title: Conserved chemosensory proteins in the proboscis and eyes of Lepidoptera.
abstract: Odorant-binding proteins (OBPs) and chemosensory proteins (CSPs) are endowed with several different functions besides being carriers for pheromones and odorants. Based on a previous report of a CSP acting as surfactant in the proboscis of the mothHelicoverpa armigera, we revealed the presence of orthologue proteins in two other mothsPlutella xylostellaandChilo suppressalis, as well as two butterfliesPapilio machaonandPieris rapae, using immunodetection and proteomic analysis. The unusual conservation of these proteins across large phylogenetic distances indicated a common specific function for these CSPs. This fact prompted us to search for other functions of these proteins and discovered that CSPs are abundantly expressed in the eyes ofH. armigeraand possibly involved as carriers for carotenoids and visual pigments. This hypothesis is supported by ligand-binding experiments and docking simulations with retinol and β-carotene. This last orange pigment, occurring in many fruits and vegetables, is an antioxidant and the precursor of visual pigments. We propose that structurally related CSPs solubilise nutritionally important carotenoids in the proboscis, while they act as carriers of both β-carotene and its derived products 3-hydroxyretinol and 3-hydroxyretinal in the eye. The use of soluble olfactory proteins, such as CSPs, as carriers for visual pigments in insects, here reported for the first time, parallels the function of retinol-binding protein in vertebrates, a lipocalin structurally related to vertebrate odorant-binding proteins.
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
authors.forename: Jiao
authors.initials: J
authors.lastname: Zhu
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, P.R. China; Dipartimento di Biologia, Università degli Studi di Firenze, 50019 Sesto Fiorentino (Firenze), Italy.
authors.forename: Immacolata
authors.initials: I
authors.lastname: Iovinella
authors.affiliation: Dipartimento di Biologia, Università degli Studi di Firenze, 50019 Sesto Fiorentino (Firenze), Italy.
authors.forename: Francesca Romana
authors.initials: FR
authors.lastname: Dani
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, P.R. China.
authors.forename: Yu-Ling
authors.initials: YL
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, P.R. China.
authors.forename: Ling-Qiao
authors.initials: LQ
authors.lastname: Huang
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
authors.forename: Yang
authors.initials: Y
authors.lastname: Liu
authors.affiliation: State Key Laboratory of Integrated Management of Pest Insects and Rodents, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, P.R. China.
authors.forename: Chen-Zhu
authors.initials: CZ
authors.lastname: Wang
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
authors.forename: Paolo
authors.initials: P
authors.lastname: Pelosi
authors.affiliation: State Key Laboratory for Biology of Plant Diseases and Insect Pests, Institute of Plant Protection, Chinese Academy of Agricultural Sciences, Beijing 100193, China.
authors.forename: Guirong
authors.initials: G
authors.lastname: Wang
mesh_terms: D000818:Animals; D005123:Eye / Q000378:metabolism*; D019476:Insect Proteins / Q000378:metabolism*; D009036:Moths / Q000378:metabolism*; D040901:Proteomics; D018035:Receptors, Odorant / Q000378:metabolism
chemical_list: D019476:Insect Proteins; D018035:Receptors, Odorant; C045648:odorant-binding protein
keywords: Chemosensory protein; Lepidoptera; Odorant-binding protein; Proboscis; Proteomics; Vision.