by TMs I, II, III, and VII. Nanosecond-scale molecular dynamics simulations of the physiologically relevant conditions of docked OR-odorant complexes enabled us to quantitatively assess the roles of individual OR amino acids in odor binding. Amino acid-odorant contact maps and distance determinations over the course of the simulations lend support to our conclusions.
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Affiliation(s)
- Peter C Lai
- Department of Genetics, Division of Research, University of Alabama at Birmingham, 720 20th Street S., Birmingham, AL 35294, USA.
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The missense of smell: functional variability in the human odorant receptor repertoire. Nat Neurosci 2013; 17:114-20. [PMID: 24316890 PMCID: PMC3990440 DOI: 10.1038/nn.3598] [Citation(s) in RCA: 193] [Impact Index Per Article: 17.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2013] [Accepted: 11/05/2013] [Indexed: 11/09/2022]
Abstract
Humans have ~400 intact odorant receptors, but each individual has a unique set of genetic variations that lead to variation in olfactory perception. We used a heterologous assay to determine how often genetic polymorphisms in odorant receptors alter receptor function. We identified agonists for 18 odorant receptors and found that 63% of the odorant receptors we examined had polymorphisms that altered in vitro function. On average, two individuals have functional differences at over 30% of their odorant receptor alleles. To show that these in vitro results are relevant to olfactory perception, we verified that variations in OR10G4 genotype explain over 15% of the observed variation in perceived intensity and over 10% of the observed variation in perceived valence for the high-affinity in vitro agonist guaiacol but do not explain phenotype variation for the lower-affinity agonists vanillin and ethyl vanillin.
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Marenco LN, Bahl G, Hyland L, Shi J, Wang R, Lai PC, Miller PL, Shepherd GM, Crasto CJ. Databases in SenseLab for the genomics, proteomics, and function of olfactory receptors. Methods Mol Biol 2013; 1003:3-22. [PMID: 23585030 DOI: 10.1007/978-1-62703-377-0_1] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/02/2023]
Abstract
We present here, the salient aspects of three databases: Olfactory Receptor Database (ORDB) is a repository of genomics and proteomics information of ORs; OdorDB stores information related to odorous compounds, specifically identifying those that have been shown to interact with olfactory rectors; and OdorModelDB disseminates information related to computational models of olfactory receptors (ORs). The data stored among these databases is integrated. Presented in this chapter are descriptions of these resources, which are part of the SenseLab suite of databases, a discussion of the computational infrastructure that enhances the efficacy of information storage, retrieval, dissemination, and automated data population from external sources.
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Affiliation(s)
- Luis N Marenco
- Center for Medical Informatics, Yale University School of Medicine, New Haven, CT, USA
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Abstract
Olfactory receptors (ORs) detect volatile chemicals that lead to the initial perception of smell in the brain. The olfactory receptor (OR) is the first protein that recognizes odorants in the olfactory signal pathway and it is present in over 1,000 genes in mice. It is also the largest member of the G protein-coupled receptors (GPCRs). Most ORs are extensively expressed in the nasal olfactory epithelium where they perform the appropriate physiological functions that fit their location. However, recent whole-genome sequencing shows that ORs have been found outside of the olfactory system, suggesting that ORs may play an important role in the ectopic expression of non-chemosensory tissues. The ectopic expressions of ORs and their physiological functions have attracted more attention recently since MOR23 and testicular hOR17-4 have been found to be involved in skeletal muscle development, regeneration, and human sperm chemotaxis, respectively. When identifying additional expression profiles and functions of ORs in non-olfactory tissues, there are limitations posed by the small number of antibodies available for similar OR genes. This review presents the results of a research series that identifies ectopic expressions and functions of ORs in non-chemosensory tissues to provide insight into future research directions. [BMB Reports 2012; 45(11): 612-622]
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Affiliation(s)
- NaNa Kang
- Department of Brain Science, Daegu Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Korea
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Schott M, Wehrenfennig C, Gasch T, Vilcinskas A. Insect Antenna-Based Biosensors for In Situ Detection of Volatiles. ADVANCES IN BIOCHEMICAL ENGINEERING/BIOTECHNOLOGY 2013; 136:101-22. [DOI: 10.1007/10_2013_210] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
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Matarazzo V, Ronin C. Human olfactory receptors: recombinant expression in the baculovirus/Sf9 insect cell system, functional characterization, and odorant identification. Methods Mol Biol 2013; 1003:109-122. [PMID: 23585037 DOI: 10.1007/978-1-62703-377-0_8] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/02/2023]
Abstract
Cell surface expression of recombinant olfactory receptors (ORs) is a major limitation in characterizing their functional nature. We have shown that the recombinant expression of a human OR, OR 17-210, in the baculovirus/Sf9 insect cell system allows this protein to be expressed at the cell surface. We used Ca(2+) imaging to demonstrate that recombinant OR 17-210 produces cellular activities upon odorant stimulation with ketones. Furthermore, this expression and functional system has been used to show that the preincubation of Human Odorant Binding Protein 2A decrease the calcium response of OR 17-210 following stimulation by acetophenone and beta ionone.
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Affiliation(s)
- Valéry Matarazzo
- Centre de Recherche en Neurobiologie et Neurophysiologie de Marseille, CRN2M, CNRS UMR6231, Université Paul Cézanne, Marseille, France
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Charlier L, Topin J, Ronin C, Kim SK, Goddard WA, Efremov R, Golebiowski J. How broadly tuned olfactory receptors equally recognize their agonists. Human OR1G1 as a test case. Cell Mol Life Sci 2012; 69:4205-13. [PMID: 22926438 PMCID: PMC11115053 DOI: 10.1007/s00018-012-1116-0] [Citation(s) in RCA: 51] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2012] [Revised: 07/25/2012] [Accepted: 07/30/2012] [Indexed: 10/28/2022]
Abstract
The molecular features that dominate the binding mode of agonists by a broadly tuned olfactory receptor are analyzed through a joint approach combining cell biology, calcium imaging, and molecular modeling. The odorant/receptor affinities, estimated through statistics accrued during molecular dynamics simulations, are in accordance with the experimental ranking. Although in many systems receptors recognize their target through a network of oriented interactions, such as H-bonding, the binding by broadly tuned olfactory receptors is dominated by non-polar terms. We show how such a feature allows chemicals belonging to different chemical families to similarly activate the receptors through compensations of interactions within the binding site.
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Affiliation(s)
- Landry Charlier
- Institut de Chimie de Nice, UMR CNRS, Université de Nice Sophia Antipolis 7272, 06108 Nice Cedex 2, France
- Present Address: Institut des Biomolécules Max Mousseron, CNRS-UMR 5247, Faculté de Pharmacie, Université Montpellier 1, Université Montpellier 2, 15 Avenue Charles Flahault, BP 14491, 34093 Montpellier Cedex 5, France
| | - Jérémie Topin
- Institut de Chimie de Nice, UMR CNRS, Université de Nice Sophia Antipolis 7272, 06108 Nice Cedex 2, France
| | - Catherine Ronin
- Laboratoire de Neuroglycobiologie, GLM, CNRS, 31 Ch. J. Aiguier, 13402 Marseille, France
| | - Soo-Kyung Kim
- Materials and Process Simulation Center (MC139-74), California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 USA
| | - William A. Goddard
- Materials and Process Simulation Center (MC139-74), California Institute of Technology, 1200 E. California Blvd., Pasadena, CA 91125 USA
| | - Roman Efremov
- Laboratory of Biomolecular Modeling, Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Ul. Miklukho-Maklaya, 16/10, 117997 Moscow, Russia
| | - Jérôme Golebiowski
- Institut de Chimie de Nice, UMR CNRS, Université de Nice Sophia Antipolis 7272, 06108 Nice Cedex 2, France
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Lai PC, Crasto CJ. Beyond modeling: all-atom olfactory receptor model simulations. Front Genet 2012; 3:61. [PMID: 22563330 PMCID: PMC3342527 DOI: 10.3389/fgene.2012.00061] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2011] [Accepted: 03/30/2012] [Indexed: 11/27/2022] Open
Abstract
Olfactory receptors (ORs) are a type of GTP-binding protein-coupled receptor (GPCR). These receptors are responsible for mediating the sense of smell through their interaction with odor ligands. OR-odorant interactions marks the first step in the process that leads to olfaction. Computational studies on model OR structures can generate focused and novel hypotheses for further bench investigation by providing a view of these interactions at the molecular level beyond inferences that are drawn merely from static docking. Here we have shown the specific advantages of simulating the dynamic environment associated with OR-odorant interactions. We present a rigorous protocol which ranges from the creation of a computationally derived model of an olfactory receptor to simulating the interactions between an OR and an odorant molecule. Given the ubiquitous occurrence of GPCRs in the membranes of cells, we anticipate that our OR-developed methodology will serve as a model for the computational structural biology of all GPCRs.
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Affiliation(s)
- Peter C Lai
- Division of Research, Department of Genetics, University of Alabama at Birmingham Birmingham, AL, USA
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Chaput MA, El Mountassir F, Atanasova B, Thomas-Danguin T, Le Bon AM, Perrut A, Ferry B, Duchamp-Viret P. Interactions of odorants with olfactory receptors and receptor neurons match the perceptual dynamics observed for woody and fruity odorant mixtures. Eur J Neurosci 2012; 35:584-97. [PMID: 22304504 DOI: 10.1111/j.1460-9568.2011.07976.x] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
The present study aimed to create a direct bridge between observations on peripheral and central responses to odorant mixtures and their components. Three experiments were performed using mixtures of fruity (isoamyl acetate; ISO) and woody (whiskey lactone; WL) odorants known to contribute to some of the major notes in Burgundy red wine. These experiments consisted of (i) calcium imaging of human embryonic kidney cells (HEK293T) transfected with olfactory receptors (ORs); (ii) single-unit electrophysiological recordings from olfactory receptor neurons (ORNs) and analyses of electro-olfactogram (EOG) responses in the rat nose in vivo; and (iii) psychophysical measurements of the perceived intensity of the mixtures as rated by human subjects. The calcium imaging and electrophysiological results revealed that ISO and WL can act simultaneously on single ORs or ORNs and confirm that receptor responses to mixtures are not the result of a simple sum of the effects of the individual mixture compounds. The addition of WL to ISO principally suppressed the ORN activation induced by ISO alone and was found to enhance this activation in a subset of cases. In the human studies, the addition of high concentrations of WL to ISO decreased the perceived intensity of the ISO. In contrast, the addition of low concentrations of WL enhanced the perceived intensity of the fruity note (ISO) in this mixture, as it enhanced EOG responses in ORNs. Thus, both OR and ORN responses to ISO + WL mixtures faithfully reflected perceptual response changes, so the odour mixture information is set up after the peripheral stage of the olfactory system.
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Affiliation(s)
- M A Chaput
- UMR 5292, Centre de recherche en neurosciences de Lyon, Université de Lyon, CNRS, INSERM, 50 avenue Tony Garnier, F-69366 Lyon, France.
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Oh EH, Song HS, Park TH. Recent advances in electronic and bioelectronic noses and their biomedical applications. Enzyme Microb Technol 2011; 48:427-37. [PMID: 22113013 DOI: 10.1016/j.enzmictec.2011.04.003] [Citation(s) in RCA: 108] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2011] [Accepted: 04/01/2011] [Indexed: 01/28/2023]
Abstract
Significant effort has been made in the development of an artificial nose system for various applications. Advances in sensor technology have facilitated the development of high-performance electronic and bioelectronic noses. Numerous articles describe the advantages of artificial nose systems for biomedical applications. Recent advances in the development of electronic and bioelectronic noses and their biomedical applications are reviewed in this article.
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Affiliation(s)
- Eun Hae Oh
- Interdisciplinary Program of Bioengineering, Seoul National University, Seoul, Republic of Korea
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42
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Glatz R, Bailey-Hill K. Mimicking nature's noses: from receptor deorphaning to olfactory biosensing. Prog Neurobiol 2010; 93:270-96. [PMID: 21130137 DOI: 10.1016/j.pneurobio.2010.11.004] [Citation(s) in RCA: 60] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2010] [Revised: 11/09/2010] [Accepted: 11/22/2010] [Indexed: 12/21/2022]
Abstract
The way in which organisms detect specific volatile compounds within their environment, and the associated neural processing which produces perception and subsequent behavioural responses, have been of interest to scientists for decades. Initially, most olfaction research was conducted using electrophysiological techniques on whole animals. However, the discovery of genes encoding the family of human olfactory receptors (ORs) paved the way for the development of a range of cellular assays, primarily used to deorphan ORs from mammals and insects. These assays have greatly advanced our knowledge of the molecular basis of olfaction, however, while there is currently good agreement on vertebrate and nematode olfactory signalling cascades, debate still surrounds the signalling mechanisms in insects. The inherent specificity and sensitivity of ORs makes them prime candidates as biological detectors of volatile ligands within biosensor devices, which have many potential applications. In the previous decade, researchers have investigated various technologies for transducing OR:ligand interactions into a readable format and thereby produce an olfactory biosensor (or bioelectronic nose) that maintains the discriminating power of the ORs in vivo. Here we review and compare the molecular mechanisms of olfaction in vertebrates and invertebrates, and also summarise the assay technologies utilising sub-tissue level sensing elements (cells and cell extracts), which have been applied to OR deorphanization and biosensor research. Although there are currently no commercial, "field-ready" olfactory biosensors of the kind discussed here, there have been several technological proof-of-concept studies suggesting that we will see their emergence within the next decade.
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Affiliation(s)
- Richard Glatz
- South Australian Research and Development Institute (SARDI), Entomology, GPO Box 397, Adelaide 5001, Australia.
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45
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Lee SH, Ko HJ, Park TH. Real-time monitoring of odorant-induced cellular reactions using surface plasmon resonance. Biosens Bioelectron 2009; 25:55-60. [DOI: 10.1016/j.bios.2009.06.007] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/14/2009] [Revised: 06/01/2009] [Accepted: 06/02/2009] [Indexed: 10/20/2022]
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Abstract
Deciphering olfactory encoding requires a thorough description of the ligands that activate each odorant receptor (OR). In mammalian systems, however, ligands are known for fewer than 50 of more than 1400 human and mouse ORs, greatly limiting our understanding of olfactory coding. We performed high-throughput screening of 93 odorants against 464 ORs expressed in heterologous cells and identified agonists for 52 mouse and 10 human ORs. We used the resulting interaction profiles to develop a predictive model relating physicochemical odorant properties, OR sequences, and their interactions. Our results provide a basis for translating odorants into receptor neuron responses and for unraveling mammalian odor coding.
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Affiliation(s)
- Harumi Saito
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Research Drive, Durham NC 27710, USA
| | - Qiuyi Chi
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Research Drive, Durham NC 27710, USA
| | - Hanyi Zhuang
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Research Drive, Durham NC 27710, USA
| | - Hiro Matsunami
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Research Drive, Durham NC 27710, USA
- Department of Neurobiology, Duke University Medical Center, Research Drive, Durham NC 27710, USA
| | - Joel D. Mainland
- Department of Molecular Genetics and Microbiology, Duke University Medical Center, Research Drive, Durham NC 27710, USA
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47
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Cometto-Muñiz JE, Abraham MH. Olfactory psychometric functions for homologous 2-ketones. Behav Brain Res 2009; 201:207-15. [PMID: 19428635 DOI: 10.1016/j.bbr.2009.02.014] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2008] [Revised: 01/16/2009] [Accepted: 02/10/2009] [Indexed: 11/29/2022]
Abstract
We measured concentration-detection (i.e., psychometric) odor functions for the homologous ketones propanone (acetone), 2-pentanone, 2-heptanone, and 2-nonanone. Under a forced-choice procedure, stimuli were presented via an 8-channel air-dilution olfactometer that allowed natural sampling of the odorant and whose output was quantified by gas chromatography. Subjects (17-22 per compound) comprised young adults from both genders, all normosmics and nonsmokers. A sigmoid (logistic) equation tightly fitted group and individual functions. The odor detection threshold (ODT) was the concentration detectable at halfway (P=0.5) between chance (P=0.0) and perfect (P=1.0) detection. Odor sensitivity increased (i.e., thresholds decreased) from acetone to heptanone, remaining constant for nonanone. This relative trend was also observed in previous work and in odor thresholds compilations, but the absolute ODTs obtained here were consistently at the lower end of those reported before. Interindividual variability of ODTs was about 1 order of magnitude. These odor functions measured behaviorally in humans were obtained at vapor concentrations 1000 times lower than functions measured via activation, with similar 2-ketones, of receptor neurons converging into individual olfactory glomeruli of mice, visualized with calcium sensitive dyes. Odorant concentrations presented as vapors (as in behavioral studies) and those presented as liquids (as in cellular/tissue studies) can be rendered equivalent via liquid-vapor partition coefficients and, then, compared in relative olfactory potency. These comparisons can reveal how sensitivity is progressively shaped across levels of the neural pathway.
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Affiliation(s)
- J Enrique Cometto-Muñiz
- Department of Surgery (Otolaryngology), University of California, San Diego, La Jolla, CA 92093-0957, USA.
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Abstract
Olfactory receptors, in addition to being involved in first step of the physiological processes that leads to olfaction, occupy an important place in mammalian genomes. ORs constitute super families in these genomes. Elucidating ol-factory receptor function at a molecular level can be aided by a computationally derived structure and an understanding of its interactions with odor molecules. Experimental functional analyses of olfactory receptors in conjunction with computational studies serve to validate findings and generate hypotheses. We present here a review of the research efforts in: creating computational models of olfactory receptors, identifying binding strategies for these receptors with odorant molecules, performing medium to long range simulation studies of odor ligands in the receptor binding region, and identifying amino acid positions within the receptor that are responsible for ligand-binding and olfactory receptor activation. Written as a primer and a teaching tool, this review will help researchers extend the methodologies described herein to other GPCRs.
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Affiliation(s)
- Chiquito J. Crasto
- Department of Genetics, University of Alabama at Birmingham, Birmingham, AL 35294, USA
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Cometto-Muñiz JE, Cain WS, Abraham MH, Gil-Lostes J. Concentration-detection functions for the odor of homologous n-acetate esters. Physiol Behav 2008; 95:658-67. [PMID: 18950650 DOI: 10.1016/j.physbeh.2008.09.021] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2008] [Revised: 09/17/2008] [Accepted: 09/19/2008] [Indexed: 10/21/2022]
Abstract
Using air-dilution olfactometry, we measured concentration-response functions for the odor detection of the homologous esters ethyl, butyl, hexyl, and octyl acetate. Stimuli were delivered by means of an 8-station vapor delivery device (VDD-8) specifically designed to capture odor detection performance by humans under environmentally realistic conditions. Groups of 16-17 (half female) normosmic (i.e., having a normal olfaction) non-smokers (ages 18-38) were tested intensively. The method involved a three-alternative forced-choice procedure against carbon-filtered air, with an ascending concentration approach. Delivered concentrations were confirmed by gas chromatography before and during actual testing. A sigmoid (logistic) model provided an excellent fit to the odor detection functions both at the group and individual levels. Odor detection thresholds (ODTs) (defined as the half-way point between chance and perfect detection) decreased from ethyl (245 ppb by volume), to butyl (4.3 ppb), to hexyl acetate (2.9 ppb), and increased for octyl acetate (20 ppb). Interindividual threshold variability was near one and always below two orders of magnitude. The steepness of the functions increased slightly but significantly with carbon chain length. The outcome showed that the present thresholds lie at the very low end of those previously reported, but share with them a similar relative trend across n-acetates. On this basis, we suggest that a recent quantitative structure-activity relationship (QSAR) for ODTs can be applied to these and additional optimized data, and used to describe and predict not just ODTs but the complete underlying psychometric odor functions.
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Affiliation(s)
- J Enrique Cometto-Muñiz
- Chemosensory Perception Laboratory, Department of Surgery (Otolaryngology), University of California, San Diego, La Jolla, CA 92093-0957, USA.
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Lai PC, Bahl G, Gremigni M, Matarazzo V, Clot-Faybesse O, Ronin C, Crasto CJ. An olfactory receptor pseudogene whose function emerged in humans: a case study in the evolution of structure-function in GPCRs. ACTA ACUST UNITED AC 2008; 9:29-40. [PMID: 18802787 DOI: 10.1007/s10969-008-9043-x] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2007] [Accepted: 08/19/2008] [Indexed: 11/25/2022]
Abstract
Human olfactory receptor, hOR17-210, is identified as a pseudogene in the human genome. Experimental data has shown however, that the gene product of frame-shifted, cloned hOR17-210 cDNA was able to bind an odorant-binding protein and is narrowly tuned for excitation by cyclic ketones. Supported by experimental results, we used the bioinformatics methods of sequence analysis (genome-wide and pair-wise), computational protein modeling and docking, to show that functionality in this receptor is retained due to sequence-structure features not previously observed in mammalian ORs. This receptor does not possess the first two transmembrane helical domains (of seven typically seen in GPCRs). It however, possesses an additional TM that has not been observed in other human olfactory receptors. By incorporating these novel structural features, we created two putative models for this receptor. We also docked odor ligands that were experimentally shown to bind hOR17-210. We show how and why structural modifications of OR17-210 do not hinder this receptor's functionality. Our studies reveal that novel gene rearrangements that result in sequence and structural diversity may have a bearing on OR and GPCR function and evolution.
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Affiliation(s)
- Peter C Lai
- Division of Natural Science, Mathematics, and Computing, Bard College at Simon's Rock, Great Barrington, MA, USA
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