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Aminopeptidase N insect

Leivi Portugal, Carlos Muñóz-Garay, Diana L Martínez de Castro, Mario Soberón, Alejandra Bravo
Bacillus thuringiensis (Bt) bacteria produce Cry toxins that are able to kill insect pests. Different models explaining the mode of action of these toxins have been proposed. The pore formation model proposes that the toxin creates pores in the membrane of the larval midgut cells after interaction with different receptors such as cadherin, aminopeptidase N and alkaline phosphatase and that this pore formation activity is responsible for the toxicity of these proteins. The alternative model proposes that interaction with cadherin receptor triggers an intracellular cascade response involving protein G, adenylate cyclase (AC) and protein kinase A (PKA)...
January 2017: Insect Biochemistry and Molecular Biology
X Y Wang, L X Du, C X Liu, L Gong, L Z Han, Y F Peng
The striped stem borer, Chilo suppressalis, is a major target pest of transgenic rice expressing the Cry1Ab protein from the bacterium Bacillus thuringiensis (Bt) in China. Evolution of resistance in this pest is a major threat to the durability of Bt rice. Since Bt exerts its activity through binding to specific receptors in the midgut of target insects, identification of functional Cry1Ab receptors in the midgut of C. suppressalis larvae is crucial to evaluate potential resistance mechanisms and develop effective strategies for delaying insect resistance...
November 4, 2016: Journal of Invertebrate Pathology
W Wei, G Wei, Z Dan, Y Xiaoping, Z Yakun
Several receptor proteins of Cry toxin have been previously identified, including cadherin-like, aminopeptidase N, and alkaline phosphatase. In the present work, a novel binding protein, V-ATPase subunit A (HpVAA), was identified in Holotricia parallela larvae and characterized. We performed reverse transcription-polymerase chain reaction and rapid amplification of cDNA ends technology to obtain the cDNA of the full-length hpvaa. Sequencing analysis showed that the open reading frame of hpvaa (GenBank accession No...
September 2, 2016: Genetics and Molecular Research: GMR
Mingxing Feng, Zhenyu He, Yuanyuan Wang, Xiufang Yan, Jiwen Zhang, Zhaonong Hu, Wenjun Wu
Periplocosides, which are insecticidal compounds isolated from the root bark of Periploca sepium Bunge, can affect the digestive system of insects. However, the mechanism though which periplocosides induces a series of symptoms remains unknown. In this study, affinity chromatography was conducted by coupling periplocoside E-semi-succinic acid ester with epoxy amino hexyl (EAH) sepharose 4B. Sodium dodecyl sulfonate-polyacrylamide gelelectrophoresis (SDS-PAGE) was performed to analyze the fraction eluted by periplocoside E...
2016: Toxins
Vijaya Sudhakara Rao Kola, P Renuka, Ayyagari Phani Padmakumari, Satendra K Mangrauthia, Sena M Balachandran, V Ravindra Babu, Maganti S Madhav
RNAi is a powerful tool to target the insect genes involved in host-pest interactions. Key insect genes are the choice for silencing to achieve pest derived resistance where resistance genes are not available in gene pool of host plant. In this study, an attempt was made to determine the effect of dsRNA designed from two genes Cytochrome P450 derivative (CYP6) and Aminopeptidase N (APN) of rice yellow stem borer (YSB) on growth and development of insect. The bioassays involved injection of chemically synthesized 5' FAM labeled 21-nt dsRNA into rice cut stems and allowing the larvae to feed on these stems which resulted in increased mortality and observed growth and development changes in larval length and weight compared with its untreated control at 12-15 days after treatment...
2016: Frontiers in Physiology
Aftab Ahmad, Muhammad R Javed, Abdul Q Rao, Muhammad A U Khan, Ammara Ahad, Salah Ud Din, Ahmad A Shahid, Tayyab Husnain
Study and research of Bt (Bacillus thuringiensis) transgenic plants have opened new ways to combat insect pests. Over the decades, however, insect pests, especially the Lepidopteran, have developed tolerance against Bt delta-endotoxins. Such issues can be addressed through the development of novel toxins with greater toxicity and affinity against a broad range of insect receptors. In this computational study, functional domains of Bacillus thuringiensis crystal delta-endotoxin (Cry1Ac) insecticidal protein and vegetative insecticidal protein (Vip3Aa) have been fused to develop a broad-range Vip3Aa-Cry1Ac fusion protein...
2015: Frontiers in Plant Science
Michi Izumi Willcoxon, Jaclyn R Dennis, Sabina I Lau, Weiping Xie, You You, Song Leng, Ryan C Fong, Takashi Yamamoto
A high-throughput, in-vitro assay for Bacillus thuringiensis (Bt) insecticidal proteins designated as Cry was developed and evaluated for screening a large number of Cry protein variants produced by DNA shuffling. This automation-amenable assay exploits an insect cell line expressing a single receptor of Bt Cry proteins. The Cry toxin used to develop this assay is a variant of the Cry1Ab protein called IP1-88, which was produced previously by DNA shuffling. Cell mortality caused by the activated Bt Cry toxin was determined by chemical cell viability assay in 96/384-well microtiter plates utilizing CellTiter 96(®) obtained from Promega...
January 10, 2016: Journal of Biotechnology
Li-Na Xu, Ying-Hui Ling, Yue-Qin Wang, Zhen-Ying Wang, Ben-Jin Hu, Zi-Yan Zhou, Fei Hu, Kang-Lai He
The Asian corn borer (ACB), Ostrinia furnacalis (Guenée), can develop strong resistance to Cry1Ab, the most widely commercialized Cry toxin for Bt maize worldwide. It is essential to understand the mechanism of resistance for management of this species, but information on the post-transcriptional regulation of Bt resistance in this target insect is limited. In the present study, RNA was extracted from the ACB in various larval stages (1-5 instar) from Cry1Ab-sensitive (ACB-BtS) and -resistant (ACB-AbR) strains, each of which included two biological replicates...
2015: Scientific Reports
Shu-Lun Tang, Lucas B Linz, Bryony C Bonning, Nicola L B Pohl
Pea enation mosaic virus (PEMV)--a plant RNA virus transmitted exclusively by aphids--causes disease in multiple food crops. However, the aphid-virus interactions required for disease transmission are poorly understood. For virus transmission, PEMV binds to a heavily glycosylated receptor aminopeptidase N in the pea aphid gut and is transcytosed across the gut epithelium into the aphid body cavity prior to release in saliva as the aphid feeds. To investigate the role of glycans in PEMV-aphid interactions and explore the possibility of viral control through blocking a glycan interaction, we synthesized insect N-glycan terminal trimannosides by automated solution-phase synthesis...
November 6, 2015: Journal of Organic Chemistry
Lucas B Linz, Sijun Liu, Nanasaheb P Chougule, Bryony C Bonning
UNLABELLED: Insect-borne plant viruses cause significant agricultural losses and jeopardize sustainable global food production. Although blocking plant virus transmission would allow for crop protection, virus receptors in insect vectors are unknown. Here we identify membrane alanyl aminopeptidase N (APN) as a receptor for pea enation mosaic virus (PEMV) coat protein (CP) in the gut of the pea aphid, Acyrthosiphon pisum, using a far-Western blot method. Pulldown and immunofluorescence binding assays and surface plasmon resonance were used to confirm and characterize CP-APN interaction...
November 2015: Journal of Virology
Anastasia Mpakali, Emmanuel Saridakis, Karl Harlos, Yuguang Zhao, Athanasios Papakyriakou, Paraskevi Kokkala, Dimitris Georgiadis, Efstratios Stratikos
Aminopeptidases that generate antigenic peptides influence immunodominance and adaptive cytotoxic immune responses. The mechanisms that allow these enzymes to efficiently process a vast number of different long peptide substrates are poorly understood. In this work, we report the structure of insulin-regulated aminopeptidase, an enzyme that prepares antigenic epitopes for cross-presentation in dendritic cells, in complex with an antigenic peptide precursor analog. Insulin-regulated aminopeptidase is found in a semiclosed conformation with an extended internal cavity with limited access to the solvent...
September 15, 2015: Journal of Immunology: Official Journal of the American Association of Immunologists
Makoto Hattori, Setsuko Komatsu, Hiroaki Noda, Yukiko Matsumoto
The green rice leafhopper, Nephotettix cincticeps, is a vascular bundle feeder that discharges watery and gelling saliva during the feeding process. To understand the potential functions of saliva for successful and safe feeding on host plants, we analyzed the complexity of proteinaceous components in the watery saliva of N. cincticeps. Salivary proteins were collected from a sucrose diet that adult leafhoppers had fed on through a membrane of stretched parafilm. Protein concentrates were separated using SDS-PAGE under reducing and non-reducing conditions...
2015: PloS One
Li-Na Xu, Yue-Qin Wang, Zhen-Ying Wang, Ben-Jin Hu, Ying-Hui Ling, Kang-Lai He
BACKGROUND: Asian corn borer (ACB), Ostrinia furnacalis (Guenée), is the major insect pest of maize in China and countries of East and Southeast Asia, the Pacific and Australasia. ACB can develop strong resistance to the transgenic Bt maize expressing Cry1Ab, the most widely commercialized Bt maize worldwide. However, the molecular basis for the resistance mechanisms of ACB to Cry1Ab remained unclear. Two biological replicates of the transcriptome of Bt susceptible (ACB-BtS) and Cry1Ab resistant (ACB-AbR) strains of ACB were sequenced using Solexa/Illumina RNA-Seq technology to identify Cry1Ab resistance-relevant genes...
2015: BMC Genomics
Wenbo Chen, Chenxi Liu, Yutao Xiao, Dandan Zhang, Yongdong Zhang, Xianchun Li, Bruce E Tabashnik, Kongming Wu
Evolution of resistance by insects threatens the continued success of pest control using insecticidal crystal (Cry) proteins from the bacterium Bacillus thuringiensis (Bt) in sprays and transgenic plants. In this study, laboratory selection with Cry1Ac yielded five strains of cotton bollworm, Helicoverpa armigera, with resistance ratios at the median lethal concentration (LC50) of activated Cry1Ac ranging from 22 to 1700. Reduced activity and reduced transcription of an alkaline phosphatase protein that binds Cry1Ac was associated with resistance to Cry1Ac in the four most resistant strains...
2015: PloS One
Aratee Aroonkesorn, Kusol Pootanakit, Gerd Katzenmeier, Chanan Angsuthanasombat
The interaction between Bacillus thuringiensis Cry toxins and their receptors on midgut cells of susceptible insect larvae is the critical determinant in toxin specificity. Besides GPI-linked alkaline phosphatase in Aedes aegypti mosquito-larval midguts, membrane-bound aminopeptidase N (AaeAPN) is widely thought to serve as a Cry4Ba receptor. Here, two full-length AaeAPN isoforms, AaeAPN2778 and AaeAPN2783, predicted to be GPI-linked were cloned and successfully expressed in Spodoptera frugiperda (Sf9) cells as 112- and 107-kDa membrane-bound proteins, respectively...
May 29, 2015: Biochemical and Biophysical Research Communications
Umut Toprak, Martin Erlandson, Doug Baldwin, Steve Karcz, Lianglu Wan, Cathy Coutu, Cedric Gillott, Dwayne D Hegedus
The peritrophic matrix (PM) is essential for insect digestive system physiology as it protects the midgut epithelium from damage by food particles, pathogens, and toxins. The PM is also an attractive target for development of new pest control strategies due to its per os accessibility. To understand how the PM performs these functions, the molecular architecture of the PM was examined using genomic and proteomic approaches in Mamestra configurata (Lepidoptera: Noctuidae), a major pest of cruciferous oilseed crops in North America...
October 2016: Insect Science
Li-Na Xu, Yue-Qin Wang, Zhen-Ying Wang, Ben-Jin Hu, Ying-Hui Ling, Kang-Lai He
BACKGROUND: Asian corn borer (ACB), Ostrinia furnacalis (Guenée), is the major insect pest of maize in China and countries of East and Southeast Asia, the Pacific and Australasia. ACB can develop strong resistance to the transgenic Bt maize expressing Cry1Ab, the most widely commercialized Bt maize worldwide. However, the molecular basis for the resistance mechanisms of ACB to Cry1Ab remained unclear. Two biological replicates of the transcriptome of Bt susceptible (ACB-BtS) and Cry1Ab resistant (ACB-AbR) strains of ACB were sequenced using Solexa/Illumina RNA-Seq technology to identify Cry1Ab resistance-relevant genes...
December 2015: BMC Genomics
Lin Qiu, Leilei Hou, Boyao Zhang, Lang Liu, Bo Li, Pan Deng, Weihua Ma, Xiaoping Wang, Jeffrey A Fabrick, Lizhen Chen, Chaoliang Lei
Bacillus thuringiensis (Bt) insecticidal crystal (Cry) proteins are effective against some insect pests in sprays and transgenic crops, although the evolution of resistance could threaten the long-term efficacy of such Bt use. One strategy to delay resistance to Bt crops is to "pyramid" two or more Bt proteins that bind to distinct receptor proteins within the insect midgut. The most common Bt pyramid in cotton (Gossypium hirsutum L.) employs Cry1Ac with Cry2Ab to target several key lepidopteran pests, including the beet armyworm, Spodoptera exigua (Hübner), which is a serious migratory pest of many vegetable crops and is increasingly important in cotton in China...
May 2015: Journal of Invertebrate Pathology
Fernando Campos de Assis Fonseca, Alexandre Augusto Pereira Firmino, Leonardo Lima Pepino de Macedo, Roberta Ramos Coelho, José Dijair Antonino de Souza Júnior, José Dijair Antonino de Sousa Júnior, Orzenil Bonfim Silva-Junior, Roberto Coiti Togawa, Georgios Joannis Pappas, Luiz Avelar Brandão de Góis, Maria Cristina Mattar da Silva, Maria Fátima Grossi-de-Sá
Sugarcane is a widely cultivated plant that serves primarily as a source of sugar and ethanol. Its annual yield can be significantly reduced by the action of several insect pests including the sugarcane giant borer (Telchin licus licus), a lepidopteran that presents a long life cycle and which efforts to control it using pesticides have been inefficient. Although its economical relevance, only a few DNA sequences are available for this species in the GenBank. Pyrosequencing technology was used to investigate the transcriptome of several developmental stages of the insect...
2015: PloS One
Isabel Gómez, Biviana Flores, Alejandra Bravo, Mario Soberón
To exert their toxic effect, Bacillus thuringiensis Cry1Ab toxin undergoes a sequential binding mechanism with different larval gut proteins including glycosyl-phosphatidyl-inositol anchored proteins like aminopeptidase-N (APN) or alkaline-phosphatase (ALP) and a transmembrane cadherin to form pre-pore structures that insert into the membrane. Cadherin binding induces oligomerization of the toxin by facilitating removal of the N-terminal region, while APN/ALP binding helps in oligomer membrane insertion. Cry1AbMod toxin was engineered to lack N-terminal region of the toxin and shown to counter resistance linked to cadherin mutations...
June 2015: Peptides
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