title: Different roles suggested by sex-biased expression and pheromone binding affinity among three pheromone binding proteins in the pink rice borer, Sesamia inferens (Walker) (Lepidoptera: Noctuidae).
abstract: Pheromone binding proteins (PBPs) are thought to bind and transport hydrophobic sex pheromone molecules across the aqueous sensillar lymph to specific pheromone receptors on the dendritic membrane of olfactory neurons. A maximum of 3 PBP genes have been consistently identified in noctuid species, and each of them shares high identity with its counterparts in other species within the family. The functionality differences of the 3 proteins are poorly understood. In the present study, 3 PBP cDNAs (SinfPBP1, 2, 3) were identified from the pink rice borer, Sesamia inferens, for the first time. The quantitative real-time PCR indicated that the 3 PBPs displayed similar temporal but very different sex related expression profiles. Expression of SinfPBP1 and SinfPBP2 were highly and moderately male biased, respectively, while SinfPBP3 was slightly female biased, as SinfPBPs were expressed at very different levels (PBP1>PBP2≫PBP3) in male antennae, but at similar levels in female antennae. Furthermore, the 3 SinfPBPs displayed different ligand binding profiles in fluorescence competitive binding assays. SinfPBP1 exhibited high and similar binding affinities to all 3 sex pheromone components (Ki=0.72-1.60 μM), while SinfPBP2 showed selective binding to the alcohol and aldehyde components (Ki=0.78-1.71 μM), and SinfPBP3 showed no obvious binding to the 3 sex pheromone components. The results suggest that SinfPBP1 plays a major role in the reception of female sex pheromones in S. inferens, while SinfPBP3 plays a least role (if any) and SinfPBP2 functions as a recognizer of alcohol and aldehyde components.
authors.affiliation: Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China; Suqian Entry-exit Inspection and Quarantine Bureau, Suqian, Jiangsu, China.
authors.forename: Jun-Yan
authors.initials: JY
authors.lastname: Jin
authors.affiliation: Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Zhao-Qun
authors.initials: ZQ
authors.lastname: Li
authors.affiliation: Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Ya-Nan
authors.initials: YN
authors.lastname: Zhang
authors.affiliation: Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China.
authors.forename: Nai-Yong
authors.initials: NY
authors.lastname: Liu
authors.affiliation: Education Ministry Key Laboratory of Integrated Management of Crop Diseases and Pests, College of Plant Protection, Nanjing Agricultural University, Nanjing 210095, China. Electronic address: sldong@njau.edu.cn.
authors.forename: Shuang-Lin
authors.initials: SL
authors.lastname: Dong
mesh_terms: D000375:Aging; D000595:Amino Acid Sequence; D000818:Animals; D002352:Carrier Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D018076:DNA, Complementary / Q000235:genetics / Q000378:metabolism; D005260:Female; D019476:Insect Proteins / Q000737:chemistry / Q000235:genetics* / Q000378:metabolism; D008297:Male; D008969:Molecular Sequence Data; D009036:Moths / Q000235:genetics* / Q000378:metabolism; D009928:Organ Specificity; D010802:Phylogeny; D060888:Real-Time Polymerase Chain Reaction; D016415:Sequence Alignment; D012724:Sex Attractants / Q000235:genetics* / Q000378:metabolism
chemical_list: D002352:Carrier Proteins; D018076:DNA, Complementary; D019476:Insect Proteins; D012724:Sex Attractants; C403713:pheromone binding protein, insect
keywords: Female sex pheromone; Functional differentiation; Ligand binding; Male biased expression; Pheromone binding protein