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Zhang H, Wang JY, Wan NF, Chen YJ, Ji XY, Jiang JX. Identification and expression profile of odorant-binding proteins in the parasitic wasp Microplitis pallidipes using PacBio long-read sequencing. Parasite 2022; 29:53. [PMID: 36350195 PMCID: PMC9645227 DOI: 10.1051/parasite/2022053] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2022] [Accepted: 10/21/2022] [Indexed: 11/11/2022] Open
Abstract
Microplitis pallidipes Szépligeti (Hymenoptera: Braconidae) is an important parasitic wasp of second and third-instar noctuid larvae such as the insect pests Spodoptera exigua, Spodoptera litura, and Spodoptera frugiperda. As in other insects, M. pallidipes has a chemosensory recognition system that is critical to foraging, mating, oviposition, and other behaviors. Odorant-binding proteins (OBPs) are important to the system, but those of M. pallidipes have not been determined. This study used PacBio long-read sequencing to identify 170,980 M. pallidipes unigenes and predicted 129,381 proteins. Following retrieval of possible OBP sequences, we removed those that were redundant or non-full-length and eventually cloned five OBP sequences: MpOBP2, MpOBP3, MpOBP8, MpOBP10, and MpPBP 429, 429, 459, 420, and 429 bp in size, respectively. Each M. pallidipes OBP had six conserved cysteine residues. Phylogenetic analysis revealed that the five OBPs were located at different branches of the phylogenetic tree. Additionally, tissue expression profiles indicated that MpOBP2 and MpPBP were mainly expressed in the antennae of male wasps, while MpOBP3, MpOBP8, and MpOBP10 were mainly expressed in the antennae of female wasps. MpOBP3 was also highly expressed in the legs of female wasps. Temporal profiles revealed that the expression of each M. pallidipes OBP peaked at different days after emergence to adulthood. In conclusion, we identified five novel odorant-binding proteins of M. pallidipes and demonstrated biologically relevant differences in expression patterns.
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Affiliation(s)
- Hao Zhang
- Eco-environmental Protection Institute, Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Engineering Research Centre of Low-Carbon Agriculture Shanghai 201403 China
| | - Jin-Yan Wang
- Eco-environmental Protection Institute, Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Engineering Research Centre of Low-Carbon Agriculture Shanghai 201403 China
| | - Nian-Feng Wan
- Shanghai Key Laboratory of Chemical Biology, School of Pharmacy, East China University of Science and Technology Shanghai 200237 China
| | - Yi-Juan Chen
- Eco-environmental Protection Institute, Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Engineering Research Centre of Low-Carbon Agriculture Shanghai 201403 China
| | - Xiang-Yun Ji
- Eco-environmental Protection Institute, Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Engineering Research Centre of Low-Carbon Agriculture Shanghai 201403 China
- Corresponding authors: ;
| | - Jie-Xian Jiang
- Eco-environmental Protection Institute, Shanghai Academy of Agricultural Sciences, Shanghai Key Laboratory of Protected Horticultural Technology, Shanghai Engineering Research Centre of Low-Carbon Agriculture Shanghai 201403 China
- Corresponding authors: ;
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Coatsworth H, Caicedo PA, Winsor G, Brinkman F, Ocampo CB, Lowenberger C. Transcriptome comparison of dengue-susceptible and -resistant field derived strains of Colombian Aedes aegypti using RNA-sequencing. Mem Inst Oswaldo Cruz 2021; 116:e200547. [PMID: 34076041 PMCID: PMC8186470 DOI: 10.1590/0074-02760200547] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2020] [Accepted: 04/28/2021] [Indexed: 11/30/2022] Open
Abstract
BACKGROUND Forty percent of the world’s population live in areas where they are at risk from dengue fever, dengue hemorrhagic fever, and dengue shock syndrome. Dengue viruses are transmitted primarily by the mosquito Aedes aegypti. In Cali, Colombia, approximately 30% of field collected Ae. aegypti are naturally refractory to all four dengue serotypes. OBJECTIVES Use RNA-sequencing to identify those genes that determine refractoriness in feral mosquitoes to dengue. This information can be used in gene editing strategies to reduce dengue transmission. METHODS We employed a full factorial design, analyzing differential gene expression across time (24, 36 and 48 h post bloodmeal), feeding treatment (blood or blood + dengue-2) and strain (susceptible or refractory). Sequences were aligned to the reference Ae. aegypti genome for identification, assembled to visualize transcript structure, and analyzed for dynamic gene expression changes. A variety of clustering techniques was used to identify the differentially expressed genes. FINDINGS We identified a subset of genes that likely assist dengue entry and replication in susceptible mosquitoes and contribute to vector competence. MAIN CONCLUSIONS The differential expression of specific genes by refractory and susceptible mosquitoes could determine the phenotype, and may be used to in gene editing strategies to reduce dengue transmission.
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Affiliation(s)
- Heather Coatsworth
- Simon Fraser University, Department of Biological Sciences, C2D2 Research Group, Burnaby, BC, Canada
| | - Paola A Caicedo
- Universidad Icesi, Natural Science Faculty, Centro Internacional de Entrenamiento e Investigaciones Médicas, Department of Biology, Vector Biology and Control, Cali, Colombia
| | - Geoffrey Winsor
- Simon Fraser University, Department of Molecular Biology and Biochemistry, Burnaby, BC, Canada
| | - Fiona Brinkman
- Simon Fraser University, Department of Molecular Biology and Biochemistry, Burnaby, BC, Canada
| | - Clara B Ocampo
- Universidad Icesi, Natural Science Faculty, Centro Internacional de Entrenamiento e Investigaciones Médicas, Department of Biology, Vector Biology and Control, Cali, Colombia
| | - Carl Lowenberger
- Simon Fraser University, Department of Biological Sciences, C2D2 Research Group, Burnaby, BC, Canada
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The 40-Year Mystery of Insect Odorant-Binding Proteins. Biomolecules 2021; 11:biom11040509. [PMID: 33808208 PMCID: PMC8067015 DOI: 10.3390/biom11040509] [Citation(s) in RCA: 84] [Impact Index Per Article: 28.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2021] [Revised: 03/17/2021] [Accepted: 03/19/2021] [Indexed: 12/26/2022] Open
Abstract
The survival of insects depends on their ability to detect molecules present in their environment. Odorant-binding proteins (OBPs) form a family of proteins involved in chemoreception. While OBPs were initially found in olfactory appendages, recently these proteins were discovered in other chemosensory and non-chemosensory organs. OBPs can bind, solubilize and transport hydrophobic stimuli to chemoreceptors across the aqueous sensilla lymph. In addition to this broadly accepted "transporter role", OBPs can also buffer sudden changes in odorant levels and are involved in hygro-reception. The physiological roles of OBPs expressed in other body tissues, such as mouthparts, pheromone glands, reproductive organs, digestive tract and venom glands, remain to be investigated. This review provides an updated panorama on the varied structural aspects, binding properties, tissue expression and functional roles of insect OBPs.
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Abstract
The term ‘odorant-binding proteins (Obps)’ is used to refer to a large family of insect proteins that are exceptional in their number, abundance and diversity. The name derives from the expression of many family members in the olfactory system of insects and their ability to bind odorants in vitro. However, an increasing body of evidence reveals a much broader role for this family of proteins. Recent results also provoke interesting questions about their mechanisms of action, both within and outside the olfactory system. Here we describe the identification of the first Obps and some cardinal properties of these proteins. We then consider their function, discussing both the prevailing orthodoxy and the increasing grounds for heterodox views. We then examine these proteins from a broader perspective and consider some intriguing questions in need of answers.
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Affiliation(s)
- Jennifer S Sun
- Department of Molecular, Cellular and Developmental Biology, Yale University , New Haven, CT 06520 , USA
| | - Shuke Xiao
- Department of Molecular, Cellular and Developmental Biology, Yale University , New Haven, CT 06520 , USA
| | - John R Carlson
- Department of Molecular, Cellular and Developmental Biology, Yale University , New Haven, CT 06520 , USA
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Bruno D, Grossi G, Salvia R, Scala A, Farina D, Grimaldi A, Zhou JJ, Bufo SA, Vogel H, Grosse-Wilde E, Hansson BS, Falabella P. Sensilla Morphology and Complex Expression Pattern of Odorant Binding Proteins in the Vetch Aphid Megoura viciae (Hemiptera: Aphididae). Front Physiol 2018; 9:777. [PMID: 29988577 PMCID: PMC6027062 DOI: 10.3389/fphys.2018.00777] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 06/04/2018] [Indexed: 12/02/2022] Open
Abstract
Chemoreception in insects is mediated by several components interacting at different levels and including odorant-binding proteins (OBPs). Although recent studies demonstrate that the function of OBPs cannot be restricted to an exclusively olfactory role, and that OBPs have been found also in organs generally not related to chemoreception, their feature of binding molecules remains undisputed. Studying the vetch aphid Megoura viciae (Buckton), we used a transcriptomic approach to identify ten OBPs in the antennae and we examined the ultrastructural morphology of sensilla and their distribution on the antennae, legs, mouthparts and cauda of wingless and winged adults by scanning electron microscopy (SEM). Three types of sensilla, trichoid, coeloconic and placoid, differently localized and distributed on antennae, mouthparts, legs and cauda, were described. The expression analysis of the ten OBPs was performed by RT-qPCR in the antennae and other body parts of the wingless adults and at different developmental stages and morphs. Five of the ten OBPs (MvicOBP1, MvicOBP3, MvicOBP6, MvicOBP7, and MvicOBP8), whose antibodies were already available, were selected for experiments of whole-mount immunolocalization on antennae, mouthparts, cornicles and cauda of adult aphids. Most of the ten OBPs were more expressed in antennae than in other body parts; MvicOBP1, MvicOBP3, MvicOBP6, MvicOBP7 were also immunolocalized in the sensilla on the antennae, suggesting a possible involvement of these proteins in chemoreception. MvicOBP6, MvicOBP7, MvicOBP8, MvicOBP9 were highly expressed in the heads and three of them (MvicOBP6, MvicOBP7, MvicOBP8) were immunolocalized in the sensilla on the mouthparts, supporting the hypothesis that also mouthparts may be involved in chemoreception. MvicOBP2, MvicOBP3, MvicOBP5, MvicOBP8 were highly expressed in the cornicles-cauda and two of them (MvicOBP3, MvicOBP8) were immunolocalized in cornicles and in cauda, suggesting a possible new function not related to chemoreception. Moreover, the response of M. viciae to different components of the alarm pheromone was assessed by behavioral assays on wingless adult morph; (-)-α-pinene and (+)-limonene were found to be the components mainly eliciting an alarm response. Taken together, our results represent a road map for subsequent in-depth analyses of the OBPs involved in several physiological functions in M. viciae, including chemoreception.
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Affiliation(s)
- Daniele Bruno
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Gerarda Grossi
- Department of Sciences, University of Basilicata, Potenza, Italy
| | - Rosanna Salvia
- Department of Sciences, University of Basilicata, Potenza, Italy
| | - Andrea Scala
- Department of Sciences, University of Basilicata, Potenza, Italy
| | - Donatella Farina
- Department of Sciences, University of Basilicata, Potenza, Italy
| | - Annalisa Grimaldi
- Department of Biotechnology and Life Sciences, University of Insubria, Varese, Italy
| | - Jing-Jiang Zhou
- Department of Biological Chemistry and Crop Protection, Rothamsted Research, Harpenden, United Kingdom
| | - Sabino A. Bufo
- Department of Sciences, University of Basilicata, Potenza, Italy
| | - Heiko Vogel
- Department of Entomology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Ewald Grosse-Wilde
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
| | - Bill S. Hansson
- Department of Evolutionary Neuroethology, Max Planck Institute for Chemical Ecology, Jena, Germany
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Brito NF, Moreira MF, Melo ACA. A look inside odorant-binding proteins in insect chemoreception. JOURNAL OF INSECT PHYSIOLOGY 2016; 95:51-65. [PMID: 27639942 DOI: 10.1016/j.jinsphys.2016.09.008] [Citation(s) in RCA: 190] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/13/2016] [Revised: 09/13/2016] [Accepted: 09/14/2016] [Indexed: 05/14/2023]
Abstract
Detection of chemical signals from the environment through olfaction is an indispensable mechanism for maintaining an insect's life, evoking critical behavioral responses. Among several proteins involved in the olfactory perception process, the odorant binding protein (OBP) has been shown to be essential for a normally functioning olfactory system. This paper discusses the role of OBPs in insect chemoreception. Here, structural aspects, mechanisms of action and binding affinity of such proteins are reviewed, as well as their promising application as molecular targets for the development of new strategies for insect population management and other technological purposes.
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Affiliation(s)
- Nathália F Brito
- Universidade Federal do Rio de Janeiro, Instituto de Química, 21941-909 Rio de Janeiro, RJ, Brazil
| | - Monica F Moreira
- Universidade Federal do Rio de Janeiro, Instituto de Química, 21941-909 Rio de Janeiro, RJ, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil
| | - Ana C A Melo
- Universidade Federal do Rio de Janeiro, Instituto de Química, 21941-909 Rio de Janeiro, RJ, Brazil; Instituto Nacional de Ciência e Tecnologia em Entomologia Molecular, Rio de Janeiro, Brazil.
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He X, He ZB, Zhang YJ, Zhou Y, Xian PJ, Qiao L, Chen B. Genome-wide identification and characterization of odorant-binding protein (OBP) genes in the malaria vector Anopheles sinensis (Diptera: Culicidae). INSECT SCIENCE 2016; 23:366-376. [PMID: 26970073 DOI: 10.1111/1744-7917.12333] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 03/03/2016] [Indexed: 06/05/2023]
Abstract
Anopheles sinensis is a major malaria vector. Insect odorant-binding proteins (OBPs) may function in the reception of odorants in the olfactory system. The classification and characterization of the An. sinensis OBP genes have not been systematically studied. In this study, 64 putative OBP genes were identified at the whole-genome level of An. sinensis based on the comparison between OBP conserved motifs, PBP_GOBP, and phylogenetic analysis with An. gambiae OBPs. The characterization of An. sinensis OBPs, including the motif's conservation, gene structure, genomic organization and classification, were investigated. A new gene, AsOBP73, belonging to the Plus-C subfamily, was identified with the support of transcript and conservative motifs. These An. sinensis OBP genes were classified into three subfamilies with 37, 15 and 12 genes in the subfamily Classic, Atypical and Plus-C, respectively. The genomic organization of An. sinensis OBPs suggests a clustered distribution across nine different scaffolds. Eight genes (OBP23-28, OBP63-64) might originate from a single gene through a series of historic duplication events at least before divergence of Anopheles, Culex and Aedes. The microsynteny analyses indicate a very high synteny between An. sinensis and An. gambiae OBPs. OBP70 and OBP71 earlier classified under Plus-C in An. gambiae are recognized as belonging to the group Obp59a of the Classic subfamily, and OBP69 earlier classified under Plus-C has been moved to the Atypical subfamily in this study. The study established a basic information frame for further study of the OBP genes in insects as well as in An. sinensis.
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Affiliation(s)
- Xiu He
- Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China
| | - Zheng-Bo He
- Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China
| | - Yu-Juan Zhang
- Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China
| | - Yong Zhou
- Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China
| | - Peng-Jie Xian
- Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China
| | - Liang Qiao
- Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China
| | - Bin Chen
- Institute of Entomology and Molecular Biology, College of Life Sciences, Chongqing Normal University, Chongqing, 401331, China
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Guidobaldi F, May-Concha IJ, Guerenstein PG. Morphology and physiology of the olfactory system of blood-feeding insects. ACTA ACUST UNITED AC 2014; 108:96-111. [PMID: 24836537 DOI: 10.1016/j.jphysparis.2014.04.006] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Revised: 04/21/2014] [Accepted: 04/29/2014] [Indexed: 01/12/2023]
Abstract
Several blood-feeding (hematophagous) insects are vectors of a number of diseases including dengue, Chagas disease and leishmaniasis which persistently affect public health throughout Latin America. The vectors of those diseases include mosquitoes, triatomine bugs and sandflies. As vector control is an efficient way to prevent these illnesses it is important to understand the sensory biology of those harmful insects. We study the physiology of the olfactory system of those insects and apply that knowledge on the development of methods to manipulate their behavior. Here we review some of the latest information on insect olfaction with emphasis on hematophagous insects. The insect olfactory sensory neurons are housed inside hair-like organs called sensilla which are mainly distributed on the antenna and mouthparts. The identity of many of the odor compounds that those neurons detect are already known in hematophagous insects. They include several constituents of host (vertebrate) odor, sex, aggregation and alarm pheromones, and compounds related to egg-deposition behavior. Recent work has contributed significant knowledge on how odor information is processed in the insect first odor-processing center in the brain, the antennal lobe. The quality, quantity, and temporal features of the odor stimuli are encoded by the neural networks of the antennal lobe. Information regarding odor mixtures is also encoded. While natural mixtures evoke strong responses, synthetic mixtures that deviate from their natural counterparts in terms of key constituents or proportions of those constituents evoke weaker responses. The processing of olfactory information is largely unexplored in hematophagous insects. However, many aspects of their olfactory behavior are known. As in other insects, responses to relevant single odor compounds are weak while natural mixtures evoke strong responses. Future challenges include studying how information about odor mixtures is processed in their brain. This could help develop highly attractive synthetic odor blends to lure them into traps.
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Affiliation(s)
- F Guidobaldi
- Laboratorio de Neuroetología Ecológica, CICyTTP-CONICET, Diamante, Entre Ríos, Argentina; Facultad de Ingeniería, UNER, Oro Verde, Entre Ríos, Argentina
| | - I J May-Concha
- Laboratorio de Neuroetología Ecológica, CICyTTP-CONICET, Diamante, Entre Ríos, Argentina; Centro Regional de Investigación en Salud Pública (CRISP), Instituto Nacional de Salud Pública (INSP), Tapachula, Chiapas, Mexico.
| | - P G Guerenstein
- Laboratorio de Neuroetología Ecológica, CICyTTP-CONICET, Diamante, Entre Ríos, Argentina; Facultad de Ingeniería, UNER, Oro Verde, Entre Ríos, Argentina
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9
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Sim S, Ramirez JL, Dimopoulos G. Dengue virus infection of the Aedes aegypti salivary gland and chemosensory apparatus induces genes that modulate infection and blood-feeding behavior. PLoS Pathog 2012; 8:e1002631. [PMID: 22479185 PMCID: PMC3315490 DOI: 10.1371/journal.ppat.1002631] [Citation(s) in RCA: 159] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2012] [Accepted: 02/22/2012] [Indexed: 11/18/2022] Open
Abstract
The female Aedes aegypti salivary gland plays a pivotal role in bloodmeal acquisition and reproduction, and thereby dengue virus (DENV) transmission. It produces numerous immune factors, as well as immune-modulatory, vasodilatory, and anti-coagulant molecules that facilitate blood-feeding. To assess the impact of DENV infection on salivary gland physiology and function, we performed a comparative genome-wide microarray analysis of the naïve and DENV infection-responsive A. aegypti salivary gland transcriptomes. DENV infection resulted in the regulation of 147 transcripts that represented a variety of functional classes, including several that are essential for virus transmission, such as immunity, blood-feeding, and host-seeking. RNAi-mediated gene silencing of three DENV infection-responsive genes--a cathepsin B, a putative cystatin, and a hypothetical ankyrin repeat-containing protein--significantly modulated DENV replication in the salivary gland. Furthermore, silencing of two DENV infection-responsive odorant-binding protein genes (OBPs) resulted in an overall compromise in blood acquisition from a single host by increasing the time for initiation of probing and the probing time before a successful bloodmeal. We also show that DENV established an extensive infection in the mosquito's main olfactory organs, the antennae, which resulted in changes of the transcript abundance of key host-seeking genes. DENV infection, however, did not significantly impact probing initiation or probing times in our laboratory infection system. Here we show for the first time that the mosquito salivary gland mounts responses to suppress DENV which, in turn, modulates the expression of chemosensory-related genes that regulate feeding behavior. These reciprocal interactions may have the potential to affect DENV transmission between humans.
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Affiliation(s)
- Shuzhen Sim
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - José L. Ramirez
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
| | - George Dimopoulos
- W. Harry Feinstone Department of Molecular Microbiology and Immunology, Bloomberg School of Public Health, Johns Hopkins University, Baltimore, Maryland, United States of America
- * E-mail:
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Yang G, Winberg G, Ren H, Zhang S. Expression, purification and functional analysis of an odorant binding protein AaegOBP22 from Aedes aegypti. Protein Expr Purif 2010; 75:165-71. [PMID: 20828619 DOI: 10.1016/j.pep.2010.09.004] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2010] [Revised: 09/02/2010] [Accepted: 09/02/2010] [Indexed: 01/07/2023]
Abstract
Mosquitoes that act as disease vectors rely upon olfactory cues for host-seeking, mating, blood feeding and oviposition. To reduce the risk of infection in humans, one of the approaches focuses on mosquitoes' semiochemical system in the effort to disrupt undesirable host-insect interaction. Odorant binding proteins (OBPs) play a key role in mosquitoes' semiochemical system. Here, we report the successful expression, purification of an odorant binding protein AaegOBP22 from Aedes aegypti in heterologous system. Protein purification methods were set up by Strep-Tactin affinity binding and size-exclusion chromatography. Analysis by SDS-PAGE and mass spectrum revealed the protein's purity and molecular weight. Circular dichroism spectra showed the AaegOBP22 secondary structure had a pH dependent conformational change. The protein functions of AaegOBP22 were tested by fluorescent probe 1-NPN binding assays and ligands competitive binding assays. The results show AaegOBP22 proteins have characteristics of selective binding with various ligands.
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Affiliation(s)
- Gang Yang
- Institute for Nanobiomedical Technology and Membrane Biology, Sichuan University, Keyuan 4 St., Gaopeng Avenue, Chengdu 610041, China.
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