PLoS Pathogens最新文献

{"title":"Skin as outermost immune organ of vertebrates that elicits robust early immune responses after immunization with glycoprotein of spring viraemia of carp virus.","authors":"Zhao Zhao, Liang Zhao, Xue-Feng Wei, Yi-Jun Jia, Bin Zhu","doi":"10.1371/journal.ppat.1012744","DOIUrl":"10.1371/journal.ppat.1012744","url":null,"abstract":"<p><p>As the outermost immune organ in vertebrates, the skin serves as the primary interface with the external environment and plays a crucial role in initiating the early immune response. The skin contains a variety of immune cells that induce mucosal and systemic immune responses, rendering it a prime target for vaccination strategies. Insight into the mechanisms through which vaccination triggers early immune responses is paramount for advancing animal and human health, yet our current understanding remains limited. Given its significance in vertebrate evolution, teleost fish emerges as an excellent model for investigating the early immune response of skin. In this study, we demonstrate that significant quantities of vaccine can be absorbed by the skin and transported to the body through dermis and muscle metabolism by immerses immune zebrafish with glycoprotein of spring viraemia of carp virus. Immersion immunization can elicit robust and enduring immune protection, with the skin triggering a potent immune response early in the immunization process. Analysis of the skin transcriptome revealed the involvement of numerous immune-related genes in the immersion immune response, with indications that HSP70 and MAPK signals might play pivotal roles in the immune process induced by glycoprotein. Co-immunoprecipitation and cell co-localization studies confirmed the interaction between glycoprotein and HSP70. Subsequent research demonstrated that overexpression or inhibition of HSP70 could respectively enhance or impede the expression of JNK and related proteins. However, the survival rate and immune response of HSP70 inhibited zebrafish with glycoprotein treatment were significantly reduced. These findings propose that the interaction between glycoprotein and HSP70 may activate JNK, thereby modulating mucosal and systemic immune responses induced by glycoprotein. This investigation offers novel insights and a foundational understanding of early skin immune reactions.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"20 12","pages":"e1012744"},"PeriodicalIF":5.5,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11627376/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802862","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Structural characterization of the full-length Hantaan virus polymerase.","authors":"Jeremy R Keown, Loïc Carrique, Benjamin E Nilsson-Payant, Ervin Fodor, Jonathan M Grimes","doi":"10.1371/journal.ppat.1012781","DOIUrl":"10.1371/journal.ppat.1012781","url":null,"abstract":"<p><p>Hantaviridae are a family of segmented negative-sense RNA viruses that contain important human and animal pathogens. Hantaviridae contain a viral RNA-dependent RNA polymerase that replicates and transcribes the viral genome. Here we establish the expression and purification of the polymerase from the Old World Hantaan virus and characterise the structure using Cryo-EM. We determine a series of structures at resolutions between 2.7 and 3.3 Å of RNA free polymerase comprising the core, core and endonuclease, and a full-length polymerase. The full-length polymerase structure depicts the location of the cap binding and C-terminal domains which are arranged in a conformation that is incompatible with transcription and in a novel conformation not observed in previous conformations of cap-snatching viral polymerases. We further describe structures with 5' vRNA promoter in the presence and absence of a nucleotide triphosphate. The nucleotide bound structure mimics a replication pre-initiation complex and the nucleotide stabilises the motif E in a conformation distinct from those previously observed. We observe motif E in four distinct conformations including β-sheet, two helical arrangements, and nucleotide primed arrangement. The insights gained here guide future mechanistic studies of both the transcription and replication activities of the hantavirus polymerase and for the development of therapeutic targets.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"20 12","pages":"e1012781"},"PeriodicalIF":5.5,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11658695/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802878","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A potent and selective reaction hijacking inhibitor of Plasmodium falciparum tyrosine tRNA synthetase exhibits single dose oral efficacy in vivo.","authors":"Stanley C Xie, Chia-Wei Tai, Craig J Morton, Liting Ma, Shih-Chung Huang, Sergio Wittlin, Yawei Du, Yongbo Hu, Con Dogovski, Mina Salimimarand, Robert Griffin, Dylan England, Elisa de la Cruz, Ioanna Deni, Tomas Yeo, Anna Y Burkhard, Josefine Striepen, Kyra A Schindler, Benigno Crespo, Francisco J Gamo, Yogesh Khandokar, Craig A Hutton, Tayla Rabie, Lyn-Marié Birkholtz, Mufuliat T Famodimu, Michael J Delves, Judith Bolsher, Karin M J Koolen, Rianne van der Laak, Anna C C Aguiar, Dhelio B Pereira, Rafael V C Guido, Darren J Creek, David A Fidock, Lawrence R Dick, Stephen L Brand, Alexandra E Gould, Steven Langston, Michael D W Griffin, Leann Tilley","doi":"10.1371/journal.ppat.1012429","DOIUrl":"10.1371/journal.ppat.1012429","url":null,"abstract":"<p><p>The Plasmodium falciparum cytoplasmic tyrosine tRNA synthetase (PfTyrRS) is an attractive drug target that is susceptible to reaction-hijacking by AMP-mimicking nucleoside sulfamates. We previously identified an exemplar pyrazolopyrimidine ribose sulfamate, ML901, as a potent reaction hijacking inhibitor of PfTyrRS. Here we examined the stage specificity of action of ML901, showing very good activity against the schizont stage, but lower trophozoite stage activity. We explored a series of ML901 analogues and identified ML471, which exhibits improved potency against trophozoites and enhanced selectivity against a human cell line. Additionally, it has no inhibitory activity against human ubiquitin-activating enzyme (UAE) in vitro. ML471 exhibits low nanomolar activity against asexual blood stage P. falciparum and potent activity against liver stage parasites, gametocytes and transmissible gametes. It is fast-acting and exhibits a long in vivo half-life. ML471 is well-tolerated and shows single dose oral efficacy in the SCID mouse model of P. falciparum malaria. We confirm that ML471 is a reaction hijacking inhibitor that is converted into a tight binding Tyr-ML471 conjugate by the PfTyrRS enzyme. A crystal structure of the PfTyrRS/ Tyr-ML471 complex offers insights into improved potency, while molecular docking into UAE provides a rationale for improved selectivity.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"20 12","pages":"e1012429"},"PeriodicalIF":5.5,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11671014/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802850","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"TNF-α exacerbates SARS-CoV-2 infection by stimulating CXCL1 production from macrophages.","authors":"Moe Kobayashi, Nene Kobayashi, Kyoka Deguchi, Seira Omori, Minami Nagai, Ryutaro Fukui, Isaiah Song, Shinji Fukuda, Kensuke Miyake, Takeshi Ichinohe","doi":"10.1371/journal.ppat.1012776","DOIUrl":"10.1371/journal.ppat.1012776","url":null,"abstract":"<p><p>Since most genetically modified mice are C57BL/6 background, a mouse-adapted SARS-CoV-2 that causes lethal infection in young C57BL/6 mice is useful for studying innate immune protection against SARS-CoV-2 infection. Here, we established two mouse-adapted SARS-CoV-2, ancestral and Delta variants, by serial passaging 80 times in C57BL/6 mice. Although young C57BL/6 mice were resistant to infection with the mouse-adapted ancestral SARS-CoV-2, the mouse-adapted SARS-CoV-2 Delta variant caused lethal infection in young C57BL/6 mice. In contrast, MyD88 and IFNAR1 KO mice exhibited resistance to lethal infection with the mouse-adapted SARS-CoV-2 Delta variant. Treatment with recombinant IFN-α/β at the time of infection protected mice from lethal infection with the mouse-adapted SARS-CoV-2 Delta variant, but intranasal administration of recombinant IFN-α/β at 2 days post infection exacerbated the disease severity following the mouse-adapted ancestral SARS-CoV-2 infection. Moreover, we showed that TNF-α amplified by type I IFN signals exacerbated the SARS-CoV-2 infection by stimulating CXCL1 production from macrophages and neutrophil recruitment into the lung tissue. Finally, we showed that intravenous administration to mice or hamsters with TNF protease inhibitor 2 alleviated the severity of SARS-CoV-2 and influenza virus infection. Our results uncover an unexpected mechanism by which type I interferon-mediated TNF-α signaling exacerbates the disease severity and will aid in the development of novel therapeutic strategies to treat respiratory virus infection and associated diseases such as influenza and COVID-19.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"20 12","pages":"e1012776"},"PeriodicalIF":5.5,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11658697/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802894","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Emerging mutation in SARS-CoV-2 facilitates escape from NK cell recognition and associates with enhanced viral fitness.","authors":"Eleni Bilev, Nicole Wild, Pouria Momayyezi, Benedetta Maria Sala, Renhua Sun, Tatyana Sandalova, Nicole Marquardt, Hans-Gustaf Ljunggren, Adnane Achour, Quirin Hammer","doi":"10.1371/journal.ppat.1012755","DOIUrl":"10.1371/journal.ppat.1012755","url":null,"abstract":"<p><p>In addition to adaptive immunity, natural killer (NK) cells of the innate immune system contribute to the control of viral infections. The HLA-E-restricted SARS-CoV-2 Nsp13232-240 epitope VMPLSAPTL renders infected cells susceptible to NK cells by preventing binding to the inhibitory receptor NKG2A. Here, we report that a recently emerged methionine to isoleucine substitution at position 2 (pM2I) of Nsp13232-240 impairs binding of the mutated epitope to HLA-E and diminishes HLA-E/peptide complex stability. Structural analyses revealed altered occupancy of the HLA-E B-pocket as the underlying cause for reduced presentation and stability of the mutated epitope. Functionally, the reduced presentation of the mutated epitope correlated with elevated binding to NKG2A as well as with increased NK cell inhibition. Moreover, the pM2I mutation associated with enhanced estimated viral fitness and was transmitted to descendants of the SARS-CoV-2 BQ.1 variant. Interestingly, the mutated epitope resembles sequences of related peptides found in endemic common cold-causing human coronaviruses. Altogether, these findings indicate compromised peptide presentation as a viral adaptation to evade NK cell-mediated immunosurveillance by enabling enhanced presentation of self-peptide and restoring NKG2A-dependent inhibition of NK cells.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"20 12","pages":"e1012755"},"PeriodicalIF":5.5,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11658698/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802853","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Mosquito-independent milk-associated transmission of zoonotic Wesselsbron virus in sheep.","authors":"Marta Zimoch, Llorenç Grau-Roma, Matthias Liniger, Noelle Donzé, Aurélie Godel, Damián Escribano, Bettina Salome Trüeb, Paraskevi Pramateftaki, Sergi Torres-Puig, José Joaqín Cerón, Volker Thiel, Jörg Jores, Artur Summerfield, Nicolas Ruggli, Charaf Benarafa, Obdulio García-Nicolás","doi":"10.1371/journal.ppat.1012751","DOIUrl":"10.1371/journal.ppat.1012751","url":null,"abstract":"<p><p>Wesselsbron virus (WSLV) is a zoonotic, mosquito-borne orthoflavivirus endemic to sub-Saharan Africa, causing abortions and stillbirths in small ruminants. The life cycle of WSLV involves Aedes mosquitoes and various wildlife and domestic animals. Seminal studies in the 1950s have shown the zoonotic potential of WSLV, notably in accidental infections of laboratory workers exposed to infected material. More recent epidemiological studies suggest the emergence of clade I WSLV strains in peri-domestic and rural areas of western and eastern Africa. The pathobiology of recent clade I WSLV strains is unknown and no virus isolate is available. To address these gaps, we generated a recombinant clade I WSLV SA999 infectious clone (rSA999) by reverse genetics. Subsequently, lactating ewes were inoculated intravenously with the WSLV rSA999 strain or the clade II SAH177 strain in insect-free biocontainment stables. Inoculated ewes developed fever, viremia, and showed high levels of viral RNA at mucosal surfaces, and elevated viral titers in milk. Milk production was reduced, which directly affected the growth of the lambs, particularly within the rSA999 group. The ewes with higher WSLV titers in their milk in each group transmitted the infection to their lambs, which developed fever, prolonged viremia, and virus secretion. All infected animals produced high antibody titers with cross-neutralizing activity against both WSLV strains. Histopathology and blood biochemistry analysis indicated liver damage associated with necrotizing hepatitis lesions and active viral replication in some cases, which was more pronounced in the rSA999 group. Notably, only the SAH177-infected animals exhibited lesions consistent with meningoencephalitis, suggesting that WSLV clade II strains are neurotropic and that clade I strain are more hepatotropic. These findings demonstrate a previously unrecognized mode of vector-free transmission of WSLV that raises significant concerns for public and animal health.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"20 12","pages":"e1012751"},"PeriodicalIF":5.5,"publicationDate":"2024-12-09","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11658706/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142802859","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"SUMO-targeted Ubiquitin Ligases as crucial mediators of protein homeostasis in Candida glabrata.","authors":"Dipika Gupta, Renu Shukla, Krishnaveni Mishra","doi":"10.1371/journal.ppat.1012742","DOIUrl":"10.1371/journal.ppat.1012742","url":null,"abstract":"<p><p>Candida glabrata is an opportunistic human pathogen, capable of causing severe systemic infections that are often resistant to standard antifungal treatments. To understand the importance of protein SUMOylation in the physiology and pathogenesis of C. glabrata, we earlier identified the components of SUMOylation pathway and demonstrated that the deSUMOylase CgUlp2 is essential for pathogenesis. In this work we show that the CgUlp2 is essential to maintain protein homeostasis via the SUMO-targeted ubiquitin ligase pathway. The dual loss of deSUMOylase and specific ubiquitin ligase, CgSlx8, results in heightened protein degradation, rendering the cells vulnerable to various stressors. This degradation affects crucial processes such as purine biosynthesis and compromises mitochondrial function in the mutants. Importantly, the absence of these ubiquitin ligases impedes the proliferation of C. glabrata in macrophages. These findings underscore the significance of SUMOylation and SUMO-mediated protein homeostasis as pivotal regulators of C. glabrata physiology and capacity to survive in host cells. Understanding these mechanisms could pave the way for the development of effective antifungal treatments.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"20 12","pages":"e1012742"},"PeriodicalIF":5.5,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11654969/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789682","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"A-synuclein prion strains differentially adapt after passage in mice.","authors":"Sara A M Holec, Chase R Khedmatgozar, Shelbe J Schure, Tiffany Pham, Amanda L Woerman","doi":"10.1371/journal.ppat.1012746","DOIUrl":"10.1371/journal.ppat.1012746","url":null,"abstract":"<p><p>In patients with synucleinopathies, the protein α-synuclein misfolds into multiple conformations, each of which determines whether a patient develops multiple system atrophy (MSA) or one of three Lewy body diseases (LBDs). However, patients may also first present with pure autonomic failure, which strictly impacts autonomic nerves in the periphery, which can then phenoconvert into MSA or a LBD. When neuroinvasion happens, it remains unknown if strain properties are retained or if strain adaptation occurs, even though neuroinvasion of some prion protein (PrP) strains is known to result in the emergence of novel PrP strain variants. To investigate this question in synucleinopathies, we inoculated TgM83+/- mice, which express human α-synuclein with the A53T mutation, with a mouse-passaged MSA patient sample either intracranially (i.c.) or into the sciatic nerve (sc.n.), and compared the biochemical and biological properties of α-synuclein prions in the brains of terminal mice. Importantly, while i.c. and sc.n. transmission studies generated pathogenic α-synuclein with similar properties, both the primary and secondary passaged MSA samples had different infectivity profiles in a panel of α-syn140-YFP cells than the starting MSA patient sample, indicating that MSA prions adapt during initial passage in TgM83+/- mice. Similarly, using i.c. inoculation of A53T preformed fibrils to study strain selection, we found both biochemical and biological evidence that mouse passage exerts a selective pressure on α-synuclein prions in which a sub-population of starting conformations emerges in terminal animals. Together, these findings demonstrate that similar conformational selective pressures known to impact PrP prion replication also impact replication of α-synuclein prions.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"20 12","pages":"e1012746"},"PeriodicalIF":5.5,"publicationDate":"2024-12-06","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11623799/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142789680","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Receptor binding and structural basis of raccoon dog ACE2 binding to SARS-CoV-2 prototype and its variants.","authors":"Chunliang Luo, Linjie Li, Yuhang Gu, Hangchuan Zhang, Zepeng Xu, Junqing Sun, Kaiyuan Shi, Sufang Ma, Wen-Xia Tian, Kefang Liu, George F Gao","doi":"10.1371/journal.ppat.1012713","DOIUrl":"10.1371/journal.ppat.1012713","url":null,"abstract":"<p><p>Raccoon dog was proposed as a potential host of SARS-CoV-2, but no evidence support such a notion. In our study, we investigated the binding affinities of raccoon dog ACE2 (rdACE2) to the spike (S) protein receptor binding domain (RBD) of SARS-CoV-2 prototype (PT) and its variants. It revealed that the binding affinities of RBD from SARS-CoV-2 variants were generally lower than that of the PT RBD. Through structural and functional analyses, we found amino acids H34 and M82 play pivotal roles in maintaining the binding affinity of ACE2 to different SARS-CoV-2 sub-variants. These results suggest that raccoon dogs exhibit lower susceptibility to SARS-CoV-2 compared to those animal species with a high prevalence of SARS-CoV-2 transmission.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"20 12","pages":"e1012713"},"PeriodicalIF":5.5,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11620640/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142787402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}

{"title":"Insights into the structural changes that trigger receptor binding upon proteolytic activation of Bacillus thuringiensis Vip3Aa insecticidal protein.","authors":"Oscar Infante, Isabel Gómez, Angel E Pélaez-Aguilar, Luis A Verduzco-Rosas, Rosalina García-Suárez, Blanca I García-Gómez, Zeyu Wang, Jie Zhang, Adan Guerrero, Alejandra Bravo, Mario Soberón","doi":"10.1371/journal.ppat.1012765","DOIUrl":"10.1371/journal.ppat.1012765","url":null,"abstract":"<p><p>Bacillus thuringiensis (Bt) bacteria produce different pore forming toxins with insecticidal activity, including Cry and Vip3 proteins. While both Cry and Vip3 cause insect death by forming pores in susceptible lepidopteran larval midgut cells, their mechanisms of action differ. The Vip3Aa protoxin adopts a tetramer-structure, where each monomer has five distinct domains. Upon proteolytic activation, the Vip3 tetramer undergoes a large conformational change forming a syringe like structure that is ready for membrane insertion and pore formation. Here we show that Vip3Aa protoxin had low binding to Spodoptera frugiperda brush border membrane vesicles (BBMV) unlike the activated toxin that bound specifically in a concentration dependent way, suggesting that a structural change upon Vip3Aa proteolytic activation is required for efficient receptor binding. Consistently, the Vip3Aa protoxin showed no toxicity to Sf9 cells compared to the activated toxin. In contrast, Cry1Fa protoxin and its activated toxin, were both highly toxic to Sf9 cells. To identify the region of Vip3 involved in binding to BBMV proteins, different overlapping peptides from Vip3Aa covering domains III, IV and V were expressed, and binding analysis were performed against BBMV, showing that domain III is the primary binding domain. Additionally, domains III, IV and V amino acid residues that become exposed upon activation of Vip3Aa were identified. Mutagenesis of these exposed residues revealed three amino acids (K385, K526 and V529) located in two structural adjacent loops, domain III loop β5-β6 and loop α11-β16 that connects domains III and IV, that are crucial for binding to the midguts of S. frugiperda larvae and for toxicity. Our results demonstrate that proteolytic activation of Vip3Aa exposes a receptor binding region essential for its toxicity.</p>","PeriodicalId":48999,"journal":{"name":"PLoS Pathogens","volume":"20 12","pages":"e1012765"},"PeriodicalIF":5.5,"publicationDate":"2024-12-05","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://www.ncbi.nlm.nih.gov/pmc/articles/PMC11651543/pdf/","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"142787401","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"医学","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}