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Sample records for ma capsid ca

  1. CaPSID: A bioinformatics platform for computational pathogen sequence identification in human genomes and transcriptomes

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    Borozan Ivan

    2012-08-01

    Full Text Available Abstract Background It is now well established that nearly 20% of human cancers are caused by infectious agents, and the list of human oncogenic pathogens will grow in the future for a variety of cancer types. Whole tumor transcriptome and genome sequencing by next-generation sequencing technologies presents an unparalleled opportunity for pathogen detection and discovery in human tissues but requires development of new genome-wide bioinformatics tools. Results Here we present CaPSID (Computational Pathogen Sequence IDentification, a comprehensive bioinformatics platform for identifying, querying and visualizing both exogenous and endogenous pathogen nucleotide sequences in tumor genomes and transcriptomes. CaPSID includes a scalable, high performance database for data storage and a web application that integrates the genome browser JBrowse. CaPSID also provides useful metrics for sequence analysis of pre-aligned BAM files, such as gene and genome coverage, and is optimized to run efficiently on multiprocessor computers with low memory usage. Conclusions To demonstrate the usefulness and efficiency of CaPSID, we carried out a comprehensive analysis of both a simulated dataset and transcriptome samples from ovarian cancer. CaPSID correctly identified all of the human and pathogen sequences in the simulated dataset, while in the ovarian dataset CaPSID’s predictions were successfully validated in vitro.

  2. Cooperative role of the MHR and the CA dimerization helix in the maturation of the functional retrovirus capsid.

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    Lokhandwala, Parvez M; Nguyen, Tam-Linh N; Bowzard, J Bradford; Craven, Rebecca C

    2008-06-20

    The second helix in the C-terminal domain of retroviral capsid (CA) protein functions as the site of dimerization between subunits in capsid assembly and is believed to participate in a unique interface between Gag molecules in immature particles. This study reports isolation of two substitutions in the dimerization helix of Rous sarcoma virus CA protein that have the ability to suppress lethal defects in core maturation imposed by alterations to the major homology region (MHR) motif just upstream. Together with two previously published suppressors, these define an extended region of the dimerization helix that is unlikely to contribute directly to CA-CA contacts but whose assembly-competence may be strongly affected by conformation. The broad-spectrum suppression and temperature-sensitivity exhibited by some mutants argues that they act through modulation of protein conformation. These findings provide important biological evidence in support of a significant conformational change involving the dimerization helix and the MHR during maturation.

  3. Cooperative role of MHR and the CA dimerization helix in the maturation of the functional retrovirus capsid

    Science.gov (United States)

    Lokhandwala, Parvez M.; Nguyen, Tam-Linh N.; Bowzard, J. Bradford; Craven, Rebecca C.

    2008-01-01

    The second helix in the C-terminal domain of retroviral capsid (CA) protein functions as the site of dimerization between subunits in capsid assembly and is believed to participate in a unique interface between Gag molecules in immature particles. This study reports isolation of two substitutions in the dimerization helix of Rous sarcoma virus CA protein that have the ability to suppress lethal defects in core maturation imposed by alterations to the major homology region (MHR) motif just upstream. Together with two previously published suppressors, these define an extended region of the dimerization helix that is unlikely to contribute directly to CA-CA contacts but whose assembly-competence may be strongly affected by conformation. The broad-spectrum suppression and temperature-sensitivity exhibited by some mutants argues that they act through modulation of protein conformation. These findings provide important biological evidence in support of a significant conformational change involving the dimerization helix and MHR during maturation. PMID:18433823

  4. Ma

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    Ingrid Berthon-Moine

    2012-01-01

    Full Text Available Ma (2009 is a single channel video of a mother and child walking together side by side, holding hands. The title is reminiscent of the affectionate nickname for a mother, 'Ma', but also a concealed way to convey maternal ambivalence. Maternal ambivalence is the result of the tension between the idealisation of motherhood and women’s lived experience of mothering. The maternal struggle finds its source in the difficulty of identifying with the ideological representation of the mother. This image still conveys an idealistic and nostalgic, patriarchal image of maternal love bounded by culture and history. http://podcast.ulcc.ac.uk/accounts/BirkbeckCollege/mamsie/MA.mov

  5. MaCaM在采后香蕉果实温度胁迫及后熟中的作用%The Role ofMaCaM Gene in Temperature Stress and Fruit Ripening of Harvested Banana

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    王海波; 龚家建; 苏新国; 张昭其

    2015-01-01

    【目的】研究香蕉CaM在温度胁迫及香蕉果实后熟过程中的表达模式,了解CaM在增强香蕉果实对温度胁迫的适应性作用,解释CaM参与调控香蕉果实褪绿转黄的机制。【方法】通过比对NCBI数据库中已有物种的CaM氨基酸序列,设计兼并引物。采用热硼酸法,从香蕉果皮中提取总RNA,通过RT-PCR与RACE方法扩增目的基因。利用DNAMAN软件和NCBI网站对CaM的氨基酸序列进行氨基酸比对和同源树分析。利用地高辛探针合成试剂盒(PCR DIG Probe Synthesis Kit)合成特异基因带有DIG标记的探针,使用Northern杂交法对MaCaM在采后香蕉果实温度胁迫及后熟中的表达规律进行分析。钙离子螯合剂EGTA及钙信号恢复处理采用香蕉果皮离体培养,采用真空渗透的方法对香蕉果皮进行试剂处理,利用色差计测定颜色 h 值。【结果】从香蕉果皮中克隆得到一个CaM,长648 bp,编码138个氨基酸,命名为MaCaM(登录号:HM061077),序列分析表明,MaCaM包含4个EF-Hand钙离子结合区域,与MaCaM、OsCaM、ZmCaM、AtCaM3、TaCaM1-2等基因同源性极高。Northern杂交结果表明,热激(52℃,3 min)处理香蕉果实0.5 h后,MaCaM表达迅速增强;香蕉果实在冷害温度(7℃)下放置10 d,MaCaM在冷藏的第7—10 d表达逐渐增强,当采后香蕉果实先经热激处理再放入7℃下贮藏,MaCaM表达在第4天和第7天强于7℃处理;乙烯催熟处理诱导香蕉MaCaM表达逐渐增强;30 mmol·L-1钙离子螯合剂EGTA处理在一定程度上抑制了香蕉果实的后熟,同时也抑制了MaCaM的表达。而在EGTA处理的同时,利用30 mmol·L-1 CaCl2进行钙信号恢复处理,能一定程度地恢复香蕉果实的正常后熟,也恢复了MaCaM的表达。【结论】MaCaM能增强香蕉果实对温度胁迫的适应性;MaCaM作为一种调控因子参与了香蕉果实后熟的褪绿转黄

  6. ID-TIMS Geochronology of ca 1 Ma leucogranites from the core of Nanga Parbat

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    Bowring, S. A.; Searle, M. P.; Waters, D. J.; Hodges, K. V.; Schmitz, M. D.; Crowley, J.

    2003-12-01

    Although isotope-dilution, themal-ioniaztion mass spectrometry (ID-TIMS) is the most precise method available for U-Th-Pb geochronology of accessory minerals, the technique is traditionally not applied to samples youger than ca. 10 Ma due to low concentrations of radiogenic Pb. However, recent analytical advances allow the routine measurement of less than 5-10 picograms of radiogenic Pb, and the reduction of laboratory blanks to extremely low levels. As a consequence, it is now possible to use ID-TIMS for U-Pb geochronology of very young accessory mineral suites to develop new insights regarding the time scales and patterns of inheritance, melt production, and segregation in collisional orogens. The Nanga Parbat syntaxis of the northwestern Himalaya has had a long and complex thermal history, but it is famous for the evidence it provides for extremely young (Nanga Parbat in less than 1 million years.

  7. High-fidelity organic preservation of bone marrow in ca. 10 Ma amphibians

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    McNamara, Maria E.; Orr, Patrick J.; Kearns, Stuart L.; Alcalá, Luis; Anadón, Pere; Peñalver-Mollá, Enrique

    2006-08-01

    Bone marrow in ca. 10 Ma frogs and salamanders from the Miocene of Libros, Spain, represents the first fossilized example of this extremely decay-prone tissue. The bone marrow, preserved in three dimensions as an organic residue, retains the original texture and red and yellow color of hematopoietic and fatty marrow, respectively; moldic osteoclasts and vascular structures are also present. We attribute exceptional preservation of the fossilized bone marrow to cryptic preservation: the bones of the amphibians formed protective microenvironments, and inhibited microbial infiltration. Specimens in which bone marrow is preserved vary in their completeness and articulation and in the extent to which the body outline is preserved as a thin film of organically preserved bacteria. Cryptic preservation of these labile tissues is thus to a large extent independent of, and cannot be predicted by, the taphonomic history of the remainder of the specimen.

  8. Protease cleavage leads to formation of mature trimer interface in HIV-1 capsid.

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    Xin Meng

    Full Text Available During retrovirus particle maturation, the assembled Gag polyprotein is cleaved by the viral protease into matrix (MA, capsid (CA, and nucleocapsid (NC proteins. To form the mature viral capsid, CA rearranges, resulting in a lattice composed of hexameric and pentameric CA units. Recent structural studies of assembled HIV-1 CA revealed several inter-subunit interfaces in the capsid lattice, including a three-fold interhexamer interface that is critical for proper capsid stability. Although a general architecture of immature particles has been provided by cryo-electron tomographic studies, the structural details of the immature particle and the maturation pathway remain unknown. Here, we used cryo-electron microscopy (cryoEM to determine the structure of tubular assemblies of the HIV-1 CA-SP1-NC protein. Relative to the mature assembled CA structure, we observed a marked conformational difference in the position of the CA-CTD relative to the NTD in the CA-SP1-NC assembly, involving the flexible hinge connecting the two domains. This difference was verified via engineered disulfide crosslinking, revealing that inter-hexamer contacts, in particular those at the pseudo three-fold axis, are altered in the CA-SP1-NC assemblies compared to the CA assemblies. Results from crosslinking analyses of mature and immature HIV-1 particles containing the same Cys substitutions in the Gag protein are consistent with these findings. We further show that cleavage of preassembled CA-SP1-NC by HIV-1 protease in vitro leads to release of SP1 and NC without disassembly of the lattice. Collectively, our results indicate that the proteolytic cleavage of Gag leads to a structural reorganization of the polypeptide and creates the three-fold interhexamer interface, important for the formation of infectious HIV-1 particles.

  9. Characterization of the invariable residue 51 mutations of human immunodeficiency virus type 1 capsid protein on in vitro CA assembly and infectivity

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    Höglund Stefan

    2007-09-01

    Full Text Available Abstract Background The mature HIV-1 conical core formation proceeds through highly regulated protease cleavage of the Gag precursor, which ultimately leads to substantial rearrangements of the capsid (CAp24 molecule involving both inter- and intra-molecular contacts of the CAp24 molecules. In this aspect, Asp51 which is located in the N-terminal domain of HIV-1 CAp24 plays an important role by forming a salt-bridge with the free imino terminus Pro1 following proteolytic cleavage and liberation of the CAp24 protein from the Pr55Gag precursor. Thus, previous substitution mutation of Asp51 to alanine (D51A has shown to be lethal and that this invariable residue was found essential for tube formation in vitro, virus replication and virus capsid formation. Results We extended the above investigation by introducing three different D51 substitution mutations (D51N, D51E, and D51Q into both prokaryotic and eukaryotic expression systems and studied their effects on in vitro capsid assembly and virus infectivity. Two substitution mutations (D51E and D51N had no substantial effect on in vitro capsid assembly, yet they impaired viral infectivity and particle production. In contrast, the D51Q mutant was defective both for in vitro capsid assembly and for virus replication in cell culture. Conclusion These results show that substitutions of D51 with glutamate, glutamine, or asparagine, three amino acid residues that are structurally related to aspartate, could partially rescue both in vitro capsid assembly and intra-cellular CAp24 production but not replication of the virus in cultured cells.

  10. Coarse-grained simulation reveals key features of HIV-1 capsid self-assembly

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    Grime, John M. A.; Dama, James F.; Ganser-Pornillos, Barbie K.; Woodward, Cora L.; Jensen, Grant J.; Yeager, Mark; Voth, Gregory A.

    2016-05-01

    The maturation of HIV-1 viral particles is essential for viral infectivity. During maturation, many copies of the capsid protein (CA) self-assemble into a capsid shell to enclose the viral RNA. The mechanistic details of the initiation and early stages of capsid assembly remain to be delineated. We present coarse-grained simulations of capsid assembly under various conditions, considering not only capsid lattice self-assembly but also the potential disassembly of capsid upon delivery to the cytoplasm of a target cell. The effects of CA concentration, molecular crowding, and the conformational variability of CA are described, with results indicating that capsid nucleation and growth is a multi-stage process requiring well-defined metastable intermediates. Generation of the mature capsid lattice is sensitive to local conditions, with relatively subtle changes in CA concentration and molecular crowding influencing self-assembly and the ensemble of structural morphologies.

  11. CA2-MA复相材料的合成与性能研究%Study on Synthesis and Performance of CA2-MA Composites

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    罗琼; 顾华志; 李正坤; 黄奥; 张家勤

    2012-01-01

    以白云石和工业氧化铝为原料,利用热力学对混合料反应过程进行分析,研究了不同Al2O3含量和烧成温度对CA2-MA复合材料的合成与性能的影响.结果发现:材料经1700℃下煅烧后可获得以CaAl4O7和MgAl2O4为主要物相的复相材料.随着配料中Al2O3含量的增加,材料中CaAl4O7含量减少,CaAl12O19含量增多,且材料显气孔率升高,体积密度略有下降.烧成温度从1600℃提高到1750℃,材料的体积密度增大,显气孔率降低,但温度过高反而有碍烧结,并对高温性能不利.%CA2-MA composites were synthesized with staring materials of dolomite and commercial alumina. Thermodynamics analysis indicated the reaction process of mixture. Effect of different content of Al2O3 and sintering temperature on the synthesize and properties of the material were studied. The results showed the main phase of material were CaAl4O7 and MgAl2O4 after firing at 1700 ℃. With increasing the content of Al2O3 ,CaAl12O19 began to appear, accompanied by the apprent porosity increased and the bulk density increased slightly. With the firing temperature rising from 1600℃ to 1750 ℃, there was much increased in bulk density, but excessive temperature may hindered the sinter process and injured the high temperture performance.

  12. Early Cretaceous (ca. 100 Ma) magmatism in the southern Qiangtang subterrane, central Tibet: Product of slab break-off?

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    Li, Yalin; He, Haiyang; Wang, Chengshan; Wei, Yushuai; Chen, Xi; He, Juan; Ning, Zijie; Zhou, Aorigele

    2016-09-01

    The lack of Early Cretaceous magmatic records with high-quality geochemical data in the southern Qiangtang subterrane has inhibited a complete understanding of the magmatic processes and geological evolution of central Tibet. In this study, we present zircon U-Pb ages, whole-rock geochemistry, and Sr-Nd-Pb and zircon Hf isotopic data for the newly discovered Moku pluton in the southern Qiangtang subterrane. Zircon U-Pb dating reveals that the Moku granites were emplaced in the Early Cretaceous (ca. 100 Ma) and are coeval with the hosted dioritic enclaves. The granites are slightly peraluminous and high-K calc-alkaline I-type granites and characterized by initial (87Sr/86Sr)i ratios of 0.70605-0.70658, negative ɛ Nd(t) values (-4.44 to -3.35), and Nd isotopic model ages of 1.19-1.29 Ga. The granites have a wide range of zircon ɛ Hf(t) values (-24.4 to 2.6) and concordant ratios of (206Pb/204Pb)t = 18.645-18.711, (207Pb/204Pb)t = 15.656-15.666, and (208Pb/204Pb)t = 38.751-38.836. The coeval dioritic enclaves are medium- to high-K calc-alkaline rocks with zircon ɛ Hf(t) values of -13.3 to +3.6. The geochemical signatures of the host granites and coeval dioritic enclaves indicate that the Moku pluton was most likely generated by partial melting of the ancient lower crust with contributions from mantle-derived melts. Our new data, together with other recently published data, indicate that the ca. 100 Ma magmatic rocks were derived from anatexis of the Qiangtang lower crust that mixed with upwelling asthenosphere materials in response to the slab break-off of the northward subduction of the Bangong-Nujiang oceanic lithosphere.

  13. Effects of Blending Routes on the Morphology and Properties of PA-6/Nano-CaCO3/MA-POE Ternary Composites

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    Na FENG; Rui HUANG; Shengling JIANG; Junlong LIU; Chun MA

    2005-01-01

    The effect of blending routes on the morphology and properties of Polyamide-6 (PA-6)/nano-CaCO3/Maleated ethylene-octane copolymer (MA-POE) ternary composite was analyzed using static mechanical test (DMA), TEM (transmission electronic microscope) and SEM (scanning electron microscope). It was found that MA-POE, as an impact modifier, had a profound effect upon the toughness of the PA-6/nano-CaCO3 composite. In particular, by adopting two-stage blending route, the microstructure of the ternary composites turned to core-shell structure, and the impact toughness was improved greatly. At the same time, tensile strength and dynamic storage modulus (E')were higher than those with one-stage blending route processed ternary composite. The results suggest that blending routes may improve the properties of PA-6/nano-CaCO3/MA-POE ternary composites.

  14. Pre-collisional, Tonian (ca. 790 Ma) continental arc magmatism in southern Mantiqueira Province, Brazil: Geochemical and isotopic constraints from the Várzea do Capivarita Complex

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    Martil, Mariana Maturano Dias; de Fátima Bitencourt, Maria; Nardi, Lauro Valentim Stoll; Koester, Edinei; Pimentel, Márcio Martins

    2017-03-01

    This paper focuses on the pre-collisional mature arc magmatism (ca. 790 Ma) recorded in orthogneisses from the Várzea do Capivarita Complex (VCC), southern Mantiqueira Province (PM), Brazil. The complex comprises ortho- and paragneisses tectonically interleaved during a transpressive high grade regime (ca. 650 Ma), possibly related to oblique collision. The VCC orthogneisses are metaluminous to peraluminous calc-alkaline rocks, with high 87Sr/86Sr(i) ratios from 0.71628 to 0.72509 and εNd(790) values from - 7.19 to - 10.06. The VCC magmatism is correlated with other ca. 800 Ma arc sequences from southern PM, as the Porongos Metamorphic Complex (PMC) metavolcanic rocks and the orthogneisses from Cerro Bori (CB), Uruguay. All associations show signatures typical of accretionary orogens, TDM and Meso to Paleoproteroic inheritance ages, and strong evidence of crustal assimilation/contamination. Their high K contents, and the tendency to move toward the post-collisional field in geotectonic diagrams suggest that they were generated in thick-crust, mature arc environments. In contrast, the CB sequence exhibits a less mature continental-arc character, suggestive of thinner crust or shorter distance to the active margin. VCC and CB orthogneisses, and part of the PMC metavolcanic rocks may be interpreted as part of the same magmatism, or at least as fragments of similar magmatic arcs. However, VCC magmatism is distinct from continental arc sequences in the São Gabriel Block (ca. 700-750 Ma). Isotope signatures for this younger magmatism indicate major contribution of Neoproterozoic juvenile sources, with only little amounts of reworked, old continental crust. Geochemical and Sr-Nd signatures presented in this paper suggest that at least part of the PMC metavolcanic rocks are the protoliths of the VCC orthogneisses. This, together with the isotope evidence of similarity between VCC and PMC igneous and sedimentary fractions, corroborates the hypothesis that the VCC and PMC

  15. Mechanochemical synthesis, structure, and properties of solid solutions of alkaline earth metal fluorides: Ma1-xMbxF2 (M: Ca, Sr, Ba)

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    Heise, M.; Scholz, G.; Düvel, A.; Heitjans, P.; Kemnitz, E.

    2016-10-01

    The capability of mechanochemical synthesis for the formation of solid solutions of alkaline earth metal fluorides Ma1-xMbxF2 (M: Ca, Sr, Ba) was tested by fluorination of metal acetates and metal hydroxides with ammonium fluoride directly at milling. Evidence was found for a mutual substitution of cations on their lattice positions in Ca1-xSrxF2 and Ba1-xSrxF2 samples. For the Ba/Ca-system this synthesis route is only partially successful. X-ray diffraction and 19F MAS NMR spectroscopy were used to characterize all samples concerning their crystal structure and local fluorine coordination. Calculations of 19F chemical shifts with the superposition model along with probability calculations for the intensity of the individual 19F lines, performed in dependence on the molar composition of the samples, perfectly agree with the experimental findings. The fluoride ion conductivity of as-prepared samples, determined by temperature dependent DC conductivity measurements, is significantly higher than those of crystalline binary fluorides. Moreover, a higher F- ion conductivity is observed for samples with higher mixing grade in the Ca/Sr-and the Ba/Sr-systems.

  16. STRUCTURAL VIROLOGY. X-ray crystal structures of native HIV-1 capsid protein reveal conformational variability.

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    Gres, Anna T; Kirby, Karen A; KewalRamani, Vineet N; Tanner, John J; Pornillos, Owen; Sarafianos, Stefan G

    2015-07-03

    The detailed molecular interactions between native HIV-1 capsid protein (CA) hexamers that shield the viral genome and proteins have been elusive. We report crystal structures describing interactions between CA monomers related by sixfold symmetry within hexamers (intrahexamer) and threefold and twofold symmetry between neighboring hexamers (interhexamer). The structures describe how CA builds hexagonal lattices, the foundation of mature capsids. Lattice structure depends on an adaptable hydration layer modulating interactions among CA molecules. Disruption of this layer alters interhexamer interfaces, highlighting an inherent structural variability. A CA-targeting antiviral affects capsid stability by binding across CA molecules and subtly altering interhexamer interfaces remote to the ligand-binding site. Inherent structural plasticity, hydration layer rearrangement, and effector binding affect capsid stability and have functional implications for the retroviral life cycle. Copyright © 2015, American Association for the Advancement of Science.

  17. Mechanical insights into tectonic reorganization of the southern San Andreas fault system at ca. 1.1-1.5 Ma

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    Fattaruso, L.; Cooke, M. L.; Dorsey, R. J.

    2013-12-01

    Reorganization of active fault systems may result from changes in relative plate motion and evolving fault geometries. Between ~1.5 and 1.1 Ma the southern San Andreas fault system underwent a major reorganization that included initiation of the San Jacinto fault zone, termination of slip on the extensional West Salton detachment fault, and reorganization of structures in the Mecca Hills northeast of the San Andreas fault during a local change from transtension to transpression conditions with no known change in Pacific-North America relative plate motion. The active trace of the southern San Andreas fault itself also evolved during this time, with shifts in activity from the Mission Creek to Mill Creek to the present-day active fault geometry of the San Bernardino, Garnet Hill, and Banning strands of the San Andreas fault. Although there is a rich geologic record of these changes, the mechanisms that controlled abandonment of active faults, initiation of new strands, and shifting loci of uplift are poorly understood. We use three-dimensional mechanical Boundary Element Method models to investigate this major tectonic reorganization at ~1.1-1.5 Ma. Previous mechanical modeling studies have examined the evolution of the southern San Andreas fault geometry in the San Gorgonio Pass using a series of snapshot models of the succession of active fault geometries. We use the same approach to explore the role of fault interaction and tectonic loading in abandonment of the West Salton detachment fault and initiation of the San Jacinto fault. The snapshots include: (1) regional transtension with an active West Salton detachment fault and active Mission Creek strand of the San Andreas fault; (2) cessation of local extension in combination with initiation of the San Jacinto fault in which we explore both north-to-south propagation and simultaneous growth; (3) shift of activity to the Mill Creek strand of the San Andreas fault; and (4) shift of activity to the present

  18. The Astrovirus Capsid: A Review

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    Arias, Carlos F.; DuBois, Rebecca M.

    2017-01-01

    Astroviruses are enterically transmitted viruses that cause infections in mammalian and avian species. Astroviruses are nonenveloped, icosahedral viruses comprised of a capsid protein shell and a positive-sense, single-stranded RNA genome. The capsid protein undergoes dramatic proteolytic processing both inside and outside of the host cell, resulting in a coordinated maturation process that affects cellular localization, virus structure, and infectivity. After maturation, the capsid protein controls the initial phases of virus infection, including virus attachment, endocytosis, and genome release into the host cell. The astrovirus capsid is the target of host antibodies including virus-neutralizing antibodies. The capsid protein also mediates the binding of host complement proteins and inhibits complement activation. Here, we will review our knowledge on the astrovirus capsid protein (CP), with particular attention to the recent structural, biochemical, and virological studies that have advanced our understanding of the astrovirus life cycle. PMID:28106836

  19. The ca. 350 Ma Beja Igneous Complex: A record of transcurrent slab break-off in the Southern Iberia Variscan Belt?

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    Pin, Christian; Fonseca, Paulo E.; Paquette, Jean-Louis; Castro, Paulo; Matte, Philippe

    2008-12-01

    We report the results of an isotopic study of the large gabbro-dioritic Beja Igneous Complex (BIC) in the boundary between the highly contrasting Ossa-Morena (OM) and South Portuguese (SP) Zones of the Southern Iberian Variscan orogen. This boundary is interpreted as a major suture zone materialized by discontinuous, scattered strips of mafic/ultramafic rocks (the so-called Beja-Acebuches ophiolite complex, BAOC), and by mélange deposits of Middle to Late Devonian age in the Pulo do Lobo accretionary prism (PLAP). The Beja gabbro was interpreted either as part of the ophiolite-like units, or as a broadly arc-related massif reflecting the northward subduction of oceanic lithosphere. U-Pb zircon (ID-TIMS) dating of two diorites and a granodiorite points to igneous emplacement ages of 350 ± 2 Ma (Serpa), 352 ± 2 Ma (Torrão), and 353 ± 4 Ma (São Pedro), respectively, whereas a felsic dyke yields a slightly younger age of 345 ± 2 Ma. These results show that published Ar/Ar dates do not represent igneous crystallization ages, but merely reflect regional cooling below ca. 500 °C, at least 10 Ma after the major intrusive event, probably as a result of uplift of the OMZ side of the suture zone relative to the subsiding SPZ. 87Sr/ 86Sr 350 and ɛNd 350 display a large range of values (from 0.7041 to 0.7093 and from + 4.0 to - 6.1, respectively) which documents a rather complex petrogenetic history, with an important role played by crustal contamination processes. The more primitive Sr and Nd isotope signatures are measured in the mafic cumulates, while radiogenic Sr and unradiogenic Nd isotope compositions occur in the more evolved rock-types. The broad trend of decreasing ɛNd 350 with decreasing Sm/Nd and increasing SiO 2 concentration is reminiscent of crustal assimilation combined with fractional assimilation (AFC). ɛNd values of flasergabbros and associated cumulates ascribed to the ophiolite-like unit in the Guadiana valley are close to zero or even slightly

  20. The Ilha Anchieta Quartz Monzonite: the southernmost expression of ca. 500 Ma post-collisional magmatism in the Ribeira Belt

    Directory of Open Access Journals (Sweden)

    José M. Azevedo Sobrinho

    2011-09-01

    Full Text Available The Ilha Anchieta Quartz Monzonite (IAQM occupies most of the homonymous island in the coast of the state of São Paulo, and is intrusive into foliated rocks of the ~565 Ma Ubatuba Charnockite. The main petrographic variety is a porphyritic biotite-hornblende quartz monzonite with 2-4 cm tabular microcline megacrysts set in a medium-grained groundmass and magmatic foliation. Outcrop-scale structures indicate cumulative processes (modal and grain-size magmatic banding and interaction with basic magmas (mafic microgranular enclaves. Lithogeochemical data indicates that the main variety is intermediate to acid (S1O2 = 63-67%, alkali-calcic, metaluminous and magnesian (mg# ~30, showing moderate Sr (300-400 ppm and Ba (~1500 ppm contents and relatively high HFSE (Nb = 40 ppm; Zr = 550-700 ppm. The older charnockites are more silicic (S1O2 = 71-78%, ferroan(mg# = 12-16, and have very low Sr (13-80 ppm contents, resulting in Ba/Sr ratios remarkably higher than the IAQM (10 versus 4. LA-MC-ICPMS U-Pb zircon dating of the IAQM yielded 499.7 ± 5.9 Ma. This is the youngest magmatic age identified so far in the crystalline basement of the state of São Paulo, and indicates that the pluton is the southernmost expression of the post-collisional "G5" magmatism in the Ribeira Belt.O Quartzo Monzonito Ilha Anchieta (QMIA ocupa a maior parte da ilha homônima na região costeira do Estado de São Paulo, e é intrusivo em rochas foliadas do Charnockito Ubatuba (~565 Ma. A principal variedade petrográfica é um biotitahornblenda quartzo monzonito porfirítico com foliação magmática e megacristais tabulares de microclínio com 2-4 cm em matriz de granulação média. Estruturas em afloramento indicam processos cumuláticos (bandamento modal e granulométrico e interação com magmas básicos (enclaves microgranulares máficos. Dados geoquímicos indicam que a variedade principal é intermediária a ácida (SiO2 = 63-67%, tem caráter

  1. Bovinos machos en pastoreo restringido complementados con caña de azúcar y maíz

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    Jorge Iraola

    2016-01-01

    Full Text Available Se evaluó el comportamiento productivo de bovinos machos en pastoreo restringido de gramíneas tropicales y leguminosas herbáceas complementados con energía. Se utilizaron 24 añojos mestizos lecheros durante el periodo seco. Se realizó análisis de varianza según diseño completamente aleatorizado con dos tratamientos. Se determinaron algunos indicadores productivos. Se encontró diferencia para la ganancia media diaria en el tratamiento con mayor inclusión de caña de azúcar. Se concluye que el pastoreo restringido de leguminosas herbáceas con complementación energética durante el periodo seco, garantizó adecuado comportamiento productivo y ganancias a favor del tratamiento con mayor nivel de caña de azúcar.

  2. Post-kinematic lithospheric delamination of the Wuyi-Yunkai orogen in South China: Evidence from ca. 435 Ma high-Mg basalts

    Science.gov (United States)

    Yao, Wei-Hua; Li, Zheng-Xiang; Li, Wu-Xian; Wang, Xuan-Ce; Li, Xian-Hua; Yang, Jin-Hui

    2012-12-01

    Understanding the processes responsible for the intra-plate early Paleozoic Wuyi-Yunkai orogeny (> 460 Ma to 420-415 Ma) in the South China Block (SCB) is important for deducing the interactions of this block with other continents at that time, as well as the tectonic evolution of East Asia. One salient feature of the orogen is that despite the wide occurrence of syn- to late-orogenic (440 Ma to 420-415 Ma) granites in the orogen, neither syn- to late-orogenic volcanic rocks nor mafic rocks of any type have been reported. Such mafic rocks could shed clues about any mantle-crust interaction during such a major orogeny, thus help to understand the dynamics of the orogenic event. We present here, for the first time, geochronological, isotopic and geochemical data for a mafic-intermediate volcanic succession in northern Guangdong, near the edge of the metamorphic core of the orogen. The volcanic rocks unconformably overlie strongly deformed Cambro-Ordovician strata, but are in low-angle unconformable contact with overlying post-orogenic mid-Devonian strata. LA-ICP-MS and SHRIMP U-Pb dating of zircons from two andesitic and dacitic samples gives a consistent crystallization age of ca. 435 Ma, younger than the 460-445 Ma peak metamorphism of the orogeny but synchronous with the widespread late-orogenic (ca. 440-415 Ma) granitic intrusions. Nine least crustally-contaminated basaltic samples are characterized by high MgO (12.3-19.2 wt.%), Ni (214-715 ppm) and Cr (724-1107 ppm), but low TiO2 (0.6-0.8 wt.%), Al2O3 (10.2-12.8 wt.%) and Fe2O3T (total Fe as Fe2O3) (8.7-11.4 wt.%) contents. The basalts also exhibit low Nb/La ratios (0.4-0.8) and constant ɛNd(t) values (- 8.0 to - 8.4) with variable SiO2 (44.8-51.5 wt.%) contents, suggesting a likely sub-continental lithospheric mantle origin. These high-magnesian basalts have chemical compositions similar to their primary magma, which was estimated using geochemical modeling at SiO2 ≈ 50 wt.%, MgO ≈ 14 wt.% and FeOT ≈ 9

  3. Ma Huang Tang Suppresses the Production and Expression of Inflammatory Chemokines via Downregulating STAT1 Phosphorylation in HaCaT Keratinocytes

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    Hye-Sun Lim

    2016-01-01

    Full Text Available Ma huang tang (MHT is a traditional herbal medicine comprising six medicinal herbs and is used to treat influenza-like illness. However, the effects of MHT on inflammatory skin diseases have not been verified scientifically. We investigated determining the inhibitory effects of MHT against inflammation responses in skin using HaCaT human keratinocyte cells. We found that MHT suppressed production of thymus and activation-regulated chemokine (TARC/CCL17, macrophage-derived chemokine (MDC/CCL22, regulated on activation of normal T-cell expressed and secreted (RANTES/CCL5, and interleukin-8 (IL-8 in tumor necrosis factor-α (TNF-α and interferon-γ- (IFN-γ- stimulated HaCaT cells. Consistently, MHT suppressed the mRNA expression of TARC, MDC, RANTES, and IL-8 in TNF-α and IFN-γ-stimulated cells. Additionally, MHT inhibited TNF-α and IFN-γ-stimulated signal transducer and activator of transcription 1 (STAT1 phosphorylation in a dose-dependent manner and nuclear translocation in HaCaT cells. Our finding indicates that MHT inhibits production and expression of inflammatory chemokines in the stimulated keratinocytes by downregulating STAT1 phosphorylation, suggesting that MHT may be a possible therapeutic agent for inflammatory skin diseases.

  4. ma a

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    Oscar del Barco, Trad. Davi Pessoa Carneiro

    2013-06-01

    Full Text Available Oscar del Barco escreveu o texto “ma a” para o catálogo ma a/Obra pictórica (Cór­doba, 2008, publicado na ocasião da exposição homônima, em que foram ex­postas 150 obras iné­ditas de distintos formatos e técnicas que del Barco vinha reali­zando há mais de 15 anos. Alguns escritores, artistas, ensaís­tas e pesquisadores, como Silvio Mattoni, Antonio Oviedo, Anamaría Ashwell, Gustavo Cosa­cov, Matías Lapezzata, entre outros, parti­ciparam da publi­cação. O texto foi posteriormente in­cluído em Alternativas de lo Posthumano (Buenos Aires: Caja Negra, 2010, com organização de Gabriel Livov e Pablo Gallardo. A tradução é do texto pu­blicado no mesmo livro (p. 279-283. [N.T.

  5. The role of East-Tethys seaway closure in the middle Miocene climatic transition (ca. 14 Ma

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    N. Hamon

    2013-04-01

    Full Text Available The middle Miocene climatic transition (MMCT, approximately 14 Ma is a key period in Cenozoic cooling and cryospheric expansion. Despite it is well documented in isotopic record, the causes of the MMCT are still a matter of debate. Among various hypotheses, some authors suggested that it was linked with the final closure of the East-Tethys seaway and subsequent oceanic circulation reorganisation. The aim of the present study is to quantify the impact of varying East-Tethys seaway depths on middle Miocene ocean and climate, in order to better understand its role in the MMCT. We present four sensitivity experiments with a fully coupled ocean-atmosphere generalized circulation model. Our results indicate the presence of a warm and salty water source in the northern Indian Ocean when the East-Tethys is deep-open (4000 or 1000 m, which corresponds to the Tethyan Indian Saline Water (TISW described on the basis of isotopic studies. This water source is absent in the experiments with shallow (250 m and closed East-Tethys, inducing strong changes in the latitudinal density gradient and ultimately the reinforcement of the Antarctic Circumpolar Current (ACC. Moreover, when the East-Tethys seaway is shallow or closed, there is a westward water flow in the Gibraltar Strait that strengthens the Atlantic meridional overturning circulation (AMOC compared to the experiments with deep-open East-Tethys. Our results therefore suggest that the shoaling and final closure of the East-Tethys seaway played a major role in the oceanic circulation reorganisation during the middle Miocene. The results presented here provide new constraints on the timing of the East-Tethys seaway closure, and particularly indicate that, prior to 14 Ma, a deep-open East-Tethys should have allow the formation of TISW. Moreover, whereas the final closure of this seaway likely played a major role in the MMCT, we suggest that it was not the only driver of the global cooling and Antarctica ice

  6. Costos de producción de vaquillas Holstein con ensilado de caña de azúcar o de maíz

    OpenAIRE

    Reyes, J. A.; Morales, I; J. M. Palma

    2006-01-01

    El objetivo del presente trabajo fue evaluar los costos de producción de vaquillas Holstein mediante la comparación de dos sistemas de alimentación, basados en ensilado de caña de azúcar (ECA) vs el sistema tradicional del rancho basado en ensilado de maíz (EM). En ambos casos, con suplementación a los animales. Se utilizaron 28 becerras posterior al destete, con una edad promedio de 80±16 días y un peso inicial de 79.5 ± 12.9 kg. El estadístico fue un análisis d...

  7. Ensilaje de cogollo de caña quemado y ensilaje de maíz en la ceba de novillos

    OpenAIRE

    Sánchez G. Hugo; Zapata O.; Morales V. F.; López B. J. A.

    2012-01-01

    Se ensiló cogollo de caña quemado, usando como aditivos melazas al 3% y úrea al 1% en base fresca. Los tratamientos consistieron en una combinación de ensilaje de cogollo quemado y ensilaje de maíz como dieta básica a voluntad y dos suplementos que contenían 1.5 kg de gallinaza, 1.0 kg de melaza y/o 0.1 kg de úrea para el tratamiento uno y 0.4 kg de torta de soya para el tratamiento dos, con nueve novillos cebú mestizos por tratamiento. Las ganancias de peso diario fueron de 0.52 y 0.54 kg; y...

  8. Costos de producción de vaquillas Holstein con ensilado de caña de azúcar o de maíz

    Directory of Open Access Journals (Sweden)

    J. A. Reyes

    2006-01-01

    Full Text Available El objetivo del presente trabajo fue evaluar los costos de producción de vaquillas Holstein mediante la comparación de dos sistemas de alimentación, basados en ensilado de caña de azúcar (ECA vs el sistema tradicional del rancho basado en ensilado de maíz (EM. En ambos casos, con suplementación a los animales. Se utilizaron 28 becerras posterior al destete, con una edad promedio de 80±16 días y un peso inicial de 79.5 ± 12.9 kg. El estadístico fue un análisis de varianza para un diseño en bloques al azar, en donde el peso fue el factor de bloqueo y se dividieron en tres grupos dentro de cada tratamiento. Cada 30 días se midió la ganancia diaria de peso GDP (kg, la condición corporal CC, la conversión alimenticia CA (kg, el consumo de forraje CF (kg, de suplemento CS (kg, costo de alimentación/ día y la determinación del costo de producción de los reemplazos ($. Las vaquillas tuvieron una GDP 0.666 y 0.743 kg/día, CC 3.1b y 3.7a, CA 7.4a y 9.8b, CF 3.2 y 5.3, CS 1.8 y 1.5, costo de alimentación/día 9.4a y 11.4b y costo de la vaquilla $6,986.82 y $8,034.39, para ECA y EM, respectivamente. La alimentación fue el rubro que mayor impacto tuvo en la obtención de vaquillas de reemplazo, con 67 a 71% de los costos totales y la etapa de mayor inversión en la producción de vaquillas correspondió a la fase del nacimiento al destete. La alimentación basada en ensilaje de caña de azúcar permitió un mejor comportamiento económico para la producción de vaquillas de reemplazo, comparado con el sistema tradicional con ensilado de maíz.

  9. Second-site suppressors of HIV-1 capsid mutations: restoration of intracellular activities without correction of intrinsic capsid stability defects

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    Yang Ruifeng

    2012-04-01

    Full Text Available Abstract Background Disassembly of the viral capsid following penetration into the cytoplasm, or uncoating, is a poorly understood stage of retrovirus infection. Based on previous studies of HIV-1 CA mutants exhibiting altered capsid stability, we concluded that formation of a capsid of optimal intrinsic stability is crucial for HIV-1 infection. Results To further examine the connection between HIV-1 capsid stability and infectivity, we isolated second-site suppressors of HIV-1 mutants exhibiting unstable (P38A or hyperstable (E45A capsids. We identified the respective suppressor mutations, T216I and R132T, which restored virus replication in a human T cell line and markedly enhanced the fitness of the original mutants as revealed in single-cycle infection assays. Analysis of the corresponding purified N-terminal domain CA proteins by NMR spectroscopy demonstrated that the E45A and R132T mutations induced structural changes that are localized to the regions of the mutations, while the P38A mutation resulted in changes extending to neighboring regions in space. Unexpectedly, neither suppressor mutation corrected the intrinsic viral capsid stability defect associated with the respective original mutation. Nonetheless, the R132T mutation rescued the selective infectivity impairment exhibited by the E45A mutant in aphidicolin-arrested cells, and the double mutant regained sensitivity to the small molecule inhibitor PF74. The T216I mutation rescued the impaired ability of the P38A mutant virus to abrogate restriction by TRIMCyp and TRIM5α. Conclusions The second-site suppressor mutations in CA that we have identified rescue virus infection without correcting the intrinsic capsid stability defects associated with the P38A and E45A mutations. The suppressors also restored wild type virus function in several cell-based assays. We propose that while proper HIV-1 uncoating in target cells is dependent on the intrinsic stability of the viral capsid, the

  10. Eocene magmatic processes and crustal thickening in southern Tibet: Insights from strongly fractionated ca. 43 Ma granites in the western Gangdese Batholith

    Science.gov (United States)

    Wang, Qing; Zhu, Di-Cheng; Cawood, Peter A.; Zhao, Zhi-Dan; Liu, Sheng-Ao; Chung, Sun-Lin; Zhang, Liang-Liang; Liu, Dong; Zheng, Yuan-Chuan; Dai, Jin-Gen

    2015-12-01

    This study reports zircon U-Pb age and Hf isotope, whole-rock major and trace element, and Sr-Nd-Pb-Hf isotope data for the Dajia pluton, western Gangdese Batholith, in southern Tibet. These data indicate that the pluton consists of moderately (Group 1) and strongly (Group 2) fractionated granites that were emplaced synchronously at ca. 43 Ma. Group 1 samples have SiO2 contents of 69-72 wt.% and vary in terms of the differentiation index (DI = 84-93). These rocks are depleted in Ba, Nb, Sr, P, and Ti, with moderate negative Eu anomalies, and display low heavy rare earth elements (HREEs) and Y abundances. Group 2 samples are characterized by high SiO2 (75-78 wt.%) and DI (95-97); significantly negative Eu anomalies; marked concave-upward middle REE (Gd-Ho) patterns; and Ba, Sr, P, and Ti anomalies that are significantly more negative than those of Group 1 samples. Group 1 samples have whole-rock εNd(t) (- 5.9 to - 6.0), εHf(t) (- 4.0 to - 4.5), and zircon εHf(t) (- 6.0 to + 5.8) values identical to those of Group 2 samples [εNd(t) = - 5.7 to - 6.7, εHf(t) = - 3.5 to - 2.9, and zircon εHf(t) = - 2.0 to + 4.2], as well as similar initial Pb isotopic compositions. These data indicate that the two groups were derived from a common source region with garnet as a residual mineral phase. Group 1 samples were most likely derived from partial melting of garnet-bearing amphibolite (rather than eclogite) within the juvenile southern Lhasa crust and mixed with the enriched components from the subducting ancient Indian continental crust and/or the ancient central Lhasa basement. Group 2 samples are interpreted as the products of extensive fractional crystallization (plagioclase, K-feldspar, biotite, apatite, allanite, titanite, monazite, and ilmenite) of the melts represented by Group 1 samples. Low HREEs and Y abundances of the Dajia pluton, together with the presence of strongly fractionated granites (Group 2) identified for the first time in the Gangdese Batholith

  11. 钙处理钢用镁尖晶石炭滑板的损毁机理%Wear mechanism of MgO-MA-C slide plate for casting Ca-treated steel

    Institute of Scientific and Technical Information of China (English)

    金从进; 邱文冬; 杨时标; 张建忠

    2000-01-01

    对宝钢试用的镁尖晶石炭滑板进行了性能检测,并与铝炭锆、锆炭质滑板一起进行了抗CaO渣侵蚀试验,其抗侵蚀性优于后者。对用后的镁尖晶石炭滑板进行了显微结构分析,探讨了滑板的损毁机理。%The properties of MgO-MA-C slide plate were tested. Comparative testing of CaO corrosion resistance wascarried out among MgO-MA-C,Al2O3-C-ZrO2 and ZrO2-C materials. The CaO corrosion resistance of MgO-MA-C material was superior to the others. The microstructure of MgO-MA-C slide plate after being usedwas analyzed, and wear mechanism of MgO-MA-C slide plate was discussed.

  12. Mid-Neoproterozoic (ca. 830-800 Ma) metamorphic P-T paths link Tarim to the circum-Rodinia subduction-accretion system

    Science.gov (United States)

    Ge, Rongfeng; Zhu, Wenbin; Wilde, Simon A.

    2016-06-01

    Long-lived exterior accretionary orogeny shapes tectonothermal evolution of the peripheral building blocks of supercontinents and leads to considerable crustal growth. However, such accretionary orogeny has only been locally recognized for the Rodinia supercontinent. Here a suite of newly discovered mid-Neoproterozoic high-grade metamorphic rocks in the northern Tarim Craton, NW China, are used to test the exterior accretion hypothesis for Rodinia. These rocks occur as dark-colored mafic and calc-silicate boudins in impure marbles and mica schists. Geochemical data suggest a protolith of arc-related basalts metasomatized by Ca-rich fluids. Mineral assemblages, phase diagram modeling, and mineral compositions for a garnet pyroxenite and a garnet clinopyroxene gneiss reveal upper amphibolite to high-pressure granulite facies peak metamorphism (660-700°C, 11-12 kbar) following a counterclockwise P-T path, which is characterized by prograde burial and heating, followed by near-isothermal burial and retrograde exhumation and cooling. This P-T path is interpreted to have recorded crustal thickening of an earlier magmatic arc transformed to a fore arc by subduction erosion and subsequent burial along bent isotherms near the subduction channel. All studied samples record ca. 830-800 Ma metamorphic zircon U-Pb ages, which probably date the early exhumation and cooling according to Ti-in-zircon temperatures, zircon rare earth element patterns, and Hf isotopes. This is the first mid-Neoproterozoic P-T-t path in Tarim, and it provides metamorphic evidence for a mid-Neoproterozoic advancing-type accretionary orogeny, which is coeval with the initial breakup events of Rodinia and thus links Tarim to the circum-Rodinia accretion system, supporting the peripheral subduction model.

  13. Ensilaje de cogollo de caña quemado y ensilaje de maíz en la ceba de novillos

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    Sánchez G. Hugo

    1990-12-01

    Full Text Available Se ensiló cogollo de caña quemado, usando como aditivos melazas al 3% y úrea al 1% en base fresca. Los tratamientos consistieron en una combinación de ensilaje de cogollo quemado y ensilaje de maíz como dieta básica a voluntad y dos suplementos que contenían 1.5 kg de gallinaza, 1.0 kg de melaza y/o 0.1 kg de úrea para el tratamiento uno y 0.4 kg de torta de soya para el tratamiento dos, con nueve novillos cebú mestizos por tratamiento. Las ganancias de peso diario fueron de 0.52 y 0.54 kg; y los consumos de materia seca por animal de 11.37 y 11.01 kg/día para los tratamientos uno y dos respectivamente. La factibilidad del uso del cogollo de caña depende de la eficiencia de los procesos de ensilado y de la suplementación adecuada y de bajo costo.Were used burned sugar cane tops silage with 3 % of molasses and 1% of urea on fresch base and com silage as basic diet. The treatments were as follow: Treatment 1 (t1 - Burned sugar cane tops silage + Com Silage + 1.5 kg of poultry litter + 1.0 kg of molasse + 0.1 kg of urea and 0.4 kg of soybean meal by urea for treatment 2 (T2, with nine crossbreed steers for treatment. The average daily gains were 0.52 and 0.54 and 0.54 kg/day and the total consumption per animal were 11.37 and 11.01 kg/day for TI and T2 respectively. The use of sugar cane tops depends on silage process efficiency and the adition of adecuate supplements with low prices.

  14. Critical role of conserved hydrophobic residues within the major homology region in mature retroviral capsid assembly.

    Science.gov (United States)

    Purdy, John G; Flanagan, John M; Ropson, Ira J; Rennoll-Bankert, Kristen E; Craven, Rebecca C

    2008-06-01

    During retroviral maturation, the CA protein undergoes dramatic structural changes and establishes unique intermolecular interfaces in the mature capsid shell that are different from those that existed in the immature precursor. The most conserved region of CA, the major homology region (MHR), has been implicated in both immature and mature assembly, although the precise contribution of the MHR residues to each event has been largely undefined. To test the roles of specific MHR residues in mature capsid assembly, an in vitro system was developed that allowed for the first-time formation of Rous sarcoma virus CA into structures resembling authentic capsids. The ability of CA to assemble organized structures was destroyed by substitutions of two conserved hydrophobic MHR residues and restored by second-site suppressors, demonstrating that these MHR residues are required for the proper assembly of mature capsids in addition to any role that these amino acids may play in immature particle assembly. The defect caused by the MHR mutations was identified as an early step in the capsid assembly process. The results provide strong evidence for a model in which the hydrophobic residues of the MHR control a conformational reorganization of CA that is needed to initiate capsid assembly and suggest that the formation of an interdomain interaction occurs early during maturation.

  15. Modification of a loop sequence between α-helices 6 and 7 of virus capsid (CA protein in a human immunodeficiency virus type 1 (HIV-1 derivative that has simian immunodeficiency virus (SIVmac239 vif and CA α-helices 4 and 5 loop improves replication in cynomolgus monkey cells

    Directory of Open Access Journals (Sweden)

    Adachi Akio

    2009-08-01

    Full Text Available Abstract Background Human immunodeficiency virus type 1 (HIV-1 productively infects only humans and chimpanzees but not cynomolgus or rhesus monkeys while simian immunodeficiency virus isolated from macaque (SIVmac readily establishes infection in those monkeys. Several HIV-1 and SIVmac chimeric viruses have been constructed in order to develop an animal model for HIV-1 infection. Construction of an HIV-1 derivative which contains sequences of a SIVmac239 loop between α-helices 4 and 5 (L4/5 of capsid protein (CA and the entire SIVmac239 vif gene was previously reported. Although this chimeric virus could grow in cynomolgus monkey cells, it did so much more slowly than did SIVmac. It was also reported that intrinsic TRIM5α restricts the post-entry step of HIV-1 replication in rhesus and cynomolgus monkey cells, and we previously demonstrated that a single amino acid in a loop between α-helices 6 and 7 (L6/7 of HIV type 2 (HIV-2 CA determines the susceptibility of HIV-2 to cynomolgus monkey TRIM5α. Results In the study presented here, we replaced L6/7 of HIV-1 CA in addition to L4/5 and vif with the corresponding segments of SIVmac. The resultant HIV-1 derivatives showed enhanced replication capability in established T cell lines as well as in CD8+ cell-depleted primary peripheral blood mononuclear cells from cynomolgus monkey. Compared with the wild type HIV-1 particles, the viral particles produced from a chimeric HIV-1 genome with those two SIVmac loops were less able to saturate the intrinsic restriction in rhesus monkey cells. Conclusion We have succeeded in making the replication of simian-tropic HIV-1 in cynomolgus monkey cells more efficient by introducing into HIV-1 the L6/7 CA loop from SIVmac. It would be of interest to determine whether HIV-1 derivatives with SIVmac CA L4/5 and L6/7 can establish infection of cynomolgus monkeys in vivo.

  16. Compositional change of granitoids from Eastern Pontides Orogenic Belt (NE Turkey) at ca. 84 Ma: Response to slab rollback of the Black Sea

    Science.gov (United States)

    Liu, Ze; Zhu, Di-Cheng; Eyuboglu, Yener; Wu, Fu-Yuan; Rızaoǧlu, Tamer; Zhao, Zhi-Dan; Xu, Li-Juan

    2016-04-01

    Magma generation and evolution is a natural consequence of mantle dynamics and crust-mantle interaction. As a result, changes of magma compositions in time and space can be used, in turn, to infer these deep processes. In this paper we report new zircon U-Pb age and Hf isotope, whole-rock major and trace element, and Nd isotope data for the granitoids from Kürtün in Eastern Pontides. These data, together with the data in the literature, reveal the occurrence of magma compositional variations at ca. 84 Ma in the region, providing new insights into the mantle dynamics responsible for the generation of the extensive Late Cretaceous felsic magmatism in Eastern Pontides Orogenic Belt (NE Turkey) (Eyuboglu et al., 2015). Group I samples (SiO2 = 77-62 wt.%) were concentrated in 91-86 Ma and are characterized by their low CaO (1.6-1.5 wt.%) and Th (8.2-3.0 ppm) contents and low K2O/Na2O (0.7-0.1) and Th/La (0.4-0.2) ratios. Group II samples (SiO2 = 71-63 wt.%) were concentrated in 82-72 Ma and include high concentrations of CaO (5.2-3.0 wt.%) and Th (29.6-14.3), high K2O/Na2O (1.5-1.1) and varying Th/La (1.0-0.5) ratios. Group I samples have positive zircon eHf(t) (+9.6 to +7.6) and whole-rock eNd(t) (+3.5 to +2.5), significantly differing from those of Group II samples with eHf(t) of +1.9 to -1.5 and whole-rock eNd(t) of -3.6 to -3.8. Modeling results indicate that the Nd-Hf isotopic compositions of Group I and II samples can be interpreted as having derived from partial melting of the low-K amphibolite within the juvenile lower crust beneath the Eastern Pontides Orogenic Belt that incorporated into 15-20% and 70-75% enriched components from the basement rocks represented by the Carboniferous granites exposed in the region, respectively. In combination with the geological observations that indicate the occurrence of regional thermal subsidence (Bektaş et al., 1999) and extensional structure (Bektaş et al., 1999, 2001) during the Campanian (83.6-72.1 Ma), the coeval

  17. Paleoceanography of marine isotope stage 31 (ca. 1.07 Ma) in the Labrador Sea based on palynological, microfaunal and isotopic data

    Science.gov (United States)

    Aubry, Aurelie; de Vernal, Anne; Hillaire-Marcel, Claude

    2014-05-01

    We have documented the paleoceanography of marine isotope stage (MIS) 31 (ca. 1.07 Ma) at IODP Site 1305 off southwest Greenland in the Labrador Sea, based on dinocyst and foraminifer populations in addition to isotopic measurements in planktonic foraminiferal shells. The planktonic foraminifer assemblages are dominated by the mesopelagic species Neogloboquadrina pachyderma sinistral (Nps). Current interpretations of Nps dominance would thus point to a polar type environment. However, dinocyst assemblages are dominated by Operculodinium centrocarpum, Nematosphaeropsis labyrinthus and Bitectatodinium tepikiense, which rather indicate temperate-subpolar environnement conditions in the photic zone. Assuming that Nps ecological requirements were unchanged, reconciling the two observations lead to hypothesize a strong stratification of the surface water layer over a subsurface water mass, with Nps ocupying the pycnocline in between. We tentatively applied the modern analogue technique (MAT) to reconstruct surface water conditions from the dinocyst assemblages. Good analogues are found in the modern dinocyst database (n=1492), notably along the southeast Canadian margins and northwest European margins. They indicate a low salinity in the surface waters (32-34.5), a large seasonal amplitude of temperatures with cool winters (3-6° C) and mild summer (10-15° C). Stable isotope measurements in Nps point to δ18O ranging 1.5-2.2o throughout most of the interval, thus significantly lower than those measured during the Holocene (>2.2o at this very site. Benthic isotopic values (~3.2o are in accordance with the global stack of Lisiecki and Raymo (Paleoceanography, 2005). This suggests the presence of relatively warm water intermediate mass in between the bottom and surface water masses. The isotopic, micropaleontological and dinocyst results together show that conditions were unfavorable for convection and intermediate or deep water formation in the Labrador Sea during this

  18. Solid-State NMR Studies of HIV-1 Capsid Protein Assemblies

    OpenAIRE

    HAN, YUN; Ahn, Jinwoo; Concel, Jason; Byeon, In-Ja L.; Gronenborn, Angela M.; YANG, Jun; Polenova, Tatyana

    2010-01-01

    In mature HIV-1 virions, a 26.6 kDa CA protein is assembled into a characteristic cone shaped core (capsid) that encloses the RNA viral genome. The assembled capsid structure is best described by a fullerene cone model that is made up from a hexameric lattice containing a variable number of CA pentamers, thus allowing for closure of tubular or conical structures. In this report, we present a solid-state NMR analysis of the wild type HIV-1 CA protein, prepared as conical and spherical assembli...

  19. Origin of the ca. 90 Ma magnesia-rich volcanic rocks in SE Nyima, central Tibet: Products of lithospheric delamination beneath the Lhasa-Qiangtang collision zone

    Science.gov (United States)

    Wang, Qing; Zhu, Di-Cheng; Zhao, Zhi-Dan; Liu, Sheng-Ao; Chung, Sun-Lin; Li, Shi-Min; Liu, Dong; Dai, Jin-Gen; Wang, Li-Quan; Mo, Xuan-Xue

    2014-06-01

    Bulk-rock major and trace element, Sr-Nd-Hf isotope, zircon U-Pb age, and zircon Hf isotopic data of the Late Cretaceous Zhuogapu volcanic rocks in the northern Lhasa subterrane provide a new insight into tectonic processes following the collision of the terrane with the Qiangtang zone. SHRIMP zircon U-Pb dating reveals that the Zhuogapu volcanic rocks crystallized at ca. 91 Ma, postdating the development of a regional angular unconformity between the Upper Cretaceous and the underlying strata in the Lhasa-Qiangtang collision zone. Compared to the Andean arc-type andesites and dacites, the Zhuogapu volcanic rocks are characterized by higher MgO of 2.78-5.86 wt.% and Mg# of 54-64 for andesites and MgO of 2.30-2.61 wt.% and Mg# of 55-58 for dacites. Eight andesite samples have whole-rock (87Sr/86Sr)i of 0.7054-0.7065, εNd(t) of - 3.2 to - 1.7, and εHf(t) of + 3.8-+ 6.4, similar to those of the three dacite samples with (87Sr/86Sr)i = 0.7056-0.7060, εNd(t) of - 2.7 to - 2.2, and εHf(t) of + 5.6-+ 7.0. Thirteen analyses from a dacite sample give positive zircon εHf(t) of + 5.6 to + 8.7. These signatures indicate that the Zhuogapu Mg-rich andesites were most likely derived from partial melting of a delaminated mafic lower crust (including the lowermost crust straddling the northern and central Lhasa subterranes) that led to the generation of the Zhuogapu primary melts with adakitic signatures and small negative εNd(t). Such melts subsequently experienced interaction of melt-asthenospheric mantle peridotite followed by the modification of highly fractionated magmas in shallow crustal magma chamber. Hornblende-controlled fractionation results in the change of geochemical composition from Mg-rich andesitic to Mg-rich dacitic magmas. Field observations, together with geochronological and geochemical data, indicate that the Zhuogapu Mg-rich volcanic rocks and coeval magmatism in the northern Lhasa subterrane may be the result of thickened lithospheric delamination

  20. Middle Neoproterozoic (ca. 705-716 Ma) arc to rift transitional magmatism in the northern margin of the Yangtze Block: Constraints from geochemistry, zircon U-Pb geochronology and Hf isotopes

    Science.gov (United States)

    Wang, Ruirui; Xu, Zhiqin; Santosh, M.; Xu, Xianbing; Deng, Qi; Fu, Xuehai

    2017-09-01

    The South Qinling Belt in Central China is an important window to investigate the Neoproterozoic tectono-magmatic processes along the northern margin of the Yangtze Block. Here we present whole-rock geochemistry, zircon U-Pb geochronology and Lu-Hf isotopes of a suite of Middle Neoproterozoic intrusion from the Wudang Uplift in South Qinling. Zircon LA-ICP-MS U-Pb ages reveal that these rocks were formed at ca. 705-716 Ma. Geochemical features indicate that the felsic magmatic rocks are I-type granitoids, belong to calcic- to calc-alkaline series, and display marked negative Nb, Ta and Ti anomalies. Moreover, the enrichment of light rare earth elements (LREEs) and large ion lithophile elements (LILEs), combined with depletion of heavy rare earth elements (HREEs) support that these rocks have affinity to typical arc magmatic rocks formed in Andean-type active continental margins. The REE patterns are highly to moderately fractionated, with (La/Yb)N = 5.13-8.10 in meta-granites, and 2.32-2.35 in granodiorite. The granitoids have a wide range of zircon εHf(t) values (-29.91 to 14.76) and zircon Hf two-stage model ages (696-3482 Ma). We suggest that the ca. 705-716 Ma granitoids were sourced from different degrees of magma mixing between partial melting of the overlying mantle wedge triggered by hydrous fluids released from subducted materials and crustal melting. The hybrid magmas were emplaced in the shallow crust accompanied by assimilation and fractional crystallization (AFC). Both isotopic and geochemical data suggest that the ca. 705-716 Ma felsic magmatic rocks were formed along a continental arc. These rocks as well as the contemporary A-type granite may mark a transitional tectonic regime from continental arc to rifting, probably related to slab rollback during the oceanic subduction beneath the northern margin of Yangtze Block.

  1. Structural Model of the Tubular Assembly of the Rous Sarcoma Virus Capsid Protein.

    Science.gov (United States)

    Jeon, Jaekyun; Qiao, Xin; Hung, Ivan; Mitra, Alok K; Desfosses, Ambroise; Huang, Daniel; Gor'kov, Peter L; Craven, Rebecca C; Kingston, Richard L; Gan, Zhehong; Zhu, Fangqiang; Chen, Bo

    2017-02-08

    The orthoretroviral capsid protein (CA) assembles into polymorphic capsids, whose architecture, assembly, and stability are still being investigated. The N-terminal and C-terminal domains of CA (NTD and CTD, respectively) engage in both homotypic and heterotypic interactions to create the capsid. Hexameric turrets formed by the NTD decorate the majority of the capsid surface. We report nearly complete solid-state NMR (ssNMR) resonance assignments of Rous sarcoma virus (RSV) CA, assembled into hexamer tubes that mimic the authentic capsid. The ssNMR assignments show that, upon assembly, large conformational changes occur in loops connecting helices, as well as the short 310 helix initiating the CTD. The interdomain linker becomes statically disordered. Combining constraints from ssNMR and cryo-electron microscopy (cryo-EM), we establish an atomic resolution model of the RSV CA tubular assembly using molecular dynamics flexible fitting (MDFF) simulations. On the basis of comparison of this MDFF model with an earlier-derived crystallographic model for the planar assembly, the induction of curvature into the RSV CA hexamer lattice arises predominantly from reconfiguration of the NTD-CTD and CTD trimer interfaces. The CTD dimer and CTD trimer interfaces are also intrinsically variable. Hence, deformation of the CA hexamer lattice results from the variable displacement of the CTDs that surround each hexameric turret. Pervasive H-bonding is found at all interdomain interfaces, which may contribute to their malleability. Finally, we find helices at the interfaces of HIV and RSV CA assemblies have very different contact angles, which may reflect differences in the capsid assembly pathway for these viruses.

  2. Meta-igneous (non-gneissic) tonalites and quartz-diorites from an extensive ca. 3800 Ma terrain south of the Isua supracrustal belt, southern West Greenland: constraints on early crust formation

    Science.gov (United States)

    Nutman, Allen P.; Bennett, Vickie C.; Friend, Clark R. L.; Norman, Marc D.

    In the Itsaq Gneiss Complex south of the Isua supracrustal belt (West Greenland) some areas of early Archaean tonalite and quartz-diorite are non-gneissic, free of pegmatite veins, and in rarer cases are undeformed with relict igneous textures and hence were little modified by heterogeneous ductile deformation under amphibolite facies conditions in several Archaean events. Such well-preserved early Archaean rocks are extremely rare. Tonalites are high Al, and have bulk compositions close to experimental liquids. Trace element abundances and modelling suggest that they probably originated as melts derived from basaltic compositions at sufficiently high pressures to require residual garnet + amphibolites +/- clinopyroxene in the source. The major element characteristics of the quartz-diorites suggest these were derived from more mafic magmas than the tonalites, and underwent either igneous differentiation or mixing with crustal material. As in modern arc magmas, high relative abundances of Sr, Ba, Pb, and alkali elements cannot be generated simply from a basaltic source formed by large degrees of melting of a depleted mantle. This may indicate an important role for fluids interacting with mafic rocks in generating the earliest preserved continental crust. The high Ba/Th, Ba/Nb, La/Nb and low Nb/Th, Ce/Pb, and Rb/Cs ratios of these tonalites are also observed in modern arc magmas. SHRIMP U-Pb zircon geochronology was undertaken on seven tonalites, one quartz-diorite, a thin pegmatitic vein and a thin diorite dyke. Cathodoluminescence images show the zircon populations of the quartz-diorite and tonalites are dominated by single-component oscillatory-zoned prismatic grains, which gave ages of 3806+/-5 to 3818+/-8Ma (2σ) (quartz-diorite and 5 tonalites) and 3795+/-3Ma (1 tonalite). Dating of recrystallised domains cutting oscillatory-zoned zircon indicates disturbance as early as 3800-3780Ma. There are rare ca. 3600Ma and 3800-3780Ma (very high U and low Th/U)<=20

  3. Critical Role of Conserved Hydrophobic Residues within the Major Homology Region in Mature Retroviral Capsid Assembly ▿

    Science.gov (United States)

    Purdy, John G.; Flanagan, John M.; Ropson, Ira J.; Rennoll-Bankert, Kristen E.; Craven, Rebecca C.

    2008-01-01

    During retroviral maturation, the CA protein undergoes dramatic structural changes and establishes unique intermolecular interfaces in the mature capsid shell that are different from those that existed in the immature precursor. The most conserved region of CA, the major homology region (MHR), has been implicated in both immature and mature assembly, although the precise contribution of the MHR residues to each event has been largely undefined. To test the roles of specific MHR residues in mature capsid assembly, an in vitro system was developed that allowed for the first-time formation of Rous sarcoma virus CA into structures resembling authentic capsids. The ability of CA to assemble organized structures was destroyed by substitutions of two conserved hydrophobic MHR residues and restored by second-site suppressors, demonstrating that these MHR residues are required for the proper assembly of mature capsids in addition to any role that these amino acids may play in immature particle assembly. The defect caused by the MHR mutations was identified as an early step in the capsid assembly process. The results provide strong evidence for a model in which the hydrophobic residues of the MHR control a conformational reorganization of CA that is needed to initiate capsid assembly and suggest that the formation of an interdomain interaction occurs early during maturation. PMID:18400856

  4. X-Ray Structures of Native HIV-1 Capsid Protein Reveal Conformational Variability

    Science.gov (United States)

    Gres, Anna T.; Kirby, Karen A.; KewalRamani, Vineet N.; Tanner, John J.; Pornillos, Owen; Sarafianos, Stefan G.

    2015-01-01

    The detailed molecular interactions between Human Immunodeficiency Virus type 1 (HIV-1) capsid protein (CA) hexamers have been elusive in the context of a native protein. We report crystal structures describing novel interactions between CA monomers related by 6-fold symmetry within a hexamer (intra-hexamer) and by 3-fold and 2-fold symmetry between neighboring hexamers (inter-hexamer). These structures help elucidate how CA builds a hexagonal lattice, the foundation of the mature capsid. Lattice structure depends on an adaptable hydration layer that modulates interactions among CA molecules. Disruption of this layer by crystal dehydration treatment alters inter-hexamer interfaces and condenses CA packing, highlighting an inherent structural variability. Capsid stability changes imparted by high concentrations of CA-targeting antiviral PF74 can be explained by variations at inter-hexamer interfaces remote to the ligand binding site. Inherent structural plasticity, hydration layer rearrangement, and effector molecule binding may perturb capsid uncoating or assembly and have functional implications for the retroviral life cycle. PMID:26044298

  5. Purification of recombinant budgerigar fledgling disease virus VP1 capsid protein and its ability for in vitro capsid assembly

    Science.gov (United States)

    Rodgers, R. E.; Chang, D.; Cai, X.; Consigli, R. A.; Spooner, B. S. (Principal Investigator)

    1994-01-01

    A recombinant system for the major capsid VP1 protein of budgerigar fledgling disease virus has been established. The VP1 gene was inserted into a truncated form of the pFlag-1 vector and expressed in Escherichia coli. The budgerigar fledgling disease virus VP1 protein was purified to near homogeneity by immunoaffinity chromatography. Fractions containing highly purified VP1 were pooled and found to constitute 3.3% of the original E. coli-expressed VP1 protein. Electron microscopy revealed that the VP1 protein was isolated as pentameric capsomeres. Electron microscopy also revealed that capsid-like particles were formed in vitro from purified VP1 capsomeres with the addition of Ca2+ ions and the removal of chelating and reducing agents.

  6. Geochemistry, U-Pb geochronology, Sm-Nd and O isotopes of ca. 50 Ma long Ediacaran High-K Syn-Collisional Magmatism in the Pernambuco Alagoas Domain, Borborema Province, NE Brazil

    Science.gov (United States)

    Francisco da Silva Filho, Adejardo; de Pinho Guimarães, Ignez; Santos, Lucilene; Armstrong, Richard; Van Schmus, William Randall

    2016-07-01

    The Pernambuco Alagoas (PEAL) domain shows the major occurrence of granitic batholiths of the Borborema Province, NE Brazil, with Archean to Neoproterozoic range of Nd TDM model ages, giving clues on the role of granites during the Brasiliano orogeny. SHRIMP U/Pb zircon geochronological data for seven granitic intrusions of the PEAL domain divide the studied granitoids into three groups: 1) early-to syn-collision granitoids with crystallization ages ca. 635 Ma (Serra do Catú pluton), 2) syn-collision granitoids with crystallization ages 610-618 Ma (Santana do Ipanema, Água Branca, Mata Grande and Correntes plutons) and 3) late-to post-collision granitoids with ages of ca. 590 Ma (Águas Belas, and Cachoeirinha plutons). The intrusions of group 1 and 2, except the Mata Grande and Correntes plutons, show Nd TDM model ages ranging from 1.2 to 1.5 Ga, while the granitoids from group 3, and Mata Grande Pluton and Correntes plutons have Nd TDM model ages ranging from 1.7 to 2.2 Ga. The studied granitoids with ages plutons, together with the available Nd isotopic data suggest that the Brasiliano orogeny strongly reworked older crust, of either Paleoproterozoic or Tonian ages. The studied granitoids are coeval with calc-alkaline granitoids of the Transversal Zone and Sergipano domains and rare high-K calc-alkaline granitoids from the Transversal Zone domain. Such large volumes of high-K granitoids with crystallization ages older than 600 Ma are not recorded in the Transversal Zone domains, suggesting that at least between 600 and 650 Ma, the granitic magmatism of these two areas were distinct. However, the studied granitoids (630-580 Ma) located in the north part of the PEAL domain, north of the Palmares shear zone are coeval with granitoids of similar geochemical compositions in the Transversal Zone domain. It suggests that the southeastern part of the Transversal Zone and the northern part of the PEAL domains belonged to the same crustal block during the Brasiliano

  7. Cyclophilin A stabilizes the HIV-1 capsid through a novel non-canonical binding site

    Science.gov (United States)

    Liu, Chuang; Perilla, Juan R.; Ning, Jiying; Lu, Manman; Hou, Guangjin; Ramalho, Ruben; Himes, Benjamin A.; Zhao, Gongpu; Bedwell, Gregory J.; Byeon, In-Ja; Ahn, Jinwoo; Gronenborn, Angela M.; Prevelige, Peter E.; Rousso, Itay; Aiken, Christopher; Polenova, Tatyana; Schulten, Klaus; Zhang, Peijun

    2016-03-01

    The host cell factor cyclophilin A (CypA) interacts directly with the HIV-1 capsid and regulates viral infectivity. Although the crystal structure of CypA in complex with the N-terminal domain of the HIV-1 capsid protein (CA) has been known for nearly two decades, how CypA interacts with the viral capsid and modulates HIV-1 infectivity remains unclear. We determined the cryoEM structure of CypA in complex with the assembled HIV-1 capsid at 8-Å resolution. The structure exhibits a distinct CypA-binding pattern in which CypA selectively bridges the two CA hexamers along the direction of highest curvature. EM-guided all-atom molecular dynamics simulations and solid-state NMR further reveal that the CypA-binding pattern is achieved by single-CypA molecules simultaneously interacting with two CA subunits, in different hexamers, through a previously uncharacterized non-canonical interface. These results provide new insights into how CypA stabilizes the HIV-1 capsid and is recruited to facilitate HIV-1 infection.

  8. X-Ray Structures of the Hexameric Building Block of the HIV Capsid

    Energy Technology Data Exchange (ETDEWEB)

    Pornillos, Owen; Ganser-Pornillos, Barbie K.; Kelly, Brian N.; Hua, Yuanzi; Whitby, Frank G.; Stout, C. David; Sundquist, Wesley I.; Hill, Christopher P.; Yeager, Mark; (Scripps); (Utah)

    2009-09-11

    The mature capsids of HIV and other retroviruses organize and package the viral genome and its associated enzymes for delivery into host cells. The HIV capsid is a fullerene cone: a variably curved, closed shell composed of approximately 250 hexamers and exactly 12 pentamers of the viral CA protein. We devised methods for isolating soluble, assembly-competent CA hexamers and derived four crystallographically independent models that define the structure of this capsid assembly unit at atomic resolution. A ring of six CA N-terminal domains form an apparently rigid core, surrounded by an outer ring of C-terminal domains. Mobility of the outer ring appears to be an underlying mechanism for generating the variably curved lattice in authentic capsids. Hexamer-stabilizing interfaces are highly hydrated, and this property may be key to the formation of quasi-equivalent interactions within hexamers and pentamers. The structures also clarify the molecular basis for capsid assembly inhibition and should facilitate structure-based drug design strategies.

  9. Magnetostratigraphy and 39Ar/40Ar studies of the Lana'i Long Volcanic Sequence (ca. 1.606+/-0.063 Ma), Hawaii, USA

    Science.gov (United States)

    Herrero-Bervera, E.; Jicha, B.; Valet, J.

    2013-12-01

    Previous published work on Lanai indicated that the volcano was formed mainly during the Matuyama Chron (Herrero-Bervera et al., 2000). In order to constrain further the timing of the active phases of the Lanai volcano, we conducted a paleomagnetic and rock magnetic study involving a ~500-m vertical thick sequence of lava flows that were erupted between 0.76+/-0.66 Ma and 1.6+/-0.09 Ma according to previous K/Ar and 40Ar/39Ar dating (Leonhardt et al., 2009). Low-field susceptibility versus temperature (k-T) and SIRM experiments performed on a dozen flows indicate that magnetite dominates the remanent magnetization (575°C). In a few cases, a low-temperature mineral phase (300-400°C) could reflect the presence of titanomagnetite with low Ti content, but the presence of maghemite or pyrrhotite cannot be completely excluded. Additional investigations are in progress on this matter. All specimens were step-wise demagnetized by alternating fields from 5 to 100 mT. Companion specimens from the same samples were demagnetized at 15 temperature steps. The demagnetization diagrams obtained with each technique showed a stable direction of remanence. In all cases, the characteristic (ChRM) component was clearly defined from at least seven successive directions isolated during step-wise demagnetization. The succession of the mean directions calculated for each lava flow reveals the existence of at least one polarity interval. Based on radiometric dates, they were assigned to the Gilsa, "excursion" (1.606+/-0.063 Ma). Thus, the present results, along with the radiometric ages of the lavas, indicate that the tholeiitic flows that formed the Lanai volcano were erupted over a short time period, and only during the Matuyama Chron (0.780-2.58 Ma). No eruptions have occurred during the Brunhes Chron (0.78 Ma) as previously indicated from K-Ar data on lavas in the Maunalei Gulch. The excursional VGPs from the onset of the Gilsa excursion recorded on Lanai are situated near the

  10. The Ni-Cu-PGE mineralized Brejo Seco mafic-ultramafic layered intrusion, Riacho do Pontal Orogen: Onset of Tonian (ca. 900 Ma) continental rifting in Northeast Brazil

    Science.gov (United States)

    Salgado, Silas Santos; Ferreira Filho, Cesar Fonseca; Caxito, Fabrício de Andrade; Uhlein, Alexandre; Dantas, Elton Luiz; Stevenson, Ross

    2016-10-01

    The Brejo Seco mafic-ultramafic Complex (BSC) occurs at the extreme northwest of the Riacho do Pontal Orogen Internal Zone, in the northern margin of the São Francisco Craton in Northeast Brazil. The stratigraphy of this medium size (3.5 km wide and 9 km long) layered intrusion consists of four main zones, from bottom to top: Lower Mafic Zone (LMZ; mainly troctolite), Ultramafic Zone (UZ; mainly dunite and minor troctolite); Transitional Mafic Zone (TMZ; mainly troctolite) and an Upper Mafic Zone (UMZ; gabbro and minor anorthosite, troctolite, and ilmenite magnetitite). Ni-Cu-PGE mineralization occurs at the contact of the UZ with the TMZ, consisting of an up to 50 m thick stratabound zone of disseminated magmatic sulfides. An Mg-tholeiitic affinity to the parental magma is indicated by the geochemical fractionation pattern, by the magmatic crystallization sequence and by the elevated Fo content in olivine. A Smsbnd Nd isochron yielded an age of 903 ± 20 Ma, interpreted as the age of crystallization, with initial εNd = 0.8. Evidence of interaction of the BSC parental magma with sialic crust is given by the Rare Earth and trace element patterns, and by slightly negative and overall low values of εNd(900 Ma) in between -0.2 and +3.3. Contrary to early interpretations that it might constitute an ophiolite complex, based mainly on the geochemistry of the host rocks (Morro Branco metavolcanosedimentary complex), here we interpret the BSC as a typical layered mafic-ultramafic intrusion in continental crust, related to an extensional regime. The BSC is chrono-correlated to mafic dyke swarms, anorogenic granites and thick bimodal volcanics of similar age and tectonic setting in the São Francisco Craton and surrounding areas. Intrusion of the BSC was followed by continued lithospheric thinning, which led to the development of the Paulistana Complex continental rift volcanics around 888 Ma and ultimately to plate separation and the generation of new oceanic crust (Monte

  11. Rationally designed interfacial peptides are efficient in vitro inhibitors of HIV-1 capsid assembly with antiviral activity.

    Directory of Open Access Journals (Sweden)

    Rebeca Bocanegra

    Full Text Available Virus capsid assembly constitutes an attractive target for the development of antiviral therapies; a few experimental inhibitors of this process for HIV-1 and other viruses have been identified by screening compounds or by selection from chemical libraries. As a different, novel approach we have undertaken the rational design of peptides that could act as competitive assembly inhibitors by mimicking capsid structural elements involved in intersubunit interfaces. Several discrete interfaces involved in formation of the mature HIV-1 capsid through polymerization of the capsid protein CA were targeted. We had previously designed a peptide, CAC1, that represents CA helix 9 (a major part of the dimerization interface and binds the CA C-terminal domain in solution. Here we have mapped the binding site of CAC1, and shown that it substantially overlaps with the CA dimerization interface. We have also rationally modified CAC1 to increase its solubility and CA-binding affinity, and designed four additional peptides that represent CA helical segments involved in other CA interfaces. We found that peptides CAC1, its derivative CAC1M, and H8 (representing CA helix 8 were able to efficiently inhibit the in vitro assembly of the mature HIV-1 capsid. Cocktails of several peptides, including CAC1 or CAC1M plus H8 or CAI (a previously discovered inhibitor of CA polymerization, or CAC1M+H8+CAI, also abolished capsid assembly, even when every peptide was used at lower, sub-inhibitory doses. To provide a preliminary proof that these designed capsid assembly inhibitors could eventually serve as lead compounds for development of anti-HIV-1 agents, they were transported into cultured cells using a cell-penetrating peptide, and tested for antiviral activity. Peptide cocktails that drastically inhibited capsid assembly in vitro were also able to efficiently inhibit HIV-1 infection ex vivo. This study validates a novel, entirely rational approach for the design of capsid

  12. Inhibition of HIV-1 Maturation via Small-Molecule Targeting of the Amino-Terminal Domain in the Viral Capsid Protein.

    Science.gov (United States)

    Wang, Weifeng; Zhou, Jing; Halambage, Upul D; Jurado, Kellie A; Jamin, Augusta V; Wang, Yujie; Engelman, Alan N; Aiken, Christopher

    2017-05-01

    The human immunodeficiency virus type 1 (HIV-1) capsid protein is an attractive therapeutic target, owing to its multifunctionality in virus replication and the high fitness cost of amino acid substitutions in capsids to HIV-1 infectivity. To date, small-molecule inhibitors have been identified that inhibit HIV-1 capsid assembly and/or impair its function in target cells. Here, we describe the mechanism of action of the previously reported capsid-targeting HIV-1 inhibitor, Boehringer-Ingelheim compound 1 (C1). We show that C1 acts during HIV-1 maturation to prevent assembly of a mature viral capsid. However, unlike the maturation inhibitor bevirimat, C1 did not significantly affect the kinetics or fidelity of Gag processing. HIV-1 particles produced in the presence of C1 contained unstable capsids that lacked associated electron density and exhibited impairments in early postentry stages of infection, most notably reverse transcription. C1 inhibited assembly of recombinant HIV-1 CA in vitro and induced aberrant cross-links in mutant HIV-1 particles capable of spontaneous intersubunit disulfide bonds at the interhexamer interface in the capsid lattice. Resistance to C1 was conferred by a single amino acid substitution within the compound-binding site in the N-terminal domain of the CA protein. Our results demonstrate that the binding site for C1 represents a new pharmacological vulnerability in the capsid assembly stage of the HIV-1 life cycle.IMPORTANCE The HIV-1 capsid protein is an attractive but unexploited target for clinical drug development. Prior studies have identified HIV-1 capsid-targeting compounds that display different mechanisms of action, which in part reflects the requirement for capsid function at both the efferent and afferent phases of viral replication. Here, we show that one such compound, compound 1, interferes with assembly of the conical viral capsid during virion maturation and results in perturbations at a specific protein

  13. Dynamic pathways for viral capsid assembly

    OpenAIRE

    Hagan, Michael F.; Chandler, David

    2006-01-01

    We develop a class of models with which we simulate the assembly of particles into T1 capsid-like objects using Newtonian dynamics. By simulating assembly for many different values of system parameters, we vary the forces that drive assembly. For some ranges of parameters, assembly is facile, while for others, assembly is dynamically frustrated by kinetic traps corresponding to malformed or incompletely formed capsids. Our simulations sample many independent trajectories at various capsomer c...

  14. Mutational Analysis and Allosteric Effects in the HIV-1 Capsid Protein Carboxyl-Terminal Dimerization Domain

    Science.gov (United States)

    2009-01-01

    The carboxyl-terminal domain (CTD, residues 146−231) of the HIV-1 capsid (CA) protein plays an important role in the CA−CA dimerization and viral assembly of the human immunodeficiency virus type 1. Disrupting the native conformation of the CA is essential for blocking viral capsid formation and viral replication. Thus, it is important to identify the exact nature of the structural changes and driving forces of the CTD dimerization that take place in mutant forms. Here, we compare the structural stability, conformational dynamics, and association force of the CTD dimers for both wild-type and mutated sequences using all-atom explicit-solvent molecular dynamics (MD). The simulations show that Q155N and E159D at the major homology region (MHR) and W184A and M185A at the helix 2 region are energetically less favorable than the wild-type, imposing profound negative effects on intermolecular CA−CA dimerization. Detailed structural analysis shows that three mutants (Q155N, E159D, and W184A) display much more flexible local structures and weaker CA−CA association than the wild-type, primarily due to the loss of interactions (hydrogen bonds, side chain hydrophobic contacts, and π-stacking) with their neighboring residues. Most interestingly, the MHR that is far from the interacting dimeric interface is more sensitive to the mutations than the helix 2 region that is located at the CA−CA dimeric interface, indicating that structural changes in the distinct motif of the CA could similarly allosterically prevent the CA capsid formation. In addition, the structural and free energy comparison of the five residues shorter CA (151−231) dimer with the CA (146−231) dimer further indicates that hydrophobic interactions, side chain packing, and hydrogen bonds are the major, dominant driving forces in stabilizing the CA interface. PMID:19199580

  15. Stabilising the Herpes Simplex Virus capsid by DNA packaging

    Science.gov (United States)

    Wuite, Gijs; Radtke, Kerstin; Sodeik, Beate; Roos, Wouter

    2009-03-01

    Three different types of Herpes Simplex Virus type 1 (HSV-1) nuclear capsids can be distinguished, A, B and C capsids. These capsids types are, respectively, empty, contain scaffold proteins, or hold DNA. We investigate the physical properties of these three capsids by combining biochemical and nanoindentation techniques. Atomic Force Microscopy (AFM) experiments show that A and C capsids are mechanically indistinguishable whereas B capsids already break at much lower forces. By extracting the pentamers with 2.0 M GuHCl or 6.0 M Urea we demonstrate an increased flexibility of all three capsid types. Remarkably, the breaking force of the B capsids without pentamers does not change, while the modified A and C capsids show a large drop in their breaking force to approximately the value of the B capsids. This result indicates that upon DNA packaging a structural change at or near the pentamers occurs which mechanically reinforces the capsids structure. The reported binding of proteins UL17/UL25 to the pentamers of the A and C capsids seems the most likely candidate for such capsids strengthening. Finally, the data supports the view that initiation of DNA packaging triggers the maturation of HSV-1 capsids.

  16. Mechanical oscillations of a viral capsid

    Science.gov (United States)

    Benson, Daryn; Sankey, Otto; Dykeman, Eric

    2010-03-01

    Viruses are sub-microscopic infectious agents that infect almost every living creature on Earth. They are unable to grow or reproduce outside of a host cell and are therefore parasitic in nature. A virus' internal genetic material is protected by an external protein coat (capsid). We developed a theoretical model which uses the interaction of light with a viral capsid to create large amplitude motions within the capsid. This work displays the results of the model on the tobacco mosaic virus (TMV) with attached RNA genome. The development of this model was motivated by the experimental work of Tsen et. al. [1] who used ultra-short laser pulses to inactivate viruses. [1] K-T. Tsen et al., J. of Physics -- Cond. Mat. 19, 472201 (2007).

  17. Dynamic pathways for viral capsid assembly

    Energy Technology Data Exchange (ETDEWEB)

    Hagan, Michael F.; Chandler, David

    2006-02-09

    We develop a class of models with which we simulate the assembly of particles into T1 capsid-like objects using Newtonian dynamics. By simulating assembly for many different values of system parameters, we vary the forces that drive assembly. For some ranges of parameters, assembly is facile, while for others, assembly is dynamically frustrated by kinetic traps corresponding to malformed or incompletely formed capsids. Our simulations sample many independent trajectories at various capsomer concentrations, allowing for statistically meaningful conclusions. Depending on subunit (i.e., capsomer) geometries, successful assembly proceeds by several mechanisms involving binding of intermediates of various sizes. We discuss the relationship between these mechanisms and experimental evaluations of capsid assembly processes.

  18. Crosslinking in viral capsids via tiling theory.

    Science.gov (United States)

    Twarock, R; Hendrix, R W

    2006-06-07

    A vital part of a virus is its protein shell, called the viral capsid, that encapsulates and hence protects the viral genome. It has been shown in Twarock [2004. A tiling approach to vius capsids assembly explaining a structural puzzle in virology. J. Theor. Biol. 226, 477-482] that the surface structures of viruses with icosahedrally symmetric capsids can be modelled in terms of tilings that encode the locations of the protein subunits. This theory is extended here to multi-level tilings in order to model crosslinking structures. The new framework is demonstrated for the case of bacteriophage HK97, and it is shown, how the theory can be used in general to decide if crosslinking, and what type of crosslinking, is compatible from a mathematical point of view with the geometrical surface structure of a virus.

  19. A CaCO3 Deposition Record During the Last 2 Ma in Southern Tasman Rise of Southern Ocean and Its Responses to the Circulation System and Orbital Cycles%南塔斯曼海隆2Ma以来碳酸钙沉积记录及其对环流系统和轨道周期的响应

    Institute of Scientific and Technical Information of China (English)

    胡正莹; 王汝建; 李文宝

    2013-01-01

    The Southern Ocean CaCO3 deposition not only records the processes of the biological pump modulating atmospheric CO2, but also the changes in Southern Ocean surface frontal system and the structure of deep o-cean circulation. CaCO3% and its mass accumulation rate (MAR) changes at Tasman Sea site ODP 1170 during the past 2 Ma indicate a "Atlantic-style" feature with low CaCO3% during glacials and high during interglacials. Three sedimentary regimes are presented roughly bounded by MIS 34/35 (1.15 Ma BP) and MIS 14/15 (0.55 Ma BP); and the MAR-CaCO3 represents five phases fluctuation. Cross-spectrum and wavelet analysis of CaCO3% and orbital parameters ETP, and benthic δ18O records show clear Mid-Pleistocene Transition ( MPT) pattern of the main cyclicity transits from 40 ka to 100 ka, from 1.15 to 0. 55 Ma BP. The changes in CaCO3 deposition are closely related to the changes in Southern Westerlies and Antarctic Circumpolar Current( ACC) frontal system, and synchronous with the MPT. During the MPT, the rapid migration of the Southern Westerlies and ACC frontal system resulted in the dilution effect of siliceous deposition and terrigeneous input to the CaCO3 deposition. The MAR-CaCO3 variability is related to the changes in deepwater structure and its chemical properties. At 1.5 ~ 0. 85 Ma BP, Southern Ocean deep water ventilation was enhanced, which favored the preservation of CaCO3 and increased the MAR-CaCO3; at 0. 85~0.55 Ma BP, CO2-3 depleted Circumpolar Deep Water was enhanced, resulting in the dissolution of CaCO3, and the rise of lysocline and decrease of MAR-CaCO3.%南大洋CaCO3沉积在记录生物泵调节大气CO2的同时,也记录了南大洋表层锋面系统和深部环流格局的重要转变.通过南塔斯曼海ODP 1170站位2 Ma以来CaCO3%和MAR-CaCO3的研究发现,CaCO3%以冰期低和间冰期高的“大西洋”型溶解作用旋回为主,并以MIS 34/35期(约1.15 Ma BP)和MIS 14/15期(约0.55 Ma BP)为界线,表现出3种沉积模式.而MAR-Ca

  20. Viral capsids: Mechanical characteristics, genome packaging and delivery mechanisms

    NARCIS (Netherlands)

    Roos, W.H.; Ivanovska, I.L.; Evilevitch, A.; Wuite, G.J.L.

    2007-01-01

    The main functions of viral capsids are to protect, transport and deliver their genome. The mechanical properties of capsids are supposed to be adapted to these tasks. Bacteriophage capsids also need to withstand the high pressures the DNA is exerting onto it as a result of the DNA packaging and its

  1. Hexagonal organization of Moloney murine leukemia virus capsid proteins.

    Science.gov (United States)

    Mayo, Keith; McDermott, Jason; Barklis, Eric

    2002-06-20

    To help elucidate the mechanisms by which retrovirus structural proteins associate to form virus particles, we have examined membrane-bound assemblies of Moloney murine leukemia virus (M-MuLV) capsid (CA) proteins. Electron microscopy and image reconstruction techniques showed that CA dimers appear to function as organizational subunits of the cage-like, membrane-bound protein arrays. However, new three-dimensional (3D) data also were consistent with hexagonal (p6) assembly models. The p6 3D reconstructions of membrane-bound M-MuLV CA proteins gave unit cells of a = b = 80.3 A, c = 110 A, gamma = 120 degrees, in which six dimer units formed a cage lattice. Neighbor cage hole-to-hole distances were 45 A, while distances between hexagonal cage holes corresponded to unit cell lengths (80.3 A). The hexagonal model predicts two types of cage holes (trimer and hexamer holes), uses symmetric head-to-head dimer building blocks, and permits the introduction of lattice curvature by conversion of hexamer to pentamer units. The M-MuLV CA lattice is similar to those formed in helical tubes by HIV CA in that hexamer units surround cage holes of 25-30 A, but differs in that M-MuLV hexamer units appear to be CA dimers, whereas HIV CA units appear to be monomers. These results suggest that while general assembly principles apply to different retroviruses, clear assembly distinctions exist between these virus types. (c) 2002 Elsevier Science (USA).

  2. Virus capsid dissolution studied by microsecond molecular dynamics simulations.

    Science.gov (United States)

    Larsson, Daniel S D; Liljas, Lars; van der Spoel, David

    2012-01-01

    Dissolution of many plant viruses is thought to start with swelling of the capsid caused by calcium removal following infection, but no high-resolution structures of swollen capsids exist. Here we have used microsecond all-atom molecular simulations to describe the dynamics of the capsid of satellite tobacco necrosis virus with and without the 92 structural calcium ions. The capsid expanded 2.5% upon removal of the calcium, in good agreement with experimental estimates. The water permeability of the native capsid was similar to that of a phospholipid membrane, but the permeability increased 10-fold after removing the calcium, predominantly between the 2-fold and 3-fold related subunits. The two calcium binding sites close to the icosahedral 3-fold symmetry axis were pivotal in the expansion and capsid-opening process, while the binding site on the 5-fold axis changed little structurally. These findings suggest that the dissociation of the capsid is initiated at the 3-fold axis.

  3. Impact of capsid conformation and Rep-capsid interactions on adeno-associated virus type 2 genome packaging.

    Science.gov (United States)

    Bleker, Svenja; Pawlita, Michael; Kleinschmidt, Jürgen A

    2006-01-01

    Single-stranded genomes of adeno-associated virus (AAV) are packaged into preformed capsids. It has been proposed that packaging is initiated by interaction of genome-bound Rep proteins to the capsid, thereby targeting the genome to the portal of encapsidation. Here we describe a panel of mutants with amino acid exchanges in the pores at the fivefold axes of symmetry on AAV2 capsids with reduced packaging and reduced Rep-capsid interaction. Mutation of two threonines at the rim of the fivefold pore nearly completely abolished Rep-capsid interaction and packaging. This suggests a Rep-binding site at the highly conserved amino acids at or close to the pores formed by the capsid protein pentamers. A different mutant (P. Wu, W. Xiao, T. Conlon, J. Hughes, M. Agbandje-McKenna, T. Ferkol, T. Flotte, and N. Muzyczka, J. Virol. 74:8635-8647, 2000) with an amino acid exchange at the interface of capsid protein pentamers led to a complete block of DNA encapsidation. Analysis of the capsid conformation of this mutant revealed that the pores at the fivefold axes were occupied by VP1/VP2 N termini, thereby preventing DNA introduction into the capsid. Nevertheless, the corresponding capsids had more Rep proteins bound than wild-type AAV, showing that correct Rep interaction with the capsid depends on a defined capsid conformation. Both mutant types together support the conclusion that the pores at the fivefold symmetry axes are involved in genome packaging and that capsid conformation-dependent Rep-capsid interactions play an essential role in the packaging process.

  4. Kinetics versus Thermodynamics in Virus Capsid Polymorphism.

    Science.gov (United States)

    Moerman, Pepijn; van der Schoot, Paul; Kegel, Willem

    2016-07-07

    Virus coat proteins spontaneously self-assemble into empty shells in aqueous solution under the appropriate physicochemical conditions, driven by an interaction free energy per bond on the order of 2-5 times the thermal energy kBT. For this seemingly modest interaction strength, each protein building block nonetheless gains a very large binding free energy, between 10 and 20 kBT. Because of this, there is debate about whether the assembly process is reversible or irreversible. Here we discuss capsid polymorphism observed in in vitro experiments from the perspective of nucleation theory and of the thermodynamics of mass action. We specifically consider the potential contribution of a curvature free energy term to the effective interaction potential between the proteins. From these models, we propose experiments that may conclusively reveal whether virus capsid assembly into a mixture of polymorphs is a reversible or an irreversible process.

  5. Parvovirus capsid disorders cholesterol-rich membranes.

    Science.gov (United States)

    Pakkanen, Kirsi; Kirjavainen, Sanna; Mäkelä, Anna R; Rintanen, Nina; Oker-Blom, Christian; Jalonen, Tuula O; Vuento, Matti

    2009-02-06

    In this study canine parvovirus, CPV, was found to induce disorder in DPPC:cholesterol membranes in acidic conditions. This acidicity-induced fluidizing effect is suggested to originate from the N-terminus of the viral capsid protein VP1. In accordance with the model membrane studies, a fluidizing effect was seen also in the endosomal membranes during CPV infection implying an important functional role of the fluidization in the endocytic entry of the virus.

  6. Mechanostability of Proteins and Virus Capsids

    Science.gov (United States)

    Cieplak, Marek

    2013-03-01

    Molecular dynamics of proteins within coarse grained models have become a useful tool in studies of large scale systems. The talk will discuss two applications of such modeling. The first is a theoretical survey of proteins' resistance to constant speed stretching as performed for a set of 17134 simple and 318 multidomain proteins. The survey has uncovered new potent force clamps. They involve formation of cysteine slipknots or dragging of a cystine plug through the cystine ring and lead to characteristic forces that are significantly larger than the common shear-based clamp such as observed in titin. The second application involves studies of nanoindentation processes in virus capsids and elucidates their molecular aspects by showing deviations in behavior compared to the continuum shell model. Across the 35 capsids studied, both the collapse force and the elastic stiffness are observed to vary by a factor of 20. The changes in mechanical properties do not correlate simply with virus size or symmetry. There is a strong connection to the mean coordination number , defined as the mean number of interactions to neighboring amino acids. The Young's modulus for thin shell capsids rises roughly quadratically with - 6, where 6 is the minimum coordination for elastic stability in three dimensions. Supported by European Regional Development Fund, through Innovative Economy grant Nanobiom (POIG.01.01.02-00-008/08)

  7. Morotochoerus from Uganda (17.5 Ma and Kenyapotamus from Kenya (13-11 Ma: implications for hippopotamid origins

    Directory of Open Access Journals (Sweden)

    Pickford, M.

    2011-12-01

    Full Text Available The aim of this paper is to describe and interpret suiform teeth from Moroto, Uganda, and Ngorora, Kenya, which contribute to the debate about hippo-anthracothere-whale relationships. The early stages of hippopotamid evolution are relatively poorly known on account of the paucity of their fossil record older than 7 Ma. New specimens of Morotochoerus from Uganda reveal that it is not closely related to Hippopotamidae; the superficial resemblances of the cheek teeth to those of hippos represent convergences and not homologies. Restricted samples of Palaeopotamus ternani are available from the Middle Miocene of Kenya {Maboko, ca 16 Ma; Muruyur, ca 14.5 Ma; Fort Ternan, ca 13.7 Ma} while from the base of the late Miocene, Kenyapotamus coryndonae is known from Kenya {Ngerngerwa, ca 10.5-10 Ma; Nakali, ca 10.5 Ma; Samburu Hills, ca 9.5 Ma}, Ethiopia {Ch’orora, ca 10.5 Ma} and Tunisia {Beglia Formation ca 11-10 Ma}. The recovery of specimens of Kenyapotamus from the Ngorora Formation, Kenya, aged ca 11 Ma, is of interest because it includes well preserved teeth, including an m/3 in good condition. These specimens support the hypothesis that hippopotamids descended from palaeochoerids and not from anthracotheres.El objetivo de este trabajo es describir e interpretar los dientes suiformes de Moroto, Uganda, y Ngorora, Kenia, que contribuyen al debate sobre las relaciones hipo-anthracothere-whale. Las primeras etapas de la evolución de los hipopotámidos son relativamente poco conocidas a causa de la escasez de su registro fósil en edades superiors a los 7 Ma. Nuevos ejemplares de Morotochoerus en Uganda revelan que no están estrechamente relacionados con Hippopotamidae, las semejanzas superficiales de los dientes de la mandíbula con los de los hipopótamos representan convergencias y no homologías. Algunas muestras de Palaeopotamus ternani aparecen en el Medio Mioceno de Kenia {Maboko, ca 16 Ma; Muruyur, ca 14.5 Ma; Fort Ternan, ca 13.7 Ma

  8. Classification and Evolutionary Trends of Icosahedral Viral Capsids

    Directory of Open Access Journals (Sweden)

    Richard Kerner

    2008-01-01

    Full Text Available A classification of icosahedral viral capsids is proposed. We show how the self-organization of capsids during their formation implies a definite composition of their elementary building blocks. The exact number of hexamers with three different admissible symmetries is related to capsids' sizes, labelled by their T-numbers. Simple rules determining these numbers for each value of T are deduced and certain consequences concerning the probabilities of mutations and evolution of viruses are discussed.

  9. Large-scale functional purification of recombinant HIV-1 capsid.

    Directory of Open Access Journals (Sweden)

    Magdeleine Hung

    Full Text Available During human immunodeficiency virus type-1 (HIV-1 virion maturation, capsid proteins undergo a major rearrangement to form a conical core that protects the viral nucleoprotein complexes. Mutations in the capsid sequence that alter the stability of the capsid core are deleterious to viral infectivity and replication. Recently, capsid assembly has become an attractive target for the development of a new generation of anti-retroviral agents. Drug screening efforts and subsequent structural and mechanistic studies require gram quantities of active, homogeneous and pure protein. Conventional means of laboratory purification of Escherichia coli expressed recombinant capsid protein rely on column chromatography steps that are not amenable to large-scale production. Here we present a function-based purification of wild-type and quadruple mutant capsid proteins, which relies on the inherent propensity of capsid protein to polymerize and depolymerize. This method does not require the packing of sizable chromatography columns and can generate double-digit gram quantities of functionally and biochemically well-behaved proteins with greater than 98% purity. We have used the purified capsid protein to characterize two known assembly inhibitors in our in-house developed polymerization assay and to measure their binding affinities. Our capsid purification procedure provides a robust method for purifying large quantities of a key protein in the HIV-1 life cycle, facilitating identification of the next generation anti-HIV agents.

  10. An atomic model of HIV-1 capsid-SP1 reveals structures regulating assembly and maturation.

    Science.gov (United States)

    Schur, Florian K M; Obr, Martin; Hagen, Wim J H; Wan, William; Jakobi, Arjen J; Kirkpatrick, Joanna M; Sachse, Carsten; Kräusslich, Hans-Georg; Briggs, John A G

    2016-07-29

    Immature HIV-1 assembles at and buds from the plasma membrane before proteolytic cleavage of the viral Gag polyprotein induces structural maturation. Maturation can be blocked by maturation inhibitors (MIs), thereby abolishing infectivity. The CA (capsid) and SP1 (spacer peptide 1) region of Gag is the key regulator of assembly and maturation and is the target of MIs. We applied optimized cryo-electron tomography and subtomogram averaging to resolve this region within assembled immature HIV-1 particles at 3.9 angstrom resolution and built an atomic model. The structure reveals a network of intra- and intermolecular interactions mediating immature HIV-1 assembly. The proteolytic cleavage site between CA and SP1 is inaccessible to protease. We suggest that MIs prevent CA-SP1 cleavage by stabilizing the structure, and MI resistance develops by destabilizing CA-SP1.

  11. Impact of Capsid Conformation and Rep-Capsid Interactions on Adeno-Associated Virus Type 2 Genome Packaging

    OpenAIRE

    Bleker, Svenja; Pawlita, Michael; Kleinschmidt, Jürgen A.

    2006-01-01

    Single-stranded genomes of adeno-associated virus (AAV) are packaged into preformed capsids. It has been proposed that packaging is initiated by interaction of genome-bound Rep proteins to the capsid, thereby targeting the genome to the portal of encapsidation. Here we describe a panel of mutants with amino acid exchanges in the pores at the fivefold axes of symmetry on AAV2 capsids with reduced packaging and reduced Rep-capsid interaction. Mutation of two threonines at the rim of the fivefol...

  12. Structure of the small outer capsid protein, Soc: a clamp for stabilizing capsids of T4-like phages.

    Science.gov (United States)

    Qin, Li; Fokine, Andrei; O'Donnell, Erin; Rao, Venigalla B; Rossmann, Michael G

    2010-01-29

    Many viruses need to stabilize their capsid structure against DNA pressure and for survival in hostile environments. The 9-kDa outer capsid protein (Soc) of bacteriophage T4, which stabilizes the virus, attaches to the capsid during the final stage of maturation. There are 870 Soc molecules that act as a "glue" between neighboring hexameric capsomers, forming a "cage" that stabilizes the T4 capsid against extremes of pH and temperature. Here we report a 1.9 A resolution crystal structure of Soc from the bacteriophage RB69, a close relative of T4. The RB69 crystal structure and a homology model of T4 Soc were fitted into the cryoelectron microscopy reconstruction of the T4 capsid. This established the region of Soc that interacts with the major capsid protein and suggested a mechanism, verified by extensive mutational and biochemical studies, for stabilization of the capsid in which the Soc trimers act as clamps between neighboring capsomers. The results demonstrate the factors involved in stabilizing not only the capsids of T4-like bacteriophages but also many other virus capsids.

  13. Molecular interactions of Epstein-Barr virus capsid proteins.

    Science.gov (United States)

    Wang, Wen-Hung; Chang, Li-Kwan; Liu, Shih-Tung

    2011-02-01

    The capsids of herpesviruses, which comprise major and minor capsid proteins, have a common icosahedral structure with 162 capsomers. An electron microscopic study shows that Epstein-Barr virus (EBV) capsids in the nucleus are immunolabeled by anti-BDLF1 and anti-BORF1 antibodies, indicating that BDLF1 and BORF1 are the minor capsid proteins of EBV. Cross-linking and electrophoresis studies of purified BDLF1 and BORF1 revealed that these two proteins form a triplex that is similar to that formed by the minor capsid proteins, VP19C and VP23, of herpes simplex virus type 1 (HSV-1). Although the interaction between VP23, a homolog of BDLF1, and the major capsid protein VP5 could not be verified biochemically in earlier studies, the interaction between BDLF1 and the EBV major capsid protein, viral capsid antigen (VCA), can be confirmed by glutathione S-transferase (GST) pulldown assay and coimmunoprecipitation. Additionally, in HSV-1, VP5 interacts with only the middle region of VP19C; in EBV, VCA interacts with both the N-terminal and middle regions of BORF1, a homolog of VP19C, revealing that the proteins in the EBV triplex interact with the major capsid protein differently from those in HSV-1. A GST pulldown study also identifies the oligomerization domains in VCA and the dimerization domain in BDLF1. The results presented herein reveal how the EBV capsid proteins interact and thereby improve our understanding of the capsid structure of the virus.

  14. Imaging of the alphavirus capsid protein during virus replication.

    Science.gov (United States)

    Zheng, Yan; Kielian, Margaret

    2013-09-01

    Alphaviruses are enveloped viruses with highly organized structures. The nucleocapsid (NC) core contains a capsid protein lattice enclosing the plus-sense RNA genome, and it is surrounded by a lipid bilayer containing a lattice of the E1 and E2 envelope glycoproteins. Capsid protein is synthesized in the cytoplasm and particle budding occurs at the plasma membrane (PM), but the traffic and assembly of viral components and the exit of virions from host cells are not well understood. To visualize the dynamics of capsid protein during infection, we developed a Sindbis virus infectious clone tagged with a tetracysteine motif. Tagged capsid protein could be fluorescently labeled with biarsenical dyes in living cells without effects on virus growth, morphology, or protein distribution. Live cell imaging and colocalization experiments defined distinct groups of capsid foci in infected cells. We observed highly motile internal puncta that colocalized with E2 protein, which may represent the transport machinery that capsid protein uses to reach the PM. Capsid was also found in larger nonmotile internal structures that colocalized with cellular G3BP and viral nsP3. Thus, capsid may play an unforeseen role in these previously observed G3BP-positive foci, such as regulation of cellular stress granules. Capsid puncta were also observed at the PM. These puncta colocalized with E2 and recruited newly synthesized capsid protein; thus, they may be sites of virus assembly and egress. Together, our studies provide the first dynamic views of the alphavirus capsid protein in living cells and a system to define detailed mechanisms during alphavirus infection.

  15. Host cofactors and pharmacologic ligands share an essential interface in HIV-1 capsid that is lost upon disassembly.

    Directory of Open Access Journals (Sweden)

    Amanda J Price

    2014-10-01

    Full Text Available The HIV-1 capsid is involved in all infectious steps from reverse transcription to integration site selection, and is the target of multiple host cell and pharmacologic ligands. However, structural studies have been limited to capsid monomers (CA, and the mechanistic basis for how these ligands influence infection is not well understood. Here we show that a multi-subunit interface formed exclusively within CA hexamers mediates binding to linear epitopes within cellular cofactors NUP153 and CPSF6, and is competed for by the antiretroviral compounds PF74 and BI-2. Each ligand is anchored via a shared phenylalanine-glycine (FG motif to a pocket within the N-terminal domain of one monomer, and all but BI-2 also make essential interactions across the N-terminal domain: C-terminal domain (NTD:CTD interface to a second monomer. Dissociation of hexamer into CA monomers prevents high affinity interaction with CPSF6 and PF74, and abolishes binding to NUP153. The second interface is conformationally dynamic, but binding of NUP153 or CPSF6 peptides is accommodated by only one conformation. NUP153 and CPSF6 have overlapping binding sites, but each makes unique CA interactions that, when mutated selectively, perturb cofactor dependency. These results reveal that multiple ligands share an overlapping interface in HIV-1 capsid that is lost upon viral disassembly.

  16. Multivalent viral capsids with internal cargo for fibrin imaging.

    Directory of Open Access Journals (Sweden)

    Allie C Obermeyer

    Full Text Available Thrombosis is the cause of many cardiovascular syndromes and is a significant contributor to life-threatening diseases, such as myocardial infarction and stroke. Thrombus targeted imaging agents have the capability to provide molecular information about pathological clots, potentially improving detection, risk stratification, and therapy of thrombosis-related diseases. Nanocarriers are a promising platform for the development of molecular imaging agents as they can be modified to have external targeting ligands and internal functional cargo. In this work, we report the synthesis and use of chemically functionalized bacteriophage MS2 capsids as biomolecule-based nanoparticles for fibrin imaging. The capsids were modified using an oxidative coupling reaction, conjugating ∼90 copies of a fibrin targeting peptide to the exterior of each protein shell. The ability of the multivalent, targeted capsids to bind fibrin was first demonstrated by determining the impact on thrombin-mediated clot formation. The modified capsids out-performed the free peptides and were shown to inhibit clot formation at effective concentrations over ten-fold lower than the monomeric peptide alone. The installation of near-infrared fluorophores on the interior surface of the capsids enabled optical detection of binding to fibrin clots. The targeted capsids bound to fibrin, exhibiting higher signal-to-background than control, non-targeted MS2-based nanoagents. The in vitro assessment of the capsids suggests that fibrin-targeted MS2 capsids could be used as delivery agents to thrombi for diagnostic or therapeutic applications.

  17. Studies towards the sex pheromone of the green capsid bug

    NARCIS (Netherlands)

    Drijfhout, F.P.

    2001-01-01

    The green capsid bug, Lygocoris pabulinus (L.) (Heteroptera: Miridae) is a serious pest in fruit orchards, which is difficult to control. Because it is difficult to determine the actual population density, fruit growers apply insecticides against the green capsid bug on

  18. Inhibition of protein kinase C phosphorylation of hepatitis B virus capsids inhibits virion formation and causes intracellular capsid accumulation.

    Science.gov (United States)

    Wittkop, Linda; Schwarz, Alexandra; Cassany, Aurelia; Grün-Bernhard, Stefanie; Delaleau, Mildred; Rabe, Birgit; Cazenave, Christian; Gerlich, Wolfram; Glebe, Dieter; Kann, Michael

    2010-07-01

    Capsids of hepatitis B virus and other hepadnaviruses contain a cellular protein kinase, which phosphorylates the capsid protein. Some phosphorylation sites are shown to be essential for distinct steps of viral replication as pregenome packaging or plus strand DNA synthesis. Although different protein kinases have been reported to phosphorylate the capsid protein, varying experimental approaches do not allow direct comparison. Furthermore, the activity of a specific protein kinase has not yet been correlated to steps in the hepadnaviral life cycle. In this study we show that capsids from various sources encapsidate active protein kinase Calpha, irrespective of hepatitis B virus genotype and host cell. Treatment of a virion expressing cell line with a pseudosubstrate inhibitor showed that inhibition of protein kinase C phosphorylation did not affect genome maturation but resulted in capsid accumulation and inhibited virion release to the medium. Our results imply that different protein kinases have distinct functions within the hepadnaviral life cycle.

  19. Virus capsid dissolution studied by microsecond molecular dynamics simulations.

    Directory of Open Access Journals (Sweden)

    Daniel S D Larsson

    Full Text Available Dissolution of many plant viruses is thought to start with swelling of the capsid caused by calcium removal following infection, but no high-resolution structures of swollen capsids exist. Here we have used microsecond all-atom molecular simulations to describe the dynamics of the capsid of satellite tobacco necrosis virus with and without the 92 structural calcium ions. The capsid expanded 2.5% upon removal of the calcium, in good agreement with experimental estimates. The water permeability of the native capsid was similar to that of a phospholipid membrane, but the permeability increased 10-fold after removing the calcium, predominantly between the 2-fold and 3-fold related subunits. The two calcium binding sites close to the icosahedral 3-fold symmetry axis were pivotal in the expansion and capsid-opening process, while the binding site on the 5-fold axis changed little structurally. These findings suggest that the dissociation of the capsid is initiated at the 3-fold axis.

  20. The Papillomavirus Major Capsid Protein L1

    Science.gov (United States)

    Buck, Christopher B.; Day, Patricia M.; Trus, Benes L.

    2013-01-01

    The elegant icosahedral surface of the papillomavirus virion is formed by a single protein called L1. Recombinant L1 proteins can spontaneously self-assemble into a highly immunogenic structure that closely mimics the natural surface of native papillomavirus virions. This has served as the basis for two highly successful vaccines against cancer-causing human papillomaviruses (HPVs). During the viral life cycle, the capsid must undergo a variety of conformational changes, allowing key functions including the encapsidation of the ~8 kb viral genomic DNA, maturation into a more stable state to survive transit between hosts, mediating attachment to new host cells, and finally releasing the viral DNA into the newly infected host cell. This brief review focuses on conserved sequence and structural features that underlie the functions of this remarkable protein. PMID:23800545

  1. Structure of the Triatoma virus capsid

    Energy Technology Data Exchange (ETDEWEB)

    Squires, Gaëlle; Pous, Joan [Laboratoire de Virologie Moléculaire et Structurale, CNRS, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette CEDEX (France); Agirre, Jon [Fundación Biofísica Bizkaia, Barrio Sarriena S/N, 48940 Leioa, Bizkaia (FBB) (Spain); Unidad de Biofísica (UBF, CSIC, UPV/EHU), PO Box 644, 48080 Bilbao (Spain); Rozas-Dennis, Gabriela S. [U.N.S., San Juan 670 (8000) Bahía Blanca (Argentina); U.N.S., Avenida Alem 1253 (8000) Bahía Blanca (Argentina); Costabel, Marcelo D. [U.N.S., Avenida Alem 1253 (8000) Bahía Blanca (Argentina); Marti, Gerardo A. [Centro de Estudios Parasitológicos y de Vectores (CEPAVE-CCT, La Plata, CONICET-UNLP), Calle 2 No. 584 (1900) La Plata (Argentina); Navaza, Jorge; Bressanelli, Stéphane [Laboratoire de Virologie Moléculaire et Structurale, CNRS, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette CEDEX (France); Guérin, Diego M. A., E-mail: diego.guerin@ehu.es [Fundación Biofísica Bizkaia, Barrio Sarriena S/N, 48940 Leioa, Bizkaia (FBB) (Spain); Unidad de Biofísica (UBF, CSIC, UPV/EHU), PO Box 644, 48080 Bilbao (Spain); Rey, Felix A., E-mail: diego.guerin@ehu.es [Laboratoire de Virologie Moléculaire et Structurale, CNRS, 1 Avenue de la Terrasse, 91198 Gif-sur-Yvette CEDEX (France)

    2013-06-01

    The crystallographic structure of TrV shows specific morphological and functional features that clearly distinguish it from the type species of the Cripavirus genus, CrPV. The members of the Dicistroviridae family are non-enveloped positive-sense single-stranded RNA (+ssRNA) viruses pathogenic to beneficial arthropods as well as insect pests of medical importance. Triatoma virus (TrV), a member of this family, infects several species of triatomine insects (popularly named kissing bugs), which are vectors for human trypanosomiasis, more commonly known as Chagas disease. The potential use of dicistroviruses as biological control agents has drawn considerable attention in the past decade, and several viruses of this family have been identified, with their targets covering honey bees, aphids and field crickets, among others. Here, the crystal structure of the TrV capsid at 2.5 Å resolution is reported, showing that as expected it is very similar to that of Cricket paralysis virus (CrPV). Nevertheless, a number of distinguishing structural features support the introduction of a new genus (Triatovirus; type species TrV) under the Dicistroviridae family. The most striking differences are the absence of icosahedrally ordered VP4 within the infectious particle and the presence of prominent projections that surround the fivefold axis. Furthermore, the structure identifies a second putative autoproteolytic DDF motif in protein VP3, in addition to the conserved one in VP1 which is believed to be responsible for VP0 cleavage during capsid maturation. The potential meaning of these new findings is discussed.

  2. MaXi Avisen

    DEFF Research Database (Denmark)

    Kanstrup, Anne Marie; Sørensen, Marianne; Bertelsen, Pernille

    2008-01-01

    maXi-projektets vision er at sprænge rammerne for sundhedsstøtte med it ved at sætte diabetikere og deres familier i centrum og ved at flytte fokus fra sygdom og hospitaler til samfund, hverdagsliv og services. maXi-projektet har til formål at afprøve og gennemføre brugerdreven innovation som...... eksperimenter i et 'living lab' - som etableres i Skagen. I 2009 udvælges nye brugere til deltagelse i projektet. maXi-projektet opbygges som et modelprojekt i samar-bejde mellem Aalborg Universitet, Fonden Skagen Helse, Teknologisk Institut og Edvantage Group. Se http://www.maxi-projektet.dk/ Projektet er...

  3. MaTeam-projektet

    DEFF Research Database (Denmark)

    Andreasen, Marikka; Damkjær, Helle Sejer; Højgaard, Tomas

    2011-01-01

    Projektet MaTeam beskrives med fokus på et toårigt forsøg hvor matematiklærerne på 4.-6. klassetrin på fire skoler i Silkeborg Kommune samarbejdede med forfatterne. Projektet handlede om udvikling af matematiklærerkompetencer med fokus på samarbejdet i de fire skolers matematiklærerfagteam...... matematiklærerfagteam og samarbejdsrelationer der indgår i projektet. Desuden beskriver vi forskellige typer af fagteam og lærere. Metodisk var MaTeam-projektet struktureret som en didaktisk modelleringsproces....

  4. Nonlinear Finite Element Analysis of Nanoindentation of Viral Capsids

    CERN Document Server

    Gibbons, M M; Gibbons, Melissa M.; Klug, William S.

    2006-01-01

    Recent Atomic Force Microscope (AFM) nanoindentation experiments measuring mechanical response of the protein shells of viruses have provided a quantitative description of their strength and elasticity. To better understand and interpret these measurements, and to elucidate the underlying mechanisms, this paper adopts a course-grained modeling approach within the framework of three-dimensional nonlinear continuum elasticity. Homogeneous, isotropic, elastic, thick shell models are proposed for two capsids: the spherical Cowpea Chlorotic Mottle Virus (CCMV), and the ellipsocylindrical bacteriophage $\\phi 29$. As analyzed by the finite element method, these models enable parametric characterization of the effects of AFM tip geometry, capsid dimensions, and capsid constitutive descriptions. The generally nonlinear force response of capsids to indentation is shown to be insensitive to constitutive details, and greatly influenced by geometry. Nonlinear stiffening and softening of the force response is dependent on ...

  5. Integrated Nanosystems Templated by Self-assembled Virus Capsids

    Science.gov (United States)

    Stephanopoulos, Nicholas

    This dissertation presents the synthesis and modeling of multicomponent nanosystems templated by self-assembled virus capsids. The design principles, synthesis, analysis, and future directions for these capsid-based materials are presented. Chapter 1 gives an overview of the literature on the application of virus capsids in constructing nanomaterials. The uses of capsids in three main areas are considered: (1) as templates for inorganic materials or nanoparticles; (2) as vehicles for biological applications like medical imaging and treatment; and (3) as scaffolds for catalytic materials. In light of this introduction, an overview of the material in this dissertation is described. Chapters 2-4 all describe integrated nanosystems templated by bacteriophage MS2, a spherical icosahedral virus capsid. MS2 possesses an interior and exterior surface that can be modified orthogonally using bioconjugation chemistry to create multivalent, multicomponent constructs with precise localization of components attached to the capsid proteins. Chapter 2 describes the use of MS2 to synthesize a photocatalytic construct by modifying the internal surface with sensitizing chromophores and the external surface with a photocatalytic porphyrin. The chromophores absorbed energy that the porphyrin could not, and transferred it to the porphyrin via FRET through the protein shell. The porphyrin was then able to utilize the energy to carry out photocatalysis at new wavelengths. In Chapter 3, porphyrins were installed on the interior surface of MS2 and DNA aptamers specific for Jurkat leukemia T cells on the exterior surface. The dual-modified capsids were able to bind to Jurkat cells, and upon illumination the porphyrins generated singlet oxygen to kill them selectively over non-targeted cells. Chapter 4 explores integrating MS2 with DNA origami in order to arrange the capsids at larger length scales. Capsids modified with fluorescent dyes inside and single-stranded DNA outside were able to

  6. Polymorphism of DNA conformation inside the bacteriophage capsid

    OpenAIRE

    Leforestier, Amélie

    2013-01-01

    Double-stranded DNA bacteriophage genomes are packaged into their icosahedral capsids at the highest densities known so far (about 50 % w:v). How the molecule is folded at such density and how its conformation changes upon ejection or packaging are fascinating questions still largely open. We review cryo-TEM analyses of DNA conformation inside partially filled capsids as a function of the physico-chemical environment (ions, osmotic pressure, temperature). We show that there exists a wide vari...

  7. MaXi Avisen

    DEFF Research Database (Denmark)

    Kanstrup, Anne Marie; Sørensen, Marianne

    2008-01-01

    eksperimenter i et 'living lab' - som etableres i Skagen. I 2009 udvælges nye brugere til deltagelse i projektet. maXi-projektet opbygges som et modelprojekt i samar-bejde mellem Aalborg Universitet, Fonden Skagen Helse, Teknologisk Institut og Edvantage Group. Se http://www.maxi-projektet.dk/ Projektet er...

  8. Woman Director Ma Yueying

    Institute of Scientific and Technical Information of China (English)

    1995-01-01

    Ma Yueying took office as director of the Jiaxing General Silk Mill, which had 200,000 yuan capital fund, in 1975. Since then, this mill has developed greatly. Now it has become an advanced enterprise with an annual output worth RMB¥30 million and fixed assets of RMB¥10 million.

  9. Quantum dot-induced viral capsid assembling in dissociation buffer.

    Science.gov (United States)

    Gao, Ding; Zhang, Zhi-Ping; Li, Feng; Men, Dong; Deng, Jiao-Yu; Wei, Hong-Ping; Zhang, Xian-En; Cui, Zong-Qiang

    2013-01-01

    Viruses encapsulating inorganic nanoparticles are a novel type of nanostructure with applications in biomedicine and biosensors. However, the encapsulation and assembly mechanisms of these hybridized virus-based nanoparticles (VNPs) are still unknown. In this article, it was found that quantum dots (QDs) can induce simian virus 40 (SV40) capsid assembly in dissociation buffer, where viral capsids should be disassembled. The analysis of the transmission electron microscope, dynamic light scattering, sucrose density gradient centrifugation, and cryo-electron microscopy single particle reconstruction experimental results showed that the SV40 major capsid protein 1 (VP1) can be assembled into ≈25 nm capsids in the dissociation buffer when QDs are present and that the QDs are encapsulated in the SV40 capsids. Moreover, it was determined that there is a strong affinity between QDs and the SV40 VP1 proteins (KD=2.19E-10 M), which should play an important role in QD encapsulation in the SV40 viral capsids. This study provides a new understanding of the assembly mechanism of SV40 virus-based nanoparticles with QDs, which may help in the design and construction of other similar virus-based nanoparticles.

  10. [MaRS Project

    Science.gov (United States)

    Aruljothi, Arunvenkatesh

    2016-01-01

    The Space Exploration Division of the Safety and Mission Assurances Directorate is responsible for reducing the risk to Human Space Flight Programs by providing system safety, reliability, and risk analysis. The Risk & Reliability Analysis branch plays a part in this by utilizing Probabilistic Risk Assessment (PRA) and Reliability and Maintainability (R&M) tools to identify possible types of failure and effective solutions. A continuous effort of this branch is MaRS, or Mass and Reliability System, a tool that was the focus of this internship. Future long duration space missions will have to find a balance between the mass and reliability of their spare parts. They will be unable take spares of everything and will have to determine what is most likely to require maintenance and spares. Currently there is no database that combines mass and reliability data of low level space-grade components. MaRS aims to be the first database to do this. The data in MaRS will be based on the hardware flown on the International Space Stations (ISS). The components on the ISS have a long history and are well documented, making them the perfect source. Currently, MaRS is a functioning excel workbook database; the backend is complete and only requires optimization. MaRS has been populated with all the assemblies and their components that are used on the ISS; the failures of these components are updated regularly. This project was a continuation on the efforts of previous intern groups. Once complete, R&M engineers working on future space flight missions will be able to quickly access failure and mass data on assemblies and components, allowing them to make important decisions and tradeoffs.

  11. Crystal Structures of a Piscine Betanodavirus: Mechanisms of Capsid Assembly and Viral Infection.

    Directory of Open Access Journals (Sweden)

    Nai-Chi Chen

    2015-10-01

    Full Text Available Betanodaviruses cause massive mortality in marine fish species with viral nervous necrosis. The structure of a T = 3 Grouper nervous necrosis virus-like particle (GNNV-LP is determined by the ab initio method with non-crystallographic symmetry averaging at 3.6 Å resolution. Each capsid protein (CP shows three major domains: (i the N-terminal arm, an inter-subunit extension at the inner surface; (ii the shell domain (S-domain, a jelly-roll structure; and (iii the protrusion domain (P-domain formed by three-fold trimeric protrusions. In addition, we have determined structures of the T = 1 subviral particles (SVPs of (i the delta-P-domain mutant (residues 35-217 at 3.1 Å resolution; and (ii the N-ARM deletion mutant (residues 35-338 at 7 Å resolution; and (iii the structure of the individual P-domain (residues 214-338 at 1.2 Å resolution. The P-domain reveals a novel DxD motif asymmetrically coordinating two Ca2+ ions, and seems to play a prominent role in the calcium-mediated trimerization of the GNNV CPs during the initial capsid assembly process. The flexible N-ARM (N-terminal arginine-rich motif appears to serve as a molecular switch for T = 1 or T = 3 assembly. Finally, we find that polyethylene glycol, which is incorporated into the P-domain during the crystallization process, enhances GNNV infection. The present structural studies together with the biological assays enhance our understanding of the role of the P-domain of GNNV in the capsid assembly and viral infection by this betanodavirus.

  12. HIV capsid is a tractable target for small molecule therapeutic intervention.

    Directory of Open Access Journals (Sweden)

    Wade S Blair

    Full Text Available Despite a high current standard of care in antiretroviral therapy for HIV, multidrug-resistant strains continue to emerge, underscoring the need for additional novel mechanism inhibitors that will offer expanded therapeutic options in the clinic. We report a new class of small molecule antiretroviral compounds that directly target HIV-1 capsid (CA via a novel mechanism of action. The compounds exhibit potent antiviral activity against HIV-1 laboratory strains, clinical isolates, and HIV-2, and inhibit both early and late events in the viral replication cycle. We present mechanistic studies indicating that these early and late activities result from the compound affecting viral uncoating and assembly, respectively. We show that amino acid substitutions in the N-terminal domain of HIV-1 CA are sufficient to confer resistance to this class of compounds, identifying CA as the target in infected cells. A high-resolution co-crystal structure of the compound bound to HIV-1 CA reveals a novel binding pocket in the N-terminal domain of the protein. Our data demonstrate that broad-spectrum antiviral activity can be achieved by targeting this new binding site and reveal HIV CA as a tractable drug target for HIV therapy.

  13. Diminished reovirus capsid stability alters disease pathogenesis and littermate transmission.

    Directory of Open Access Journals (Sweden)

    Joshua D Doyle

    2015-03-01

    Full Text Available Reovirus is a nonenveloped mammalian virus that provides a useful model system for studies of viral infections in the young. Following internalization into host cells, the outermost capsid of reovirus virions is removed by endosomal cathepsin proteases. Determinants of capsid disassembly kinetics reside in the viral σ3 protein. However, the contribution of capsid stability to reovirus-induced disease is unknown. In this study, we found that mice inoculated intramuscularly with a serotype 3 reovirus containing σ3-Y354H, a mutation that reduces viral capsid stability, succumbed at a higher rate than those infected with wild-type virus. At early times after inoculation, σ3-Y354H virus reached higher titers than wild-type virus at several sites within the host. Animals inoculated perorally with a serotype 1 reassortant reovirus containing σ3-Y354H developed exaggerated myocarditis accompanied by elaboration of pro-inflammatory cytokines. Surprisingly, unchallenged littermates of mice infected with σ3-Y354H virus displayed higher titers in the intestine, heart, and brain than littermates of mice inoculated with wild-type virus. Together, these findings suggest that diminished capsid stability enhances reovirus replication, dissemination, lethality, and host-to-host spread, establishing a new virulence determinant for nonenveloped viruses.

  14. RNA-binding region of Macrobrachium rosenbergii nodavirus capsid protein.

    Science.gov (United States)

    Goh, Zee Hong; Mohd, Nur Azmina Syakirin; Tan, Soon Guan; Bhassu, Subha; Tan, Wen Siang

    2014-09-01

    White tail disease (WTD) kills prawn larvae and causes drastic losses to the freshwater prawn (Macrobrachium rosenbergii) industry. The main causative agent of WTD is Macrobrachium rosenbergii nodavirus (MrNV). The N-terminal end of the MrNV capsid protein is very rich in positively charged amino acids and is postulated to interact with RNA molecules. N-terminal and internal deletion mutagenesis revealed that the RNA-binding region is located at positions 20-29, where 80 % of amino acids are positively charged. Substitution of all these positively charged residues with alanine abolished the RNA binding. Mutants without the RNA-binding region still assembled into virus-like particles, suggesting that this region is not a part of the capsid assembly domain. This paper is, to the best of our knowledge, the first to report the specific RNA-binding region of MrNV capsid protein.

  15. Polymorphism of DNA conformation inside the bacteriophage capsid.

    Science.gov (United States)

    Leforestier, Amélie

    2013-03-01

    Double-stranded DNA bacteriophage genomes are packaged into their icosahedral capsids at the highest densities known so far (about 50 % w:v). How the molecule is folded at such density and how its conformation changes upon ejection or packaging are fascinating questions still largely open. We review cryo-TEM analyses of DNA conformation inside partially filled capsids as a function of the physico-chemical environment (ions, osmotic pressure, temperature). We show that there exists a wide variety of DNA conformations. Strikingly, the different observed structures can be described by some of the different models proposed over the years for DNA organisation inside bacteriophage capsids: either spool-like structures with axial or concentric symmetries, or liquid crystalline structures characterised by a DNA homogeneous density. The relevance of these conformations for the understanding of DNA folding and unfolding upon ejection and packaging in vivo is discussed.

  16. The Mammalian Cell Cycle Regulates Parvovirus Nuclear Capsid Assembly

    Science.gov (United States)

    Riolobos, Laura; Domínguez, Carlos; Kann, Michael; Almendral, José M.

    2015-01-01

    It is unknown whether the mammalian cell cycle could impact the assembly of viruses maturing in the nucleus. We addressed this question using MVM, a reference member of the icosahedral ssDNA nuclear parvoviruses, which requires cell proliferation to infect by mechanisms partly understood. Constitutively expressed MVM capsid subunits (VPs) accumulated in the cytoplasm of mouse and human fibroblasts synchronized at G0, G1, and G1/S transition. Upon arrest release, VPs translocated to the nucleus as cells entered S phase, at efficiencies relying on cell origin and arrest method, and immediately assembled into capsids. In synchronously infected cells, the consecutive virus life cycle steps (gene expression, proteins nuclear translocation, capsid assembly, genome replication and encapsidation) proceeded tightly coupled to cell cycle progression from G0/G1 through S into G2 phase. However, a DNA synthesis stress caused by thymidine irreversibly disrupted virus life cycle, as VPs became increasingly retained in the cytoplasm hours post-stress, forming empty capsids in mouse fibroblasts, thereby impairing encapsidation of the nuclear viral DNA replicative intermediates. Synchronously infected cells subjected to density-arrest signals while traversing early S phase also blocked VPs transport, resulting in a similar misplaced cytoplasmic capsid assembly in mouse fibroblasts. In contrast, thymidine and density arrest signals deregulating virus assembly neither perturbed nuclear translocation of the NS1 protein nor viral genome replication occurring under S/G2 cycle arrest. An underlying mechanism of cell cycle control was identified in the nuclear translocation of phosphorylated VPs trimeric assembly intermediates, which accessed a non-conserved route distinct from the importin α2/β1 and transportin pathways. The exquisite cell cycle-dependence of parvovirus nuclear capsid assembly conforms a novel paradigm of time and functional coupling between cellular and virus life

  17. Quantum dot-induced viral capsid assembling in dissociation buffer

    Directory of Open Access Journals (Sweden)

    Gao D

    2013-06-01

    Full Text Available Ding Gao,1,2 Zhi-Ping Zhang,1 Feng Li,3 Dong Men,1 Jiao-Yu Deng,1 Hong-Ping Wei,1 Xian-En Zhang,1 Zong-Qiang Cui1 1State Key Laboratory of Virology, Wuhan Institute of Virology, Chinese Academy of Sciences, Wuhan, 2Graduate University of Chinese Academy of Sciences, Beijing, 3Division of Nanobiomedicine and i-Lab, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences, Suzhou, People's Republic of China Abstract: Viruses encapsulating inorganic nanoparticles are a novel type of nanostructure with applications in biomedicine and biosensors. However, the encapsulation and assembly mechanisms of these hybridized virus-based nanoparticles (VNPs are still unknown. In this article, it was found that quantum dots (QDs can induce simian virus 40 (SV40 capsid assembly in dissociation buffer, where viral capsids should be disassembled. The analysis of the transmission electron microscope, dynamic light scattering, sucrose density gradient centrifugation, and cryo-electron microscopy single particle reconstruction experimental results showed that the SV40 major capsid protein 1 (VP1 can be assembled into ≈25 nm capsids in the dissociation buffer when QDs are present and that the QDs are encapsulated in the SV40 capsids. Moreover, it was determined that there is a strong affinity between QDs and the SV40 VP1 proteins (KD = 2.19E-10 M, which should play an important role in QD encapsulation in the SV40 viral capsids. This study provides a new understanding of the assembly mechanism of SV40 virus-based nanoparticles with QDs, which may help in the design and construction of other similar virus-based nanoparticles. Keywords: quantum dots, simian virus 40, self-assembly, encapsulation, virus-based nanoparticles

  18. Sphingomyelin induces structural alteration in canine parvovirus capsid

    OpenAIRE

    Pakkanen, Kirsi; Karttunen, Jenni; Virtanen, Salla; Vuento, Matti

    2008-01-01

    One of the essential steps in canine parvovirus (CPV) infection, the release from endosomal vesicles, is dominated by interactions between the virus capsid and the endosomal membranes. In this study, the effect of sphingomyelin and phosphatidyl serine on canine parvovirus capsid and on the phospholipase A2 (PLA2) activity of CPV VP1 unique N-terminus was analyzed. Accordingly, a significant (P ≤ 0.05) shift of tryptophan fluorescence emission peak was detected at pH 5.5 in the presen...

  19. All-atom molecular dynamics calculation study of entire poliovirus empty capsids in solution

    Science.gov (United States)

    Andoh, Y.; Yoshii, N.; Yamada, A.; Fujimoto, K.; Kojima, H.; Mizutani, K.; Nakagawa, A.; Nomoto, A.; Okazaki, S.

    2014-10-01

    Small viruses that belong, for example, to the Picornaviridae, such as poliovirus and foot-and-mouth disease virus, consist simply of capsid proteins and a single-stranded RNA (ssRNA) genome. The capsids are quite stable in solution to protect the genome from the environment. Here, based on long-time and large-scale 6.5 × 106 all-atom molecular dynamics calculations for the Mahoney strain of poliovirus, we show microscopic properties of the viral capsids at a molecular level. First, we found equilibrium rapid exchange of water molecules across the capsid. The exchange rate is so high that all water molecules inside the capsid (about 200 000) can leave the capsid and be replaced by water molecules from the outside in about 25 μs. This explains the capsid's tolerance to high pressures and deactivation by exsiccation. In contrast, the capsid did not exchange ions, at least within the present simulation time of 200 ns. This implies that the capsid can function, in principle, as a semipermeable membrane. We also found that, similar to the xylem of trees, the pressure of the solution inside the capsid without the genome was negative. This is caused by coulombic interaction of the solution inside the capsid with the capsid excess charges. The negative pressure may be compensated by positive osmotic pressure by the solution-soluble ssRNA and the counter ions introduced into it.

  20. All-atom molecular dynamics calculation study of entire poliovirus empty capsids in solution

    Energy Technology Data Exchange (ETDEWEB)

    Andoh, Y.; Yoshii, N.; Yamada, A.; Kojima, H.; Mizutani, K.; Okazaki, S., E-mail: okazaki@apchem.nagoya-u.ac.jp [Department of Applied Chemistry, Nagoya University, Furo-cho, Chikusa-ku, Nagoya 464-8603 (Japan); Fujimoto, K. [Department of Pharmacy, College of Pharmaceutical Sciences, Ritsumeikan University, Nojihigashi, Kusatsu, Shiga 525-8577 (Japan); Nakagawa, A. [Institute for Protein Research, Osaka University, Yamadaoka, Suita, Osaka 565-0871 (Japan); Nomoto, A. [Institute of Microbial Chemistry, Kamiosaki, Shinagawa-ku, Tokyo 141-0021 (Japan)

    2014-10-28

    Small viruses that belong, for example, to the Picornaviridae, such as poliovirus and foot-and-mouth disease virus, consist simply of capsid proteins and a single-stranded RNA (ssRNA) genome. The capsids are quite stable in solution to protect the genome from the environment. Here, based on long-time and large-scale 6.5 × 10{sup 6} all-atom molecular dynamics calculations for the Mahoney strain of poliovirus, we show microscopic properties of the viral capsids at a molecular level. First, we found equilibrium rapid exchange of water molecules across the capsid. The exchange rate is so high that all water molecules inside the capsid (about 200 000) can leave the capsid and be replaced by water molecules from the outside in about 25 μs. This explains the capsid's tolerance to high pressures and deactivation by exsiccation. In contrast, the capsid did not exchange ions, at least within the present simulation time of 200 ns. This implies that the capsid can function, in principle, as a semipermeable membrane. We also found that, similar to the xylem of trees, the pressure of the solution inside the capsid without the genome was negative. This is caused by coulombic interaction of the solution inside the capsid with the capsid excess charges. The negative pressure may be compensated by positive osmotic pressure by the solution-soluble ssRNA and the counter ions introduced into it.

  1. Crystal Structure of the Human Astrovirus Capsid Protein

    Science.gov (United States)

    Toh, Yukimatsu; Harper, Justin; Dryden, Kelly A.; Yeager, Mark; Méndez, Ernesto

    2016-01-01

    ABSTRACT Human astrovirus (HAstV) is a leading cause of viral diarrhea in infants and young children worldwide. HAstV is a nonenveloped virus with a T=3 capsid and a positive-sense RNA genome. The capsid protein (CP) of HAstV is synthesized as a 90-kDa precursor (VP90) that can be divided into three linear domains: a conserved N-terminal domain, a hypervariable domain, and an acidic C-terminal domain. Maturation of HAstV requires proteolytic processing of the astrovirus CP both inside and outside the host cell, resulting in the removal of the C-terminal domain and the breakdown of the rest of the CP into three predominant protein species with molecular masses of ∼34, 27/29, and 25/26 kDa, respectively. We have now solved the crystal structure of VP9071–415 (amino acids [aa] 71 to 415 of VP90) of human astrovirus serotype 8 at a 2.15-Å resolution. VP9071–415 encompasses the conserved N-terminal domain of VP90 but lacks the hypervariable domain, which forms the capsid surface spikes. The structure of VP9071–415 is comprised of two domains: an S domain, which adopts the typical jelly-roll β-barrel fold, and a P1 domain, which forms a squashed β-barrel consisting of six antiparallel β-strands similar to what was observed in the hepatitis E virus (HEV) capsid structure. Fitting of the VP9071–415 structure into the cryo-electron microscopy (EM) maps of HAstV produced an atomic model for a continuous, T=3 icosahedral capsid shell. Our pseudoatomic model of the human HAstV capsid shell provides valuable insights into intermolecular interactions required for capsid assembly and trypsin-mediated proteolytic maturation needed for virus infectivity. Such information has potential applications in the development of a virus-like particle (VLP) vaccine as well as small-molecule drugs targeting astrovirus assembly/maturation. IMPORTANCE Human astrovirus (HAstV) is a leading cause of viral diarrhea in infants and young children worldwide. As a nonenveloped virus

  2. Phylogenetic Diversity of Marine Cyanophage Isolates and Natural Virus Communities as Revealed by Sequences of Viral Capsid Assembly Protein Gene g20†

    OpenAIRE

    Zhong, Yan; Chen, Feng; Wilhelm, Steven W.; Poorvin, Leo; Hodson, Robert E.

    2002-01-01

    In order to characterize the genetic diversity and phylogenetic affiliations of marine cyanophage isolates and natural cyanophage assemblages, oligonucleotide primers CPS1 and CPS8 were designed to specifically amplify ca. 592-bp fragments of the gene for viral capsid assembly protein g20. Phylogenetic analysis of isolated cyanophages revealed that the marine cyanophages were highly diverse yet more closely related to each other than to enteric coliphage T4. Genetically related marine cyanoph...

  3. L2, the minor capsid protein of papillomavirus

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Joshua W. [Department of Pathology, The Johns Hopkins University, Baltimore, MD 21287 (United States); Roden, Richard B.S., E-mail: roden@jhmi.edu [Department of Pathology, The Johns Hopkins University, Baltimore, MD 21287 (United States); Department of Oncology, The Johns Hopkins University, Baltimore, MD 21287 (United States); Department of Gynecology and Obstetrics, The Johns Hopkins University, Baltimore, MD 21287 (United States)

    2013-10-15

    The capsid protein L2 plays major roles in both papillomavirus assembly and the infectious process. While L1 forms the majority of the capsid and can self-assemble into empty virus-like particles (VLPs), L2 is a minor capsid component and lacks the capacity to form VLPs. However, L2 co-assembles with L1 into VLPs, enhancing their assembly. L2 also facilitates encapsidation of the ∼8 kbp circular and nucleosome-bound viral genome during assembly of the non-enveloped T=7d virions in the nucleus of terminally differentiated epithelial cells, although, like L1, L2 is not detectably expressed in infected basal cells. With respect to infection, L2 is not required for particles to bind to and enter cells. However L2 must be cleaved by furin for endosome escape. L2 then travels with the viral genome to the nucleus, wherein it accumulates at ND-10 domains. Here, we provide an overview of the biology of L2. - Highlights: • L2 is the minor antigen of the non-enveloped T=7d icosahedral Papillomavirus capsid. • L2 is a nuclear protein that can traffic to ND-10 and facilitate genome encapsidation. • L2 is critical for infection and must be cleaved by furin. • L2 is a broadly protective vaccine antigen recognized by neutralizing antibodies.

  4. Sphingomyelin induces structural alteration in canine parvovirus capsid.

    Science.gov (United States)

    Pakkanen, Kirsi; Karttunen, Jenni; Virtanen, Salla; Vuento, Matti

    2008-03-01

    One of the essential steps in canine parvovirus (CPV) infection, the release from endosomal vesicles, is dominated by interactions between the virus capsid and the endosomal membranes. In this study, the effect of sphingomyelin and phosphatidyl serine on canine parvovirus capsid and on the phospholipase A(2) (PLA(2)) activity of CPV VP1 unique N-terminus was analyzed. Accordingly, a significant (P< or =0.05) shift of tryptophan fluorescence emission peak was detected at pH 5.5 in the presence of sphingomyelin, whereas at pH 7.4 a similar but minor shift was observed. This effect may relate to the exposure of VP1 N-terminus in acidic pH as well as to interactions between sphingomyelin and CPV. When the phenomenon was further characterized using circular dichroism spectroscopy, differences in CPV capsid CD spectra with and without sphingomyelin and phosphatidyl serine were detected, corresponding to data obtained with tryptophan fluorescence. However, when the enzymatic activity of CPV PLA(2) was tested in the presence of sphingomyelin, no significant effect in the function of the enzyme was detected. Thus, the structural changes observed with spectroscopic techniques appear not to manipulate the activity of CPV PLA(2), and may therefore implicate alternative interactions between CPV capsid and sphingomyelin.

  5. Periodic table of virus capsids: implications for natural selection and design.

    Science.gov (United States)

    Mannige, Ranjan V; Brooks, Charles L

    2010-03-04

    For survival, most natural viruses depend upon the existence of spherical capsids: protective shells of various sizes composed of protein subunits. So far, general evolutionary pressures shaping capsid design have remained elusive, even though an understanding of such properties may help in rationally impeding the virus life cycle and designing efficient nano-assemblies. This report uncovers an unprecedented and species-independent evolutionary pressure on virus capsids, based on the the notion that the simplest capsid designs (or those capsids with the lowest "hexamer complexity", C(h)) are the fittest, which was shown to be true for all available virus capsids. The theories result in a physically meaningful periodic table of virus capsids that uncovers strong and overarching evolutionary pressures, while also offering geometric explanations to other capsid properties (rigidity, pleomorphy, auxiliary requirements, etc.) that were previously considered to be unrelatable properties of the individual virus. Apart from describing a universal rule for virus capsid evolution, our work (especially the periodic table) provides a language with which highly diverse virus capsids, unified only by geometry, may be described and related to each other. Finally, the available virus structure databases and other published data reiterate the predicted geometry-derived rules, reinforcing the role of geometry in the natural selection and design of virus capsids.

  6. Antigenic properties of avian hepatitis E virus capsid protein.

    Science.gov (United States)

    Zhao, Qin; Syed, Shahid Faraz; Zhou, En-Min

    2015-10-22

    Avian hepatitis E virus (HEV) is the main causative agent of big liver and spleen disease and hepatitis-splenomegaly syndrome in chickens, and is genetically and antigenically related to mammalian HEVs. HEV capsid protein contains immunodominant epitopes and induces a protective humoral immune response. A better understanding of the antigenic composition of this protein is critically important for the development of effective vaccine and sensitive and specific serological assays. To date, six linear antigenic domains (I-VI) have been characterized in avian HEV capsid protein and analyzed for their applications in the serological diagnosis and vaccine design. Domains I and V induce strong immune response in chickens and are common to avian, human, and swine HEVs, indicating that the shared epitopes hampering differential diagnosis of avian HEV infection. Domains III and IV are not immunodominant and elicit a weak immune response. Domain VI, located in the N-terminal region of the capsid protein, can also trigger an intense immune response, but the anti-domain VI antibodies are transient. The protection analysis showed that the truncated capsid protein containing the C-terminal 268 amino acid residues expressed by the bacterial system can provide protective immunity against avian HEV infection in chickens. However, the synthetic peptides incorporating the different linear antigenic domains (I-VI) and epitopes are non-protective. The antigenic composition of avian HEV capsid protein is altogether complex. To develop an effective vaccine and accurate serological diagnostic methods, more conformational antigenic domains or epitopes are to be characterized in detail.

  7. Physical properties of the HIV-1 capsid from all-atom molecular dynamics simulations

    Science.gov (United States)

    Perilla, Juan R.; Schulten, Klaus

    2017-07-01

    Human immunodeficiency virus type 1 (HIV-1) infection is highly dependent on its capsid. The capsid is a large container, made of ~1,300 proteins with altogether 4 million atoms. Although the capsid proteins are all identical, they nevertheless arrange themselves into a largely asymmetric structure made of hexamers and pentamers. The large number of degrees of freedom and lack of symmetry pose a challenge to studying the chemical details of the HIV capsid. Simulations of over 64 million atoms for over 1 μs allow us to conduct a comprehensive study of the chemical-physical properties of an empty HIV-1 capsid, including its electrostatics, vibrational and acoustic properties, and the effects of solvent (ions and water) on the capsid. The simulations reveal critical details about the capsid with implications to biological function.

  8. Role of electrostatic interactions in the assembly of empty spherical viral capsids

    CERN Document Server

    Siber, Antonio

    2007-01-01

    We examine the role of electrostatic interactions in the assembly of empty spherical viral capsids. The charges on the protein subunits that make the viral capsid mutually interact and are expected to yield electrostatic repulsion acting against the assembly of capsids. Thus, attractive protein-protein interactions of non-electrostatic origin must act to enable the capsid formation. We investigate whether the interplay of repulsive electrostatic and attractive interactions between the protein subunits can result in the formation of spherical viral capsids of a preferred radius. For this to be the case, we find that the attractive interactions must depend on the angle between the neighboring protein subunits (i.e. on the mean curvature of the viral capsid) so that a particular angle(s) is (are) preferred energywise. Our results for the electrostatic contributions to energetics of viral capsids nicely correlate with recent experimental determinations of the energetics of protein-protein contacts in Hepatitis B ...

  9. Discovery and utilization of sorghum genes (Ma5/Ma6)

    Science.gov (United States)

    Mullet, John E; Rooney, William L; Klein, Patricia E; Morishige, Daryl; Murphy, Rebecca; Brady, Jeff A

    2012-11-13

    Methods and composition for the production of non-flowering or late flowering sorghum hybrid. For example, in certain aspects methods for use of molecular markers that constitute the Ma5/Ma6 pathway to modulate photoperiod sensitivity are described. The invention allows the production of plants having improved productivity and biomass generation.

  10. CapsidMaps: protein-protein interaction pattern discovery platform for the structural analysis of virus capsids using Google Maps.

    Science.gov (United States)

    Carrillo-Tripp, Mauricio; Montiel-García, Daniel Jorge; Brooks, Charles L; Reddy, Vijay S

    2015-04-01

    Structural analysis and visualization of protein-protein interactions is a challenging task since it is difficult to appreciate easily the extent of all contacts made by the residues forming the interfaces. In the case of viruses, structural analysis becomes even more demanding because several interfaces coexist and, in most cases, these are formed by hundreds of contacting residues that belong to multiple interacting coat proteins. CapsidMaps is an interactive analysis and visualization tool that is designed to benefit the structural virology community. Developed as an improved extension of the φ-ψ Explorer, here we describe the details of its design and implementation. We present results of analysis of a spherical virus to showcase the features and utility of the new tool. CapsidMaps also facilitates the comparison of quaternary interactions between two spherical virus particles by computing a similarity (S)-score. The tool can also be used to identify residues that are solvent exposed and in the process of locating antigenic epitope regions as well as residues forming the inside surface of the capsid that interact with the nucleic acid genome. CapsidMaps is part of the VIPERdb Science Gateway, and is freely available as a web-based and cross-browser compliant application at http://viperdb.scripps.edu.

  11. Antiviral activity of α-helical stapled peptides designed from the HIV-1 capsid dimerization domain

    Directory of Open Access Journals (Sweden)

    Cowburn David

    2011-05-01

    Full Text Available Abstract Background The C-terminal domain (CTD of HIV-1 capsid (CA, like full-length CA, forms dimers in solution and CTD dimerization is a major driving force in Gag assembly and maturation. Mutations of the residues at the CTD dimer interface impair virus assembly and render the virus non-infectious. Therefore, the CTD represents a potential target for designing anti-HIV-1 drugs. Results Due to the pivotal role of the dimer interface, we reasoned that peptides from the α-helical region of the dimer interface might be effective as decoys to prevent CTD dimer formation. However, these small peptides do not have any structure in solution and they do not penetrate cells. Therefore, we used the hydrocarbon stapling technique to stabilize the α-helical structure and confirmed by confocal microscopy that this modification also made these peptides cell-penetrating. We also confirmed by using isothermal titration calorimetry (ITC, sedimentation equilibrium and NMR that these peptides indeed disrupt dimer formation. In in vitro assembly assays, the peptides inhibited mature-like virus particle formation and specifically inhibited HIV-1 production in cell-based assays. These peptides also showed potent antiviral activity against a large panel of laboratory-adapted and primary isolates, including viral strains resistant to inhibitors of reverse transcriptase and protease. Conclusions These preliminary data serve as the foundation for designing small, stable, α-helical peptides and small-molecule inhibitors targeted against the CTD dimer interface. The observation that relatively weak CA binders, such as NYAD-201 and NYAD-202, showed specificity and are able to disrupt the CTD dimer is encouraging for further exploration of a much broader class of antiviral compounds targeting CA. We cannot exclude the possibility that the CA-based peptides described here could elicit additional effects on virus replication not directly linked to their ability to bind

  12. Increasing Type 1 Poliovirus Capsid Stability by Thermal Selection

    Science.gov (United States)

    Adeyemi, Oluwapelumi O.; Nicol, Clare

    2016-01-01

    ABSTRACT Poliomyelitis is a highly infectious disease caused by poliovirus (PV). It can result in paralysis and may be fatal. Integrated global immunization programs using live-attenuated oral (OPV) and/or inactivated (IPV) PV vaccines have systematically reduced its spread and paved the way for eradication. Immunization will continue posteradication to ensure against reintroduction of the disease, but there are biosafety concerns for both OPV and IPV. They could be addressed by the production and use of virus-free virus-like particle (VLP) vaccines that mimic the “empty” capsids (ECs) normally produced in viral infection. Although ECs are antigenically indistinguishable from mature virus particles, they are less stable and readily convert into an alternative conformation unsuitable for vaccine purposes. Stabilized ECs, expressed recombinantly as VLPs, could be ideal candidate vaccines for a polio-free world. However, although genome-free PV ECs have been expressed as VLPs in a variety of systems, their inherent antigenic instability has proved a barrier to further development. In this study, we selected thermally stable ECs of type 1 PV (PV-1). The ECs are antigenically stable at temperatures above the conversion temperature of wild-type (wt) virions. We have identified mutations on the capsid surface and in internal networks that are responsible for EC stability. With reference to the capsid structure, we speculate on the roles of these residues in capsid stability and postulate that such stabilized VLPs could be used as novel vaccines. IMPORTANCE Poliomyelitis is a highly infectious disease caused by PV and is on the verge of eradication. There are biosafety concerns about reintroduction of the disease from current vaccines that require live virus for production. Recombinantly expressed virus-like particles (VLPs) could address these inherent problems. However, the genome-free capsids (ECs) of wt PV are unstable and readily change antigenicity to a form not

  13. Parvovirus Capsid Structures Required for Infection: Mutations Controlling Receptor Recognition and Protease Cleavages.

    Science.gov (United States)

    Callaway, Heather M; Feng, Kurtis H; Lee, Donald W; Allison, Andrew B; Pinard, Melissa; McKenna, Robert; Agbandje-McKenna, Mavis; Hafenstein, Susan; Parrish, Colin R

    2017-01-15

    Parvovirus capsids are small but complex molecular machines responsible for undertaking many of the steps of cell infection, genome packing, and cell-to-cell as well as host-to-host transfer. The details of parvovirus infection of cells are still not fully understood, but the processes must involve small changes in the capsid structure that allow the endocytosed virus to escape from the endosome, pass through the cell cytoplasm, and deliver the single-stranded DNA (ssDNA) genome to the nucleus, where viral replication occurs. Here, we examine capsid substitutions that eliminate canine parvovirus (CPV) infectivity and identify how those mutations changed the capsid structure or altered interactions with the infectious pathway. Amino acid substitutions on the exterior surface of the capsid (Gly299Lys/Ala300Lys) altered the binding of the capsid to transferrin receptor type 1 (TfR), particularly during virus dissociation from the receptor, but still allowed efficient entry into both feline and canine cells without successful infection. These substitutions likely control specific capsid structural changes resulting from TfR binding required for infection. A second set of changes on the interior surface of the capsid reduced viral infectivity by >100-fold and included two cysteine residues and neighboring residues. One of these substitutions, Cys270Ser, modulates a VP2 cleavage event found in ∼10% of the capsid proteins that also was shown to alter capsid stability. A neighboring substitution, Pro272Lys, significantly reduced capsid assembly, while a Cys273Ser change appeared to alter capsid transport from the nucleus. These mutants reveal additional structural details that explain cell infection processes of parvovirus capsids. Parvoviruses are commonly found in both vertebrate and invertebrate animals and cause widespread disease. They are also being developed as oncolytic therapeutics and as gene therapy vectors. Most functions involved in infection or transduction

  14. Development of Cell Lines Stably Expressing Staphylococcal Nuclease Fused to Dengue 2 Virus Capsid Protein for CTVI

    Institute of Scientific and Technical Information of China (English)

    Cheng-Feng QIN; E-De QIN

    2004-01-01

    To explore the potential application of capsid-targeted viral inactivation(CTVI)strategy in prophylactic model against dengue virus(DV)infection,here we fused a Ca2+-dependent nuclease,staphylococcal nuclease(SN),to the capsid protein of dengue 2 virus(D2C)at the carboxyl terminal,and constructed the desired expression plasmid pc/D2C-SN and control plasmids pc/D2C-SN* and pc/D2C.A mammalian cell line BHK-21 was transfected by electroporation with those plasmids and thereafter selected by 5 μg/ml blasticidin.The resistant cell clones were then expanding cultured and screened by RT-PCR and Western Blot assays.The nuclease activity of the expressed fusion protein D2C-SN was analyzed by in vitro DNA digestion assay.It was confirmed cell lines stably expressing D2C-SN and control constructs were obtained.The intracellular expressed fusion protein D2C-SN had ideal nuclease activity and no cytotoxicity on mammalian cells.Those engineered cell lines provided the experimental system for CTVI application in prophylactic model and paved the new road for combating DV infection with CTVI.

  15. Biophysical and Structural Studies on the Capsid Protein of the Human Immunodeficiency Virus Type 1: A New Drug Target?

    Directory of Open Access Journals (Sweden)

    José L. Neira

    2009-01-01

    Full Text Available AIDS affects 30 million people worldwide and is one of the deadliest epidemics in human history. It is caused by a retrovirus, HIV, whose mature capsid (enclosing the RNA with other proteins is formed by the assembly of several hundred copies of a protein, CA*. The C-terminal domain of such protein, CAC, is a driving force in virus assembly and the connections in the mature capsid lattice indicate that CAC joins through homodimerization of the CA hexamers. In the first part of this work, I shall review the biophysical studies carried out with the dimeric wild-type CAC protein and a mutant monomeric variant. The results open new venues for the development of drugs able to interact either with the dimeric species, hampering its assembly, or with the monomeric species, obstructing its folding. In the second part of this review, I shall describe the structures of complexes of CAC with small molecules able to weaken its dimerization. Furthermore, interactions with other proteins and lipids are also described. The whole set of results suggests that much of the surface of CAC does not accommodate binding per se, but rather binding sites in the protein are predefined, i.e., there are “hot” spots for binding in CAC (whatever be the molecule to bind. These “hot” residues involve most of the dimerization interface (an α-helix of the CAC wild-type protein, but also polypeptide patches at the other helices.

  16. High affinity anchoring of the decoration protein pb10 onto the bacteriophage T5 capsid

    Science.gov (United States)

    Vernhes, Emeline; Renouard, Madalena; Gilquin, Bernard; Cuniasse, Philippe; Durand, Dominique; England, Patrick; Hoos, Sylviane; Huet, Alexis; Conway, James F.; Glukhov, Anatoly; Ksenzenko, Vladimir; Jacquet, Eric; Nhiri, Naïma; Zinn-Justin, Sophie; Boulanger, Pascale

    2017-01-01

    Bacteriophage capsids constitute icosahedral shells of exceptional stability that protect the viral genome. Many capsids display on their surface decoration proteins whose structure and function remain largely unknown. The decoration protein pb10 of phage T5 binds at the centre of the 120 hexamers formed by the major capsid protein. Here we determined the 3D structure of pb10 and investigated its capsid-binding properties using NMR, SAXS, cryoEM and SPR. Pb10 consists of an α-helical capsid-binding domain and an Ig-like domain exposed to the solvent. It binds to the T5 capsid with a remarkably high affinity and its binding kinetics is characterized by a very slow dissociation rate. We propose that the conformational exchange events observed in the capsid-binding domain enable rearrangements upon binding that contribute to the quasi-irreversibility of the pb10-capsid interaction. Moreover we show that pb10 binding is a highly cooperative process, which favours immediate rebinding of newly dissociated pb10 to the 120 hexamers of the capsid protein. In extreme conditions, pb10 protects the phage from releasing its genome. We conclude that pb10 may function to reinforce the capsid thus favouring phage survival in harsh environments. PMID:28165000

  17. High capsid-genome correlation facilitates creation of AAV libraries for directed evolution.

    Science.gov (United States)

    Nonnenmacher, Mathieu; van Bakel, Harm; Hajjar, Roger J; Weber, Thomas

    2015-04-01

    Directed evolution of adeno-associated virus (AAV) through successive rounds of phenotypic selection is a powerful method to isolate variants with improved properties from large libraries of capsid mutants. Importantly, AAV libraries used for directed evolution are based on the "natural" AAV genome organization where the capsid proteins are encoded in cis from replicating genomes. This is necessary to allow the recovery of the capsid DNA after each step of phenotypic selection. For directed evolution to be used successfully, it is essential to minimize the random mixing of capsomers and the encapsidation of nonmatching viral genomes during the production of the viral libraries. Here, we demonstrate that multiple AAV capsid variants expressed from Rep/Cap containing viral genomes result in near-homogeneous capsids that display an unexpectedly high capsid-DNA correlation. Next-generation sequencing of AAV progeny generated by bulk transfection of a semi-random peptide library showed a strong counter-selection of capsid variants encoding premature stop codons, which further supports a strong capsid-genome identity correlation. Overall, our observations demonstrate that production of "natural" AAVs results in low capsid mosaicism and high capsid-genome correlation. These unique properties allow the production of highly diverse AAV libraries in a one-step procedure with a minimal loss in phenotype-genotype correlation.

  18. The Suramin Derivative NF449 Interacts with the 5-fold Vertex of the Enterovirus A71 Capsid to Prevent Virus Attachment to PSGL-1 and Heparan Sulfate.

    Directory of Open Access Journals (Sweden)

    Yorihiro Nishimura

    2015-10-01

    Full Text Available NF449, a sulfated compound derived from the antiparasitic drug suramin, was previously reported to inhibit infection by enterovirus A71 (EV-A71. In the current work, we found that NF449 inhibits virus attachment to target cells, and specifically blocks virus interaction with two identified receptors--the P-selectin ligand, PSGL-1, and heparan sulfate glycosaminoglycan--with no effect on virus binding to a third receptor, the scavenger receptor SCARB2. We also examined a number of commercially available suramin analogues, and newly synthesized derivatives of NF449; among these, NF110 and NM16, like NF449, inhibited virus attachment at submicromolar concentrations. PSGL-1 and heparan sulfate, but not SCARB2, are both sulfated molecules, and their interaction with EV-A71 is thought to involve positively charged capsid residues, including a conserved lysine at VP1-244, near the icosahedral 5-fold vertex. We found that mutation of VP1-244 resulted in resistance to NF449, suggesting that this residue is involved in NF449 interaction with the virus capsid. Consistent with this idea, NF449 and NF110 prevented virus interaction with monoclonal antibody MA28-7, which specifically recognizes an epitope overlapping VP1-244 at the 5-fold vertex. Based on these observations we propose that NF449 and related compounds compete with sulfated receptor molecules for a binding site at the 5-fold vertex of the EV-A71 capsid.

  19. Capsid proteins from human immunodeficiency virus type 1 and simian immunodeficiency virus SIVmac can coassemble into mature cores of infectious viruses.

    Science.gov (United States)

    Chen, Jianbo; Pathak, Vinay K; Peng, Weiqun; Hu, Wei-Shau

    2008-09-01

    We have recently shown that the Gag polyproteins from human immunodeficiency virus type 1 (HIV-1) and HIV-2 can coassemble and functionally complement each other. During virion maturation, the Gag polyproteins undergo proteolytic cleavage to release mature proteins including capsid (CA), which refolds and forms the outer shell of a cone-shaped mature core. Less than one-half of the CA proteins present within the HIV-1 virion are required to form the mature core. Therefore, it is unclear whether the mature core in virions containing both HIV-1 and HIV-2 Gag consists of CA proteins from a single virus or from both viruses. To determine whether CA proteins from two different viruses can coassemble into mature cores of infectious viruses, we exploited the specificity of the tripartite motif 5alpha protein from the rhesus monkey (rhTRIM5alpha) for cores containing HIV-1 CA (hCA) but not the simian immunodeficiency virus SIV(mac) CA protein (sCA). If hCA and sCA cannot coassemble into the same core when equal amounts of sCA and hCA are coexpressed, the infectivities of such virus preparations in cells should be inhibited less than twofold by rhTRIM5alpha. However, if hCA and sCA can coassemble into the same core structure to form a mixed core, rhTRIM5alpha would be able to recognize such cores and significantly restrict virus infectivity. We examined the restriction phenotypes of viruses containing both hCA and sCA. Our results indicate that hCA and sCA can coassemble into the same mature core to produce infectious virus. To our knowledge, this is the first demonstration of functional coassembly of heterologous CA protein into the retroviral core.

  20. Useful scars: Physics of the capsids of archaeal viruses

    Science.gov (United States)

    Perotti, L. E.; Dharmavaram, S.; Klug, W. S.; Marian, J.; Rudnick, J.; Bruinsma, R. F.

    2016-07-01

    We propose a physical model for the capsids of tailed archaeal viruses as viscoelastic membranes under tension. The fluidity is generated by thermal motion of scarlike structures that are an intrinsic feature of the ground state of large particle arrays covering surfaces with nonzero Gauss curvature. The tension is generated by a combination of the osmotic pressure of the enclosed genome and an extension force generated by filamentous structure formation that drives the formation of the tails. In continuum theory, the capsid has the shape of a surface of constant mean curvature: an unduloid. Particle arrays covering unduloids are shown to exhibit pronounced subdiffusive and diffusive single-particle transport at temperatures that are well below the melting temperature of defect-free particle arrays on a surface with zero Gauss curvature.

  1. Refinement of herpesvirus B-capsid structure on parallel supercomputers.

    Science.gov (United States)

    Zhou, Z H; Chiu, W; Haskell, K; Spears, H; Jakana, J; Rixon, F J; Scott, L R

    1998-01-01

    Electron cryomicroscopy and icosahedral reconstruction are used to obtain the three-dimensional structure of the 1250-A-diameter herpesvirus B-capsid. The centers and orientations of particles in focal pairs of 400-kV, spot-scan micrographs are determined and iteratively refined by common-lines-based local and global refinement procedures. We describe the rationale behind choosing shared-memory multiprocessor computers for executing the global refinement, which is the most computationally intensive step in the reconstruction procedure. This refinement has been implemented on three different shared-memory supercomputers. The speedup and efficiency are evaluated by using test data sets with different numbers of particles and processors. Using this parallel refinement program, we refine the herpesvirus B-capsid from 355-particle images to 13-A resolution. The map shows new structural features and interactions of the protein subunits in the three distinct morphological units: penton, hexon, and triplex of this T = 16 icosahedral particle.

  2. Structure of the HIV-1 Full-Length Capsid Protein in a Conformationally Trapped Unassembled State Induced by Small-Molecule Binding

    Energy Technology Data Exchange (ETDEWEB)

    Du, Shoucheng; Betts, Laurie; Yang, Ruifeng; Shi, Haibin; Concel, Jason; Ahn, Jinwoo; Aiken, Christopher; Zhang, Peijun; Yeh, Joanne I. (Pitt); (Vanderbilt); (UNC)

    2012-11-26

    The capsid (CA) protein plays crucial roles in HIV infection and replication, essential to viral maturation. The absence of high-resolution structural data on unassembled CA hinders the development of antivirals effective in inhibiting assembly. Unlike enzymes that have targetable, functional substrate-binding sites, the CA does not have a known site that affects catalytic or other innate activity, which can be more readily targeted in drug development efforts. We report the crystal structure of the HIV-1 CA, revealing the domain organization in the context of the wild-type full-length (FL) unassembled CA. The FL CA adopts an antiparallel dimer configuration, exhibiting a domain organization sterically incompatible with capsid assembly. A small compound, generated in situ during crystallization, is bound tightly at a hinge site ('H site'), indicating that binding at this interdomain region stabilizes the ADP conformation. Electron microscopy studies on nascent crystals reveal both dimeric and hexameric lattices coexisting within a single condition, in agreement with the interconvertibility of oligomeric forms and supporting the feasibility of promoting assembly-incompetent dimeric states. Solution characterization in the presence of the H-site ligand shows predominantly unassembled dimeric CA, even under conditions that promote assembly. Our structure elucidation of the HIV-1 FL CA and characterization of a potential allosteric binding site provides three-dimensional views of an assembly-defective conformation, a state targeted in, and thus directly relevant to, inhibitor development. Based on our findings, we propose an unprecedented means of preventing CA assembly, by 'conformationally trapping' CA in assembly-incompetent conformational states induced by H-site binding.

  3. Assembly of recombinant Israeli Acute Paralysis Virus capsids.

    Directory of Open Access Journals (Sweden)

    Junyuan Ren

    Full Text Available The dicistrovirus Israeli Acute Paralysis Virus (IAPV has been implicated in the worldwide decline of honey bees. Studies of IAPV and many other bee viruses in pure culture are restricted by available isolates and permissive cell culture. Here we show that coupling the IAPV major structural precursor protein ORF2 to its cognate 3C-like processing enzyme results in processing of the precursor to the individual structural proteins in a number of insect cell lines following expression by a recombinant baculovirus. The efficiency of expression is influenced by the level of IAPV 3C protein and moderation of its activity is required for optimal expression. The mature IAPV structural proteins assembled into empty capsids that migrated as particles on sucrose velocity gradients and showed typical dicistrovirus like morphology when examined by electron microscopy. Monoclonal antibodies raised to recombinant capsids were configured into a diagnostic test specific for the presence of IAPV. Recombinant capsids for each of the many bee viruses within the picornavirus family may provide virus specific reagents for the on-going investigation of the causes of honeybee loss.

  4. L2, the minor capsid protein of papillomavirus

    Science.gov (United States)

    Wang, Joshua W.; Roden, Richard B.S.

    2013-01-01

    The capsid protein L2 plays major roles in both papillomavirus assembly and the infectious process. While L1 forms the majority of the capsid and can self-assemble into empty virus-like particles (VLPs), L2 is a minor capsid component and lacks the capacity to form VLPs. However, L2 co-assembles with L1 into VLPs, enhancing their assembly. L2 also facilitates encapsidation of the ~8kbp circular and nucleosome-bound viral genome during assembly of the non-enveloped T=7d virions in the nucleus of terminally differentiated epithelial cells, although, like L1, L2 is not detectably expressed in infected basal cells. With respect to infection, L2 is not required for particles to bind to and enter cells. However L2 must be cleaved by furin for endosome escape. L2 then travels with the viral genome to the nucleus, wherein it accumulates at ND-10 domains. Here, we provide an overview of the biology of L2. PMID:23689062

  5. The Pseudorabies Virus VP1/2 Tegument Protein Is Required for Intracellular Capsid Transport†

    OpenAIRE

    Luxton, G.W. Gant; Lee, Joy I-Hsuan; Haverlock-Moyns, Sarah; Schober, Joseph Martin; Smith, Gregory Allan

    2006-01-01

    Transport of capsids in cells is critical to alphaherpesvirus infection and pathogenesis; however, viral factors required for transport have yet to be identified. Here we provide a detailed examination of capsid dynamics during the egress phase of infection in Vero cells infected with pseudorabies virus. We demonstrate that the VP1/2 tegument protein is required for processive microtubule-based transport of capsids in the cytoplasm. A second tegument protein that binds to VP1/2, UL37, was nec...

  6. Three-dimensional structure determination of capsid of Aedes albopicus C6/36 cell densovirus

    Institute of Scientific and Technical Information of China (English)

    CHENG Lingpeng; CHEN Senxiong; Jenifer M.Brannan; Joanita Jakana; ZHANG Qinfen; Z.H.Zhou; ZHANG Jingqiang

    2004-01-01

    The three-dimensional structure of capsid of Aedes albopictus C6/36 densovirus was determined to 14-(A) resolution by electron cryomicroscopy and computer reconstruction. The triangulation number of the capsid is 1. There are 12 holes in each triangular face and a spike on each 5-fold vertex. The validity of the capsid and nucleic acid densities in the reconstructions was discussed.

  7. Data of evolutionary structure change: 1C7MA-1CTYA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1C7MA-1CTYA 1C7M 1CTY A A MADPAAGEKVFGK-CKACHKLDG--NDGVGPHLNGVVGR...ID> A 1C7MA HKLDG--NDGVG ...ure> EE -- ure> ATOM 234 CA HIS A ...hain> 1CTY A 1CTYA H...TVEKGGPHKVG ure> ure>

  8. Primate TRIM5 proteins form hexagonal nets on HIV-1 capsids

    Science.gov (United States)

    Li, Yen-Li; Chandrasekaran, Viswanathan; Carter, Stephen D; Woodward, Cora L; Christensen, Devin E; Dryden, Kelly A; Pornillos, Owen; Yeager, Mark; Ganser-Pornillos, Barbie K; Jensen, Grant J; Sundquist, Wesley I

    2016-01-01

    TRIM5 proteins are restriction factors that block retroviral infections by binding viral capsids and preventing reverse transcription. Capsid recognition is mediated by C-terminal domains on TRIM5α (SPRY) or TRIMCyp (cyclophilin A), which interact weakly with capsids. Efficient capsid recognition also requires the conserved N-terminal tripartite motifs (TRIM), which mediate oligomerization and create avidity effects. To characterize how TRIM5 proteins recognize viral capsids, we developed methods for isolating native recombinant TRIM5 proteins and purifying stable HIV-1 capsids. Biochemical and EM analyses revealed that TRIM5 proteins assembled into hexagonal nets, both alone and on capsid surfaces. These nets comprised open hexameric rings, with the SPRY domains centered on the edges and the B-box and RING domains at the vertices. Thus, the principles of hexagonal TRIM5 assembly and capsid pattern recognition are conserved across primates, allowing TRIM5 assemblies to maintain the conformational plasticity necessary to recognize divergent and pleomorphic retroviral capsids. DOI: http://dx.doi.org/10.7554/eLife.16269.001 PMID:27253068

  9. A minimal representation of the self-assembly of virus capsids

    CERN Document Server

    Llorente, J M Gomez; Breton, J

    2013-01-01

    Viruses are biological nanosystems with a capsid of protein-made capsomer units that encloses and protects the genetic material responsible for their replication. Here we show how the geometrical constraints of the capsomer-capsomer interaction in icosahedral capsids fix the form of the shortest and universal truncated multipolar expansion of the two-body interaction between capsomers. The structures of many of the icosahedral and related virus capsids are located as single lowest energy states of this potential energy surface. Our approach unveils relevant features of the natural design of the capsids and can be of interest in fields of nanoscience and nanotechnology where similar hollow convex structures are relevant.

  10. MA-verpakking : oude techniek, nieuwe toepassing

    NARCIS (Netherlands)

    Stijger, H.; Boogaard, van den G.J.P.M.

    2004-01-01

    Toepassing van MA-verpakking (Modified Atmosphere) bij houtig kleinfruit. Bij MA-verpakking wordt het product in een speciale MA-folie ingepakt, het zogenoemde flowpacken, en al dan niet begast, zodat kwetsbare producten langer in goede conditie blijven

  11. Adeno-associated virus type 2 (AAV2) capsid-specific cytotoxic T lymphocytes eliminate only vector-transduced cells coexpressing the AAV2 capsid in vivo.

    Science.gov (United States)

    Li, Chengwen; Hirsch, Matthew; Asokan, Aravind; Zeithaml, Brian; Ma, Hong; Kafri, Tal; Samulski, R Jude

    2007-07-01

    A recent clinical trial has suggested that recombinant adeno-associated virus (rAAV) vector transduction in humans induces a cytotoxic T-lymphocyte (CTL) response against the AAV2 capsid. To directly address the ability of AAV capsid-specific CTLs to eliminate rAAV-transduced cells in vitro and in vivo in mice, we first demonstrated that AAV2 capsid-specific CTLs could be induced by dendritic cells with endogenous AAV2 capsid expression or pulsed with AAV2 vectors. These CTLs were able to kill a cell line stable for capsid expression in vitro and also in a mouse tumor xenograft model in vivo. Parent colon carcinoma (CT26) cells transduced with a large amount of AAV2 vectors in vitro were also destroyed by these CTLs. To determine the effect of CTLs on the elimination of target cells transduced by AAV2 vectors in vivo, we carried out adoptive transfer experiments. CTLs eliminated liver cells with endogenous AAV2 capsid expression but not liver cells transduced by AAV2 vectors, regardless of the reporter genes. Similar results were obtained for rAAV2 transduction in muscle. Our data strongly suggest that AAV vector-transduced cells are rarely eliminated by AAV2 capsid-specific CTLs in vivo, even though the AAV capsid can induce a CTL response. In conclusion, AAV capsid-specific CTLs do not appear to play a role in elimination of rAAV-transduced cells in a mouse model. In addition, our data suggest that the mouse model may not mimic the immune response noted in humans and additional modification to AAV vectors may be required for further study in order to elicit a similar cellular immune response.

  12. Adeno-Associated Virus Type 2 (AAV2) Capsid-Specific Cytotoxic T Lymphocytes Eliminate Only Vector-Transduced Cells Coexpressing the AAV2 Capsid In Vivo▿

    Science.gov (United States)

    Li, Chengwen; Hirsch, Matthew; Asokan, Aravind; Zeithaml, Brian; Ma, Hong; Kafri, Tal; Samulski, R. Jude

    2007-01-01

    A recent clinical trial has suggested that recombinant adeno-associated virus (rAAV) vector transduction in humans induces a cytotoxic T-lymphocyte (CTL) response against the AAV2 capsid. To directly address the ability of AAV capsid-specific CTLs to eliminate rAAV-transduced cells in vitro and in vivo in mice, we first demonstrated that AAV2 capsid-specific CTLs could be induced by dendritic cells with endogenous AAV2 capsid expression or pulsed with AAV2 vectors. These CTLs were able to kill a cell line stable for capsid expression in vitro and also in a mouse tumor xenograft model in vivo. Parent colon carcinoma (CT26) cells transduced with a large amount of AAV2 vectors in vitro were also destroyed by these CTLs. To determine the effect of CTLs on the elimination of target cells transduced by AAV2 vectors in vivo, we carried out adoptive transfer experiments. CTLs eliminated liver cells with endogenous AAV2 capsid expression but not liver cells transduced by AAV2 vectors, regardless of the reporter genes. Similar results were obtained for rAAV2 transduction in muscle. Our data strongly suggest that AAV vector-transduced cells are rarely eliminated by AAV2 capsid-specific CTLs in vivo, even though the AAV capsid can induce a CTL response. In conclusion, AAV capsid-specific CTLs do not appear to play a role in elimination of rAAV-transduced cells in a mouse model. In addition, our data suggest that the mouse model may not mimic the immune response noted in humans and additional modification to AAV vectors may be required for further study in order to elicit a similar cellular immune response. PMID:17475652

  13. Development of recombinant capsid antigen/transmembrane epitope fusion proteins for serological diagnosis of animal lentivirus infections.

    Science.gov (United States)

    Rosati, S; Profiti, M; Lorenzetti, R; Bandecchi, P; Mannelli, A; Ortoffi, M; Tolari, F; Ciabatti, I M

    2004-10-01

    Among animal lentiviruses, Feline immunodeficiency virus (FIV), Equine infectious anaemia virus (EIAV) and Small ruminant lentiviruses (SRLV) are important pathogens associated with a variety of clinical pictures including immunodeficiency, anaemia, arthritis, pneumonia. The detection of viral antibody response represents a practical diagnostic approach in all lentivirus infections since they remain detectable long life. Capsid antigen (CA) is the major viral core protein and specific antibodies against this antigen are usually first recognised in infected sheep, goat and horse, remaining detectable for long period. Transmembrane (TM) domain of envelope glycoprotein contains a well conserved motif known to form an immunodominant epitope in several lentiviruses. In this study a simple strategy was developed to express the entire CA and the TM epitope in a single fusion protein from equine, feline and small ruminant lentiviruses in prokaryotic system and evaluated the diagnostic utility of a purified preparation in an indirect ELISA for each of the three infections. Results demonstrate that, for FIV and SRLV infections, the combination of CA and TM fractions increases the sensitivity of diagnostic tests based only on CA. The corresponding CA/TM antigen from EIAV showed excellent agreement with Coggins test.

  14. Functional and Structural Characterization of Novel Type of Linker Connecting Capsid and Nucleocapsid Protein Domains in Murine Leukemia Virus.

    Science.gov (United States)

    Doležal, Michal; Hadravová, Romana; Kožíšek, Milan; Bednárová, Lucie; Langerová, Hana; Ruml, Tomáš; Rumlová, Michaela

    2016-09-23

    The assembly of immature retroviral particles is initiated in the cytoplasm by the binding of the structural polyprotein precursor Gag with viral genomic RNA. The protein interactions necessary for assembly are mediated predominantly by the capsid (CA) and nucleocapsid (NC) domains, which have conserved structures. In contrast, the structural arrangement of the CA-NC connecting region differs between retroviral species. In HIV-1 and Rous sarcoma virus, this region forms a rod-like structure that separates the CA and NC domains, whereas in Mason-Pfizer monkey virus, this region is densely packed, thus holding the CA and NC domains in close proximity. Interestingly, the sequence connecting the CA and NC domains in gammaretroviruses, such as murine leukemia virus (MLV), is unique. The sequence is called a charged assembly helix (CAH) due to a high number of positively and negatively charged residues. Although both computational and deletion analyses suggested that the MLV CAH forms a helical conformation, no structural or biochemical data supporting this hypothesis have been published. Using an in vitro assembly assay, alanine scanning mutagenesis, and biophysical techniques (circular dichroism, NMR, microcalorimetry, and electrophoretic mobility shift assay), we have characterized the structure and function of the MLV CAH. We provide experimental evidence that the MLV CAH belongs to a group of charged, E(R/K)-rich, single α-helices. This is the first single α-helix motif identified in viral proteins.

  15. A triclinic crystal structure of the carboxy-terminal domain of HIV-1 capsid protein with four molecules in the asymmetric unit reveals a novel packing interface

    Science.gov (United States)

    Lampel, Ayala; Yaniv, Oren; Berger, Or; Bacharach, Eran; Gazit, Ehud; Frolow, Felix

    2013-01-01

    The Gag precursor is the major structural protein of the virion of human immunodeficiency virus-1 (HIV-1). Capsid protein (CA), a cleavage product of Gag, plays an essential role in virus assembly both in Gag-precursor multimerization and in capsid core formation. The carboxy-terminal domain (CTD) of CA contains 20 residues that are highly conserved across retroviruses and constitute the major homology region (MHR). Genetic evidence implies a role for the MHR in interactions between Gag precursors during the assembly of the virus, but the structural basis for this role remains elusive. This paper describes a novel triclinic structure of the HIV-1 CA CTD at 1.6 Å resolution with two canonical dimers of CA CTD in the asymmetric unit. The canonical dimers form a newly identified packing interface where interactions of four conserved MHR residues take place. This is the first structural indication that these MHR residues participate in the putative CTD–CTD interactions. These findings suggest that the molecules forming this novel interface resemble an intermediate structure that participates in the early steps of HIV-1 assembly. This interface may therefore provide a novel target for antiviral drugs. PMID:23722834

  16. Production, purification, and capsid stability of rhinovirus C types.

    Science.gov (United States)

    Griggs, Theodor F; Bochkov, Yury A; Nakagome, Kazuyuki; Palmenberg, Ann C; Gern, James E

    2015-06-01

    The rhinovirus C (RV-C) were discovered in 2006 and these agents are an important cause of respiratory morbidity. Little is known about their biology. RV-C15 (C15) can be produced by transfection of recombinant viral RNA into cells and subsequent purification over a 30% sucrose cushion, even though yields and infectivity of other RV-C genotypes with this protocol are low. The goal of this study was to determine whether poor RV-C yields were due to capsid instability, and moreover, to develop a robust protocol suitable for the purification of many RV-C types. Capsid stability assays indicated that virions of RV-C41 (refractory to purification) have similar tolerance for osmotic and temperature stress as RV-A16 (purified readily), although C41 is more sensitive to low pH. Modification to the purification protocol by removing detergent increased the yield of RV-C. Addition of nonfat dry milk to the sucrose cushion increased the virus yield but sacrificed purity of the viral suspension. Analysis of virus distribution following centrifugation indicated that the majority of detectable viral RNA (vRNA) was found in pellets refractory to resuspension. Reduction of the centrifugal force with commiserate increase in spin-time improved the recovery of RV-C for both C41 and C2. Transfection of primary lung fibroblasts (WisL cells) followed by the modified purification protocol further improved yields of infectious C41 and C2. Described herein is a higher yield purification protocol suitable for RV-C types refractory to the standard purification procedure. The findings suggest that aggregation-adhesion problems rather than capsid instability influence RV-C yield during purification.

  17. Scaling of X pinches from 1 MA to 6 MA.

    Energy Technology Data Exchange (ETDEWEB)

    Bland, Simon Nicholas (Imperial College, London, United Kingdom); McBride, Ryan D.; Wenger, David Franklin; Sinars, Daniel Brian; Chittenden, Jeremy Paul (imperial College, London, United Kingdom); Pikuz, Sergei A. (Cornell University, Ithaca, NY); Harding, Eric; Jennings, Christopher A.; Ampleford, David J.; Yu, Edmund P.; Cuneo, Michael Edward; Shelkovenko, Tatiana A. (Cornell University, Ithaca, NY); Hansen, Stephanie B.

    2010-09-01

    This final report for Project 117863 summarizes progress made toward understanding how X-pinch load designs scale to high currents. The X-pinch load geometry was conceived in 1982 as a method to study the formation and properties of bright x-ray spots in z-pinch plasmas. X-pinch plasmas driven by 0.2 MA currents were found to have source sizes of 1 micron, temperatures >1 keV, lifetimes of 10-100 ps, and densities >0.1 times solid density. These conditions are believed to result from the direct magnetic compression of matter. Physical models that capture the behavior of 0.2 MA X pinches predict more extreme parameters at currents >1 MA. This project developed load designs for up to 6 MA on the SATURN facility and attempted to measure the resulting plasma parameters. Source sizes of 5-8 microns were observed in some cases along with evidence for high temperatures (several keV) and short time durations (<500 ps).

  18. Human sapovirus classification based on complete capsid nucleotide sequences.

    Science.gov (United States)

    Oka, Tomoichiro; Mori, Kohji; Iritani, Nobuhiro; Harada, Seiya; Ueki, You; Iizuka, Setsuko; Mise, Keiji; Murakami, Kosuke; Wakita, Takaji; Katayama, Kazuhiko

    2012-02-01

    The genetically diverse sapoviruses (SaVs) are a significant cause of acute human gastroenteritis. Human SaV surveillance is becoming more critical, and a better understanding of the diversity and distribution of the viral genotypes is needed. In this study, we analyzed 106 complete human SaV capsid nucleotide sequences to provide a better understanding of their diversity. Based on those results, we propose a novel standardized classification scheme that meets the requirements of the International Calicivirus Scientific Committee. We believe the classification scheme and strains described here will be of value for the molecular characterization and classification of newly detected SaV genotypes and for comparing data worldwide.

  19. Varicella-zoster virus induces the formation of dynamic nuclear capsid aggregates

    Energy Technology Data Exchange (ETDEWEB)

    Lebrun, Marielle [University of Liege (ULg), GIGA-Infection Immunity and Inflammation, Laboratory of Virology and Immunology, Liege (Belgium); Thelen, Nicolas; Thiry, Marc [University of Liege (ULg), GIGA-Neurosciences, Laboratory of Cellular and Tissular Biology, Liege (Belgium); Riva, Laura; Ote, Isabelle; Condé, Claude; Vandevenne, Patricia [University of Liege (ULg), GIGA-Infection Immunity and Inflammation, Laboratory of Virology and Immunology, Liege (Belgium); Di Valentin, Emmanuel [University of Liege (ULg), GIGA-Viral Vectors Platform, Liege (Belgium); Bontems, Sébastien [University of Liege (ULg), GIGA-Infection Immunity and Inflammation, Laboratory of Virology and Immunology, Liege (Belgium); Sadzot-Delvaux, Catherine, E-mail: csadzot@ulg.ac.be [University of Liege (ULg), GIGA-Infection Immunity and Inflammation, Laboratory of Virology and Immunology, Liege (Belgium)

    2014-04-15

    The first step of herpesviruses virion assembly occurs in the nucleus. However, the exact site where nucleocapsids are assembled, where the genome and the inner tegument are acquired, remains controversial. We created a recombinant VZV expressing ORF23 (homologous to HSV-1 VP26) fused to the eGFP and dually fluorescent viruses with a tegument protein additionally fused to a red tag (ORF9, ORF21 and ORF22 corresponding to HSV-1 UL49, UL37 and UL36). We identified nuclear dense structures containing the major capsid protein, the scaffold protein and maturing protease, as well as ORF21 and ORF22. Correlative microscopy demonstrated that the structures correspond to capsid aggregates and time-lapse video imaging showed that they appear prior to the accumulation of cytoplasmic capsids, presumably undergoing the secondary egress, and are highly dynamic. Our observations suggest that these structures might represent a nuclear area important for capsid assembly and/or maturation before the budding at the inner nuclear membrane. - Highlights: • We created a recombinant VZV expressing the small capsid protein fused to the eGFP. • We identified nuclear dense structures containing capsid and procapsid proteins. • Correlative microscopy showed that the structures correspond to capsid aggregates. • Procapsids and partial capsids are found within the aggregates of WT and eGFP-23 VZV. • FRAP and FLIP experiments demonstrated that they are dynamic structures.

  20. Antigenic structure of the capsid protein of rabbit haemorrhagic disease virus

    DEFF Research Database (Denmark)

    Martinez-Torrecuadrada, Jorge L.; Cortes, Elena; Vela, Carmen;

    1998-01-01

    Rabbit haemorrhagic disease virus (RHDV) causes an important disease in rabbits. The virus capsid is composed of a single 60 kDa protein. The capsid protein gene was cloned in Escherichia coli using the pET3 system, and the antigenic structure of RHDV VP60 was dissected using 11 monoclonal...

  1. Evaluation of engineered AAV capsids for hepatic factor IX gene transfer in murine and canine models.

    Science.gov (United States)

    Markusic, David M; Nichols, Timothy C; Merricks, Elizabeth P; Palaschak, Brett; Zolotukhin, Irene; Marsic, Damien; Zolotukhin, Sergei; Srivastava, Arun; Herzog, Roland W

    2017-05-01

    Adeno-associated virus (AAV) gene therapy vectors have shown the best outcomes in human clinical studies for the treatment of genetic diseases such as hemophilia. However, these pivotal investigations have also identified several challenges. For example, high vector doses are often used for hepatic gene transfer, and cytotoxic T lymphocyte responses against viral capsid may occur. Therefore, achieving therapy at reduced vector doses and other strategies to reduce capsid antigen presentation are desirable. We tested several engineered AAV capsids for factor IX (FIX) expression for the treatment of hemophilia B by hepatic gene transfer. These capsids lack potential phosphorylation or ubiquitination sites, or had been generated through molecular evolution. AAV2 capsids lacking either a single lysine residue or 3 tyrosine residues directed substantially higher coagulation FIX expression in mice compared to wild-type sequence or other mutations. In hemophilia B dogs, however, expression from the tyrosine-mutant vector was merely comparable to historical data on AAV2. Evolved AAV2-LiC capsid was highly efficient in hemophilia B mice but lacked efficacy in a hemophilia B dog. Several alternative strategies for capsid modification improve the in vivo performance of AAV vectors in hepatic gene transfer for correction of hemophilia. However, capsid optimization solely in mouse liver may not predict efficacy in other species and thus is of limited translational utility.

  2. Epitope-distal effects accompany the binding of two distinct antibodies to hepatitis B virus capsids

    NARCIS (Netherlands)

    Bereszczak, J.Z.; Rose, R.J.; Duijn, E. van; Watts, N.R.; Wingfield, P.T.; Steven, A.C.; Heck, A.J.R.

    2013-01-01

    Infection of humans by hepatitis B virus (HBV) induces the copious production of antibodies directed against the capsid protein (Cp). A large variety of anticapsid antibodies have been identified that differ in their epitopes. These data, and the status of the capsid as a major clinical antigen, mot

  3. The hepatitis B virus core protein intradimer interface modulates capsid assembly and stability.

    Science.gov (United States)

    Selzer, Lisa; Katen, Sarah P; Zlotnick, Adam

    2014-09-02

    During the hepatitis B virus (HBV) life cycle, capsid assembly and disassembly must ensure correct packaging and release of the viral genome. Here we show that changes in the dynamics of the core protein play an important role in regulating these processes. The HBV capsid assembles from 120 copies of the core protein homodimer. Each monomer contains a conserved cysteine at position 61 that can form an intradimer disulfide that we use as a marker for dimer conformational states. We show that dimers in the context of capsids form intradimer disulfides relatively rapidly. Surprisingly, compared to reduced dimers, fully oxidized dimers assembled slower and into capsids that were morphologically similar but less stable. We hypothesize that oxidized protein adopts a geometry (or constellation of geometries) that is unfavorable for capsid assembly, resulting in weaker dimer-dimer interactions as well as slower assembly kinetics. Our results suggest that structural flexibility at the core protein intradimer interface is essential for regulating capsid assembly and stability. We further suggest that capsid destabilization by the C61-C61 disulfide has a regulatory function to support capsid disassembly and release of the viral genome.

  4. Single hepatitis-B virus core capsid binding to individual nuclear pore complexes in Hela cells.

    Science.gov (United States)

    Lill, Yoriko; Lill, Markus A; Fahrenkrog, Birthe; Schwarz-Herion, Kyrill; Paulillo, Sara; Aebi, Ueli; Hecht, Bert

    2006-10-15

    We investigate the interaction of hepatitis B virus capsids lacking a nuclear localization signal with nuclear pore complexes (NPCs) in permeabilized HeLa cells. Confocal and wide-field optical images of the nuclear envelope show well-spaced individual NPCs. Specific interactions of capsids with single NPCs are characterized by extended residence times of capsids in the focal volume which are characterized by fluorescence correlation spectroscopy. In addition, single-capsid-tracking experiments using fast wide-field fluorescence microscopy at 50 frames/s allow us to directly observe specific binding via a dual-color colocalization of capsids and NPCs. We find that binding occurs with high probability on the nuclear-pore ring moiety, at 44 +/- 9 nm radial distance from the central axis.

  5. Capsid modification of adeno-associated virus and tumor targeting gene therapy

    Institute of Scientific and Technical Information of China (English)

    XU ZengHu; ZHOU XiuMei; SHI WenFang; QIAN QiJun

    2008-01-01

    Targeting is critical for successful tumor gene therapy. The adeno-associated virus (AAV) has aroused wide concern due to its excellent advantages over other viral vectors in gene therapy. AAV has a broad infection spectrum, which also results in poor specificity towards tissues or cells and low transduction efficiency. Therefore, it is imperative to improve target and transduction efficiency in AAV-mediated gene therapy. Up to now, researchers have developed many strategies to modify AAV capsids for improving targeting or retargeting only desired cells. These strategies include not only traditional chemical modification, phage display technology, modification of AAV capsid genome, chimeric vectors and so on, but also many novel strategies involved in marker rescue strategy, direct evolution of capsid proteins, direct display random peptides on AAV capsid, AAVP (AAV-Phage), and etc. This review will summarize the advances of researches on the capsid modification of AAV to target malignant cells.

  6. Modeling of the rotavirus group C capsid predicts a surface topology distinct from other rotavirus species.

    Science.gov (United States)

    Eren, Elif; Zamuda, Kimberly; Patton, John T

    2016-01-01

    Rotavirus C (RVC) causes sporadic gastroenteritis in adults and is an established enteric pathogen of swine. Because RVC strains grow poorly in cell culture, which hinders generation of virion-derived RVC triple-layered-particle (TLP) structures, we used the known Rotavirus A (RVA) capsid structure to model the human RVC (Bristol) capsid. Comparative analysis of RVA and RVC capsid proteins showed major differences at the VP7 layer, an important target region for vaccine development due to its antigenic properties. Our model predicted the presence of a surface extended loop in RVC, which could form a major antigenic site on the capsid. We analyzed variations in the glycosylation patterns among RV capsids and identified group specific conserved sites. In addition, our results showed a smaller RVC VP4 foot, which protrudes toward the intermediate VP6 layer, in comparison to that of RVA. Finally, our results showed major structural differences at the VP8* glycan recognition sites.

  7. Reactive oxygen species promote heat shock protein 90-mediated HBV capsid assembly

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Yoon Sik, E-mail: yumshak@naver.com; Seo, Hyun Wook, E-mail: suruk@naver.com; Jung, Guhung, E-mail: drjung@snu.ac.kr

    2015-02-13

    Hepatitis B virus (HBV) infection induces reactive oxygen species (ROS) production and has been associated with the development of hepatocellular carcinoma (HCC). ROS are also an important factor in HCC because the accumulated ROS leads to abnormal cell proliferation and chromosome mutation. In oxidative stress, heat shock protein 90 (Hsp90) and glutathione (GSH) function as part of the defense mechanism. Hsp90 prevents cellular component from oxidative stress, and GSH acts as antioxidants scavenging ROS in the cell. However, it is not known whether molecules regulated by oxidative stress are involved in HBV capsid assembly. Based on the previous study that Hsp90 facilitates HBV capsid assembly, which is an important step for the packing of viral particles, here, we show that ROS enrich Hsp90-driven HBV capsid formation. In cell-free system, HBV capsid assembly was facilitated by ROS with Hsp90, whereas it was decreased without Hsp90. In addition, GSH inhibited the function of Hsp90 to decrease HBV capsid assembly. Consistent with the result of cell-free system, ROS and buthionine sulfoximine (BS), an inhibitor of GSH synthesis, increased HBV capsid formation in HepG2.2.15 cells. Thus, our study uncovers the interplay between ROS and Hsp90 during HBV capsid assembly. - Highlights: • We examined H{sub 2}O{sub 2} and GSH modulate HBV capsid assembly. • H{sub 2}O{sub 2} facilitates HBV capsid assembly in the presence of Hsp90. • GSH inhibits function of Hsp90 in facilitating HBV capsid assembly. • H{sub 2}O{sub 2} and GSH induce conformation change of Hsp90.

  8. Revised Mimivirus major capsid protein sequence reveals intron-containing gene structure and extra domain

    Directory of Open Access Journals (Sweden)

    Suzan-Monti Marie

    2009-05-01

    Full Text Available Abstract Background Acanthamoebae polyphaga Mimivirus (APM is the largest known dsDNA virus. The viral particle has a nearly icosahedral structure with an internal capsid shell surrounded with a dense layer of fibrils. A Capsid protein sequence, D13L, was deduced from the APM L425 coding gene and was shown to be the most abundant protein found within the viral particle. However this protein remained poorly characterised until now. A revised protein sequence deposited in a database suggested an additional N-terminal stretch of 142 amino acids missing from the original deduced sequence. This result led us to investigate the L425 gene structure and the biochemical properties of the complete APM major Capsid protein. Results This study describes the full length 3430 bp Capsid coding gene and characterises the 593 amino acids long corresponding Capsid protein 1. The recombinant full length protein allowed the production of a specific monoclonal antibody able to detect the Capsid protein 1 within the viral particle. This protein appeared to be post-translationnally modified by glycosylation and phosphorylation. We proposed a secondary structure prediction of APM Capsid protein 1 compared to the Capsid protein structure of Paramecium Bursaria Chlorella Virus 1, another member of the Nucleo-Cytoplasmic Large DNA virus family. Conclusion The characterisation of the full length L425 Capsid coding gene of Acanthamoebae polyphaga Mimivirus provides new insights into the structure of the main Capsid protein. The production of a full length recombinant protein will be useful for further structural studies.

  9. Data of evolutionary structure change: 1BEDA-2B6MA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available 1BEDA-2B6MA 1BED 2B6M A A AQFKEGEHYQVLKTPASSSPVVSEFFSFYCPHCNTF---...HHHHHHHHHH EEEE EEEEE HHHHHHHHHHHHHH - 0 1BED... A 1BEDA HCNTF---E...e> ALA CA 306 SER CA 272 1BED... A 1BEDA HTLRKPPKDEQ

  10. Portraits de Maîtres offerts à Olga Weijers

    NARCIS (Netherlands)

    Teeuwen, M.J.; Angotti, C.; Brînzei, M.

    2013-01-01

    En 2011, le répertoire d’Olga Weijers, Le travail intellectuel à la faculté des arts de Paris : textes et maîtres (ca. 1200-1500), en neuf volumes, est arrivé à son terme. Cet instrument de travail a également inauguré la collection Studia Artistarum dans laquelle Olga Weijers a accueilli ces quinze

  11. Pyroxenite in the Galapagos plume source at 65 Ma

    Science.gov (United States)

    Whalen, W. T.; Gazel, E.; Vidito, C. A.; Herzberg, C. T.; Class, C.; Bizimis, M.; Alvarado-Induni, G.

    2013-12-01

    Mantle plumes originate from boundary layers below the upper mantle. Their surface expressions as hotspot tracks have been linked to voluminous outpourings of lava in the form of large igneous provinces. The Galapagos hotspot has been active since ~90 Ma and the oldest lavas of its associated submarine ridge have been dated to ~14 Ma, subducting at the Middle America Trench, off Costa Rica. The Galapagos plume head magmatic production is preserved as the Caribbean Large Igneous Province (CLIP). A series of 15-65 Ma accreted Galapagos paleo-ridges and islands/seamounts are accreted in the Pacific coast of Costa Rica and Panama. One of these accreted terranes, the Quepos block on the west coast of Costa Rica is an ancient, ~65 Ma Galapagos island. Olivine phenocrysts from Quepos picrites have elevated Ni and low Ca and Mn and Fe/Mn indicative of a dominant pyroxenite source component while CLIP samples are dominated by a peridotite source. The mantle potential temperature (max) of the plume changed from ~1650 to ~1550 C at 65 Ma. This change correlates with the first appearance of the pyroxenite component and an EMII signature (Northern Galapagos Domain) in the Galapagos plume. A relatively dense pyroxenite component may provide a mechanism for the change in Tp due to its effect on the plume's bouyancy. Alternatively, the pyroxenite component was diluted by high peridotite melt fraction during the massive production of the CLIP.

  12. 赣东北蛇绿岩带新元古代(~800 Ma)高镁安山岩的发现及其意义%Recognition and Significance of Neoproterozoic (ca.800 Ma) High-Mg Andesites in the NE Jiangxi Ophiolite Belt

    Institute of Scientific and Technical Information of China (English)

    王存智; 余明刚; 黄志忠; 洪文涛; 赵希林; 姜杨; 周效华; 段政; 邢光福

    2016-01-01

    The newly discovered Neoproterozoic high-Mg andesites are located at Zhangshudun of the NE Jiangxi ophiolite belt and are dated at a zircon U-Pb age of 794.8 ±6.0 Ma.They have variable SiO2(54.90%~58.45%),CaO (2.46%~6.73%),relatively consistent Al2O3 (15.31%~16.77%,mostly less than 16%) and FeOT/MgO values (0.87~1.20),and show relatively high MgO contents (6.22~8.47%),high Mg#(64~7 1 ),which clearly exhibits the diagnostic features of typical high-Mg andesites.The study samples are enriched in LREE and have slightly negative Eu anomalies.In spider diagram,they show enrichment of LILE (eg.Rb,Ba) while depleted in Nb and Sr elements.These andesites have relatively low Sr abundance and Sr/Y ratios (4.1 1 ~7.29),similar to Sanukitoids of the Setouchi volcanic belt in Japan.The zircon Hf isotopes show positive initial epsilon Hf values ranging from +10.3 to +17.8.These geochemical data indicate Zhangshudun high-Mg andesites should derived from the deplted mantle wedge metasomatized by fluids released from the subducted slab,within an oceanic arc setting.Therefore,it is inferred that the Shuangxiwu arc was away from the southeastern margin of the Yangtze Block,and the Yangtze and Cathaysia blocks had not collided at least at ca.800Ma.%在赣东北蛇绿岩带中的樟树墩地区新发现新元古代高镁安山岩,其LA-ICP-MS锆石U-Pb法年龄为794.8±6.0 Ma。它们的 SiO2介于54.90%~58.45%,Al2O3介于15.31%~16.77%(平均小于16%);CaO 为2.46%~6.73%,FeOT/MgO变化于0.87~1.20,具有高MgO(6.39%~8.76%)、高Mg#(64~71)特点;富集轻稀土元素且具弱负Eu异常,明显富集LILE而亏损HFSE,Sr含量(普遍<200×10-6)和Sr/Y比值(4.11~7.29)均较低,具有典型高镁安山岩的地球化学特征,类似于日本Setouchi火山带的Sanukitoids。锆石εHf(t)值介于10.23~17.79之间,反映它们起源于亏损地幔。主、微量及同位素特征均表明,本区

  13. Structure of the pseudorabies virus capsid: comparison with herpes simplex virus type 1 and differential binding of essential minor proteins.

    Science.gov (United States)

    Homa, F L; Huffman, J B; Toropova, K; Lopez, H R; Makhov, A M; Conway, J F

    2013-09-23

    The structure of pseudorabies virus (PRV) capsids isolated from the nucleus of infected cells and from PRV virions was determined by cryo-electron microscopy (cryo-EM) and compared to herpes simplex virus type 1 (HSV-1) capsids. PRV capsid structures closely resemble those of HSV-1, including distribution of the capsid vertex specific component (CVSC) of HSV-1, which is a heterodimer of the pUL17 and pUL25 proteins. Occupancy of CVSC on all PRV capsids is near 100%, compared to ~50% reported for HSV-1 C-capsids and 25% or less that we measure for HSV-1 A- and B-capsids. A PRV mutant lacking pUL25 does not produce C-capsids and lacks visible CVSC density in the cryo-EM-based reconstruction. A reconstruction of PRV capsids in which green fluorescent protein was fused within the N-terminus of pUL25 confirmed previous studies with a similar HSV-1 capsid mutant localizing pUL25 to the CVSC density region that is distal to the penton. However, comparison of the CVSC density in a 9-Å-resolution PRV C-capsid map with the available crystal structure of HSV-1 pUL25 failed to find a satisfactory fit, suggesting either a different fold for PRV pUL25 or a capsid-bound conformation for pUL25 that does not match the X-ray model determined from protein crystallized in solution. The PRV capsid imaged within virions closely resembles C-capsids with the addition of weak but significant density shrouding the pentons that we attribute to tegument proteins. Our results demonstrate significant structure conservation between the PRV and HSV capsids. © 2013 Elsevier Ltd. All rights reserved.

  14. Cinéma / Canada

    OpenAIRE

    Berthomé, Jean-Pierre; Coulombe, Michel; Dvorak, Marta; Garel, Sylvain; Noguez, Dominique; Suchet, Simone; Vimenet, Pascal

    2013-01-01

    Longtemps connue en France par le biais de cinéastes québécois tels que Claude Jutra, Gilles Carle, ou Pierre Perrault, l'industrie cinématographique du Canada a dû se développer dans l'ombre d'Hollywood. Elle s'est forgée une réputation internationale d'excellence dans les domaines qui ne concurrençaient pas les studios américains : le documentaire, le court-métrage, et les films d'animation. Nous sommes en présence d'un cinéma fortement subventionné (et même d'un cinéma d'État) qui repose s...

  15. Residues of the UL25 Protein of Herpes Simplex Virus That Are Required for Its Stable Interaction with Capsids

    OpenAIRE

    Cockrell, Shelley K.; Huffman, Jamie B.; Toropova, Katerina; James F Conway; Homa, Fred L.

    2011-01-01

    The herpes simplex virus 1 (HSV-1) UL25 gene product is a minor capsid component that is required for encapsidation, but not cleavage, of replicated viral DNA. UL25 is located on the capsid surface in a proposed heterodimer with UL17, where five copies of the heterodimer are found at each of the capsid vertices. Previously, we demonstrated that amino acids 1 to 50 of UL25 are essential for its stable interaction with capsids. To further define the UL25 capsid binding domain, we generated reco...

  16. BaMa / Raivo Juurak

    Index Scriptorium Estoniae

    Juurak, Raivo, 1949-

    2002-01-01

    Eesti ülikoolide üleminekust 3+2 süsteemile. Lühend BaMa on tulnud kasutusele seoses Euroopa ülikoolide õppekavade reformimisega ning tähistab õppekava, kus esimese astme läbimise järel omandatakse bakalaureuse- ja teise järel magistrikraad. Õppekavade tüüpidest Eesti ja Euroopa Liidu kõrgkoolides ning Bologna deklaratsioonist

  17. Structural, Mechanistic, and Antigenic Characterization of the Human Astrovirus Capsid

    Science.gov (United States)

    York, Royce L.; Yousefi, Payam A.; Bogdanoff, Walter; Haile, Sara; Tripathi, Sarvind

    2015-01-01

    ABSTRACT Human astroviruses (HAstVs) are nonenveloped, positive-sense, single-stranded RNA viruses that are a leading cause of viral gastroenteritis. HAstV particles display T=3 icosahedral symmetry formed by 180 copies of the capsid protein (CP), which undergoes proteolytic maturation to generate infectious HAstV particles. Little is known about the molecular features that govern HAstV particle assembly, maturation, infectivity, and immunogenicity. Here we report the crystal structures of the two main structural domains of the HAstV CP: the core domain at 2.60-Å resolution and the spike domain at 0.95-Å resolution. Fitting of these structures into the previously determined 25-Å-resolution electron cryomicroscopy density maps of HAstV allowed us to characterize the molecular features on the surfaces of immature and mature T=3 HAstV particles. The highly electropositive inner surface of HAstV supports a model in which interaction of the HAstV CP core with viral RNA is a driving force in T=3 HAstV particle formation. Additionally, mapping of conserved residues onto the HAstV CP core and spike domains in the context of the immature and mature HAstV particles revealed dramatic changes to the exposure of conserved residues during virus maturation. Indeed, we show that antibodies raised against mature HAstV have reactivity to both the HAstV CP core and spike domains, revealing for the first time that the CP core domain is antigenic. Together, these data provide new molecular insights into HAstV that have practical applications for the development of vaccines and antiviral therapies. IMPORTANCE Astroviruses are a leading cause of viral diarrhea in young children, immunocompromised individuals, and the elderly. Despite the prevalence of astroviruses, little is known at the molecular level about how the astrovirus particle assembles and is converted into an infectious, mature virus. In this paper, we describe the high-resolution structures of the two main astrovirus

  18. Structure of the capsid of Kilham rat virus from small-angle neutron scattering

    Energy Technology Data Exchange (ETDEWEB)

    Wobbe, C.R.; Mitra, S.; Ramakrishnan, V.

    1984-12-18

    The structure of empty capsids of Kilham rat virus, an autonomous parvovirus with icosahedral symmetry, was investigated by small-angle neutron scattering. From the forward scatter, the molecular weight was determined to be 4.0 x 10(6), and from the Guinier region, the radius of gyration was found to be 105 A in D2O and 104 A in H/sub 2/O. On the basis of the capsid molecular weight and the molecular weights and relative abundances of the capsid proteins, the authors propose that the capsid has a triangulation number of 1. Extended scattering curves and mathematical modeling revealed that the capsid consists of two shells of protein, the inner shell extending from 58 to 91 A in D2O and from 50 to 91 A in H/sub 2/O and containing 11% of the capsid scattering mass, and the outer shell extending to 121 A in H/sub 2/O and D2O. The inner shell appears to have a higher content of basic amino acids than the outer shell, based on its lower scattering density in D2O than in H/sub 2/O. The authors propose that all three capsid proteins contribute to the inner shell and that this basic region serves DNA binding and partial charge neutralization functions.

  19. The delta domain of the HK97 major capsid protein is essential for assembly.

    Science.gov (United States)

    Oh, Bonnie; Moyer, Crystal L; Hendrix, Roger W; Duda, Robert L

    2014-05-01

    The 102 residue N-terminal extension of the HK97 major capsid protein, the delta domain, is normally present during the assembly of immature HK97 procapsids, but it is removed during maturation like well-known internal scaffolding proteins of other tailed phages and herpesviruses. The delta domain also shares other unusual properties usually found in other viral and phage scaffolding proteins, including its location on the inside of the capsid, a high predicted and measured α-helical content, and an additional prediction for the ability to form parallel coiled-coils. Viral scaffolding proteins are essential for capsid assembly and phage viability, so we tested whether the HK97 delta domain was essential for capsid assembly. We studied the effects of deleting all or parts of the delta domain on capsid assembly and on complementation of capsid-protein-defective phage, and our results demonstrate that the delta domain is required for HK97 capsid assembly. Copyright © 2014 Elsevier Inc. All rights reserved.

  20. Role of dynamic capsomere supply for viral capsid self-assembly

    Science.gov (United States)

    Boettcher, Marvin A.; Klein, Heinrich C. R.; Schwarz, Ulrich S.

    2015-02-01

    Many viruses rely on the self-assembly of their capsids to protect and transport their genomic material. For many viral systems, in particular for human viruses like hepatitis B, adeno or human immunodeficiency virus, that lead to persistent infections, capsomeres are continuously produced in the cytoplasm of the host cell while completed capsids exit the cell for a new round of infection. Here we use coarse-grained Brownian dynamics simulations of a generic patchy particle model to elucidate the role of the dynamic supply of capsomeres for the reversible self-assembly of empty T1 icosahedral virus capsids. We find that for high rates of capsomere influx only a narrow range of bond strengths exists for which a steady state of continuous capsid production is possible. For bond strengths smaller and larger than this optimal value, the reaction volume becomes crowded by small and large intermediates, respectively. For lower rates of capsomere influx a broader range of bond strengths exists for which a steady state of continuous capsid production is established, although now the production rate of capsids is smaller. Thus our simulations suggest that the importance of an optimal bond strength for viral capsid assembly typical for in vitro conditions can be reduced by the dynamic influx of capsomeres in a cellular environment.

  1. Immobilization and One-Dimensional Arrangement of Virus Capsids with Nanoscale Precision Using DNA Origami

    Energy Technology Data Exchange (ETDEWEB)

    Stephanopoulos, Nicholas [Univ. of California, Berkeley, CA (United States); Liu, Minghui [Arizona State Univ., Tempe, AZ (United States); Tong, Gary J [Univ. of California, Berkeley, CA (United States); Li, Zhe [Arizona State Univ., Tempe, AZ (United States); Liu, Yan [Arizona State Univ., Tempe, AZ (United States); Yan, Hao [Arizona State Univ., Tempe, AZ (United States); Francis, Matthew B [Univ. of California, Berkeley, CA (United States)

    2010-06-24

    DNA origami was used as a scaffold to arrange spherical virus capsids into one-dimensional arrays with precise nanoscale positioning. To do this, we first modified the interior surface of bacteriophage MS2 capsids with fluorescent dyes as a model cargo. An unnatural amino acid on the external surface was then coupled to DNA strands that were complementary to those extending from origami tiles. Two different geometries of DNA tiles (rectangular and triangular) were used. The capsids associated with tiles of both geometries with virtually 100% efficiency under mild annealing conditions, and the location of capsid immobilization on the tile could be controlled by the position of the probe strands. The rectangular tiles and capsids could then be arranged into one-dimensional arrays by adding DNA strands linking the corners of the tiles. The resulting structures consisted of multiple capsids with even spacing (~100 nm). We also used a second set of tiles that had probe strands at both ends, resulting in a one-dimensional array of alternating capsids and tiles. This hierarchical self-assembly allows us to position the virus particles with unprecedented control and allows the future construction of integrated multicomponent systems from biological scaffolds using the power of rationally engineered DNA nanostructures.

  2. Controlling AAV Tropism in the Nervous System with Natural and Engineered Capsids

    Science.gov (United States)

    Castle, Michael J.; Turunen, Heikki T.; Vandenberghe, Luk H.; Wolfe, John H.

    2016-01-01

    More than one hundred naturally occurring variants of adeno-associated virus (AAV) have been identified, and this library has been further expanded by an array of techniques for modification of the viral capsid. AAV capsid variants possess unique antigenic profiles and demonstrate distinct cellular tropisms driven by differences in receptor binding. AAV capsids can be chemically modified to alter tropism, can be produced as hybrid vectors that combine the properties of multiple serotypes, and can carry peptide insertions that introduce novel receptor-binding activity. Furthermore, directed evolution of shuffled genome libraries can identify engineered variants with unique properties, and rational modification of the viral capsid can alter tropism, reduce blockage by neutralizing antibodies, or enhance transduction efficiency. This large number of AAV variants and engineered capsids provides a varied toolkit for gene delivery to the CNS and retina, with specialized vectors available for many applications, but selecting a capsid variant from the array of available vectors can be difficult. This chapter describes the unique properties of a range of AAV variants and engineered capsids, and provides a guide for selecting the appropriate vector for specific applications in the CNS and retina. PMID:26611584

  3. Structural rigidity in the capsid assembly of cowpea chlorotic mottle virus

    Science.gov (United States)

    Hespenheide, B. M.; Jacobs, D. J.; Thorpe, M. F.

    2004-11-01

    The cowpea chlorotic mottle virus (CCMV) has a protein cage, or capsid, which encloses its genetic material. The structure of the capsid consists of 180 copies of a single protein that self-assemble inside a cell to form a complete capsid with icosahedral symmetry. The icosahedral surface can be naturally divided into pentagonal and hexagonal faces, and the formation of either of these faces has been proposed to be the first step in the capsid assembly process. We have used the software FIRST to analyse the rigidity of pentameric and hexameric substructures of the complete capsid to explore the viability of certain capsid assembly pathways. FIRST uses the 3D pebble game to determine structural rigidity, and a brief description of this algorithm, as applied to body-bar networks, is given here. We find that the pentameric substructure, which corresponds to a pentagonal face on the icosahedral surface, provides the best structural properties for nucleating the capsid assembly process, consistent with experimental observations.

  4. Structural rigidity in the capsid assembly of cowpea chlorotic mottle virus

    Energy Technology Data Exchange (ETDEWEB)

    Hespenheide, B M [Department of Physics and Astronomy, Arizona State University, PO Box 871504, Tempe, AZ 85287-1504 (United States); Jacobs, D J [Department of Physics and Astronomy, California State University, 18111 Nordhoff Street, Northridge, CA 91330-8268 (United States); Thorpe, M F [Department of Physics and Astronomy, Arizona State University, PO Box 871504, Tempe, AZ 85287-1504 (United States)

    2004-11-10

    The cowpea chlorotic mottle virus (CCMV) has a protein cage, or capsid, which encloses its genetic material. The structure of the capsid consists of 180 copies of a single protein that self-assemble inside a cell to form a complete capsid with icosahedral symmetry. The icosahedral surface can be naturally divided into pentagonal and hexagonal faces, and the formation of either of these faces has been proposed to be the first step in the capsid assembly process. We have used the software FIRST to analyse the rigidity of pentameric and hexameric substructures of the complete capsid to explore the viability of certain capsid assembly pathways. FIRST uses the 3D pebble game to determine structural rigidity, and a brief description of this algorithm, as applied to body-bar networks, is given here. We find that the pentameric substructure, which corresponds to a pentagonal face on the icosahedral surface, provides the best structural properties for nucleating the capsid assembly process, consistent with experimental observations.

  5. TNPO3 protects HIV-1 replication from CPSF6-mediated capsid stabilization in the host cell cytoplasm.

    Science.gov (United States)

    De Iaco, Alberto; Santoni, Federico; Vannier, Anne; Guipponi, Michel; Antonarakis, Stylianos; Luban, Jeremy

    2013-02-15

    Despite intensive investigation the mechanism by which HIV-1 reaches the host cell nucleus is unknown. TNPO3, a karyopherin mediating nuclear entry of SR-proteins, was shown to be required for HIV-1 infectivity. Some investigators have reported that TNPO3 promotes HIV-1 nuclear import, as would be expected for a karyopherin. Yet, an equal number of investigators have failed to obtain evidence that supports this model. Here, a series of experiments were performed to better elucidate the mechanism by which TNPO3 promotes HIV-1 infectivity. To examine the role of TNPO3 in HIV-1 replication, the 2-LTR circles that are commonly used as a marker for HIV-1 nuclear entry were cloned after infection of TNPO3 knockdown cells. Potential explanation for the discrepancy in the literature concerning the effect of TNPO3 was provided by sequencing hundreds of these clones: a significant fraction resulted from autointegration into sites near the LTRs and therefore were not bona fide 2-LTR circles. In response to this finding, new techniques were developed to monitor HIV-1 cDNA, including qPCR reactions that distinguish 2-LTR circles from autointegrants, as well as massive parallel sequencing of HIV-1 cDNA. With these assays, TNPO3 knockdown was found to reduce the levels of 2-LTR circles. This finding was puzzling, though, since previous work has shown that the HIV-1 determinant for TNPO3-dependence is capsid (CA), an HIV-1 protein that forms a mega-dalton protein lattice in the cytoplasm. TNPO3 imports cellular splicing factors via their SR-domain. Attention was therefore directed towards CPSF6, an SR-protein that binds HIV-1 CA and inhibits HIV-1 nuclear import when the C-terminal SR-domain is deleted. The effect of 27 HIV-1 capsid mutants on sensitivity to TNPO3 knockdown was then found to correlate strongly with sensitivity to inhibition by a C-terminal deletion mutant of CPSF6 (R2 = 0.883, p HIV-1 replication. Additionally, targeting CPSF6 to the nucleus by fusion to a

  6. Assembly of the small outer capsid protein, Soc, on bacteriophage T4: a novel system for high density display of multiple large anthrax toxins and foreign proteins on phage capsid.

    Science.gov (United States)

    Li, Qin; Shivachandra, Sathish B; Zhang, Zhihong; Rao, Venigalla B

    2007-07-27

    Bacteriophage T4 capsid is a prolate icosahedron composed of the major capsid protein gp23*, the vertex protein gp24*, and the portal protein gp20. Assembled on its surface are 810 molecules of the non-essential small outer capsid protein, Soc (10 kDa), and 155 molecules of the highly antigenic outer capsid protein, Hoc (39 kDa). In this study Soc, a "triplex" protein that stabilizes T4 capsid, is targeted for molecular engineering of T4 particle surface. Using a defined in vitro assembly system, anthrax toxins, protective antigen, lethal factor and their domains, fused to Soc were efficiently displayed on the capsid. Both the N and C termini of the 80 amino acid Soc polypeptide can be simultaneously used to display antigens. Proteins as large as 93 kDa can be stably anchored on the capsid through Soc-capsid interactions. Using both Soc and Hoc, up to 1662 anthrax toxin molecules are assembled on the phage T4 capsid under controlled conditions. We infer from the binding data that a relatively high affinity capsid binding site is located in the middle of the rod-shaped Soc, with the N and C termini facing the 2- and 3-fold symmetry axes of the capsid, respectively. Soc subunits interact at these interfaces, gluing the adjacent capsid protein hexamers and generating a cage-like outer scaffold. Antigen fusion does interfere with the inter-subunit interactions, but these interactions are not essential for capsid binding and antigen display. These features make the T4-Soc platform the most robust phage display system reported to date. The study offers insights into the architectural design of bacteriophage T4 virion, one of the most stable viruses known, and how its capsid surface can be engineered for novel applications in basic molecular biology and biotechnology.

  7. Cryo-EM reconstruction of the Cafeteria roenbergensis virus capsid suggests novel assembly pathway for giant viruses.

    Science.gov (United States)

    Xiao, Chuan; Fischer, Matthias G; Bolotaulo, Duer M; Ulloa-Rondeau, Nancy; Avila, Gustavo A; Suttle, Curtis A

    2017-07-14

    Whereas the protein composition and overall shape of several giant virus capsids have been described, the mechanism by which these large capsids assemble remains enigmatic. Here, we present a reconstruction of the capsid of Cafeteria roenbergensis virus (CroV), one of the largest viruses analyzed by cryo-electron microscopy (cryo-EM) to date. The CroV capsid has a diameter of 3,000 Å and a Triangulation number of 499. Unlike related mimiviruses, the CroV capsid is not decorated with glycosylated surface fibers, but features 30 Å-long surface protrusions that are formed by loops of the major capsid protein. Based on the orientation of capsomers in the cryo-EM reconstruction, we propose that the capsids of CroV and related giant viruses are assembled by a newly conceived assembly pathway that initiates at a five-fold vertex and continuously proceeds outwards in a spiraling fashion.

  8. On the geometry of regular icosahedral capsids containing disymmetrons

    CERN Document Server

    Ang, Kai-Siang

    2016-01-01

    Icosahedral virus capsids are composed of symmetrons, organized arrangements of capsomers. There are three types of symmetrons: disymmetrons, trisymmetrons, and pentasymmetrons, which have different shapes and are centered on the icosahedral 2-fold, 3-fold and 5-fold axes of symmetry, respectively. In 2010 [Sinkovits & Baker] gave a classification of all possible ways of building an icosahedral structure solely from trisymmetrons and pentasymmetrons, which requires the triangulation number T to be odd. In the present paper we incorporate disymmetrons to obtain a geometric classification of icosahedral viruses formed by regular penta-, tri-, and disymmetrons. For every class of solutions, we further provide formulas for symmetron sizes and parity restrictions on h, k, and T numbers. We also present several methods in which invariants may be used to classify a given configuration.

  9. Assembly of bacteriophage T7. Dimensions of the bacteriophage and its capsids

    Energy Technology Data Exchange (ETDEWEB)

    Stroud, R.M.; Serwer, P.; Ross, M.J.

    1981-12-01

    The dimensions of bacteriophage T7 and T7 capsids have been investigated by small-angle x-ray scattering. Phage T7 behaves like a sphere of uniform density with an outer radius of 301 +/- 2 A (excluding the phage tail) and a calculated volume for protein plus nucleic acid of 1.14 +/- 0.05 x 10/sup -16/ ml. The outer radius determined of T7 phage in solution is approx.30% greater than the radius measured from electron micrographs, which indicates that considerable shrinkage occurs during preparation for electron microscopy. Capsids that have a phagelike envelope and do not contain DNA were obtained from lysates of T7-infected Escherichia coli (capsid II) and by separating the capsid component of T7 phage from the phage DNA by means of temperature shock (capsid IV). In both cases the peak protein density is at a radius of 275 A; the outer radius is 286 +/- 4 A, approx.5% smaller than the envelope of T7 phage. The thickness of the envelope of capsid II is 22 +/- 4 A, consistent with the thickness of protein estimated to be 23 +/- 5 A in whole T7 phage, as seen on electron micrographs in which the internal DNA is positively stained. The volume in T7 phage available to package DNA is estimated to be 9.2 +/- 0.4 x 10/sup -17/ ml. The packaged DNA adopts a regular packing with 23.6 A interplanar spacing between DNA strands. The angular width of the 23.6 A reflection shows that the mean DNA-DNA spacing throughout the phage head is 27.5 +/- <2.2 A. A T7 precursor capsid (capsid I) expands when pelleted for x-ray scattering in the ultracentrifuge to essentially the same outer dimensions as for capsids II and IV. This expansion of capsid I can be prevented by fixing with glutaraldehyde; fixed capsid I has peak density at a radius of 247 A, 10% less than capsid II or IV.

  10. AAV8 capsid variable regions at the two-fold symmetry axis contribute to high liver transduction by mediating nuclear entry and capsid uncoating

    Energy Technology Data Exchange (ETDEWEB)

    Tenney, Rebeca M.; Bell, Christie L.; Wilson, James M., E-mail: wilsonjm@mail.med.upenn.edu

    2014-04-15

    Adeno-associated virus serotype 8 (AAV8) is a promising vector for liver-directed gene therapy. Although efficient uncoating of viral capsids has been implicated in AAV8's robust liver transduction, much about the biology of AAV8 hepatotropism remains unclear. Our study investigated the structural basis of AAV8 liver transduction efficiency by constructing chimeric vector capsids containing sequences derived from AAV8 and AAV2 – a highly homologous yet poorly hepatotropic serotype. Engineered vectors containing capsid variable regions (VR) VII and IX from AAV8 in an AAV2 backbone mediated near AAV8-like transduction in mouse liver, with higher numbers of chimeric genomes detected in whole liver cells and isolated nuclei. Interestingly, chimeric capsids within liver nuclei also uncoated similarly to AAV8 by 6 weeks after administration, in contrast with AAV2, of which a significantly smaller proportion were uncoated. This study links specific AAV capsid regions to the transduction ability of a clinically relevant AAV serotype. - Highlights: • We construct chimeric vectors to identify determinants of AAV8 liver transduction. • An AAV2-based vector with 17 AAV8 residues exhibited high liver transduction in mice. • This vector also surpassed AAV2 in cell entry, nuclear entry and onset of expression. • Most chimeric vector particles were uncoated at 6 weeks, like AAV8 and unlike AAV2. • Chimera retained heparin binding and was antigenically distinct from AAV2 and AAV8.

  11. Simulations of HIV capsid protein dimerization reveal the effect of chemistry and topography on the mechanism of hydrophobic protein association

    CERN Document Server

    Yu, Naiyin

    2015-01-01

    Recent work has shown that the hydrophobic protein surfaces in aqueous solution sit near a drying transition. The tendency for these surfaces to expel water from their vicinity leads to self assembly of macromolecular complexes. In this article we show with a realistic model for a biologically pertinent system how this phenomenon appears at the molecular level. We focus on the association of the C-terminal domain (CA-C) of the human immunodeficiency virus (HIV) capsid protein. By combining all-atom simulations with specialized sampling techniques we measure the water density distribution during the approach of two CA-C proteins as a function of separation and amino acid sequence in the interfacial region. The simulations demonstrate that CA-C protein-protein interactions sit at the edge of a dewetting transition and that this mesoscopic manifestation of the underlying liquid-vapor phase transition can be readily manipulated by biology or protein engineering to significantly affect association behavior. While ...

  12. Cyclophilin A potentiates TRIM5α inhibition of HIV-1 nuclear import without promoting TRIM5α binding to the viral capsid.

    Science.gov (United States)

    Burse, Mallori; Shi, Jiong; Aiken, Christopher

    2017-01-01

    The host immunophilin cyclophilin A (CypA) binds to the capsid protein (CA) of HIV-1 and regulates its infectivity. Depending on the target cell type, CypA can either promote or inhibit HIV-1 infection. The ability of CypA to promote HIV-1 infection has been extensively studied and linked to several steps in early replication including uncoating, reverse transcription and nuclear import. By contrast, the mechanism by which CypA inhibits infection is less well understood. We investigated the mechanism by which CypA potentiates restriction of HIV-1 by the tripartite motif-containing protein 5 (TRIM5α). Depletion of TRIM5α in the African green monkey cell line Vero, resulted in a loss of inhibition of infection by CypA, demonstrating that inhibition by CypA is mediated by TRIM5α. Complementary genetic and biochemical assays failed to demonstrate an ability of CypA to promote binding of TRIM5α to the viral capsid. TRIM5α inhibits HIV-1 reverse transcription in a proteasome-dependent manner; however, we observed that inhibition of proteasome activity did not reduce the ability of CypA to inhibit infection, suggesting that CypA acts at a step after reverse transcription. Accordingly, we observed a CypA-dependent reduction in the accumulation of nuclear HIV-1 DNA, indicating that CypA specifically promotes TRIM5α inhibition of HIV-1 nuclear import. We also observed that the ability of CypA to inhibit HIV-1 infection is abolished by amino acid substitutions within the conserved CPSF6-binding surface in CA. Our results indicate that CypA inhibits HIV-1 infection in Vero cells not by promoting TRIM5α binding to the capsid but by blocking nuclear import of the HIV-1 preintegration complex.

  13. Magic-angle spinning NMR of intact bacteriophages: Insights into the capsid, DNA and their interface

    Science.gov (United States)

    Abramov, Gili; Morag, Omry; Goldbourt, Amir

    2015-04-01

    Bacteriophages are viruses that infect bacteria. They are complex macromolecular assemblies, which are composed of multiple protein subunits that protect genomic material and deliver it to specific hosts. Various biophysical techniques have been used to characterize their structure in order to unravel phage morphogenesis. Yet, most bacteriophages are non-crystalline and have very high molecular weights, in the order of tens of MegaDaltons. Therefore, complete atomic-resolution characterization on such systems that encompass both capsid and DNA is scarce. In this perspective article we demonstrate how magic-angle spinning solid-state NMR has and is used to characterize in detail bacteriophage viruses, including filamentous and icosahedral phage. We discuss the process of sample preparation, spectral assignment of both capsid and DNA and the use of chemical shifts and dipolar couplings to probe the capsid-DNA interface, describe capsid structure and dynamics and extract structural differences between viruses.

  14. Remodeling nuclear architecture allows efficient transport of herpesvirus capsids by diffusion.

    Science.gov (United States)

    Bosse, Jens B; Hogue, Ian B; Feric, Marina; Thiberge, Stephan Y; Sodeik, Beate; Brangwynne, Clifford P; Enquist, Lynn W

    2015-10-20

    The nuclear chromatin structure confines the movement of large macromolecular complexes to interchromatin corrals. Herpesvirus capsids of approximately 125 nm assemble in the nucleoplasm and must reach the nuclear membranes for egress. Previous studies concluded that nuclear herpesvirus capsid motility is active, directed, and based on nuclear filamentous actin, suggesting that large nuclear complexes need metabolic energy to escape nuclear entrapment. However, this hypothesis has recently been challenged. Commonly used microscopy techniques do not allow the imaging of rapid nuclear particle motility with sufficient spatiotemporal resolution. Here, we use a rotating, oblique light sheet, which we dubbed a ring-sheet, to image and track viral capsids with high temporal and spatial resolution. We do not find any evidence for directed transport. Instead, infection with different herpesviruses induced an enlargement of interchromatin domains and allowed particles to diffuse unrestricted over longer distances, thereby facilitating nuclear egress for a larger fraction of capsids.

  15. SCHEMA computational design of virus capsid chimeras: calibrating how genome packaging, protection, and transduction correlate with calculated structural disruption.

    Science.gov (United States)

    Ho, Michelle L; Adler, Benjamin A; Torre, Michael L; Silberg, Jonathan J; Suh, Junghae

    2013-12-20

    Adeno-associated virus (AAV) recombination can result in chimeric capsid protein subunits whose ability to assemble into an oligomeric capsid, package a genome, and transduce cells depends on the inheritance of sequence from different AAV parents. To develop quantitative design principles for guiding site-directed recombination of AAV capsids, we have examined how capsid structural perturbations predicted by the SCHEMA algorithm correlate with experimental measurements of disruption in seventeen chimeric capsid proteins. In our small chimera population, created by recombining AAV serotypes 2 and 4, we found that protection of viral genomes and cellular transduction were inversely related to calculated disruption of the capsid structure. Interestingly, however, we did not observe a correlation between genome packaging and calculated structural disruption; a majority of the chimeric capsid proteins formed at least partially assembled capsids and more than half packaged genomes, including those with the highest SCHEMA disruption. These results suggest that the sequence space accessed by recombination of divergent AAV serotypes is rich in capsid chimeras that assemble into 60-mer capsids and package viral genomes. Overall, the SCHEMA algorithm may be useful for delineating quantitative design principles to guide the creation of libraries enriched in genome-protecting virus nanoparticles that can effectively transduce cells. Such improvements to the virus design process may help advance not only gene therapy applications but also other bionanotechnologies dependent upon the development of viruses with new sequences and functions.

  16. Residues of the UL25 protein of herpes simplex virus that are required for its stable interaction with capsids.

    Science.gov (United States)

    Cockrell, Shelley K; Huffman, Jamie B; Toropova, Katerina; Conway, James F; Homa, Fred L

    2011-05-01

    The herpes simplex virus 1 (HSV-1) UL25 gene product is a minor capsid component that is required for encapsidation, but not cleavage, of replicated viral DNA. UL25 is located on the capsid surface in a proposed heterodimer with UL17, where five copies of the heterodimer are found at each of the capsid vertices. Previously, we demonstrated that amino acids 1 to 50 of UL25 are essential for its stable interaction with capsids. To further define the UL25 capsid binding domain, we generated recombinant viruses with either small truncations or amino acid substitutions in the UL25 N terminus. Studies of these mutants demonstrated that there are two important regions within the capsid binding domain. The first 27 amino acids are essential for capsid binding of UL25, while residues 26 to 39, which are highly conserved in the UL25 homologues of other alphaherpesviruses, were found to be critical for stable capsid binding. Cryo-electron microscopy reconstructions of capsids containing either a small tag on the N terminus of UL25 or the green fluorescent protein (GFP) fused between amino acids 50 and 51 of UL25 demonstrate that residues 1 to 27 of UL25 contact the hexon adjacent to the penton. A second region, most likely centered on amino acids 26 to 39, contacts the triplex that is one removed from the penton. Importantly, both of these UL25 capsid binding regions are essential for the stable packaging of full-length viral genomes.

  17. Residues of the UL25 Protein of Herpes Simplex Virus That Are Required for Its Stable Interaction with Capsids

    Science.gov (United States)

    Cockrell, Shelley K.; Huffman, Jamie B.; Toropova, Katerina; Conway, James F.; Homa, Fred L.

    2011-01-01

    The herpes simplex virus 1 (HSV-1) UL25 gene product is a minor capsid component that is required for encapsidation, but not cleavage, of replicated viral DNA. UL25 is located on the capsid surface in a proposed heterodimer with UL17, where five copies of the heterodimer are found at each of the capsid vertices. Previously, we demonstrated that amino acids 1 to 50 of UL25 are essential for its stable interaction with capsids. To further define the UL25 capsid binding domain, we generated recombinant viruses with either small truncations or amino acid substitutions in the UL25 N terminus. Studies of these mutants demonstrated that there are two important regions within the capsid binding domain. The first 27 amino acids are essential for capsid binding of UL25, while residues 26 to 39, which are highly conserved in the UL25 homologues of other alphaherpesviruses, were found to be critical for stable capsid binding. Cryo-electron microscopy reconstructions of capsids containing either a small tag on the N terminus of UL25 or the green fluorescent protein (GFP) fused between amino acids 50 and 51 of UL25 demonstrate that residues 1 to 27 of UL25 contact the hexon adjacent to the penton. A second region, most likely centered on amino acids 26 to 39, contacts the triplex that is one removed from the penton. Importantly, both of these UL25 capsid binding regions are essential for the stable packaging of full-length viral genomes. PMID:21411517

  18. Conformational Changes in the Capsid of a Calicivirus upon Interaction with Its Functional Receptor

    Energy Technology Data Exchange (ETDEWEB)

    Ossiboff, Robert J.; Zhou, Yi; Lightfoot, Patrick J.; Prasad, B.V. Venkataram; Parker, John S.L. (Baylor); (Cornell)

    2010-07-19

    Nonenveloped viral capsids are metastable structures that undergo conformational changes during virus entry that lead to interactions of the capsid or capsid fragments with the cell membrane. For members of the Caliciviridae, neither the nature of these structural changes in the capsid nor the factor(s) responsible for inducing these changes is known. Feline functional adhesion molecule A (fJAM-A) mediates the attachment and infectious viral entry of feline calicivirus (FCV). Here, we show that the infectivity of some FCV isolates is neutralized following incubation with the soluble receptor at 37 C. We used this property to select mutants resistant to preincubation with the soluble receptor. We isolated and sequenced 24 soluble receptor-resistant (srr) mutants and characterized the growth properties and receptor-binding activities of eight mutants. The location of the mutations within the capsid structure of FCV was mapped using a new 3.6-{angstrom} structure of native FCV. The srr mutations mapped to the surface of the P2 domain were buried at the protruding domain dimer interface or were present in inaccessible regions of the capsid protein. Coupled with data showing that both the parental FCV and the srr mutants underwent increases in hydrophobicity upon incubation with the soluble receptor at 37 C, these findings indicate that FCV likely undergoes conformational change upon interaction with its receptor. Changes in FCV capsid conformation following its interaction with fJAM-A may be important for subsequent interactions of the capsid with cellular membranes, membrane penetration, and genome delivery.

  19. Packaging Double-Helical DNA into Viral Capsids: Structures, Forces, and Energetics

    OpenAIRE

    Petrov, Anton S.; Harvey, Stephen C.

    2008-01-01

    Small, icosahedral double-stranded DNA bacteriophage pack their genomes tightly into preformed protein capsids using an ATP-driven motor. Coarse-grain molecular-mechanics models provide a detailed picture of DNA packaging in bacteriophage, revealing how conformation depends on capsid size and shape, and the presence or absence of a protein core. The forces that oppose packaging have large contributions from both electrostatic repulsions and the entropic penalty of confining the DNA into the c...

  20. Lentiviral Gag assembly analyzed through the functional characterization of chimeric simian immunodeficiency viruses expressing different domains of the feline immunodeficiency virus capsid protein.

    Directory of Open Access Journals (Sweden)

    María J Esteva

    Full Text Available To gain insight into the functional relationship between the capsid (CA domains of the Gag polyproteins of simian and feline immunodeficiency viruses (SIV and FIV, respectively, we constructed chimeric SIVs in which the CA-coding region was partially or totally replaced by the equivalent region of the FIV CA. The phenotypic characterization of the chimeras allowed us to group them into three categories: the chimeric viruses that, while being assembly-competent, exhibit a virion-associated unstable FIV CA; a second group represented only by the chimeric SIV carrying the N-terminal domain (NTD of the FIV CA which proved to be assembly-defective; and a third group constituted by the chimeric viruses that produce virions exhibiting a mature and stable FIV CA protein, and which incorporate the envelope glycoprotein and contain wild-type levels of viral genome RNA and reverse transcriptase. Further analysis of the latter group of chimeric SIVs demonstrated that they are non-infectious due to a post-entry impairment, such as uncoating of the viral core, reverse transcription or nuclear import of the preintegration complex. Furthermore, we show here that the carboxyl-terminus domain (CTD of the FIV CA has an intrinsic ability to dimerize in vitro and form high-molecular-weight oligomers, which, together with our finding that the FIV CA-CTD is sufficient to confer assembly competence to the resulting chimeric SIV Gag polyprotein, provides evidence that the CA-CTD exhibits more functional plasticity than the CA-NTD. Taken together, our results provide relevant information on the biological relationship between the CA proteins of primate and nonprimate lentiviruses.

  1. Nucleoporin NUP153 phenylalanine-glycine motifs engage a common binding pocket within the HIV-1 capsid protein to mediate lentiviral infectivity.

    Directory of Open Access Journals (Sweden)

    Kenneth A Matreyek

    Full Text Available Lentiviruses can infect non-dividing cells, and various cellular transport proteins provide crucial functions for lentiviral nuclear entry and integration. We previously showed that the viral capsid (CA protein mediated the dependency on cellular nucleoporin (NUP 153 during HIV-1 infection, and now demonstrate a direct interaction between the CA N-terminal domain and the phenylalanine-glycine (FG-repeat enriched NUP153 C-terminal domain (NUP153(C. NUP153(C fused to the effector domains of the rhesus Trim5α restriction factor (Trim-NUP153(C potently restricted HIV-1, providing an intracellular readout for the NUP153(C-CA interaction during retroviral infection. Primate lentiviruses and equine infectious anemia virus (EIAV bound NUP153(C under these conditions, results that correlated with direct binding between purified proteins in vitro. These binding phenotypes moreover correlated with the requirement for endogenous NUP153 protein during virus infection. Mutagenesis experiments concordantly identified NUP153(C and CA residues important for binding and lentiviral infectivity. Different FG motifs within NUP153(C mediated binding to HIV-1 versus EIAV capsids. HIV-1 CA binding mapped to residues that line the common alpha helix 3/4 hydrophobic pocket that also mediates binding to the small molecule PF-3450074 (PF74 inhibitor and cleavage and polyadenylation specific factor 6 (CPSF6 protein, with Asn57 (Asp58 in EIAV playing a particularly important role. PF74 and CPSF6 accordingly each competed with NUP153(C for binding to the HIV-1 CA pocket, and significantly higher concentrations of PF74 were needed to inhibit HIV-1 infection in the face of Trim-NUP153(C expression or NUP153 knockdown. Correlation between CA mutant viral cell cycle and NUP153 dependencies moreover indicates that the NUP153(C-CA interaction underlies the ability of HIV-1 to infect non-dividing cells. Our results highlight similar mechanisms of binding for disparate host factors

  2. Oral Administration of Astrovirus Capsid Protein Is Sufficient To Induce Acute Diarrhea In Vivo

    Directory of Open Access Journals (Sweden)

    Victoria A. Meliopoulos

    2016-11-01

    Full Text Available The disease mechanisms associated with the onset of astrovirus diarrhea are unknown. Unlike other enteric virus infections, astrovirus infection is not associated with an inflammatory response or cellular damage. In vitro studies in differentiated Caco-2 cells demonstrated that human astrovirus serotype 1 (HAstV-1 capsid protein alone disrupts the actin cytoskeleton and tight junction complex, leading to increased epithelial barrier permeability. In this study, we show that oral administration of purified recombinant turkey astrovirus 2 (TAstV-2 capsid protein results in acute diarrhea in a dose- and time-dependent manner in turkey poults. Similarly to that induced by infectious virus, TAstV-2 capsid-induced diarrhea was independent of inflammation or histological changes but was associated with increased intestinal barrier permeability, as well as redistribution of sodium hydrogen exchanger 3 (NHE3 from the membrane to the cytoplasm of the intestinal epithelium. Unlike other viral enterotoxins that have been identified, astrovirus capsid induces diarrhea after oral administration, reproducing the natural route of infection and demonstrating that ingestion of intact noninfectious capsid protein may be sufficient to provoke acute diarrhea. Based on these data, we hypothesize that the astrovirus capsid acts like an enterotoxin and induces intestinal epithelial barrier dysfunction.

  3. An alphavirus temperature-sensitive capsid mutant reveals stages of nucleocapsid assembly

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Yan, E-mail: yzheng15@students.kgi.edu; Kielian, Margaret, E-mail: margaret.kielian@einstein.yu.edu

    2015-10-15

    Alphaviruses have a nucleocapsid core composed of the RNA genome surrounded by an icosahedral lattice of capsid protein. An insertion after position 186 in the capsid protein produced a strongly temperature-sensitive growth phenotype. Even when the structural proteins were synthesized at the permissive temperature (28 °C), subsequent incubation of the cells at the non-permissive temperature (37 °C) dramatically decreased mutant capsid protein stability and particle assembly. Electron microscopy confirmed the presence of cytoplasmic nucleocapsids in mutant-infected cells cultured at the permissive temperature, but these nucleocapsids were not stable to sucrose gradient separation. In contrast, nucleocapsids isolated from mutant virus particles had similar stability to that of wildtype virus. Our data support a model in which cytoplasmic nucleocapsids go through a maturation step during packaging into virus particles. The insertion site lies in the interface between capsid proteins in the assembled nucleocapsid, suggesting the region where such a stabilizing transition occurs. - Highlights: • We characterize an alphavirus capsid insertion mutation. • These capsid mutants are highly temperature sensitive for growth. • The insertion affects nucleocapsid stability. • Results suggest that the nucleocapsid is stabilized during virus budding.

  4. High Relaxivity Gadolinium Hydroxypyridonate-Viral Capsid Conjugates: Nano-sized MRI Contrast Agents

    Energy Technology Data Exchange (ETDEWEB)

    Meux, Susan C.; Datta, Ankona; Hooker, Jacob M.; Botta, Mauro; Francis, Matthew B.; Aime, Silvio; Raymond, Kenneth N.

    2007-08-29

    High relaxivity macromolecular contrast agents based on the conjugation of gadolinium chelates to the interior and exterior surfaces of MS2 viral capsids are assessed. The proton nuclear magnetic relaxation dispersion (NMRD) profiles of the conjugates show up to a five-fold increase in relaxivity, leading to a peak relaxivity (per Gd{sup 3+} ion) of 41.6 mM{sup -1}s{sup -1} at 30 MHz for the internally modified capsids. Modification of the exterior was achieved through conjugation to flexible lysines, while internal modification was accomplished by conjugation to relatively rigid tyrosines. Higher relaxivities were obtained for the internally modified capsids, showing that (1) there is facile diffusion of water to the interior of capsids and (2) the rigidity of the linker attaching the complex to the macromolecule is important for obtaining high relaxivity enhancements. The viral capsid conjugated gadolinium hydroxypyridonate complexes appear to possess two inner-sphere water molecules (q = 2) and the NMRD fittings highlight the differences in the local motion for the internal ({tau}{sub RI} = 440 ps) and external ({tau}{sub RI} = 310 ps) conjugates. These results indicate that there are significant advantages of using the internal surface of the capsids for contrast agent attachment, leaving the exterior surface available for the installation of tissue targeting groups.

  5. 33 CFR 80.125 - Marblehead Neck, MA to Nahant, MA.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Marblehead Neck, MA to Nahant, MA... INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Atlantic Coast § 80.125 Marblehead Neck, MA to Nahant, MA. The 72 COLREGS apply on the harbors, bays, and inlets on the east coast of Massachusetts...

  6. 33 CFR 80.135 - Hull, MA to Race Point, MA.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Hull, MA to Race Point, MA. 80.135 Section 80.135 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Atlantic Coast § 80.135 Hull, MA to Race Point, MA....

  7. Limited cross-reactivity of mouse monoclonal antibodies against Dengue virus capsid protein among four serotypes

    Directory of Open Access Journals (Sweden)

    Noda M

    2012-11-01

    Full Text Available Megumi Noda,1 Promsin Masrinoul,1 Chaweewan Punkum,1 Chonlatip Pipattanaboon,2,3 Pongrama Ramasoota,2,4 Chayanee Setthapramote,2,3 Tadahiro Sasaki,6 Mikiko Sasayama,1 Akifumi Yamashita,1,5 Takeshi Kurosu,6 Kazuyoshi Ikuta,6 Tamaki Okabayashi11Mahidol-Osaka Center for Infectious Diseases, 2Center of Excellence for Antibody Research, 3Department of Microbiology and Immunology, 4Department of Social and Environmental Medicine, Faculty of Tropical Medicine, Mahidol University, Ratchathewi, Bangkok, Thailand; 5Graduate School of Life Science, Tohoku University, Sendai, Miyagi, 6Department of Virology, Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, JapanBackground: Dengue illness is one of the important mosquito-borne viral diseases in tropical and subtropical regions. Four serotypes of dengue virus (DENV-1, DENV-2, DENV-3, and DENV-4 are classified in the Flavivirus genus of the family Flaviviridae. We prepared monoclonal antibodies against DENV capsid protein from mice immunized with DENV-2 and determined the cross-reactivity with each serotype of DENV and Japanese encephalitis virus.Methods and results: To clarify the relationship between the cross-reactivity of monoclonal antibodies and the diversity of these viruses, we examined the situations of flaviviruses by analyses of phylogenetic trees. Among a total of 60 prepared monoclonal antibodies specific for DENV, five monoclonal antibodies stained the nuclei of infected cells and were found to be specific to the capsid protein. Three were specific to DENV-2, while the other two were cross-reactive with DENV-2 and DENV-4. No monoclonal antibodies were cross-reactive with all four serotypes. Phylogenetic analysis of DENV amino acid sequences of the capsid protein revealed that DENV-2 and DENV-4 were clustered in the same branch, while DENV-1 and DENV-3 were clustered in the other branch. However, these classifications of the capsid protein were different from those of the

  8. Baculovirus capsid display potentiates OVA cytotoxic and innate immune responses.

    Directory of Open Access Journals (Sweden)

    Paula Molinari

    Full Text Available Baculoviruses (BV are DNA viruses that are pathogenic for insects. Although BV infect a range of mammalian cell types, they do not replicate in these cells. Indeed, the potential effects of these insect viruses on the immune responses of mammals are only just beginning to be studied. We show in this paper that a recombinant Autographa californica multiple nuclear polyhedrosis virus carrying a fragment of ovalbumin (OVA on the VP39 capsid protein (BV-OVA has the capacity to act as an adjuvant and vector of antigens in mice, thereby promoting specific CD4 and cytotoxic T cell responses against OVA. BV also induced in vivo maturation of dendritic cells and the production of inflammatory cytokines, thus promoting innate and adaptive immune responses. The OVA-specific response induced by BV-OVA was strong enough to reject a challenge with OVA-expressing melanoma cells (MO5 cells and effectively prolonged survival of MO5 bearing mice. All these findings, together with the absence of pre-existing immunity to BV in humans and the lack of viral gene expression in mammalian cells, make BV a candidate for vaccination.

  9. Characterization of the DNA binding properties of polyomavirus capsid protein

    Science.gov (United States)

    Chang, D.; Cai, X.; Consigli, R. A.; Spooner, B. S. (Principal Investigator)

    1993-01-01

    The DNA binding properties of the polyomavirus structural proteins VP1, VP2, and VP3 were studied by Southwestern analysis. The major viral structural protein VP1 and host-contributed histone proteins of polyomavirus virions were shown to exhibit DNA binding activity, but the minor capsid proteins VP2 and VP3 failed to bind DNA. The N-terminal first five amino acids (Ala-1 to Lys-5) were identified as the VP1 DNA binding domain by genetic and biochemical approaches. Wild-type VP1 expressed in Escherichia coli (RK1448) exhibited DNA binding activity, but the N-terminal truncated VP1 mutants (lacking Ala-1 to Lys-5 and Ala-1 to Cys-11) failed to bind DNA. The synthetic peptide (Ala-1 to Cys-11) was also shown to have an affinity for DNA binding. Site-directed mutagenesis of the VP1 gene showed that the point mutations at Pro-2, Lys-3, and Arg-4 on the VP1 molecule did not affect DNA binding properties but that the point mutation at Lys-5 drastically reduced DNA binding affinity. The N-terminal (Ala-1 to Lys-5) region of VP1 was found to be essential and specific for DNA binding, while the DNA appears to be non-sequence specific. The DNA binding domain and the nuclear localization signal are located in the same N-terminal region.

  10. Coat as a Dagger: The Use of Capsid Proteins to Perforate Membranes during Non-Enveloped DNA Viruses Trafficking

    Science.gov (United States)

    Bilkova, Eva; Forstova, Jitka; Abrahamyan, Levon

    2014-01-01

    To get access to the replication site, small non-enveloped DNA viruses have to cross the cell membrane using a limited number of capsid proteins, which also protect the viral genome in the extracellular environment. Most of DNA viruses have to reach the nucleus to replicate. The capsid proteins involved in transmembrane penetration are exposed or released during endosomal trafficking of the virus. Subsequently, the conserved domains of capsid proteins interact with cellular membranes and ensure their efficient permeabilization. This review summarizes our current knowledge concerning the role of capsid proteins of small non-enveloped DNA viruses in intracellular membrane perturbation in the early stages of infection. PMID:25055856

  11. Structural Characterization of H-1 Parvovirus: Comparison of Infectious Virions to Empty Capsids

    Science.gov (United States)

    Halder, Sujata; Nam, Hyun-Joo; Govindasamy, Lakshmanan; Vogel, Michèle; Dinsart, Christiane; Salomé, Nathalie; McKenna, Robert

    2013-01-01

    The structure of single-stranded DNA (ssDNA) packaging H-1 parvovirus (H-1PV), which is being developed as an antitumor gene delivery vector, has been determined for wild-type (wt) virions and noninfectious (empty) capsids to 2.7- and 3.2-Å resolution, respectively, using X-ray crystallography. The capsid viral protein (VP) structure consists of an α-helix and an eight-stranded anti-parallel β-barrel with large loop regions between the strands. The β-barrel and loops form the capsid core and surface, respectively. In the wt structure, 600 nucleotides are ordered in an interior DNA binding pocket of the capsid. This accounts for ∼12% of the H-1PV genome. The wt structure is identical to the empty capsid structure, except for side chain conformation variations at the nucleotide binding pocket. Comparison of the H-1PV nucleotides to those observed in canine parvovirus and minute virus of mice, two members of the genus Parvovirus, showed both similarity in structure and analogous interactions. This observation suggests a functional role, such as in capsid stability and/or ssDNA genome recognition for encapsulation. The VP structure differs from those of other parvoviruses in surface loop regions that control receptor binding, tissue tropism, pathogenicity, and antibody recognition, including VP sequences reported to determine tumor cell tropism for oncotropic rodent parvoviruses. These structures of H-1PV provide insight into structural features that dictate capsid stabilization following genome packaging and three-dimensional information applicable for rational design of tumor-targeted recombinant gene delivery vectors. PMID:23449783

  12. Structural Studies of Adeno-Associated Virus Serotype 8 Capsid Transitions Associated with Endosomal Trafficking

    Energy Technology Data Exchange (ETDEWEB)

    Nam, Hyun-Joo; Gurda, Brittney L.; McKenna, Robert; Potter, Mark; Byrne, Barry; Salganik, Maxim; Muzyczka, Nicholas; Agbandje-McKenna, Mavis (Florida)

    2012-09-17

    The single-stranded DNA (ssDNA) parvoviruses enter host cells through receptor-mediated endocytosis, and infection depends on processing in the early to late endosome as well as in the lysosome prior to nuclear entry for replication. However, the mechanisms of capsid endosomal processing, including the effects of low pH, are poorly understood. To gain insight into the structural transitions required for this essential step in infection, the crystal structures of empty and green fluorescent protein (GFP) gene-packaged adeno-associated virus serotype 8 (AAV8) have been determined at pH values of 6.0, 5.5, and 4.0 and then at pH 7.5 after incubation at pH 4.0, mimicking the conditions encountered during endocytic trafficking. While the capsid viral protein (VP) topologies of all the structures were similar, significant amino acid side chain conformational rearrangements were observed on (i) the interior surface of the capsid under the icosahedral 3-fold axis near ordered nucleic acid density that was lost concomitant with the conformational change as pH was reduced and (ii) the exterior capsid surface close to the icosahedral 2-fold depression. The 3-fold change is consistent with DNA release from an ordering interaction on the inside surface of the capsid at low pH values and suggests transitions that likely trigger the capsid for genome uncoating. The surface change results in disruption of VP-VP interface interactions and a decrease in buried surface area between VP monomers. This disruption points to capsid destabilization which may (i) release VP1 amino acids for its phospholipase A2 function for endosomal escape and nuclear localization signals for nuclear targeting and (ii) trigger genome uncoating.

  13. Structural studies of adeno-associated virus serotype 8 capsid transitions associated with endosomal trafficking.

    Science.gov (United States)

    Nam, Hyun-Joo; Gurda, Brittney L; McKenna, Robert; Potter, Mark; Byrne, Barry; Salganik, Maxim; Muzyczka, Nicholas; Agbandje-McKenna, Mavis

    2011-11-01

    The single-stranded DNA (ssDNA) parvoviruses enter host cells through receptor-mediated endocytosis, and infection depends on processing in the early to late endosome as well as in the lysosome prior to nuclear entry for replication. However, the mechanisms of capsid endosomal processing, including the effects of low pH, are poorly understood. To gain insight into the structural transitions required for this essential step in infection, the crystal structures of empty and green fluorescent protein (GFP) gene-packaged adeno-associated virus serotype 8 (AAV8) have been determined at pH values of 6.0, 5.5, and 4.0 and then at pH 7.5 after incubation at pH 4.0, mimicking the conditions encountered during endocytic trafficking. While the capsid viral protein (VP) topologies of all the structures were similar, significant amino acid side chain conformational rearrangements were observed on (i) the interior surface of the capsid under the icosahedral 3-fold axis near ordered nucleic acid density that was lost concomitant with the conformational change as pH was reduced and (ii) the exterior capsid surface close to the icosahedral 2-fold depression. The 3-fold change is consistent with DNA release from an ordering interaction on the inside surface of the capsid at low pH values and suggests transitions that likely trigger the capsid for genome uncoating. The surface change results in disruption of VP-VP interface interactions and a decrease in buried surface area between VP monomers. This disruption points to capsid destabilization which may (i) release VP1 amino acids for its phospholipase A2 function for endosomal escape and nuclear localization signals for nuclear targeting and (ii) trigger genome uncoating.

  14. Structure of a Human Astrovirus Capsid-Antibody Complex and Mechanistic Insights into Virus Neutralization

    Energy Technology Data Exchange (ETDEWEB)

    Bogdanoff, Walter A.; Campos, Jocelyn; Perez, Edmundo I.; Yin, Lu; Alexander, David L.; DuBois, Rebecca M. (UCSC)

    2016-11-02

    ABSTRACT

    Human astroviruses (HAstVs) are a leading cause of viral diarrhea in young children, the immunocompromised, and the elderly. There are no vaccines or antiviral therapies against HAstV disease. Several lines of evidence point to the presence of protective antibodies in healthy adults as a mechanism governing protection against reinfection by HAstV. However, development of anti-HAstV therapies is hampered by the gap in knowledge of protective antibody epitopes on the HAstV capsid surface. Here, we report the structure of the HAstV capsid spike domain bound to the neutralizing monoclonal antibody PL-2. The antibody uses all six complementarity-determining regions to bind to a quaternary epitope on each side of the dimeric capsid spike. We provide evidence that the HAstV capsid spike is a receptor-binding domain and that the antibody neutralizes HAstV by blocking virus attachment to cells. We identify patches of conserved amino acids that overlap the antibody epitope and may comprise a receptor-binding site. Our studies provide a foundation for the development of therapies to prevent and treat HAstV diarrheal disease.

    IMPORTANCEHuman astroviruses (HAstVs) infect nearly every person in the world during childhood and cause diarrhea, vomiting, and fever. Despite the prevalence of this virus, little is known about how antibodies in healthy adults protect them against reinfection. Here, we determined the crystal structure of a complex of the HAstV capsid protein and a virus-neutralizing antibody. We show that the antibody binds to the outermost spike domain of the capsid, and we provide evidence that the antibody blocks virus attachment to human cells. Importantly, our findings suggest that a subunit-based vaccine focusing the immune system on the HAstV capsid spike domain could be effective in protecting children against HAstV disease.

  15. Ma Ying-jeou’s Presidential Discourse

    OpenAIRE

    2012-01-01

    "Despite the substantial advances made in cross-Strait relations during Ma Ying-jeou's (Ma Yingjiu) first term, the ROC president's rhetoric varied considerably as he grappled with the difficult reality of implementing campaign and inauguration pledges to establish better relations with China while striving to maintain national respect and sovereignty. In this article, the authors put forward a framework for measuring, analyzing and explaining this variation in President Ma's first-term disco...

  16. Ovine progressive pneumonia virus capsid antigen as found in CD163- and CD172a-positive alveolar macrophages of persistently infected sheep.

    Science.gov (United States)

    Herrmann-Hoesing, L M; Noh, S M; Snekvik, K R; White, S N; Schneider, D A; Truscott, T; Knowles, D P

    2010-05-01

    In situ detection of ovine progressive pneumonia virus (OPPV) and the phenotypic identification of the cells that harbor OPPV have not been described for the OPPV-affected tissues, which include lung, mammary gland, synovial membranes of the carpal joint, and choroid plexus of the brain. In this study, the authors first developed a single enzyme-based automated immunohistochemical (IHC) analysis for detection of OPPV capsid antigen (CA) on OPPV-affected tissues, using 2 anti-CAEV CA monoclonal antibodies, 5A1 and 10A1, and 2 enzyme-based IHC systems. Out of 10 naturally and persistently OPPV-infected ewes, OPPV CA was detected in intercellular regions of the carpal synovial membrane of 1 ewe, in cells resembling alveolar macrophages and pulmonary interstitial macrophages in lung tissue of 3 ewes, and in mammary alveolar cells of 1 ewe. Furthermore, dual enzyme-based automated IHC analyses revealed that OPPV CA was predominantly detected in CD172a- or CD163-positive alveolar macrophages of the lungs and mammary gland. That anti-inflammatory (CD163) and downregulatory (CD172a) types of alveolar macrophage harbor OPPV CA leads to the possibility that during persistent infection with OPPV, the host alveolar macrophage might serve to limit inflammation while OPPV persists undetected by the host adaptive immune response in the lung and mammary gland.

  17. A molecular thermodynamic model for the stability of hepatitis B capsids

    Energy Technology Data Exchange (ETDEWEB)

    Kim, Jehoon; Wu, Jianzhong, E-mail: jwu@engr.ucr.edu [Department of Chemical and Environmental Engineering, University of California, Riverside, California 92521 (United States)

    2014-06-21

    Self-assembly of capsid proteins and genome encapsidation are two critical steps in the life cycle of most plant and animal viruses. A theoretical description of such processes from a physiochemical perspective may help better understand viral replication and morphogenesis thus provide fresh insights into the experimental studies of antiviral strategies. In this work, we propose a molecular thermodynamic model for predicting the stability of Hepatitis B virus (HBV) capsids either with or without loading nucleic materials. With the key components represented by coarse-grained thermodynamic models, the theoretical predictions are in excellent agreement with experimental data for the formation free energies of empty T4 capsids over a broad range of temperature and ion concentrations. The theoretical model predicts T3/T4 dimorphism also in good agreement with the capsid formation at in vivo and in vitro conditions. In addition, we have studied the stability of the viral particles in response to physiological cellular conditions with the explicit consideration of the hydrophobic association of capsid subunits, electrostatic interactions, molecular excluded volume effects, entropy of mixing, and conformational changes of the biomolecular species. The course-grained model captures the essential features of the HBV nucleocapsid stability revealed by recent experiments.

  18. A molecular thermodynamic model for the stability of hepatitis B capsids

    Science.gov (United States)

    Kim, Jehoon; Wu, Jianzhong

    2014-06-01

    Self-assembly of capsid proteins and genome encapsidation are two critical steps in the life cycle of most plant and animal viruses. A theoretical description of such processes from a physiochemical perspective may help better understand viral replication and morphogenesis thus provide fresh insights into the experimental studies of antiviral strategies. In this work, we propose a molecular thermodynamic model for predicting the stability of Hepatitis B virus (HBV) capsids either with or without loading nucleic materials. With the key components represented by coarse-grained thermodynamic models, the theoretical predictions are in excellent agreement with experimental data for the formation free energies of empty T4 capsids over a broad range of temperature and ion concentrations. The theoretical model predicts T3/T4 dimorphism also in good agreement with the capsid formation at in vivo and in vitro conditions. In addition, we have studied the stability of the viral particles in response to physiological cellular conditions with the explicit consideration of the hydrophobic association of capsid subunits, electrostatic interactions, molecular excluded volume effects, entropy of mixing, and conformational changes of the biomolecular species. The course-grained model captures the essential features of the HBV nucleocapsid stability revealed by recent experiments.

  19. Sequence analysis and structural implications of rotavirus capsid proteins.

    Science.gov (United States)

    Parbhoo, N; Dewar, J B; Gildenhuys, S

    Rotavirus is the major cause of severe virus-associated gastroenteritis worldwide in children aged 5 and younger. Many children lose their lives annually due to this infection and the impact is particularly pronounced in developing countries. The mature rotavirus is a non-enveloped triple-layered nucleocapsid containing 11 double stranded RNA segments. Here a global view on the sequence and structure of the three main capsid proteins, VP2, VP6 and VP7 is shown by generating a consensus sequence for each of these rotavirus proteins, for each species obtained from published data of representative rotavirus genotypes from across the world and across species. Degree of conservation between species was represented on homology models for each of the proteins. VP7 shows the highest level of variation with 14-45 amino acids showing conservation of less than 60%. These changes are localised to the outer surface alluding to a possible mechanism in evading the immune system. The middle layer, VP6 shows lower variability with only 14-32 sites having lower than 70% conservation. The inner structural layer made up of VP2 showed the lowest variability with only 1-16 sites having less than 70% conservation across species. The results correlate with each protein's multiple structural roles in the infection cycle. Thus, although the nucleotide sequences vary due to the error-prone nature of replication and lack of proof reading, the corresponding amino acid sequence of VP2, 6 and 7 remain relatively conserved. Benefits of this knowledge about the conservation include the ability to target proteins at sites that cannot undergo mutational changes without influencing viral fitness; as well as possibility to study systems that are highly evolved for structure and function in order to determine how to generate and manipulate such systems for use in various biotechnological applications.

  20. M&A Negotiations and Lawyer Expertise

    NARCIS (Netherlands)

    Karsten, C.; Malmendier, U.; Sautner, Z.

    2013-01-01

    We use proprietary data to look into the "black box" of M&A negotiations and to shed light on the effects of lawyer expertise on M&A contract design, the bargaining process, and acquisition pricing. Measuring the effects of buyer relative to seller lawyer expertise, we document that more expertise i

  1. Data of evolutionary structure change: 1DSUA-1C1MA [Confc[Archive

    Lifescience Database Archive (English)

    Full Text Available n>1DSUA SVQLN----GAHLC >EEEE ---- Eucture... A 1C1MA SLQYRSGSSWAHTC ...>EEEEEE EEE E> ATOM 123 CA SER A 32 -2.328 59.41...CAESN-RRDSC e>EE - EEEture...ence>CAGGDGVRSGC >EE EEE> ATOM 1

  2. 33 CFR 80.120 - Cape Ann, MA to Marblehead Neck, MA.

    Science.gov (United States)

    2010-07-01

    ... 33 Navigation and Navigable Waters 1 2010-07-01 2010-07-01 false Cape Ann, MA to Marblehead Neck, MA. 80.120 Section 80.120 Navigation and Navigable Waters COAST GUARD, DEPARTMENT OF HOMELAND SECURITY INTERNATIONAL NAVIGATION RULES COLREGS DEMARCATION LINES Atlantic Coast § 80.120 Cape Ann, MA...

  3. A Ginzburg-Landau model for the expansion of a dodecahedral viral capsid

    Science.gov (United States)

    Zappa, E.; Indelicato, G.; Albano, A.; Cermelli, P.

    2013-11-01

    We propose a Ginzburg-Landau model for the expansion of a dodecahedral viral capsid during infection or maturation. The capsid is described as a dodecahedron whose faces, meant to model rigid capsomers, are free to move independent of each other, and has therefore twelve degrees of freedom. We assume that the energy of the system is a function of the twelve variables with icosahedral symmetry. Using techniques of the theory of invariants, we expand the energy as the sum of invariant polynomials up to fourth order, and classify its minima in dependence of the coefficients of the Ginzburg-Landau expansion. Possible conformational changes of the capsid correspond to symmetry breaking of the equilibrium closed form. The results suggest that the only generic transition from the closed state leads to icosahedral expanded form. Our approach does not allow to study the expansion pathway, which is likely to be non-icosahedral.

  4. Isolation of capsid proteins of foot-and-mouth disease virus by chromatofocusing.

    Science.gov (United States)

    Murdin, A D; Doel, T R; Spier, R E

    1983-10-01

    A method for the isolation of foot-and-mouth disease virus (FMDV) capsid proteins was developed. The FMDV capsid proteins VP1, VP2, VP3 and VP0 were isolated from sucrose gradient purified virus by chromatofocusing in a pH 7.4-4.0 gradient on Polybuffer exchanger PBE 94. Under the conditions used the proteins eluted in the sequence VP1, VP2, VP0 (when present) and VP3. Capsid protein VP4 did not elute and could not be isolated by this method. Protein concentration in the eluate was monitored by the use of a radiolabelled marker and recoveries of approximately 50% of the input marker could be achieved when using up to 15 mg of virus and a 30-ml column. The high capacity and relative simplicity of chromatofocusing make it a useful alternative to other methods of purifying proteins.

  5. The three-dimensional structure of Infectious flacherie virus capsid determined by cryo-electron microscopy

    Institute of Scientific and Technical Information of China (English)

    2009-01-01

    Cryo-electron microscopy and image reconstruction were used to determine the three-dimensional structure of Infectious flacherie virus (IFV). 5047 particles were selected for the final reconstruction. The FSC curve showed that the resolution of this capsid structure was 18 ·. The structure is a psuedo T=3 (P=3) icosahedral capsid with a diameter of 302.4 · and a single shell thickness of 15 ·. The density map showed that IFV has a smooth surface without any prominent protrude or depression. Comparison of the IFV structure with those of the insect picorna-like virus-Cricket paralysis virus (CrPV)and human picornavirus-Human rhinovirus 14 (HRV 14) revealed that the IFV structure resembles the CrPV structure. The "Rossmann canyon" is absent in both IFV and CrPV particles. The polypeptide topology of IFV VP2, IFV VP3 was predicted and the subunit location at the capsid surface was further analyzed.

  6. Structural Transitions and Energy Landscape for Cowpea Chlorotic Mottle Virus Capsid Mechanics from Nanomanipulation in Vitro and in Silico

    NARCIS (Netherlands)

    Kononova, Olga; Snijder, Joost; Brasch, Melanie; Cornelissen, Jeroen; Dima, Ruxandra I.; Marx, Kenneth A.; Wuite, Gijs J. L.; Roos, Wouter H.; Barsegov, Valeri

    2013-01-01

    Physical properties of capsids of plant and animal viruses are important factors in capsid self-assembly, survival of viruses in the extracellular environment, and their cell infectivity. Combined AFM experiments and computational modeling on subsecond timescales of the indentation nanomechanics of

  7. Poliovirus-associated protein kinase: Destabilization of the virus capsid and stimulation of the phosphorylation reaction by Zn sup 2+

    Energy Technology Data Exchange (ETDEWEB)

    Ratka, M.; Lackmann, M.; Ueckermann, C.; Karlins, U.; Koch, G. (Univ. of Hamburg (West Germany))

    1989-09-01

    The previously described poliovirus-associated protein kinase activity phosphorylates viral proteins VP0 and VP2 as well as exogenous proteins in the presence of Mg{sup 2+}. In this paper, the effect of Zn{sup 2+} on the phosphorylation reaction and the stability of the poliovirus capsid has been studied in detail and compared to that of Mg{sup 2+}. In the presence of Zn{sup 2+}, phosphorylation of capsid proteins VP2 and VP4 is significantly higher while phosphorylation of VP0 and exogenous phosphate acceptor proteins is not detected. The results indicate the activation of more than one virus-associated protein kinase by Zn{sup 2+}. The ion-dependent behavior of the enzyme activities is observed independently of whether the virus was obtained from HeLa or green monkey kidney cells. The poliovirus capsid is destabilized by Zn{sup 2+}. This alteration of the poliovirus capsid structure is a prerequisite for effective phosphorylation of viral capsid proteins. The increased level of phosphorylation of viral capsid proteins results in further destabilization of the viral capsid. As a result of the conformational changes, poliovirus-associated protein kinase activities dissociate from the virus particle. The authors suggest that the destabilizing effect of phosphorylation on the viral capsid plays a role in uncoating of poliovirus.

  8. Assembly and characterization of foot-and-mouth disease virus empty capsid particles expressed within mammalian cells

    DEFF Research Database (Denmark)

    Gullberg, Maria; Muszynski, Bartosz; Organtini, Lindsey J.;

    2013-01-01

    The foot-and-mouth disease virus (FMDV) structural protein precursor, P1-2A, is cleaved by the virus-encoded 3C protease (3Cpro) into the capsid proteins VP0, VP1 and VP3 (and 2A). In some systems, it is difficult to produce large amounts of these processed capsid proteins since 3Cpro can be toxic...

  9. Hepatitis B Virus Core Protein Phosphorylation Sites Affect Capsid Stability and Transient Exposure of the C-terminal Domain.

    Science.gov (United States)

    Selzer, Lisa; Kant, Ravi; Wang, Joseph C-Y; Bothner, Brian; Zlotnick, Adam

    2015-11-20

    Hepatitis B virus core protein has 183 amino acids divided into an assembly domain and an arginine-rich C-terminal domain (CTD) that regulates essential functions including genome packaging, reverse transcription, and intracellular trafficking. Here, we investigated the CTD in empty hepatitis B virus (HBV) T=4 capsids. We examined wild-type core protein (Cp183-WT) and a mutant core protein (Cp183-EEE), in which three CTD serines are replaced with glutamate to mimic phosphorylated protein. We found that Cp183-WT capsids were less stable than Cp183-EEE capsids. When we tested CTD sensitivity to trypsin, we detected two different populations of CTDs differentiated by their rate of trypsin cleavage. Interestingly, CTDs from Cp183-EEE capsids exhibited a much slower rate of proteolytic cleavage when compared with CTDs of Cp183-WT capsids. Cryo-electron microscopy studies of trypsin-digested capsids show that CTDs at five-fold symmetry vertices are most protected. We hypothesize that electrostatic interactions between glutamates and arginines in Cp183-EEE, particularly at five-fold, increase capsid stability and reduce CTD exposure. Our studies show that quasi-equivalent CTDs exhibit different rates of exposure and thus might perform distinct functions during the hepatitis B virus lifecycle. Our results demonstrate a structural role for CTD phosphorylation and indicate crosstalk between CTDs within a capsid particle. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

  10. Structural Transitions and Energy Landscape for Cowpea Chlorotic Mottle Virus Capsid Mechanics from Nanomanipulation in Vitro and in Silico

    Science.gov (United States)

    Kononova, Olga; Snijder, Joost; Brasch, Melanie; Cornelissen, Jeroen; Dima, Ruxandra I.; Marx, Kenneth A.; Wuite, Gijs J. L.; Roos, Wouter H.; Barsegov, Valeri

    2013-10-01

    Physical properties of capsids of plant and animal viruses are important factors in capsid self-assembly, survival of viruses in the extracellular environment, and their cell infectivity. Virus shells can have applications as nanocontainers and delivery vehicles in biotechnology and medicine. Combined AFM experiments and computational modeling on sub-second timescales of the indentation nanomechanics of Cowpea Chlorotic Mottle Virus (CCMV) capsid show that the capsid's physical properties are dynamic and local characteristics of the structure, which depend on the magnitude and geometry of mechanical input. Surprisingly, under large deformations the CCMV capsid transitions to the collapsed state without substantial local structural alterations. The enthalpy change in this deformation state dH = 11.5 - 12.8 MJ/mol is mostly due to large-amplitude out-of-plane excitations, which contribute to the capsid bending, and the entropy change TdS = 5.1 - 5.8 MJ/mol is mostly due to coherent in-plane rearrangements of protein chains, which result in the capsid stiffening. Dynamic coupling of these modes defines the extent of elasticity and reversibility of capsid mechanical deformation. This emerging picture illuminates how unique physico-chemical properties of protein nanoshells help define their structure and morphology, and determine their viruses' biological function.

  11. Breaking a virus: Identifying molecular level failure modes of a viral capsid by multiscale modeling

    Science.gov (United States)

    Krishnamani, V.; Globisch, C.; Peter, C.; Deserno, M.

    2016-07-01

    We use coarse-grained (CG) simulations to study the deformation of empty Cowpea Chlorotic Mottle Virus (CCMV) capsids under uniaxial compression, from the initial elastic response up to capsid breakage. Our CG model is based on the MARTINI force field and has been amended by a stabilizing elastic network, acting only within individual proteins, that was tuned to capture the fluctuation spectrum of capsid protein dimers, obtained from all atom simulations. We have previously shown that this model predicts force-compression curves that match AFM indentation experiments on empty CCMV capsids. Here we investigate details of the actual breaking events when the CCMV capsid finally fails. We present a symmetry classification of all relevant protein contacts and show that they differ significantly in terms of stability. Specifically, we show that interfaces which break readily are precisely those which are believed to form last during assembly, even though some of them might share the same contacts as other non-breaking interfaces. In particular, the interfaces that form pentamers of dimers never break, while the virtually identical interfaces within hexamers of dimers readily do. Since these units differ in the large-scale geometry and, most noticeably, the cone-angle at the center of the 5- or 6-fold vertex, we propose that the hexameric unit fails because it is pre-stressed. This not only suggests that hexamers of dimers form less frequently during the early stages of assembly; it also offers a natural explanation for the well-known β-barrel motif at the hexameric center as a post-aggregation stabilization mechanism. Finally, we identify those amino acid contacts within all key protein interfaces that are most persistent during compressive deformation of the capsid, thereby providing potential targets for mutation studies aiming to elucidate the key contacts upon which overall stability rests.

  12. Breaking a virus: Identifying molecular level failure modes of a viral capsid by multiscale modeling

    Science.gov (United States)

    Krishnamani, V.; Globisch, C.; Peter, C.; Deserno, M.

    2016-10-01

    We use coarse-grained (CG) simulations to study the deformation of empty Cowpea Chlorotic Mottle Virus (CCMV) capsids under uniaxial compression, from the initial elastic response up to capsid breakage. Our CG model is based on the MARTINI force field and has been amended by a stabilizing elastic network, acting only within individual proteins, that was tuned to capture the fluctuation spectrum of capsid protein dimers, obtained from all atom simulations. We have previously shown that this model predicts force-compression curves that match AFM indentation experiments on empty CCMV capsids. Here we investigate details of the actual breaking events when the CCMV capsid finally fails. We present a symmetry classification of all relevant protein contacts and show that they differ significantly in terms of stability. Specifically, we show that interfaces which break readily are precisely those which are believed to form last during assembly, even though some of them might share the same contacts as other non-breaking interfaces. In particular, the interfaces that form pentamers of dimers never break, while the virtually identical interfaces within hexamers of dimers readily do. Since these units differ in the large-scale geometry and, most noticeably, the cone-angle at the center of the 5- or 6-fold vertex, we propose that the hexameric unit fails because it is pre-stressed. This not only suggests that hexamers of dimers form less frequently during the early stages of assembly; it also offers a natural explanation for the well-known β-barrel motif at the hexameric center as a post-aggregation stabilization mechanism. Finally, we identify those amino acid contacts within all key protein interfaces that are most persistent during compressive deformation of the capsid, thereby providing potential targets for mutation studies aiming to elucidate the key contacts upon which overall stability rests.

  13. Rethinking the capsid proteins of enveloped viruses: multifunctionality from genome packaging to genome transfection.

    Science.gov (United States)

    Freire, João M; Santos, Nuno C; Veiga, Ana Salomé; Da Poian, Andrea T; Castanho, Miguel A R B

    2015-06-01

    Regardless of the debate on whether there is a place for viruses in the tree of life, it is consensual that they co-evolve with their hosts under the pressure of genome minimization. The abundance of multifunctional viral structural proteins is a consequence of this pressure. The molecular key to multifunctionality is the existence of intrinsically disordered domains together with ordered domains in the same protein. Capsid proteins, the hallmark of viruses, are not exceptions because they have coexisting ordered and disordered domains that are crucial for multifunctionality. It is also frequent to find supercharged proteins (i.e. proteins for which the net charge per unit molecular mass is > +0.75/kDa) among viral capsid proteins. All flaviviruses having annotated proteins in the ExPASy Viralzone database have supercharged capsid proteins. Moreover, cell-penetrating sequences/domains are frequent in viral proteins, even when they are not supercharged. Altogether, the findings strongly suggest that the ability to translocate membranes was acquired, conserved and optimized throughout the evolution of some viral proteins as part of their multifunctionality. The fitness of capsid proteins to translocate membranes carrying genomes was experimentally demonstrated with dengue virus capsid protein. This protein is potentially able to help the fusion process and translocate the RNA genome across the hemifused membrane formed by the viral envelope and the endosomal membrane. In addition, one of the cell-penetrating domains of the capsid protein also has antibacterial activity. This may be reminiscent of parasitic bacteria-bacteria competition for the same host and shed light on the origins of enveloped viruses. © 2015 FEBS.

  14. Internal Proteins of the Procapsid and Mature Capsids of Herpes Simplex Virus 1 Mapped by Bubblegram Imaging

    Science.gov (United States)

    Wu, Weimin; Newcomb, William W.; Cheng, Naiqian; Aksyuk, Anastasia; Winkler, Dennis C.

    2016-01-01

    ABSTRACT The herpes simplex virus 1 (HSV-1) capsid is a huge assembly, ∼1,250 Å in diameter, and is composed of thousands of protein subunits with a combined mass of ∼200 MDa, housing a 100-MDa genome. First, a procapsid is formed through coassembly of the surface shell with an inner scaffolding shell; then the procapsid matures via a major structural transformation, triggered by limited proteolysis of the scaffolding proteins. Three mature capsids are found in the nuclei of infected cells. A capsids are empty, B capsids retain a shrunken scaffolding shell, and C capsids—which develop into infectious virions—are filled with DNA and ostensibly have expelled the scaffolding shell. The possible presence of other internal proteins in C capsids has been moot as, in cryo-electron microscopy (cryo-EM), they would be camouflaged by the surrounding DNA. We have used bubblegram imaging to map internal proteins in all four capsids, aided by the discovery that the scaffolding protein is exceptionally prone to radiation-induced bubbling. We confirmed that this protein forms thick-walled inner shells in the procapsid and the B capsid. C capsids generate two classes of bubbles: one occupies positions beneath the vertices of the icosahedral surface shell, and the other is distributed throughout its interior. A likely candidate is the viral protease. A subpopulation of C capsids bubbles particularly profusely and may represent particles in which expulsion of scaffold and DNA packaging are incomplete. Based on the procapsid structure, we propose that the axial channels of hexameric capsomers afford the pathway via which the scaffolding protein is expelled. IMPORTANCE In addition to DNA, capsids of tailed bacteriophages and their distant relatives, herpesviruses, contain internal proteins. These proteins are often essential for infectivity but are difficult to locate within the virion. A novel adaptation of cryo-EM based on detecting gas bubbles generated by radiation

  15. Identification, expression, and immunogenicity of Kaposi's sarcoma-associated herpesvirus-encoded small viral capsid antigen.

    OpenAIRE

    Lin, S F; Sun, R; Heston, L; Gradoville, L; Shedd, D; Haglund, K; Rigsby, M; Miller, G.

    1997-01-01

    We describe a recombinant antigen for use in serologic tests for antibodies to Kaposi's sarcoma (KS)-associated herpesvirus (KSHV). The cDNA for a small viral capsid antigen (sVCA) was identified by immunoscreening of a library prepared from the BC-1 body cavity lymphoma cell line induced into KSHV lytic gene expression by sodium butyrate. The cDNA specified a 170-amino-acid peptide with homology to small viral capsid proteins encoded by the BFRF3 gene of Epstein-Barr virus and the ORF65 gene...

  16. Virus Capsids as Targeted Nanoscale Delivery Vessels of Photoactive Compounds for Site-Specific Photodynamic Therapy

    Science.gov (United States)

    Cohen, Brian A.

    The research presented in this work details the use of a viral capsid as an addressable delivery vessel of photoactive compounds for use in photodynamic therapy. Photodynamic therapy is a treatment that involves the interaction of light with a photosensitizing molecule to create singlet oxygen, a reactive oxygen species. Overproduction of singlet oxygen in cells can cause oxidative damage leading to cytotoxicity and eventually cell death. Challenges with the current generation of FDA-approved photosensitizers for photodynamic therapy primarily stem from their lack of tissue specificity. This work describes the packaging of photoactive cationic porphyrins inside the MS2 bacteriophage capsid, followed by external modification of the capsid with cancer cell-targeting G-quadruplex DNA aptamers to generate a tumor-specific photosensitizing agent. First, a cationic porphyrin is loaded into the capsids via nucleotide-driven packaging, a process that involves charge interaction between the porphyrin and the RNA inside the capsid. Results show that over 250 porphyrin molecules associate with the RNA within each MS2 capsid. Removal of RNA from the capsid severely inhibits the packaging of the cationic porphyrins. Porphyrin-virus constructs were then shown to photogenerate singlet oxygen, and cytotoxicity in non-targeted photodynamic treatment experiments. Next, each porphyrin-loaded capsid is externally modified with approximately 60 targeting DNA aptamers by employing a heterobifunctional crosslinking agent. The targeting aptamer is known to bind the protein nucleolin, a ubiquitous protein that is overexpressed on the cell surface by many cancer cell types. MCF-7 human breast carcinoma cells and MCF-10A human mammary epithelial cells were selected as an in vitro model for breast cancer and normal tissue, respectively. Fluorescently tagged virus-aptamer constructs are shown to selectively target MCF-7 cells versus MCF-10A cells. Finally, results are shown in which porphyrin

  17. Stages of late Paleozoic to early Mesozoic magmatism in the Song Ma belt, NW Vietnam: evidence from zircon U-Pb geochronology and Hf isotope composition

    Science.gov (United States)

    Hieu, Pham Trung; Li, Shuang-Qing; Yu, Yang; Thanh, Ngo Xuan; Dung, Le Tien; Tu, Vu Le; Siebel, Wolfgang; Chen, Fukun

    2016-05-01

    The Song Ma zone in NW Vietnam bears important tectonic implications as a potential subduction corridor between the Indochina and South China blocks. On the basis of U-Pb ages, the Hf isotopic characteristics of zircons and the geochemical composition of granitoids, a two-stage magmatic evolution process of the Song Ma zone at ~290-260 and ~245-230 Ma can be proposed. Isotopic analyses indicate magmatic contributions from Neoproterozoic oceanic island basalt, Proterozoic continental crust, and depleted mantle or juvenile lithosphere. By combining geochronological and geochemical data from the granitoid rocks, we suggest that the staged magmatic processes of Song Ma zone may be related to a long-lasting period of ocean subduction (ca. 290-260 Ma) and subsequent syn-/post-collisional evolution (ca. 245-230 Ma).

  18. Ma olin Saddami poeg / Latif Jahija

    Index Scriptorium Estoniae

    Jahija, Latif

    1995-01-01

    Järg Jan/21.,28. lk. 7,5. L. Jahija sensatsiooniline raamat "Ma olin Saddami poeg", milles ta pajatab kuidas ta a. 1987-1991 oli Iraagi presidendi vanema poja teisik. Lühikokkuvõte sellest jutustusest

  19. Disassociation of the SV40 genome from capsid proteins prior to nuclear entry.

    Science.gov (United States)

    Kuksin, Dmitry; Norkin, Leonard C

    2012-08-10

    Previously, we demonstrated that input SV40 particles undergo a partial disassembly in the endoplasmic reticulum, which exposes internal capsid proteins VP2 and VP3 to immunostaining. Then, in the cytoplasm, disassembly progresses further to also make the genomic DNA accessible to immune detection, as well as to detection by an ethynyl-2-deoxyuridine (EdU)-based chemical reaction. The cytoplasmic partially disassembled SV40 particles retain some of the SV40 capsid proteins, VP1, VP2, and VP3, in addition to the viral genome. In the current study, we asked where in the cell the SV40 genome might disassociate from capsid components. We observed partially disassembled input SV40 particles around the nucleus and, beginning at 12 hours post-infection, 5-Bromo-2-deoxyuridine (BrdU)-labeled parental SV40 DNA in the nucleus, as detected using anti-BrdU antibodies. However, among the more than 1500 cells examined, we never detected input VP2/VP3 in the nucleus. Upon translocation of the BrdU-labeled SV40 genomes into nuclei, they were transcribed and, thus, are representative of productive infection. Our findings imply that the SV40 genome disassociates from the capsid proteins before or at the point of entry into the nucleus, and then enters the nucleus devoid of VP2/3.

  20. Cloning and Sequence Analysis of Capsid Protein Gene of Iridovirus Indonesian Isolates

    Directory of Open Access Journals (Sweden)

    Murwantoko .

    2015-11-01

    Full Text Available generated by an Adobe application 11.5606 Iridovirus was known as agents that caused serious systemic disease in freshwater and marine fishes. The mortality up to 100% of orange-spotted grouper (Epinephelus coioides due to iridovirus infection has been reported in Indonesia. The gene encoding capsid protein of iridovirus is supposed to be conserved and has the potency for the development of control methods. The objectives of this study are to clone the gene encoding capsid protein iridovirus and to analyze their sequences. The   spleen tissues of orange-spotted grouper were collected and extracted their DNA. The DNA fragment of capsid protein of iridovirus genes were amplified by PCR using designed primers with the extraction DNA as templates. The amplified DNA fragments were cloned in pBSKSII and sequenced.  The genes encoding capsid protein of iridovirus from Jepara and Bali were successfully amplified and cloned. The Jepara clone (IJP03 contained complete open reading frame (ORF of the gene composed by 1362 bp nucleotides which encoded 453 amino acids. Those Jepara and Bali (IGD01 clones shared 99.8% similarity in nucleotide level and 99.4% at amino acid level. Based on those sequences, Indonesian iridovirus was belonged to genus Megalocystivirus and shared 99,6-99,9% similarity on nucleotide level with DGIV, ISKNV, MCIV, and ALIV Normal 0 36 false false false

  1. Production of monoclonal antibodies specific to Macrobrachium rosenbergii nodavirus using recombinant capsid protein.

    Science.gov (United States)

    Wangman, Pradit; Senapin, Saengchan; Chaivisuthangkura, Parin; Longyant, Siwaporn; Rukpratanporn, Sombat; Sithigorngul, Paisarn

    2012-03-20

    The gene encoding the capsid protein of Macrobrachium rosenbergii nodavirus (MrNV) was cloned into pGEX-6P-1 expression vector and then transformed into the Escherichia coli strain BL21. After induction, capsid protein-glutathione-S-transferase (GST-MrNV; 64 kDa) was produced. The recombinant protein was separated using SDS-PAGE, excised from the gel, electro-eluted and then used for immunization for monoclonal antibody (MAb) production. Four MAbs specific to the capsid protein were selected and could be used to detect natural MrNV infections in M. rosenbergii by dot blotting, Western blotting and immunohistochemistry without cross-reaction with uninfected shrimp tissues or other common shrimp viruses. The detection sensitivity of the MAbs was 10 fmol µl-1 of the GST-MrNV, as determined using dot blotting. However, the sensitivity of the MAb on dot blotting with homogenate from naturally infected M. rosenbergii was approximately 200-fold lower than that of 1-step RT-PCR. Immunohistochemical analysis using these MAbs with infected shrimp tissues demonstrated staining in the muscles, nerve cord, gill, heart, loose connective tissue and inter-tubular tissue of the hepatopancreas. Although the positive reactions occurred in small focal areas, the immunoreactivity was clearly demonstrated. The MAbs targeted different epitopes of the capsid protein and will be used to develop a simple immunoassay strip test for rapid detection of MrNV.

  2. The conformation of double-stranded DNA inside bacteriophages depends on capsid size and shape.

    Science.gov (United States)

    Petrov, Anton S; Boz, Mustafa Burak; Harvey, Stephen C

    2007-11-01

    The packaging of double-stranded DNA into bacteriophages leads to the arrangement of the genetic material into highly-packed and ordered structures. Although modern experimental techniques reveal the most probable location of DNA inside viral capsids, the individual conformations of DNA are yet to be determined. In the current study we present the results of molecular dynamics simulations of the DNA packaging into several bacteriophages performed within the framework of a coarse-grained model. The final DNA conformations depend on the size and shape of the capsid, as well as the size of the protein portal, if any. In particular, isometric capsids with small or absent portals tend to form concentric spools, whereas the presence of a large portal favors coaxial spooling; slightly and highly elongated capsids result in folded and twisted toroidal conformations, respectively. The results of the simulations also suggest that the predominant factor in defining the global DNA arrangement inside bacteriophages is the minimization of the bending stress upon packaging.

  3. Functional dissection of the alphavirus capsid protease: sequence requirements for activity

    Directory of Open Access Journals (Sweden)

    Pützer Brigitte M

    2010-11-01

    Full Text Available Abstract Background The alphavirus capsid is multifunctional and plays a key role in the viral life cycle. The nucleocapsid domain is released by the self-cleavage activity of the serine protease domain within the capsid. All alphaviruses analyzed to date show this autocatalytic cleavage. Here we have analyzed the sequence requirements for the cleavage activity of Chikungunya virus capsid protease of genus alphavirus. Results Amongst alphaviruses, the C-terminal amino acid tryptophan (W261 is conserved and found to be important for the cleavage. Mutating tryptophan to alanine (W261A completely inactivated the protease. Other amino acids near W261 were not having any effect on the activity of this protease. However, serine protease inhibitor AEBSF did not inhibit the activity. Through error-prone PCR we found that isoleucine 227 is important for the effective activity. The loss of activity was analyzed further by molecular modelling and comparison of WT and mutant structures. It was found that lysine introduced at position 227 is spatially very close to the catalytic triad and may disrupt electrostatic interactions in the catalytic site and thus inactivate the enzyme. We are also examining other sequence requirements for this protease activity. Conclusions We analyzed various amino acid sequence requirements for the activity of ChikV capsid protease and found that amino acids outside the catalytic triads are important for the activity.

  4. Porcine circovirus-2 capsid protein induces cell death in PK15 cells

    Energy Technology Data Exchange (ETDEWEB)

    Walia, Rupali; Dardari, Rkia, E-mail: rdardari@ucalgary.ca; Chaiyakul, Mark; Czub, Markus

    2014-11-15

    Studies have shown that Porcine circovirus (PCV)-2 induces apoptosis in PK15 cells. Here we report that cell death is induced in PCV2b-infected PK15 cells that express Capsid (Cap) protein and this effect is enhanced in interferon gamma (IFN-γ)-treated cells. We further show that transient PCV2a and 2b-Cap protein expression induces cell death in PK15 cells at rate similar to PCV2 infection, regardless of Cap protein localization. These data suggest that Cap protein may have the capacity to trigger different signaling pathways involved in cell death. Although further investigation is needed to gain deeper insights into the nature of the pathways involved in Cap-induced cell death, this study provides evidence that PCV2-induced cell death in kidney epithelial PK15 cells can be mapped to the Cap protein and establishes the need for future research regarding the role of Cap-induced cell death in PCV2 pathogenesis. - Highlights: • IFN-γ enhances PCV2 replication that leads to cell death in PK15 cells. • IFN-γ enhances nuclear localization of the PCV2 Capsid protein. • Transient PCV2a and 2b-Capsid protein expression induces cell death. • Cell death is not dictated by specific Capsid protein sub-localization.

  5. Nanofluidic Devices with Two Pores in Series for Resistive-Pulse Sensing of Single Virus Capsids

    DEFF Research Database (Denmark)

    Harms, Zachary D.; Mogensen, Klaus Bo; Rodrigues de Sousa Nunes, Pedro André;

    2011-01-01

    We report fabrication and characterization of nanochannel devices with two nanopores in series for resistive-pulse sensing of hepatitis B virus (HBV) capsids. The nanochannel and two pores are patterned by electron beam lithography between two microchannels and etched by reactive ion etching. The...

  6. Essential C-Terminal region of the baculovirus minor capsid protein VP80 binds DNA

    NARCIS (Netherlands)

    Marek, M.; Merten, O.W.; Francis-Devaraj, F.; Oers, van M.M.

    2012-01-01

    The essential Autographa californica multicapsid nucleopolyhedrovirus (AcMNPV) minor capsid protein VP80 has been recently shown to interact with the virus-triggered, nuclear F-actin cytoskeleton. A role for VP80 in virus morphogenesis has been proposed in the maturation of progeny nucleocapsids and

  7. Immobilization and One-Dimensional Arrangement of Virus Capsids With Nanoscale Precision Using DNA Origami

    Science.gov (United States)

    Stephanopoulos, Nicholas; Liu, Minghui; Tong, Gary J.; Li, Zhe; Liu, Yan; Yan, Hao; Francis, Matthew B.

    2011-01-01

    Self-assembly has proven to be one of the most effective ways to arrange matter at the nanometer level. Biology, in particular, makes extensive use of self-assembly to position molecules over several length scales with a high degree of spatial control over structure. In recent years, one promising approach that takes advantage of biological self-assembly in order to build synthetic materials employs virus capsids, the protein shells that encapsulate the genetic material of viruses.1 Capsids are composed of multiple protein subunits that can assemble (either spontaneously or under an external stimulus) into a monodisperse structure with different geometries depending on the virus. By appropriately functionalizing the proteins that comprise the capsid, multiple copies of a molecule or other entity can be positioned with a predictable arrangement. A wide variety of components have been attached to and arranged by virus capsids, including chromophores,2 catalysts,3 nanoparticles and quantum dots,4 polymers,5 drug molecules,6 and imaging agents.7 PMID:20575574

  8. Capsid coding sequences of foot-and-mouth disease viruses are determinants of pathogenicity in pigs

    DEFF Research Database (Denmark)

    Lohse, Louise; Jackson, Terry; Bøtner, Anette

    2012-01-01

    showed symptoms of disease within the time frame of the experiment (10 days). All pigs that developed clinical disease showed a high level of viral RNA in serum and infected pigs that survived the acute phase of infection developed a serotype specific antibody response. It is concluded that the capsid...

  9. Disassociation of the SV40 Genome from Capsid Proteins Prior to Nuclear Entry

    Directory of Open Access Journals (Sweden)

    Kuksin Dmitry

    2012-08-01

    Full Text Available Abstract Background Previously, we demonstrated that input SV40 particles undergo a partial disassembly in the endoplasmic reticulum, which exposes internal capsid proteins VP2 and VP3 to immunostaining. Then, in the cytoplasm, disassembly progresses further to also make the genomic DNA accessible to immune detection, as well as to detection by an ethynyl-2-deoxyuridine (EdU-based chemical reaction. The cytoplasmic partially disassembled SV40 particles retain some of the SV40 capsid proteins, VP1, VP2, and VP3, in addition to the viral genome. Findings In the current study, we asked where in the cell the SV40 genome might disassociate from capsid components. We observed partially disassembled input SV40 particles around the nucleus and, beginning at 12 hours post-infection, 5-Bromo-2-deoxyuridine (BrdU-labeled parental SV40 DNA in the nucleus, as detected using anti-BrdU antibodies. However, among the more than 1500 cells examined, we never detected input VP2/VP3 in the nucleus. Upon translocation of the BrdU-labeled SV40 genomes into nuclei, they were transcribed and, thus, are representative of productive infection. Conclusions Our findings imply that the SV40 genome disassociates from the capsid proteins before or at the point of entry into the nucleus, and then enters the nucleus devoid of VP2/3.

  10. The Herpes Simplex Virus 1 UL17 Protein Is the Second Constituent of the Capsid Vertex-Specific Component Required for DNA Packaging and Retention▿

    OpenAIRE

    Toropova, Katerina; Huffman, Jamie B.; Homa, Fred L.; James F Conway

    2011-01-01

    The herpes simplex virus (HSV) UL17 and UL25 minor capsid proteins are essential for DNA packaging. They are thought to comprise a molecule arrayed in five copies around each of the capsid vertices. This molecule was initially termed the “C-capsid-specific component” (CCSC) (B. L. Trus et al., Mol. Cell 26:479-489, 2007), but as we have subsequently observed this feature on reconstructions of A, B, and C capsids, we now refer to it more generally as the “capsid vertex-specific component” (CVS...

  11. Hidden symmetry of small spherical viruses and organization principles in "anomalous" and double-shelled capsid nanoassemblies.

    Science.gov (United States)

    Rochal, S B; Konevtsova, O V; Myasnikova, A E; Lorman, V L

    2016-09-29

    We propose the principles of structural organization in spherical nanoassemblies with icosahedral symmetry constituted by asymmetric protein molecules. The approach modifies the paradigmatic geometrical Caspar and Klug (CK) model of icosahedral viral capsids and demonstrates the common origin of both the "anomalous" and conventional capsid structures. In contrast to all previous models of "anomalous" viral capsids the proposed modified model conserves the basic structural principles of the CK approach and reveals the common hidden symmetry underlying all small viral shells. We demonstrate the common genesis of the "anomalous" and conventional capsids and explain their structures in the same frame. The organization principles are derived from the group theory analysis of the positional order on the spherical surface. The relationship between the modified CK geometrical model and the theory of two-dimensional spherical crystallization is discussed. We also apply the proposed approach to complex double-shelled capsids and capsids with protruding knob-like proteins. The introduced notion of commensurability for the concentric nanoshells explains the peculiarities of their organization and helps to predict analogous, but yet undiscovered, double-shelled viral capsid nanostructures.

  12. Electrostatic potential of human immunodeficiency virus type 2 and rhesus macaque simian immunodeficiency virus capsid proteins

    Directory of Open Access Journals (Sweden)

    Katarzyna eBozek

    2012-06-01

    Full Text Available Human immunodeficiency virus type 2 (HIV-2 and simian immunodeficiency virus isolated from a macaque monkey (SIVmac are assumed to have originated from simian immunodeficiency virus isolated from sooty mangabey (SIVsm. Despite their close similarity in genome structure, HIV-2 and SIVmac show different sensitivities to TRIM5α, a host restriction factor against retroviruses. The replication of HIV-2 strains is potently restricted by rhesus (Rh monkey TRIM5α, while that of SIVmac strain 239 (SIVmac239 is not. Viral capsid protein is the determinant of this differential sensitivity to TRIM5α, as the HIV-2 mutant carrying SIVmac239 capsid protein evaded Rh TRIM5α-mediated restriction. However, the molecular determinants of this restriction mechanism are unknown. Electrostatic potential on the protein-binding site is one of the properties regulating protein-protein interactions. In this study, we investigated the electrostatic potential on the interaction surface of capsid protein of HIV-2 strain GH123 and SIVmac239. Although HIV-2 GH123 and SIVmac239 capsid proteins share more than 87% amino acid identity, we observed a large difference between the two molecules with the HIV-2 GH123 molecule having predominantly positive and SIVmac239 predominantly negative electrostatic potential on the surface of the loop between α-helices 4 and 5 (L4/5. As L4/5 is one of the major determinants of Rh TRIM5α sensitivity of these viruses, the present results suggest that the binding site of the Rh TRIM5α may show complementarity to the HIV-2 GH123 capsid surface charge distribution.

  13. Mutation of the N-Terminal Region of Chikungunya Virus Capsid Protein: Implications for Vaccine Design

    Science.gov (United States)

    Liu, Xiang; Zaid, Ali; Goh, Lucas Y. H.; Hobson-Peters, Jody; Hall, Roy A.; Merits, Andres

    2017-01-01

    ABSTRACT Mosquito-transmitted chikungunya virus (CHIKV) is an arthritogenic alphavirus of the Togaviridae family responsible for frequent outbreaks of arthritic disease in humans. Capsid protein, a structural protein encoded by the CHIKV RNA genome, is able to translocate to the host cell nucleolus. In encephalitic alphaviruses, nuclear translocation induces host cell transcriptional shutoff; however, the role of capsid protein nucleolar localization in arthritogenic alphaviruses remains unclear. Using recombinant enhanced green fluorescent protein (EGFP)-tagged expression constructs and CHIKV infectious clones, we describe a nucleolar localization sequence (NoLS) in the N-terminal region of capsid protein, previously uncharacterized in CHIKV. Mutation of the NoLS by site-directed mutagenesis reduced efficiency of nuclear import of CHIKV capsid protein. In the virus, mutation of the capsid protein NoLS (CHIKV-NoLS) attenuated replication in mammalian and mosquito cells, producing a small-plaque phenotype. Attenuation of CHIKV-NoLS is likely due to disruption of the viral replication cycle downstream of viral RNA synthesis. In mice, CHIKV-NoLS infection caused no disease signs compared to wild-type CHIKV (CHIKV-WT)-infected mice; lack of disease signs correlated with significantly reduced viremia and decreased expression of proinflammatory factors. Mice immunized with CHIKV-NoLS, challenged with CHIKV-WT at 30 days postimmunization, develop no disease signs and no detectable viremia. Serum from CHIKV-NoLS-immunized mice is able to efficiently neutralize CHIKV infection in vitro. Additionally, CHIKV-NoLS-immunized mice challenged with the related alphavirus Ross River virus showed reduced early and peak viremia postchallenge, indicating a cross-protective effect. The high degree of CHIKV-NoLS attenuation may improve CHIKV antiviral and rational vaccine design. PMID:28223458

  14. Mutation of the N-Terminal Region of Chikungunya Virus Capsid Protein: Implications for Vaccine Design

    Directory of Open Access Journals (Sweden)

    Adam Taylor

    2017-02-01

    Full Text Available Mosquito-transmitted chikungunya virus (CHIKV is an arthritogenic alphavirus of the Togaviridae family responsible for frequent outbreaks of arthritic disease in humans. Capsid protein, a structural protein encoded by the CHIKV RNA genome, is able to translocate to the host cell nucleolus. In encephalitic alphaviruses, nuclear translocation induces host cell transcriptional shutoff; however, the role of capsid protein nucleolar localization in arthritogenic alphaviruses remains unclear. Using recombinant enhanced green fluorescent protein (EGFP-tagged expression constructs and CHIKV infectious clones, we describe a nucleolar localization sequence (NoLS in the N-terminal region of capsid protein, previously uncharacterized in CHIKV. Mutation of the NoLS by site-directed mutagenesis reduced efficiency of nuclear import of CHIKV capsid protein. In the virus, mutation of the capsid protein NoLS (CHIKV-NoLS attenuated replication in mammalian and mosquito cells, producing a small-plaque phenotype. Attenuation of CHIKV-NoLS is likely due to disruption of the viral replication cycle downstream of viral RNA synthesis. In mice, CHIKV-NoLS infection caused no disease signs compared to wild-type CHIKV (CHIKV-WT-infected mice; lack of disease signs correlated with significantly reduced viremia and decreased expression of proinflammatory factors. Mice immunized with CHIKV-NoLS, challenged with CHIKV-WT at 30 days postimmunization, develop no disease signs and no detectable viremia. Serum from CHIKV-NoLS-immunized mice is able to efficiently neutralize CHIKV infection in vitro. Additionally, CHIKV-NoLS-immunized mice challenged with the related alphavirus Ross River virus showed reduced early and peak viremia postchallenge, indicating a cross-protective effect. The high degree of CHIKV-NoLS attenuation may improve CHIKV antiviral and rational vaccine design.

  15. Topography of the Human Papillomavirus Minor Capsid Protein L2 during Vesicular Trafficking of Infectious Entry

    Science.gov (United States)

    DiGiuseppe, Stephen; Keiffer, Timothy R.; Bienkowska-Haba, Malgorzata; Luszczek, Wioleta; Guion, Lucile G. M.; Müller, Martin

    2015-01-01

    ABSTRACT The human papillomavirus (HPV) capsid is composed of the major capsid protein L1 and the minor capsid protein L2. During entry, the HPV capsid undergoes numerous conformational changes that result in endosomal uptake and subsequent trafficking of the L2 protein in complex with the viral DNA to the trans-Golgi network. To facilitate this transport, the L2 protein harbors a number of putative motifs that, if capable of direct interaction, would interact with cytosolic host cell factors. These data imply that a portion of L2 becomes cytosolic during infection. Using a low concentration of digitonin to selectively permeabilize the plasma membrane of infected cells, we mapped the topography of the L2 protein during infection. We observed that epitopes within amino acid residues 64 to 81 and 163 to 170 and a C-terminal tag of HPV16 L2 are exposed on the cytosolic side of intracellular membranes, whereas an epitope within residues 20 to 38, which are upstream of a putative transmembrane region, is luminal. Corroborating these findings, we also found that L2 protein is sensitive to trypsin digestion during infection. These data demonstrate that the majority of the L2 protein becomes accessible on the cytosolic side of intracellular membranes in order to interact with cytosolic factors to facilitate vesicular trafficking. IMPORTANCE In order to complete infectious entry, nonenveloped viruses have to pass cellular membranes. This is often achieved through the viral capsid protein associating with or integrating into intracellular membrane. Here, we determine the topography of HPV L2 protein in the endocytic vesicular compartment, suggesting that L2 becomes a transmembrane protein with a short luminal portion and with the majority facing the cytosolic side for interaction with host cell transport factors. PMID:26246568

  16. Highly conserved serine residue 40 in HIV-1 p6 regulates capsid processing and virus core assembly

    Directory of Open Access Journals (Sweden)

    Solbak Sara MØ

    2011-02-01

    Full Text Available Abstract Background The HIV-1 p6 Gag protein regulates the final abscission step of nascent virions from the cell membrane by the action of two late assembly (L- domains. Although p6 is located within one of the most polymorphic regions of the HIV-1 gag gene, the 52 amino acid peptide binds at least to two cellular budding factors (Tsg101 and ALIX, is a substrate for phosphorylation, ubiquitination, and sumoylation, and mediates the incorporation of the HIV-1 accessory protein Vpr into viral particles. As expected, known functional domains mostly overlap with several conserved residues in p6. In this study, we investigated the importance of the highly conserved serine residue at position 40, which until now has not been assigned to any known function of p6. Results Consistently with previous data, we found that mutation of Ser-40 has no effect on ALIX mediated rescue of HIV-1 L-domain mutants. However, the only feasible S40F mutation that preserves the overlapping pol open reading frame (ORF reduces virus replication in T-cell lines and in human lymphocyte tissue cultivated ex vivo. Most intriguingly, L-domain mediated virus release is not dependent on the integrity of Ser-40. However, the S40F mutation significantly reduces the specific infectivity of released virions. Further, it was observed that mutation of Ser-40 selectively interferes with the cleavage between capsid (CA and the spacer peptide SP1 in Gag, without affecting cleavage of other Gag products. This deficiency in processing of CA, in consequence, led to an irregular morphology of the virus core and the formation of an electron dense extra core structure. Moreover, the defects induced by the S40F mutation in p6 can be rescued by the A1V mutation in SP1 that generally enhances processing of the CA-SP1 cleavage site. Conclusions Overall, these data support a so far unrecognized function of p6 mediated by Ser-40 that occurs independently of the L-domain function, but selectively

  17. MaRIE Undulator & XFEL Systems

    Energy Technology Data Exchange (ETDEWEB)

    Nguyen, Dinh Cong [Los Alamos National Laboratory; Marksteiner, Quinn R. [Los Alamos National Laboratory; Anisimov, Petr Mikhaylovich [Los Alamos National Laboratory; Buechler, Cynthia Eileen [Los Alamos National Laboratory

    2015-03-23

    The 22 slides in this presentation treat the subject under the following headings: MaRIE XFEL Performance Parameters, Input Electron Beam Parameters, Undulator Design, Genesis Simulations, Risks, and Summary It is concluded that time-dependent Genesis simulations show the MaRIE XFEL can deliver the number of photons within the required bandwidth, provided a number of assumptions are met; the highest risks are associated with the electron beam driving the XFEL undulator; and risks associated with the undulator and/or distributed seeding technique may be evaluated or retired by performing early validation experiments.

  18. M&A Takeover Fever Heats Up

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ China's M&A activity is in turbo-drive. Outward investment is soaring, as many more Chinese companies need and are able to pursue opportunities overseas. Inward investment is accelerating, as foreign firms seek a foothold in the potentially lucrative Chinese market. And domestic consolidation is heating up among the country's fragmented industries due to overcapacity. Now that the Chinese government plans to address policy hurdles affecting M&A and relax foreign currency controls, activity levels should rise across most sectors. But while this may improve market positions and increase synergies for local and foreign investors, credit risks could intensify.

  19. Operation and maintenance in ST-MA

    CERN Document Server

    Nunes, R

    2003-01-01

    This paper will review the Operation & Maintenance (O&M) activities in the ST-MA group, giving an overview of the services provided by the Group as well as the contract activities. As an introduction, a conceptual framework for O&M is proposed in order to better situate the domains of Operation and Maintenance respectively. The ST-MA activities shall be looked at through the three main service axes and special emphasis will be given to the contractual implementation, supervision and follow-up methodology.

  20. M&A information technology best practices

    CERN Document Server

    Roehl-Anderson, Janice M

    2013-01-01

    Add value to your organization via the mergers & acquisitions IT function  As part of Deloitte Consulting, one of the largest mergers and acquisitions (M&A) consulting practice in the world, author Janice Roehl-Anderson reveals in M&A Information Technology Best Practices how companies can effectively and efficiently address the IT aspects of mergers, acquisitions, and divestitures. Filled with best practices for implementing and maintaining systems, this book helps financial and technology executives in every field to add value to their mergers, acquisitions, and/or divestitures via the IT

  1. Drawing a high-resolution functional map of adeno-associated virus capsid by massively parallel sequencing.

    Science.gov (United States)

    Adachi, Kei; Enoki, Tatsuji; Kawano, Yasuhiro; Veraz, Michael; Nakai, Hiroyuki

    2014-01-01

    Adeno-associated virus (AAV) capsid engineering is an emerging approach to advance gene therapy. However, a systematic analysis on how each capsid amino acid contributes to multiple functions remains challenging. Here we show proof-of-principle and successful application of a novel approach, termed AAV Barcode-Seq, that allows us to characterize phenotypes of hundreds of different AAV strains in a high-throughput manner and therefore overcomes technical difficulties in the systematic analysis. In this approach, we generate DNA barcode-tagged AAV libraries and determine a spectrum of phenotypes of each AAV strain by Illumina barcode sequencing. By applying this method to AAV capsid mutant libraries tagged with DNA barcodes, we can draw a high-resolution map of AAV capsid amino acids important for the structural integrity and functions including receptor binding, tropism, neutralization and blood clearance. Thus, Barcode-Seq provides a new tool to generate a valuable resource for virus and gene therapy research.

  2. The herpesvirus VP1/2 protein is an effector of dynein-mediated capsid transport and neuroinvasion

    National Research Council Canada - National Science Library

    Zaichick, Sofia V; Bohannon, Kevin P; Hughes, Ami; Sollars, Patricia J; Pickard, Gary E; Smith, Gregory A

    2013-01-01

    Microtubule transport of herpesvirus capsids from the cell periphery to the nucleus is imperative for viral replication and, in the case of many alphaherpesviruses, transmission into the nervous system...

  3. Bacteriophage P23-77 capsid protein structures reveal the archetype of an ancient branch from a major virus lineage.

    Science.gov (United States)

    Rissanen, Ilona; Grimes, Jonathan M; Pawlowski, Alice; Mäntynen, Sari; Harlos, Karl; Bamford, Jaana K H; Stuart, David I

    2013-05-07

    It has proved difficult to classify viruses unless they are closely related since their rapid evolution hinders detection of remote evolutionary relationships in their genetic sequences. However, structure varies more slowly than sequence, allowing deeper evolutionary relationships to be detected. Bacteriophage P23-77 is an example of a newly identified viral lineage, with members inhabiting extreme environments. We have solved multiple crystal structures of the major capsid proteins VP16 and VP17 of bacteriophage P23-77. They fit the 14 Å resolution cryo-electron microscopy reconstruction of the entire virus exquisitely well, allowing us to propose a model for both the capsid architecture and viral assembly, quite different from previously published models. The structures of the capsid proteins and their mode of association to form the viral capsid suggest that the P23-77-like and adeno-PRD1 lineages of viruses share an extremely ancient common ancestor.

  4. Rationally Designed Interfacial Peptides Are Efficient In Vitro Inhibitors of HIV-1 Capsid Assembly with Antiviral Activity

    OpenAIRE

    Rebeca Bocanegra; María Nevot; Rosa Doménech; Inmaculada López; Olga Abián; Alicia Rodríguez-Huete; Cavasotto, Claudio N.; Adrián Velázquez-Campoy; Javier Gómez; Miguel Ángel Martínez; José Luis Neira; Mateu, Mauricio G.

    2011-01-01

    Virus capsid assembly constitutes an attractive target for the development of antiviral therapies; a few experimental inhibitors of this process for HIV-1 and other viruses have been identified by screening compounds or by selection from chemical libraries. As a different, novel approach we have undertaken the rational design of peptides that could act as competitive assembly inhibitors by mimicking capsid structural elements involved in intersubunit interfaces. Several discrete interfaces in...

  5. Location of the Bacteriophage P22 Coat Protein C-terminus Provides Opportunities for the Design of Capsid Based Materials

    OpenAIRE

    Servid, Amy; Jordan, Paul; O’Neil, Alison; Prevelige, Peter; Douglas, Trevor

    2013-01-01

    Rational design of modifications to the interior and exterior surfaces of virus-like particles (VLPs) for future therapeutic and materials applications is based on structural information about the capsid. Existing cryo-electron microscopy based models suggest that the C-terminus of the bacteriophage P22 coat protein (CP) extends towards the capsid exterior. Our biochemical analysis through genetic manipulations of the C-terminus supports the model where the CP C-terminus is exposed on the ext...

  6. Targeting of herpesvirus capsid transport in axons is coupled to association with specific sets of tegument proteins

    OpenAIRE

    Luxton, G.W. Gant; Haverlock, Sarah; Coller, Kelly Elizabeth; Antinone, Sarah Elizabeth; Pincetic, Andrew; Smith, Gregory Allan

    2005-01-01

    The capsids of neurotropic herpesviruses have the remarkable ability to move in specific directions within axons. By modulating bidirectional capsid transport to favor either retrograde (minus-end) or anterograde (plus-end) motion, these viruses travel to sensory ganglia or peripheral tissue at specific stages of infection. By using correlative motion analysis to simultaneously monitor the trafficking of distinct viral proteins in living neurons, we demonstrate that viral “tegument” proteins ...

  7. Pelagic records from the Equatorial Ninetyeast Ridge and significant environmental events during the past 3.5 Ma

    Institute of Scientific and Technical Information of China (English)

    2008-01-01

    This paper presents pelagic records of planktic foraminifera,as well as data of stable isotope stratigraphy and carbonate stratigraphy since 3.5 Ma B.P.from site ODP758 in the Ninetyeast Ridge of the Indian Ocean.Based on these data,manifestations and related mechanisms of major tectonic and environmental events such as the rapid uplift of the Himalaya Mountains,"middle Pleistocene climatic transition" and""mid-Brunhes dissolution event"in the region are discussed.According to the analysis and comparison of various indices and changes in terms of foraminifera assemblage,paleotemperature,paleosalinity and themocline from site ODP758,the authors deduce that the paleoclimatic changes might correlate with the mid-Pleistocene transition at 1.4-1.7 Ma B.P.The changes of CaCO3,mass accumulation rates (MAR) of CaCO3 and non- CaCO3 MAR indicate that the loaded terrigenous sediments increased at 1.7 Ma,which is in agreement with the uplift history of the Qinghai-Tibet plateau as shown by the available data.The last two changes coincide with the uplift of the Qinghai-Tibet plateau,hence they are called"Qinghai-Tibet movement" (1.7 Ma),and the"Kunlun-Yellow River movement"(1.2-0.6 Ma).The changes of the CaCO3 content,coarse fraction (>150 μm) content and planktonic foraminifera biostratigraphy show that strong dissolution of abyssal CaCO3 occurred in the study region during 0.5-0.4 Ma.The event was consistent with the "mid-Brunhes dissolution event"in the sedimentary records of the Atlantic Ocean,Pacific Ocean,Indian Ocean and Nansha sea area of the South China Sea.

  8. Microplate-based assay for identifying small molecules that bind a specific intersubunit interface within the assembled HIV-1 capsid.

    Science.gov (United States)

    Halambage, Upul D; Wong, Jason P; Melancon, Bruce J; Lindsley, Craig W; Aiken, Christopher

    2015-09-01

    Despite the availability of >30 effective drugs for managing HIV-1 infection, no current therapy is curative, and long-term management is challenging owing to the emergence and spread of drug-resistant mutants. Identification of drugs against novel HIV-1 targets would expand the current treatment options and help to control resistance. The highly conserved HIV-1 capsid protein represents an attractive target because of its multiple roles in replication of the virus. However, the low antiviral potencies of the reported HIV-1 capsid-targeting inhibitors render them unattractive for therapeutic development. To facilitate the identification of more-potent HIV-1 capsid inhibitors, we developed a scintillation proximity assay to screen for small molecules that target a biologically active and specific intersubunit interface in the HIV-1 capsid. The assay, which is based on competitive displacement of a known capsid-binding small-molecule inhibitor, exhibited a signal-to-noise ratio of >9 and a Z factor of >0.8. In a pilot screen of a chemical library containing 2,400 druglike compounds, we obtained a hit rate of 1.8%. This assay has properties that are suitable for screening large compound libraries to identify novel HIV-1 capsid ligands with antiviral activity.

  9. Structural transitions and energy landscape for Cowpea Chlorotic Mottle Virus capsid mechanics from nanomanipulation in vitro and in silico

    CERN Document Server

    Kononova, Olga; Brasch, Melanie; Cornelissen, Jeroen; Dima, Ruxandra I; Marx, Kenneth A; Wuite, Gijs J L; Roos, Wouter H; Barsegov, Valeri

    2015-01-01

    Physical properties of capsids of plant and animal viruses are important factors in capsid self-assembly, survival of viruses in the extracellular environment, and their cell infectivity. Virus shells can have applications as nanocontainers and delivery vehicles in biotechnology and medicine. Combined AFM experiments and computational modeling on sub-second timescales of the indentation nanomechanics of Cowpea Chlorotic Mottle Virus (CCMV) capsid show that the capsid's physical properties are dynamic and local characteristics of the structure, which depend on the magnitude and geometry of mechanical input. Surprisingly, under large deformations the CCMV capsid transitions to the collapsed state without substantial local structural alterations. The enthalpy change in this deformation state dH = 11.5 - 12.8 MJ/mol is mostly due to large-amplitude out-of-plane excitations, which contribute to the capsid bending, and the entropy change TdS = 5.1 - 5.8 MJ/mol is mostly due to coherent in-plane rearrangements of pr...

  10. Selective Inhibitor of Nuclear Export (SINE) Compounds Alter New World Alphavirus Capsid Localization and Reduce Viral Replication in Mammalian Cells.

    Science.gov (United States)

    Lundberg, Lindsay; Pinkham, Chelsea; de la Fuente, Cynthia; Brahms, Ashwini; Shafagati, Nazly; Wagstaff, Kylie M; Jans, David A; Tamir, Sharon; Kehn-Hall, Kylene

    2016-11-01

    The capsid structural protein of the New World alphavirus, Venezuelan equine encephalitis virus (VEEV), interacts with the host nuclear transport proteins importin α/β1 and CRM1. Novel selective inhibitor of nuclear export (SINE) compounds, KPT-185, KPT-335 (verdinexor), and KPT-350, target the host's primary nuclear export protein, CRM1, in a manner similar to the archetypical inhibitor Leptomycin B. One major limitation of Leptomycin B is its irreversible binding to CRM1; which SINE compounds alleviate because they are slowly reversible. Chemically inhibiting CRM1 with these compounds enhanced capsid localization to the nucleus compared to the inactive compound KPT-301, as indicated by immunofluorescent confocal microscopy. Differences in extracellular versus intracellular viral RNA, as well as decreased capsid in cell free supernatants, indicated the inhibitors affected viral assembly, which led to a decrease in viral titers. The decrease in viral replication was confirmed using a luciferase-tagged virus and through plaque assays. SINE compounds had no effect on VEEV TC83_Cm, which encodes a mutated form of capsid that is unable to enter the nucleus. Serially passaging VEEV in the presence of KPT-185 resulted in mutations within the nuclear localization and nuclear export signals of capsid. Finally, SINE compound treatment also reduced the viral titers of the related eastern and western equine encephalitis viruses, suggesting that CRM1 maintains a common interaction with capsid proteins across the New World alphavirus genus.

  11. Salatoimikud : ma tahan uskuda / Mart Rummo

    Index Scriptorium Estoniae

    Rummo, Mart

    2008-01-01

    USA sarjale "The X-Files" põhinev teine järjefilm "Salatoimikud: Ma tahan uskuda" ("The X-Files: I Want to Believe") : režissöör Chris Carter : peaosades David Duchovny, Gillian Anderson : Ameerika Ühendriigid - Kanada 2008

  12. Maíz I (Zea mays)

    OpenAIRE

    Sánchez Ortega, Iván; Pérez-Urria Carril, Elena

    2014-01-01

    El maíz es uno de los cultivos básicos más importantes y extendidos en todo el mundo. Constituye una de las fuentes principales de alimento de millones depersonas, sobre todo en América y Asia. Se trata de una de las primeras plantas que se domesticaron y se difundieron por todo el mundo.

  13. 76 FR 36953 - Massachusetts Disaster #MA-00036

    Science.gov (United States)

    2011-06-23

    ... From the Federal Register Online via the Government Publishing Office ] SMALL BUSINESS ADMINISTRATION Massachusetts Disaster MA-00036 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for the State...

  14. 77 FR 76585 - Massachusetts Disaster # MA-00052

    Science.gov (United States)

    2012-12-28

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster MA-00052 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the Commonwealth...

  15. 77 FR 66214 - Massachusetts Disaster # MA-00049

    Science.gov (United States)

    2012-11-02

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster MA-00049 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the Commonwealth...

  16. 76 FR 56859 - Massachusetts Disaster #MA-00039

    Science.gov (United States)

    2011-09-14

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster MA-00039 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for the Commonwealth...

  17. 75 FR 45681 - Massachusetts Disaster #MA-00028.

    Science.gov (United States)

    2010-08-03

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster MA-00028. AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the Commonwealth...

  18. 75 FR 22874 - Massachusetts Disaster # MA-00027

    Science.gov (United States)

    2010-04-30

    ... From the Federal Register Online via the Government Publishing Office ] SMALL BUSINESS ADMINISTRATION Massachusetts Disaster MA-00027 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for Public Assistance...

  19. 76 FR 56853 - Massachusetts Disaster #MA-00040

    Science.gov (United States)

    2011-09-14

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster MA-00040 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for Public Assistance...

  20. Teacher MA Attainment Rates, 1970-2000

    Science.gov (United States)

    Larsen, S. Eric

    2010-01-01

    The share of female teachers in the U.S. with an MA more than doubled between 1970 and 2000. This increase is puzzling, as it is much larger than that of other college-educated women, and it occurred over a period of declining teacher aptitude. I estimate the contribution of changes in teacher demographic characteristics, increases in the returns…

  1. 76 FR 65557 - Massachusetts Disaster #MA-00043

    Science.gov (United States)

    2011-10-21

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster MA-00043 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the Commonwealth...

  2. 75 FR 17177 - Massachusetts Disaster #MA-00025

    Science.gov (United States)

    2010-04-05

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster MA-00025 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for the State...

  3. 76 FR 36952 - Massachusetts Disaster #MA-00037

    Science.gov (United States)

    2011-06-23

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster MA-00037 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for Public Assistance...

  4. 77 FR 76584 - Massachusetts Disaster # MA-00051

    Science.gov (United States)

    2012-12-28

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster MA-00051 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the Commonwealth...

  5. 77 FR 2600 - Massachusetts Disaster #MA-00046

    Science.gov (United States)

    2012-01-18

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster MA-00046 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for Public Assistance...

  6. 76 FR 13697 - Massachusetts Disaster #MA-00032

    Science.gov (United States)

    2011-03-14

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster MA-00032 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a Notice of the Presidential declaration of a major disaster for Public Assistance...

  7. 78 FR 2708 - Massachusetts Disaster # MA-00050

    Science.gov (United States)

    2013-01-14

    ... ADMINISTRATION Massachusetts Disaster MA-00050 AGENCY: U.S. Small Business Administration. ACTION: Notice... completed loan applications to: U.S. Small Business Administration, Processing and Disbursement Center... Disaster Assistance, U.S. Small Business Administration, 409 3rd Street SW., Suite 6050, Washington,...

  8. 78 FR 25336 - Massachusetts Disaster #MA-00054

    Science.gov (United States)

    2013-04-30

    ... ADMINISTRATION Massachusetts Disaster MA-00054 AGENCY: U.S. Small Business Administration. ACTION: Notice...: 01/21/2014. ADDRESSES: Submit completed loan applications to: U.S. Small Business Administration... CONTACT: A. Escobar, Office of Disaster Assistance, U.S. Small Business Administration, 409 3rd Street...

  9. Fabrication technology for ODS Alloy MA957

    Energy Technology Data Exchange (ETDEWEB)

    ML Hamilton; DS Gelles; RJ Lobsinger; MM Paxton; WF Brown

    2000-03-16

    A successful fabrication schedule has been developed at Carpenter Technology Corporation for the production of MA957 fuel and blanket cladding. Difficulties with gun drilling, plug drawing and recrystallization were overcome to produce a pilot lot of tubing. This report documents the fabrication efforts of two qualified vendors and the support studies performed at WHC to develop the fabrication-schedule.

  10. Vaccines against stimulants: cocaine and MA.

    Science.gov (United States)

    Kosten, Thomas; Domingo, Coreen; Orson, Frank; Kinsey, Berma

    2014-02-01

    While the worldwide prevalence of cocaine use remains significant, medications, or small molecule approaches, to treat drug addictions have met with limited success. Anti-addiction vaccines, on the other hand, have demonstrated great potential for treating drug abuse using a distinctly different mechanism of eliciting an antibody response that blocks the pharmacological effects of drugs. We provide a review of vaccine-based approaches to treating stimulant addictions; specifically and cocaine addictions. This selective review article focuses on the one cocaine vaccine that has been into clinical trials and presents new data related to pre-clinical development of a methamphetamine (MA) vaccine. We also review the mechanism of action for vaccine induced antibodies to abused drugs, which involves kinetic slowing of brain entry as well as simple blocking properties. We present pre-clinical innovations for MA vaccines including hapten design, linkage to carrier proteins and new adjuvants beyond alum. We provide some new information on hapten structures and linkers and variations in protein carriers. We consider a carrier, outer membrance polysaccharide coat protein (OMPC), that provides some self-adjuvant through lipopolysaccharide components and provide new results with a monophosopholipid adjuvant for the more standard carrier proteins with cocaine and MA. The review then covers the clinical trials with the cocaine vaccine TA-CD. The clinical prospects for advances in this field over the next few years include a multi-site cocaine vaccine clinical trial to be reported in 2013 and phase 1 clinical trials of a MA vaccine in 2014.

  11. Salatoimikud : ma tahan uskuda / Mart Rummo

    Index Scriptorium Estoniae

    Rummo, Mart

    2008-01-01

    USA sarjale "The X-Files" põhinev teine järjefilm "Salatoimikud: Ma tahan uskuda" ("The X-Files: I Want to Believe") : režissöör Chris Carter : peaosades David Duchovny, Gillian Anderson : Ameerika Ühendriigid - Kanada 2008

  12. Global Plate Driving Forces at 50Ma

    Science.gov (United States)

    Butterworth, N. P.; Quevedo, L. E.; Müller, R. D.

    2011-12-01

    We apply a novel workflow utilising the BEM-Earth geodynamic software to analyse the global coupled plate-mantle dynamics at 50 Ma. A subduction history model based on kinematic data going as far back as 80 Ma was developed using the GPlates software. Advection of the plates into the mantle takes into account the absolute plate motions and lithospheric thickness derived from its age to produce an estimated density heterogeneity initial model condition in the upper mantle. The resulting global model consists of regions of a mantle viscosity and density structure that is post-processed to ensure smooth non-overlapping 3D surfaces. BEM-Earth is then free to evolve the model toward the 50 Ma solution. The evolution of the model is driven by self-consistent buoyancy driven mantle dynamics. We use the model velocity output to quantify changes in forces driving the plates before and after 50 Ma. We analyse the rapid change in plate motion of India, Africa and plates in the Pacific Ocean basin by considering slab-pull, ridge-push and mantle drag/suction forces that naturally result from such top-down driven mantle flow. We compare the results with plate kinematic reconstructions and other geological observations.

  13. 77 FR 33263 - Massachusetts Disaster #MA-00048

    Science.gov (United States)

    2012-06-05

    ... ADMINISTRATION Massachusetts Disaster MA-00048 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the Commonwealth of Massachusetts dated 05/29/2012. Incident: Lake Williams Condominium Complex Fire. Incident Period:...

  14. 76 FR 30748 - Massachusetts Disaster #MA-00033

    Science.gov (United States)

    2011-05-26

    ... ADMINISTRATION Massachusetts Disaster MA-00033 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the Commonwealth of Massachusetts dated 05/19/2011. Incident: Apartment Building Fire. Incident Period: 04/30/2011. Effective...

  15. 75 FR 79064 - Massachusetts Disaster #MA-00030

    Science.gov (United States)

    2010-12-17

    ... ADMINISTRATION Massachusetts Disaster MA-00030 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the Commonwealth of Massachusetts dated 12/07/2010. Incident: Apartment complex fire. Incident Period: 11/21/2010. Effective...

  16. 76 FR 40766 - Massachusetts Disaster #MA-00035

    Science.gov (United States)

    2011-07-11

    ... ADMINISTRATION Massachusetts Disaster MA-00035 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the Commonwealth of Massachusetts dated 06/29/2011. Incident: Johnsonia Apartment Building Fire Incident Period:...

  17. 77 FR 12350 - Massachusetts Disaster #MA-00047

    Science.gov (United States)

    2012-02-29

    ... ADMINISTRATION Massachusetts Disaster MA-00047 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the Commonwealth of Massachusetts dated 02/21/2012. Incident: Brookline Apartment Building Fire. Incident Period:...

  18. 75 FR 3764 - Massachusetts Disaster # MA-00024

    Science.gov (United States)

    2010-01-22

    ... ADMINISTRATION Massachusetts Disaster MA-00024 AGENCY: U.S. Small Business Administration. ACTION: Notice. SUMMARY: This is a notice of an Administrative declaration of a disaster for the Commonwealth of Massachusetts dated 01/15/2010. Incident: Mystic Side Estates Apartment Building Fire. Incident Period:...

  19. Chronic hepatitis B infection and HBV DNA-containing capsids: Modeling and analysis

    Science.gov (United States)

    Manna, Kalyan; Chakrabarty, Siddhartha P.

    2015-05-01

    We analyze the dynamics of chronic HBV infection taking into account both uninfected and infected hepatocytes along with the intracellular HBV DNA-containing capsids and the virions. While previous HBV models have included either the uninfected hepatocytes or the intracellular HBV DNA-containing capsids, our model accounts for both these two populations. We prove the conditions for local and global stability of both the uninfected and infected steady states in terms of the basic reproduction number. Further, we incorporate a time lag in the model to encompass the intracellular delay in the production of the infected hepatocytes and find that this delay does not affect the overall dynamics of the system. The results for the model and the delay model are finally numerically illustrated.

  20. Theory of morphological transformation of viral capsid shells during maturation process

    CERN Document Server

    Konevtsova, O V; Rochal, S B

    2015-01-01

    In the frame of the Landau-Ginzburg formalism we propose a minimal phenomenological model for a morphological transformation in viral capsid shells. The transformation takes place during virus maturation process which renders virus infectious. The theory is illustrated on the example of the HK97 bacteriophage and viruses with similar morphological changes in the protective protein shell. The transformation is shown to be a structural phase transition driven by two order parameters. The first order parameter describes the isotropic expansion of the protein shell while the second one is responsible for the shape symmetry breaking and the resulting shell faceting. The group theory analysis and the resulting thermodynamic model make it possible to choose the parameter which discriminates between the icosahedral shell faceting often observed in viral capsids and the dodecahedral one observed in viruses of the Parvovirus family. Calculated phase diagram illustrates the discontinuous character of the virus morpholog...

  1. Expression and subcellular targeting of canine parvovirus capsid proteins in baculovirus-transduced NLFK cells.

    Science.gov (United States)

    Gilbert, Leona; Välilehto, Outi; Kirjavainen, Sanna; Tikka, Päivi J; Mellett, Mark; Käpylä, Pirjo; Oker-Blom, Christian; Vuento, Matti

    2005-01-17

    A mammalian baculovirus delivery system was developed to study targeting in Norden Laboratories feline kidney (NLFK) cells of the capsid proteins of canine parvovirus (CPV), VP1 and VP2, or corresponding counterparts fused to EGFP. VP1 and VP2, when expressed alone, both had equal nuclear and cytoplasmic distribution. However, assembled form of VP2 had a predominantly cytoplasmic localization. When VP1 and VP2 were simultaneously present in cells, their nuclear localization increased. Thus, confocal immunofluorescence analysis of cells transduced with the different baculovirus constructs or combinations thereof in the absence or presence of infecting CPV revealed that the VP1 protein is a prerequisite for efficient targeting of VP2 to the nucleus. The baculovirus vectors were functional and the genes of interest efficiently introduced to this CPV susceptible mammalian cell line. Thus, we show evidence that the system could be utilized to study targeting of the CPV capsid proteins.

  2. Two-Dimensional Phase Transition of Viral Capsid Gives Insights into Subunit Interactions

    Science.gov (United States)

    Tresset, Guillaume; Chen, Jingzhi; Chevreuil, Maelenn; Nhiri, Naïma; Jacquet, Eric; Lansac, Yves

    2017-01-01

    We show that the thermal dissociation of icosahedral viral capsids can be interpreted in terms of a two-dimensional phase transition. The approach provides a useful framework to get direct insights into the interactions at work between viral components. We devise a mean-field lattice model that relates the melting temperature to subunit attractive energy, effective charge, and chemical potential. Through fluorescence thermal shift assay on a plant viral system, we illustrate how the model gives access to the interaction parameters for empty and loaded viral capsids in various ionic conditions. This work should help construct physical models accounting for the assembly and disassembly mechanisms of viruses, with possible fallout in the development of therapeutic inhibitors.

  3. DNA condensates organized by the capsid protein VP15 in White Spot Syndrome Virus.

    Science.gov (United States)

    Liu, Yingjie; Wu, Jinlu; Chen, Hu; Hew, Choy Leong; Yan, Jie

    2010-12-20

    The White Spot Syndrome Virus (WSSV) has a large circular double-stranded DNA genome of around 300kb and it replicates in the nucleus of the host cells. The machinery of how the viral DNA is packaged has been remained unclear. VP15, a highly basic protein, is one of the major capsid proteins found in the virus. Previously, it was shown to be a DNA binding protein and was hypothesized to participate in the viral DNA packaging process. Using Atomic Force Microscopy imaging, we show that the viral DNA is associated with a (or more) capsid proteins. The organized viral DNA qualitatively resembles the conformations of VP15 induced DNA condensates in vitro. Furthermore, single-DNA manipulation experiments revealed that VP15 is able to condense single DNA against forces of a few pico Newtons. Our results suggest that VP15 may aid in the viral DNA packaging process by directly condensing DNA.

  4. 46 CFR 308.550 - Certificate, Form MA-320.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Certificate, Form MA-320. 308.550 Section 308.550... Risk Cargo Insurance Iv-General § 308.550 Certificate, Form MA-320. Wherever any provision of this... execute a certificate on Form MA-320-A for an individual, on Form MA-320-B for a partnership, or on...

  5. 42 CFR 422.4 - Types of MA plans.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Types of MA plans. 422.4 Section 422.4 Public...) MEDICARE PROGRAM MEDICARE ADVANTAGE PROGRAM General Provisions § 422.4 Types of MA plans. (a) General rule. An MA plan may be a coordinated care plan, a combination of an MA MSA plan and a contribution into...

  6. Anti-HERV-K (HML-2) capsid antibody responses in HIV elite controllers.

    Science.gov (United States)

    de Mulder, Miguel; SenGupta, Devi; Deeks, Steven G; Martin, Jeffrey N; Pilcher, Christopher D; Hecht, Frederick M; Sacha, Jonah B; Nixon, Douglas F; Michaud, Henri-Alexandre

    2017-08-22

    Human endogenous retroviruses (HERVs) comprise approximately 8% of the human genome and while the majority are transcriptionally silent, the most recently integrated HERV, HERV-K (HML-2), remains active. During HIV infection, HERV-K (HML-2) specific mRNA transcripts and viral proteins can be detected. In this study, we aimed to understand the antibody response against HERV-K (HML-2) Gag in the context of HIV-1 infection. We developed an ELISA assay using either recombinant protein or 164 redundant "15mer" HERV-K (HML-2) Gag peptides to test sera for antibody reactivity. We identified a total of eight potential HERV-K (HML-2) Gag immunogenic domains: two on the matrix (peptides 16 and 31), one on p15 (peptide 85), three on the capsid (peptides 81, 97 and 117), one on the nucleocapsid (peptide 137) and one on the QP1 protein (peptide 157). Four epitopes (peptides 16, 31, 85 and 137) were highly immunogenic. No significant differences in antibody responses were found between HIV infected participants (n = 40) and uninfected donors (n = 40) for 6 out of the 8 epitopes tested. The antibody response against nucleocapsid (peptide 137) was significantly lower (p K (HML-2) capsid recombinant peptide in gamma interferon (IFN-γ) enzyme immunospot (Elispot) assays. We found that the HERV-K (HML-2) Gag antibody and T cell response by Elispot were significantly correlated. HIV elite controllers had a strong cellular and antibody response against HERV-K (HML-2) Gag directed mainly against the Capsid region. Collectively, these data suggest that anti-HERV-K (HML-2) antibodies targeting capsid could have an immunoprotective effect in HIV infection.

  7. Interactions of the HSV-1 UL25 Capsid Protein with Cellular Microtubule-associated Protein

    Institute of Scientific and Technical Information of China (English)

    Lei GUO; Ying ZHANG; Yan-chun CHE; Wen-juan WU; Wei-zhong LI; Li-chun WANG; Yun LIAO; Long-ding LIU; Qi-han LI

    2008-01-01

    An interaction between the HSV-1 UL25 capsid protein and cellular microtubule-associated protein was found using a yeast two-hybrid screen and β-D-galactosidase activity assays. Immunofluorescence microscopy of the UL25 protein demonstrated its co-localization with cellular microtubule-associated protein in the plasma membrane. Further investigations with deletion mutants suggest that UL25 is likely to have a function in the nucleus.

  8. Mapping the AAV capsid host antibody response towards the development of second generation gene delivery vectors

    Directory of Open Access Journals (Sweden)

    Yu-Shan eTseng

    2014-01-01

    Full Text Available The recombinant Adeno-associated virus (rAAV gene delivery system is entering a crucial and exciting phase with the promise of more than 20 years of intense research now realized in a number of successful human clinical trials. However, as a natural host to AAV infection, anti-AAV antibodies are prevalent in the human population. For example, ~70% of human sera samples are positive for AAV serotype 2 (AAV2. Furthermore, low levels of pre-existing neutralizing antibodies in the circulation are detrimental to the efficacy of corrective therapeutic AAV gene delivery. A key component to overcoming this obstacle is the identification of regions of the AAV capsid that participate in interactions with host immunity, especially neutralizing antibodies, to be modified for neutralization escape. Three main approaches have been utilized to map antigenic epitopes on AAV capsids. The first is directed evolution in which AAV variants are selected in the presence of monoclonal antibodies or pooled human sera. This results in AAV variants with mutations on important neutralizing epitopes. The second is epitope searching, achieved by peptide scanning, peptide insertion or site-directed mutagenesis. The third, a structure biology-based approach, utilizes cryo-electron microscopy and image reconstruction of AAV capsids complexed to fragment antibodies, which are generated from monoclonal antibodies, to directly visualize the epitopes. In this review, the contribution of these three approaches to the current knowledge of AAV epitopes and success in their use to create second generation vectors will be discussed.

  9. Detection of major capsid protein of infectious myonecrosis virus in shrimps using monoclonal antibodies.

    Science.gov (United States)

    Seibert, Caroline H; Borsa, Mariana; Rosa, Rafael D; Cargnin-Ferreira, Eduardo; Pereira, Alitiene M L; Grisard, Edmundo C; Zanetti, Carlos R; Pinto, Aguinaldo R

    2010-10-01

    Infectious myonecrosis virus (IMNV) has been causing a progressive disease in farm-reared shrimps in Brazil and Indonesia. Immunodiagnostic methods for IMNV detection, although reliable, are not employed currently because monoclonal antibodies (MAbs) against this virus are not available. In this study, a fragment of the IMNV major capsid protein gene, comprising amino acids 300-527 (IMNV(300-527)), was cloned and expressed in Escherichia coli. The nucleotide sequence of the recombinant IMNV(300-527) fragment displayed a high degree of identity to the major capsid protein of IMNV isolates from Brazil (99%) and Indonesia (98%). Ten MAbs were generated against the expressed fragment, and eight of these, mostly IgG(2a) or IgG(2b), were able to bind to IMNV in tissue extracts from shrimps infected naturally in immunodot-blot assays. Six of these MAbs recognized a approximately 100 kDa protein in a Western-blot, which is the predicted mass of IMNV major capsid protein, and also bound to viral inclusions present in muscle fibroses and in coagulative myonecrosis, as demonstrated by immunohistochemistry. Among all those MAbs created, four did not cross-react with non-infected shrimp tissues; this observation supports their applicability as a sensitive and specific immunodiagnosis of IMNV infection in shrimps.

  10. In vitro protease cleavage and computer simulations reveal the HIV-1 capsid maturation pathway

    Science.gov (United States)

    Ning, Jiying; Erdemci-Tandogan, Gonca; Yufenyuy, Ernest L.; Wagner, Jef; Himes, Benjamin A.; Zhao, Gongpu; Aiken, Christopher; Zandi, Roya; Zhang, Peijun

    2016-12-01

    HIV-1 virions assemble as immature particles containing Gag polyproteins that are processed by the viral protease into individual components, resulting in the formation of mature infectious particles. There are two competing models for the process of forming the mature HIV-1 core: the disassembly and de novo reassembly model and the non-diffusional displacive model. To study the maturation pathway, we simulate HIV-1 maturation in vitro by digesting immature particles and assembled virus-like particles with recombinant HIV-1 protease and monitor the process with biochemical assays and cryoEM structural analysis in parallel. Processing of Gag in vitro is accurate and efficient and results in both soluble capsid protein and conical or tubular capsid assemblies, seemingly converted from immature Gag particles. Computer simulations further reveal probable assembly pathways of HIV-1 capsid formation. Combining the experimental data and computer simulations, our results suggest a sequential combination of both displacive and disassembly/reassembly processes for HIV-1 maturation.

  11. Characterization of a nuclear localization signal of canine parvovirus capsid proteins.

    Science.gov (United States)

    Vihinen-Ranta, M; Kakkola, L; Kalela, A; Vilja, P; Vuento, M

    1997-12-01

    We investigated the abilities of synthetic peptides mimicking the potential nuclear localization signal of canine parvovirus (CPV) capsid proteins to translocate a carrier protein to the nucleus following microinjection into the cytoplasm of A72 cells. Possible nuclear localization sequences were chosen for synthesis from CPV capsid protein sequences (VP1, VP2) on the basis of the presence of clustered basic residues, which is a common theme in most of the previously identified targeting peptides. Nuclear targeting activity was found within the N-terminal residues 4-13 (PAKRARRGYK) of the VP1 capsid protein. While replacement of Arg10 with glycine did not affect the activity, replacement of Lys6, Arg7, or Arg9 with glycine abolished it. The targeting activity was found to residue in a cluster of basic residues, Lys5, Arg7, and Arg9. Nuclear import was saturated by excess of unlabelled peptide conjugates (showing that it was a receptor-mediated process). Transport into the nucleus was an energy-dependent and temperature-dependent process actively mediated by the nuclear pores and inhibited by wheat germ agglutinin.

  12. Viral capsid is a pathogen-associated molecular pattern in adenovirus keratitis.

    Directory of Open Access Journals (Sweden)

    Ashish V Chintakuntlawar

    2010-04-01

    Full Text Available Human adenovirus (HAdV infection of the human eye, in particular serotypes 8, 19 and 37, induces the formation of corneal subepithelial leukocytic infiltrates. Using a unique mouse model of adenovirus keratitis, we studied the role of various virus-associated molecular patterns in subsequent innate immune responses of resident corneal cells to HAdV-37 infection. We found that neither viral DNA, viral gene expression, or viral replication was necessary for the development of keratitis. In contrast, empty viral capsid induced keratitis and a chemokine profile similar to intact virus. Transfected viral DNA did not induce leukocyte infiltration despite CCL2 expression similar to levels in virus infected corneas. Mice without toll-like receptor 9 (Tlr9 signaling developed clinical keratitis upon HAdV-37 infection similar to wild type mice, although the absolute numbers of activated monocytes in the cornea were less in Tlr9(-/- mice. Virus induced leukocytic infiltrates and chemokine expression in mouse cornea could be blocked by treatment with a peptide containing arginine glycine aspartic acid (RGD. These results demonstrate that adenovirus infection of the cornea induces chemokine expression and subsequent infiltration by leukocytes principally through RGD contact between viral capsid and the host cell, possibly through direct interaction between the viral capsid penton base and host cell integrins.

  13. Dengue Virus Capsid Protein Binds Core Histones and Inhibits Nucleosome Formation in Human Liver Cells

    Science.gov (United States)

    Colpitts, Tonya M.; Barthel, Sebastian; Wang, Penghua; Fikrig, Erol

    2011-01-01

    Dengue virus (DENV) is a member of the Flaviviridae and a globally (re)emerging pathogen that causes serious human disease. There is no specific antiviral or vaccine for dengue virus infection. Flavivirus capsid (C) is a structural protein responsible for gathering the viral RNA into a nucleocapsid that forms the core of a mature virus particle. Flaviviral replication is known to occur in the cytoplasm yet a large portion of capsid protein localizes to the nucleus during infection. The reasons for the nuclear presences of capsid are not completely understood. Here, we expressed mature DENV C in a tandem affinity purification assay to identify potential binding partners in human liver cells. DENV C targeted the four core histones, H2A, H2B, H3 and H4. DENV C bound recombinant histones in solution and colocalized with histones in the nucleus and cytoplasm of liver cells during DENV infection. We show that DENV C acts as a histone mimic, forming heterodimers with core histones, binding DNA and disrupting nucleosome formation. We also demonstrate that DENV infection increases the amounts of core histones in livers cells, which may be a cellular response to C binding away the histone proteins. Infection with DENV additionally alters levels of H2A phosphorylation in a time-dependent manner. The interactions of C and histones add an interesting new role for the presence of C in the nucleus during DENV infection. PMID:21909430

  14. Transient Bluetongue virus serotype 8 capsid protein expression in Nicotiana benthamiana

    Directory of Open Access Journals (Sweden)

    Albertha R. van Zyl

    2016-03-01

    Full Text Available Bluetongue virus (BTV causes severe disease in domestic and wild ruminants, and has recently caused several outbreaks in Europe. Current vaccines include live-attenuated and inactivated viruses; while these are effective, there is risk of reversion to virulence by mutation or reassortment with wild type viruses. Subunit or virus-like particle (VLP vaccines are safer options: VLP vaccines produced in insect cells by expression of the four BTV capsid proteins are protective against challenge; however, this is a costly production method. We investigated production of BTV VLPs in plants via Agrobacterium-mediated transient expression, an inexpensive production system very well suited to developing country use. Leaves infiltrated with recombinant pEAQ-HT vectors separately encoding the four BTV-8 capsid proteins produced more proteins than recombinant pTRA vectors. Plant expression using the pEAQ-HT vector resulted in both BTV-8 core-like particles (CLPs and VLPs; differentially controlling the concentration of infiltrated bacteria significantly influenced yield of the VLPs. In situ localisation of assembled particles was investigated by using transmission electron microscopy (TEM and it was shown that a mixed population of core-like particles (CLPs, consisting of VP3 and VP7 and VLPs were present as paracrystalline arrays in the cytoplasm of plant cells co-expressing all four capsid proteins.

  15. Phage-displayed peptides that mimic epitopes of hepatitis E virus capsid.

    Science.gov (United States)

    Larralde, Osmany; Petrik, Juraj

    2017-08-01

    Hepatitis E is an emerging zoonotic infection of increasing public health threat for the UK, especially for immunosuppressed individuals. A human recombinant vaccine has been licensed only in China and is not clear whether it protects against hepatitis E virus (HEV) genotype 3, the most prevalent in Europe. The aim of this study was to use phage display technology as a tool to identify peptides that mimic epitopes of HEV capsid (mimotopes). We identified putative linear and conformational mimotopes using sera from Scottish blood donors that have the immunological imprint of past HEV infection. Four mimotopes did not have homology with the primary sequence of HEV ORF2 capsid but competed effectively with a commercial HEV antigen for binding to anti-HEV reference serum. When the reactivity profile of each mimotope was compared with Wantai HEV-IgG ELISA, the most sensitive HEV immunoassay, mimotopes showed 95.2-100% sensitivity while the specificity ranged from 81.5 to 95.8%. PepSurf algorithm was used to map affinity-selected peptides onto the ORF2 crystal structure of HEV genotype 3, which predicted that these four mimototopes are clustered in the P domain of ORF2 capsid, near conformational epitopes of anti-HEV neutralising monoclonal antibodies. These HEV mimotopes may have potential applications in the design of structural vaccines and the development of new diagnostic tests.

  16. The Feline Calicivirus Leader of the Capsid Protein Is Associated with Cytopathic Effect

    Science.gov (United States)

    Abente, Eugenio J.; Sosnovtsev, Stanislav V.; Sandoval-Jaime, Carlos; Parra, Gabriel I.; Bok, Karin

    2013-01-01

    Open reading frame 2 (ORF2) of the feline calicivirus (FCV) genome encodes a capsid precursor that is posttranslationally processed to release the mature capsid protein (VP1) and a small protein of 124 amino acids, designated the leader of the capsid (LC). To investigate the role of the LC protein in the virus life cycle, mutations and deletions were introduced into the LC coding region of an infectious FCV cDNA clone. Three cysteine residues that are conserved among all vesivirus LC sequences were found to be critical for the recovery of FCV with a characteristic cytopathic effect in feline kidney cells. A cell-rounding phenotype associated with the transient expression of wild-type and mutagenized forms of the LC correlated with the cytopathic and growth properties of the corresponding engineered viruses. The host cellular protein annexin A2 was identified as a binding partner of the LC protein, consistent with a role for the LC in mediating host cell interactions that alter the integrity of the cell and enable virus spread. PMID:23269802

  17. Addition of exogenous polypeptides on the mammalian reovirus outer capsid using reverse genetics.

    Science.gov (United States)

    Brochu-Lafontaine, Virginie; Lemay, Guy

    2012-02-01

    Addition of exogenous peptide sequences on viral capsids is a powerful approach to study the process of viral infection or to retarget viruses toward defined cell types. Until recently, it was not possible to manipulate the genome of mammalian reovirus and this was an obstacle to the addition of exogenous sequence tags onto the capsid of a replicating virus. This obstacle has now been overcome by the availability of the plasmid-based reverse genetics system. In the present study, reverse genetics was used to introduce different exogenous peptides, up to 40 amino acids long, at the carboxyl-terminal end of the σ1 outer capsid protein. The tagged viruses obtained were infectious, produce plaques of similar size, and could be easily propagated at high titers. However, attempts to introduce a 750 nucleotides-long sequence failed, even when it was added after the stop codon, suggesting a possible size limitation at the nucleic acid level. Copyright © 2011 Elsevier B.V. All rights reserved.

  18. Motion of an antiviral compound in a rhinovirus capsid under rotational symmetry boundary conditions.

    Science.gov (United States)

    Yoneda, Shigetaka; Yoneda, Teruyo; Kurihara, Youji; Umeyama, Hideaki

    2002-08-01

    A molecular dynamics (MD) simulation of a complex of a rhinovirus protein shell referred to as a "capsid" and an anti-rhinovirus drug, WIN52084s, was performed under the rotational symmetry boundary conditions. For the simulation, the energy parameters of WIN52084s in all-atom approximations were determined by ab initio calculations using a 6-31G* basis set and the two-conformational two-stage restricted electrostatic potential fit method. The motion of WIN52084s and the capsid was focused on in the analysis of the trajectory of the simulation. The root mean square deviations of WIN52084s from the X-ray structure were decomposed to conformational, translational, and rotational components. The translation was further decomposed to radial, longitudinal, and lateral components. The conformation of WIN52084s was rigid, but moving in the pocket. The easiest path of motion for WlN52084s was on the longitudinal line, providing a track for the binding process required of the anti-rhinovirus drug to enter the pocket. The conformation of the pocket was also preserved in the simulation, although the position of the pocket in the capsid fluctuated in the lateral and radial directions.

  19. Enhancing the clinical potential of AAV vectors by capsid engineering to evade pre-existing immunity

    Directory of Open Access Journals (Sweden)

    Melissa eBartel

    2011-10-01

    Full Text Available Vectors based on adeno-associated viruses have shown considerable promise in both preclinical models and increasingly in clinical trials. However, one formidable challenge is pre-existing immunity due to widespread exposure to numerous AAV variants and serotypes within the human population, which affect efficacy of clinical trials due to the accompanying high levels of anti-capsid neutralizing antibodies. Transient immunosuppression has promise in mitigating cellular and humoral responses induced by vector application in naïve hosts, but cannot overcome the problem that pre-existing neutralizing antibodies pose towards the goal of safe and efficient gene delivery. Shielding of AAV from antibodies, however, may be possible by covalent attachment of polymers to the viral capsid or by encapsulation of vectors inside biomaterials. In addition, there has been considerable progress in using rational mutagenesis, combinatorial libraries, and directed evolution approaches to engineer capsid variants that are not recognized by anti-AAV antibodies generally present in the human population. While additional progress must be made, such strategies, alone or in combination with immunosuppression to avoid de novo induction of antibodies, have strong potential to significantly enhance the clinical efficacy of AAV vectors.

  20. Hierarchical Assembly of Plasmonic Nanostructures using Virus Capsid Scaffolds on DNA Origami Tiles

    Energy Technology Data Exchange (ETDEWEB)

    Wang, Debin; Capehart, Stacy L.; Pal, Suchetan; Liu, Minghui; Zhang, Lei; Schuck, P. J.; Liu, Yan; Yan, Hao; Francis, Matthew B.; De Yoreo, James J.

    2014-07-07

    Plasmonic nanoarchitectures using biological scaffolds have shown the potential to attain controllable plasmonic fluorescence via precise spatial arrangement of fluorophores and plasmonic antennae. However, previous studies report a predominance of fluorescence quenching for small metal nanoparticles (less than ~60 nm) due to their small scattering cross-sections. In this work, we report the design and performance of fluorescent plasmonic structures composed of fluorophore-modified virus capsids and gold nanoparticles (AuNPs) assembled on DNA origami tiles. The virus capsid creates a scaffold for control over the three dimensional arrangement of the fluorophores, whereas the DNA origami tile provides precise control over the distance between the capsid and the AuNP. Using finite-difference time-domain (FDTD) numerical simulations and multimodal single-particle imaging measurements, we show that the judicial design of these structures places the dye molecules near the hot spot of the AuNP. This effectively increases the fluorescence intensity in the quenching regime of the AuNP, with an enhancement factor that increases with increasing AuNP size. This strategy of using biological scaffolds to control fluorescence paves the way for exploring the parameters that determine plasmonic fluorescence. It may lead to a better understanding of the antenna effects of photon absorption and emission, enabling the construction of multicomponent plasmonic systems.

  1. Modeling of the human rhinovirus C capsid suggests possible causes for antiviral drug resistance.

    Science.gov (United States)

    Basta, Holly A; Ashraf, Shamaila; Sgro, Jean-Yves; Bochkov, Yury A; Gern, James E; Palmenberg, Ann C

    2014-01-05

    Human rhinoviruses of the RV-C species are recently discovered pathogens with greater clinical significance than isolates in the RV-A+B species. The RV-C cannot be propagated in typical culture systems; so much of the virology is necessarily derivative, relying on comparative genomics, relative to the better studied RV-A+B. We developed a bioinformatics-based structural model for a C15 isolate. The model showed the VP1-3 capsid proteins retain their fundamental cores relative to the RV-A+B, but conserved, internal RV-C residues affect the shape and charge of the VP1 hydrophobic pocket that confers antiviral drug susceptibility. When predictions of the model were tested in organ cultures or ALI systems with recombinant C15 virus, there was a resistance to capsid-binding drugs, including pleconaril, BTA-188, WIN56291, WIN52035 and WIN52084. Unique to all RV-C, the model predicts conserved amino acids within the pocket and capsid surface pore leading to the pocket may correlate with this activity.

  2. Dengue virus capsid protein binds core histones and inhibits nucleosome formation in human liver cells.

    Directory of Open Access Journals (Sweden)

    Tonya M Colpitts

    Full Text Available Dengue virus (DENV is a member of the Flaviviridae and a globally (reemerging pathogen that causes serious human disease. There is no specific antiviral or vaccine for dengue virus infection. Flavivirus capsid (C is a structural protein responsible for gathering the viral RNA into a nucleocapsid that forms the core of a mature virus particle. Flaviviral replication is known to occur in the cytoplasm yet a large portion of capsid protein localizes to the nucleus during infection. The reasons for the nuclear presences of capsid are not completely understood. Here, we expressed mature DENV C in a tandem affinity purification assay to identify potential binding partners in human liver cells. DENV C targeted the four core histones, H2A, H2B, H3 and H4. DENV C bound recombinant histones in solution and colocalized with histones in the nucleus and cytoplasm of liver cells during DENV infection. We show that DENV C acts as a histone mimic, forming heterodimers with core histones, binding DNA and disrupting nucleosome formation. We also demonstrate that DENV infection increases the amounts of core histones in livers cells, which may be a cellular response to C binding away the histone proteins. Infection with DENV additionally alters levels of H2A phosphorylation in a time-dependent manner. The interactions of C and histones add an interesting new role for the presence of C in the nucleus during DENV infection.

  3. Solid-to-fluid DNA transition inside HSV-1 capsid close to the temperature of infection

    Energy Technology Data Exchange (ETDEWEB)

    Sae-Ueng, Udom; Li, Dong; Zuo, Xiaobing; Huffman, Jamie B.; Homa, Fred L.; Rau, Donald; Evilevitch, Alex

    2014-10-01

    DNA in the human Herpes simplex virus type 1 (HSV-1) capsid is packaged to a tight density. This leads to tens of atmospheres of internal pressure responsible for the delivery of the herpes genome into the cell nucleus. In this study we show that, despite its liquid crystalline state inside the capsid, the DNA is fluid-like, which facilitates its ejection into the cell nucleus during infection. We found that the sliding friction between closely packaged DNA strands, caused by interstrand repulsive interactions, is reduced by the ionic environment of epithelial cells and neurons susceptible to herpes infection. However, variations in the ionic conditions corresponding to neuronal activity can restrict DNA mobility in the capsid, making it more solid-like. This can inhibit intranuclear DNA release and interfere with viral replication. In addition, the temperature of the human host (37 °C) induces a disordering transition of the encapsidated herpes genome, which reduces interstrand interactions and provides genome mobility required for infection.

  4. Mañana remisión de V. crepúsculo de la mañana.

    OpenAIRE

    2011-01-01

    [ES] Definición del término Mañana remisión de V. crepúsculo de la mañana. en el diccionario Dicter. [EN] Definition of the word Mañana remisión de V. crepúsculo de la mañana. in the dictionary Dicter.

  5. MaJAZ1 Attenuates the MaLBD5-Mediated Transcriptional Activation of Jasmonate Biosynthesis Gene MaAOC2 in Regulating Cold Tolerance of Banana Fruit.

    Science.gov (United States)

    Ba, Liang-jie; Kuang, Jian-fei; Chen, Jian-ye; Lu, Wang-jin

    2016-02-01

    Previous studies indicated that methyl jasmonate (MeJA) treatment could effectively reduce the chilling injury of many fruits, including banana, but the underlying mechanism is poorly understood. In this study, one lateral organ boundaries (LOB) domain (LBD) gene, designated as MaLBD5, was isolated and characterized from banana fruit. Expression analysis revealed that accumulation of MaLBD5 was induced by cold temperature and MeJA treatment. Subcellular localization and transactivation assays showed that MaLBD5 was localized to the nucleus and possessed transcriptional activation activity. Protein-protein interaction analysis demonstrated that MaLBD5 physically interacted with MaJAZ1, a potential repressor of jasmonate signaling. Furthermore, transient expression assays indicated that MaLBD5 transactivated a jasmonate biosynthesis gene, termed MaAOC2, which was also induced by cold and MeJA. More interestingly, MaJAZ1 attenuated the MaLBD5-mediated transactivation of MaAOC2. These results suggest that MaLBD5 and MaJAZ1 might act antagonistically in relation to MeJA-induced cold tolerance of banana fruit, at least partially via affecting jasmonate biosynthesis. Collectively, our findings expand the knowledge of the transcriptional regulatory network of MeJA-mediated cold tolerance of banana fruit.

  6. Mass and Reliability System (MaRS)

    Science.gov (United States)

    Barnes, Sarah

    2016-01-01

    The Safety and Mission Assurance (S&MA) Directorate is responsible for mitigating risk, providing system safety, and lowering risk for space programs from ground to space. The S&MA is divided into 4 divisions: The Space Exploration Division (NC), the International Space Station Division (NE), the Safety & Test Operations Division (NS), and the Quality and Flight Equipment Division (NT). The interns, myself and Arun Aruljothi, will be working with the Risk & Reliability Analysis Branch under the NC Division's. The mission of this division is to identify, characterize, diminish, and communicate risk by implementing an efficient and effective assurance model. The team utilizes Reliability and Maintainability (R&M) and Probabilistic Risk Assessment (PRA) to ensure decisions concerning risks are informed, vehicles are safe and reliable, and program/project requirements are realistic and realized. This project pertains to the Orion mission, so it is geared toward a long duration Human Space Flight Program(s). For space missions, payload is a critical concept; balancing what hardware can be replaced by components verse by Orbital Replacement Units (ORU) or subassemblies is key. For this effort a database was created that combines mass and reliability data, called Mass and Reliability System or MaRS. The U.S. International Space Station (ISS) components are used as reference parts in the MaRS database. Using ISS components as a platform is beneficial because of the historical context and the environment similarities to a space flight mission. MaRS uses a combination of systems: International Space Station PART for failure data, Vehicle Master Database (VMDB) for ORU & components, Maintenance & Analysis Data Set (MADS) for operation hours and other pertinent data, & Hardware History Retrieval System (HHRS) for unit weights. MaRS is populated using a Visual Basic Application. Once populated, the excel spreadsheet is comprised of information on ISS components including

  7. pH shift assembly of adenoviral serotype 5 capsid protein nanosystems for enhanced delivery of nanoparticles, proteins and nucleic acids.

    Science.gov (United States)

    Rao, Vidhya R; Upadhyay, Arun K; Kompella, Uday B

    2013-11-28

    Empty adenovirus serotype 5 (Ad5) capsids devoid of viral genome were developed as a novel delivery system for nanoparticles, proteins, and nucleic acids. Ad5 capsids of 110 nm diameter undergo an increase in particle size to 1637 nm in 1mM acetic acid at pH4.0 and then shrink to 60 nm, following pH reversal to 7.4. These pH shifts induced reversible changes in capsid zeta potential and secondary structure and irreversible changes in tertiary structure of capsid proteins. Using pH shift dependent changes in capsid size and structure, 20 nm fluorescent nanoparticles, FITC-BSA, and Alexa Fluor® 488 conjugated siRNA were encapsulated with high efficiency in Ad5 capsids, as confirmed by electron microscopy and/or flow cytometry. HEK cell uptake with capsid delivery system was 7.8-, 7.4-, and 2.9-fold greater for nanoparticles, FITC-BSA, and Alexa-siRNA, respectively, when compared to plain solutes. Physical mixtures of capsids and fluorescent solutes exhibited less capsid associated fluorescence intensity and cell uptake. Further, unlike physical mixture, pH shift assembled Ad5 capsids protected siRNA from RNase degradation. Ad5 capsids before and after pH shift exhibited endolysosomal escape. Thus, empty Ad5 capsids can encapsulate a variety of solutes based on pH shift assembly, resulting in enhanced cellular delivery. © 2013. Published by Elsevier B.V. All rights reserved.

  8. Mutational Analysis of the Adeno-Associated Virus Type 2 (AAV2) Capsid Gene and Construction of AAV2 Vectors with Altered Tropism

    OpenAIRE

    Wu, Pei; Xiao, Wu; Conlon, Thomas; Hughes, Jeffrey; Agbandje-McKenna, Mavis; FERKOL, THOMAS; Flotte, Terence; Muzyczka, Nicholas

    2000-01-01

    Adeno-associated virus type 2 (AAV2) has proven to be a valuable vector for gene therapy. Characterization of the functional domains of the AAV capsid proteins can facilitate our understanding of viral tissue tropism, immunoreactivity, viral entry, and DNA packaging, all of which are important issues for generating improved vectors. To obtain a comprehensive genetic map of the AAV capsid gene, we have constructed 93 mutants at 59 different positions in the AAV capsid gene by site-directed mut...

  9. Cinéma en France

    Directory of Open Access Journals (Sweden)

    Michel VIGOUROUX

    1992-06-01

    Full Text Available Le cinéma est l’objet de bases de données exhaustives sur les équipements et les fréquentations. Les données sur les salles permettent d’identifier le phénomène de concentration de propriété et d’exploitation. La perspective dynamique peut être observée sur 45 ans. À l’échelle régionale, on peut apprécier le dynamisme du cinéma en haute montagne alpine et la différence de réseaux sur le territoire (France de l’Ouest.

  10. Sobre Juan Bautista Maíno

    Directory of Open Access Journals (Sweden)

    Pérez Sánchez, Alfonso E.

    1997-06-01

    Full Text Available This article published new documents about the activity of the Domenican painter Juan Bautista Maíno specially concerning his concept of the practice of Painting in relation to the other arts. Works hitherto unknown are published here for the first time. Also illustrated are portraits of the Conde de Añover de Tajo and his wife, whose collections were, in addition given valuation by the artista.No disponible

  11. Sobre Juan Bautista Maíno

    OpenAIRE

    Pérez Sánchez, Alfonso E.

    1997-01-01

    This article published new documents about the activity of the Domenican painter Juan Bautista Maíno specially concerning his concept of the practice of Painting in relation to the other arts. Works hitherto unknown are published here for the first time. Also illustrated are portraits of the Conde de Añover de Tajo and his wife, whose collections were, in addition given valuation by the artista.No disponible

  12. Vaccines against stimulants: cocaine and MA

    Science.gov (United States)

    Kosten, Thomas; Domingo, Coreen; Orson, Frank; Kinsey, Berma

    2014-01-01

    While the worldwide prevalence of cocaine use remains significant, medications, or small molecule approaches, to treat drug addictions have met with limited success. Anti-addiction vaccines, on the other hand, have demonstrated great potential for treating drug abuse using a distinctly different mechanism of eliciting an antibody response that blocks the pharmacological effects of drugs. We provide a review of vaccine-based approaches to treating stimulant addictions; specifically and cocaine addictions. This selective review article focuses on the one cocaine vaccine that has been into clinical trials and presents new data related to pre-clinical development of a methamphetamine (MA) vaccine. We also review the mechanism of action for vaccine induced antibodies to abused drugs, which involves kinetic slowing of brain entry as well as simple blocking properties. We present pre-clinical innovations for MA vaccines including hapten design, linkage to carrier proteins and new adjuvants beyond alum. We provide some new information on hapten structures and linkers and variations in protein carriers. We consider a carrier, outer membrance polysaccharide coat protein (OMPC), that provides some self-adjuvant through lipopolysaccharide components and provide new results with a monophosopholipid adjuvant for the more standard carrier proteins with cocaine and MA. The review then covers the clinical trials with the cocaine vaccine TA-CD. The clinical prospects for advances in this field over the next few years include a multi-site cocaine vaccine clinical trial to be reported in 2013 and phase 1 clinical trials of a MA vaccine in 2014. PMID:23509915

  13. Study on anticorrosive property and synthesis of AA/MA/AMPS copolymer scale inhibitor%AA/MA/AMPS共聚物阻垢剂的合成及缓蚀性研究

    Institute of Scientific and Technical Information of China (English)

    袁鹰; 刘明源

    2013-01-01

    Using water as solvent, sodium hypophosphite and peroxide as initiator, iron salts as catalyst, maleic anhydride ( MA ) , acrylic acid ( AA) and 2-acryloyl amino-2 -methyl propane sulfonic acid (AMPS) as monomers, through aqueous solution polymerization method, the synthesis of AA-MA-AMPS three copolymer resistance scale dispersant, and its performance were studied. Results showed that with concentration of 2.5~20 mg/L AA/MA/AMPS copolymer scale inhibitor and HEDP,HPMA agent on the deposition of CaCO3 maximal inhibition ability is respectively 96% ,77. 8% and 88. 4% , AA/MA/ AMPS copolymer scale inhibitor has good scale inhibition performance.%以水为溶剂,次亚磷酸钠-过氧化物(过氧化氢、过硫酸钠、过硫酸铵)为引发剂,铁盐为催化剂,马来酸酐(MA)、丙烯酸(AA)和2-丙烯酰氨基-2-甲基丙磺酸(AMPS)为单体,通过水溶液聚合方法,合成AA-MA-AMPS三元共聚物阻垢分散剂,并对其缓蚀性进行研究.结果表明,在质量浓度为2.5~ 20 mg/L的AA/MA/AMPS共聚物阻垢剂、HEDP、HPMA时,对CaCO3沉积的最大抑制能力分别为96%,77.8%,88.4%,AA/MA/AMPS共聚物阻垢剂具有良好的阻垢性能.

  14. Microcap M&A: An Exploratory Study

    Directory of Open Access Journals (Sweden)

    Keith Turpie

    2014-06-01

    Full Text Available A substantial body of accounting and finance literature has been devoted to the study of Mergers and Acquisitions (M&As dominated by discussions relating to the gains and losses that accrue from transactions involving large public companies. This paper makes a unique contribution to the literature by investigating the M&A experience of microcap businesses. Transactions involving microcap M&A are substantially different to those involving large companies on a number of dimensions. This paper explores the determinants of microcap M&A success and pitfalls and problems from an integration perspective. Due to the paucity of research in the area an exploratory research design is employed, conducting interviews with five CEOs of companies that had each managed multiple transactions. We find microcap M&As are successful when measured against identified goals but generally take longer and cost more than expected. Further, culture and communication are key issues in determining success/failure. We also find the in-house management of integration aspects is problematic for these businesses and suggest this warrants further study.

  15. Cell-Free Hepatitis B Virus Capsid Assembly Dependent on the Core Protein C-Terminal Domain and Regulated by Phosphorylation

    Science.gov (United States)

    Ludgate, Laurie; Liu, Kuancheng; Luckenbaugh, Laurie; Streck, Nicholas; Eng, Stacey; Voitenleitner, Christian; Delaney, William E.

    2016-01-01

    ABSTRACT Multiple subunits of the hepatitis B virus (HBV) core protein (HBc) assemble into an icosahedral capsid that packages the viral pregenomic RNA (pgRNA). The N-terminal domain (NTD) of HBc is sufficient for capsid assembly, in the absence of pgRNA or any other viral or host factors, under conditions of high HBc and/or salt concentrations. The C-terminal domain (CTD) is deemed dispensable for capsid assembly although it is essential for pgRNA packaging. We report here that HBc expressed in a mammalian cell lysate, rabbit reticulocyte lysate (RRL), was able to assemble into capsids when (low-nanomolar) HBc concentrations mimicked those achieved under conditions of viral replication in vivo and were far below those used previously for capsid assembly in vitro. Furthermore, at physiologically low HBc concentrations in RRL, the NTD was insufficient for capsid assembly and the CTD was also required. The CTD likely facilitated assembly under these conditions via RNA binding and protein-protein interactions. Moreover, the CTD underwent phosphorylation and dephosphorylation events in RRL similar to those seen in vivo which regulated capsid assembly. Importantly, the NTD alone also failed to accumulate in mammalian cells, likely resulting from its failure to assemble efficiently. Coexpression of the full-length HBc rescued NTD assembly in RRL as well as NTD expression and assembly in mammalian cells, resulting in the formation of mosaic capsids containing both full-length HBc and the NTD. These results have important implications for HBV assembly during replication and provide a facile cell-free system to study capsid assembly under physiologically relevant conditions, including its modulation by host factors. IMPORTANCE Hepatitis B virus (HBV) is an important global human pathogen and the main cause of liver cancer worldwide. An essential component of HBV is the spherical capsid composed of multiple copies of a single protein, the core protein (HBc). We have

  16. Capsid protein expression and adeno-associated virus like particles assembly in Saccharomyces cerevisiae

    Directory of Open Access Journals (Sweden)

    Backovic Ana

    2012-09-01

    Full Text Available Abstract Background The budding yeast Saccharomyces cerevisiae supports replication of many different RNA or DNA viruses (e.g. Tombusviruses or Papillomaviruses and has provided means for up-scalable, cost- and time-effective production of various virus-like particles (e.g. Human Parvovirus B19 or Rotavirus. We have recently demonstrated that S. cerevisiae can form single stranded DNA AAV2 genomes starting from a circular plasmid. In this work, we have investigated the possibility to assemble AAV capsids in yeast. Results To do this, at least two out of three AAV structural proteins, VP1 and VP3, have to be simultaneously expressed in yeast cells and their intracellular stoichiometry has to resemble the one found in the particles derived from mammalian or insect cells. This was achieved by stable co-transformation of yeast cells with two plasmids, one expressing VP3 from its natural p40 promoter and the other one primarily expressing VP1 from a modified AAV2 Cap gene under the control of the inducible yeast promoter Gal1. Among various induction strategies we tested, the best one to yield the appropriate VP1:VP3 ratio was 4.5 hour induction in the medium containing 0.5% glucose and 5% galactose. Following such induction, AAV virus like particles (VLPs were isolated from yeast by two step ultracentrifugation procedure. The transmission electron microscopy analysis revealed that their morphology is similar to the empty capsids produced in human cells. Conclusions Taken together, the results show for the first time that yeast can be used to assemble AAV capsid and, therefore, as a genetic system to identify novel cellular factors involved in AAV biology.

  17. Exacerbated Leishmaniasis Caused by a Viral Endosymbiont can be Prevented by Immunization with Its Viral Capsid

    Science.gov (United States)

    Castiglioni, Patrik; Hartley, Mary-Anne; Rossi, Matteo; Prevel, Florence; Desponds, Chantal; Utzschneider, Daniel T.; Eren, Remzi-Onur; Zangger, Haroun; Brunner, Livia; Collin, Nicolas; Zehn, Dietmar; Kuhlmann, F. Matthew; Beverley, Stephen M.; Ronet, Catherine

    2017-01-01

    Recent studies have shown that a cytoplasmic virus called Leishmaniavirus (LRV) is present in some Leishmania species and acts as a potent innate immunogen, aggravating lesional inflammation and development in mice. In humans, the presence of LRV in Leishmania guyanensis and in L. braziliensis was significantly correlated with poor treatment response and symptomatic relapse. So far, no clinical effort has used LRV for prophylactic purposes. In this context, we designed an original vaccine strategy that targeted LRV nested in Leishmania parasites to prevent virus-related complications. To this end, C57BL/6 mice were immunized with a recombinant LRV1 Leishmania guyanensis viral capsid polypeptide formulated with a T helper 1-polarizing adjuvant. LRV1-vaccinated mice had significant reduction in lesion size and parasite load when subsequently challenged with LRV1+ Leishmania guyanensis parasites. The protection conferred by this immunization could be reproduced in naïve mice via T-cell transfer from vaccinated mice but not by serum transfer. The induction of LRV1 specific T cells secreting IFN-γ was confirmed in vaccinated mice and provided strong evidence that LRV1-specific protection arose via a cell mediated immune response against the LRV1 capsid. Our studies suggest that immunization with LRV1 capsid could be of a preventive benefit in mitigating the elevated pathology associated with LRV1 bearing Leishmania infections and possibly avoiding symptomatic relapses after an initial treatment. This novel anti-endosymbiotic vaccine strategy could be exploited to control other infectious diseases, as similar viral infections are largely prevalent across pathogenic pathogens and could consequently open new vaccine opportunities. PMID:28099431

  18. Capsid structure and dynamics of a human rhinovirus probed by hydrogen exchange mass spectrometry.

    Science.gov (United States)

    Wang, Lintao; Smith, David L

    2005-06-01

    Viral capsids are dynamic protein assemblies surrounding viral genomes. Despite the high-resolution structures determined by X-ray crystallography and cryo-electron microscopy, their in-solution structure and dynamics can be probed by hydrogen exchange. We report here using hydrogen exchange combined with protein enzymatic fragmentation and mass spectrometry to determine the capsid structure and dynamics of a human rhinovirus, HRV14. Capsid proteins (VP1-4) were labeled with deuterium by incubating intact virus in D(2)O buffer at neutral pH. The labeled proteins were digested by immobilized pepsin to give peptides analyzed by capillary reverse-phase HPLC coupled with nano-electrospray mass spectrometry. Deuterium levels incorporated at amide linkages in peptic fragments were measured for different exchange times from 12 sec to 30 h to assess the amide hydrogen exchange rates along each of the four protein backbones. Exchange results generally agree with the crystal structure of VP1-4,with extended, flexible terminal and surface-loop regions in fast exchange and folded helical and sheet structures in slow exchange. In addition, three alpha-helices, one from each of VP1-3, exhibited very slow exchange, indicating high stability of the protomeric interface. The beta-strands at VP3 N terminus also had very slow exchange, suggesting stable pentamer contacts. It was noted, however, that the interface around the fivefold axis had fast and intermediate exchange, indicating relatively more flexibility. Even faster exchange rates were found in the N terminus of VP1 and most segments of VP4, suggesting high flexibilities, which may correspond to their potential roles in virus uncoating.

  19. Exploring MaNGA's kinematic maps

    Science.gov (United States)

    Weijmans, Anne-Marie; MaNGA Team

    2016-01-01

    Different galaxy formation processes leave different imprints on the gas and stellar kinematic patterns for a galaxy. With MaNGA, we now have after one year of observations an unprecedented sample of 1400 nearby galaxies for which we can study gas and stellar kinematics in much detail, based on integral-field spectroscopy. We are measuring kinematic quantities such as LambdaR (angular momentum) and their (possible) correlations with other galaxy properties such as mass, morphology and environment. By quantifying the kinematic (sub)structures in velocity and dispersion maps, we will construct a kinematic galaxy classification that can be linked to their formation processes.

  20. B- and T-cell epitope mapping of human sapovirus capsid protein: an immunomics approach.

    Science.gov (United States)

    Amin, M Ruhul; Siddiqui, Mohammad S; Ahmed, Dilruba; Ahmed, Firoz; Hossain, Anowar

    2011-01-01

    Human sapovirus is one of the major causes of viral gastroenteritis. Although the capsid protein (VP1) confers antigenic cross-reactivity, immunity against sapovirus is still unclear. Using immunoinformatics approach, we defined putative T- and B-cell epitopes of VP1 and mapped on to its predicted three-dimensional structure. Identified five putative T-cell epitopes also occupied the putative B-cell epitope region. These putative epitopes were conserved in all existing serotypes. Predicted epitopes can be generated through proteasome cleavage and may be useful in designing peptide-based subunit vaccine to confer both humoral and cell-mediated immunity.

  1. Optimization of Substitution Matrix for Sequence Alignment of Major Capsid Proteins of Human Herpes Simplex Virus

    Directory of Open Access Journals (Sweden)

    Vipan Kumar Sohpal

    2011-12-01

    Full Text Available Protein sequence alignment has become an informative tool in modern molecular biology research. A number of substitution matrices have been readily available for sequence alignments, but it is challenging task to compute optimal matrices for alignment accuracy. Here, we used the parameter optimization procedure to select the optimal Q of substitution matrices for major viral capsid protein of human herpes simplex virus. Results predict that Blosum matrix is most accurate on alignment benchmarks, and Blosum 60 provides the optimal Q in all substitution matrices. PAM 200 matrices results slightly below than Blosum 60, while VTML matrices are intermediate of PAM and VT matrices under dynamic programming.

  2. 76 FR 58105 - Regulated Navigation Area; Saugus River, Lynn, MA

    Science.gov (United States)

    2011-09-20

    ... SECURITY Coast Guard 33 CFR Part 165 RIN 1625-AA11 Regulated Navigation Area; Saugus River, Lynn, MA AGENCY... River in Lynn, MA. Establishing this temporary rule will allow the necessary stabilization work to be... on the Energy Systems Pipeline Bridge on the Saugus River in Lynn, MA. The regulated area...

  3. Foot-and-mouth disease virus capsid proteins; analysis of protein processing, assembly and utility as vaccines

    DEFF Research Database (Denmark)

    Belsham, Graham

    precursor enhances the yield of processed capsid proteins and their assembly into empty capsid particles within mammalian cells. Such particles can potentially form the basis of a vaccine but they may only have the same properties as the current inactivated vaccines. We have expressed the FMDV P1-2A alone...... or with FMDV 3Cpro using a “single cycle” alphavirus vector based on Semliki Forest virus (SFV). Cattle vaccinated with these rSFV-FMDV vectors alone, produced anti-FMDV antibodies but the immune response was insufficient to give protection against FMDV challenge. However, vaccination with these vectors primed...... a much stronger immune response against FMDV post-challenge. In subsequent experiments, cattle were sequentially vaccinated with a rSFV-FMDV followed by recombinant FMDV empty capsid particles, or vice versa, prior to challenge. Animals given a primary vaccination with the rSFV-FMDV vector...

  4. In vivo functions of CPSF6 for HIV-1 as revealed by HIV-1 capsid evolution in HLA-B27-positive subjects.

    Directory of Open Access Journals (Sweden)

    Matthew S Henning

    2014-01-01

    Full Text Available The host protein CPSF6 possesses a domain that can interact with the HIV-1 capsid (CA protein. CPSF6 has been implicated in regulating HIV-1 nuclear entry. However, its functional significance for HIV-1 replication has yet to be firmly established. Here we provide evidence for two divergent functions of CPSF6 for HIV-1 replication in vivo. We demonstrate that endogenous CPSF6 exerts an inhibitory effect on naturally occurring HIV-1 variants in individuals carrying the HLA-B27 allele. Conversely, we find a strong selective pressure in these individuals to preserve CPSF6 binding, while escaping from the restrictive activity by CPSF6. This active maintenance of CPSF6 binding during HIV-1 CA evolution in vivo contrasts with the in vitro viral evolution, which can reduce CPSF6 binding to evade from CPSF6-mediated restriction. Thus, these observations argue for a beneficial role of CPSF6 for HIV-1 in vivo. CPSF6-mediated restriction renders HIV-1 less dependent or independent from TNPO3, RanBP2 and Nup153, host factors implicated in HIV-1 nuclear entry. However, viral evolution that maintains CPSF6 binding in HLA-B27+ subjects invariably restores the ability to utilize these host factors, which may be the major selective pressure for CPSF6 binding in vivo. Our study uncovers two opposing CA-dependent functions of CPSF6 in HIV-1 replication in vivo; however, the benefit for binding CPSF6 appears to outweigh the cost, providing support for a vital function of CPSF6 during HIV-1 replication in vivo.

  5. Sizing up large protein complexes by electrospray ionisation-based electrophoretic mobility and native mass spectrometry : morphology selective binding of Fabs to hepatitis B virus capsids

    NARCIS (Netherlands)

    Bereszczak, Jessica Z; Havlik, Marlene; Weiss, Victor U; Marchetti-Deschmann, Martina; van Duijn, Esther; Watts, Norman R; Wingfield, Paul T; Allmaier, Guenter; Steven, Alasdair C; Heck, Albert J R

    2014-01-01

    The capsid of hepatitis B virus (HBV) is a major viral antigen and important diagnostic indicator. HBV capsids have prominent protrusions ('spikes') on their surface and are unique in having either T = 3 or T = 4 icosahedral symmetry. Mouse monoclonal and also human polyclonal antibodies bind either

  6. Understanding the Concentration Dependence of Viral Capsid Assembly Kinetics—the Origin of the Lag Time and Identifying the Critical Nucleus Size

    National Research Council Canada - National Science Library

    Hagan, Michael F; Elrad, Oren M

    2010-01-01

    ... )), but extracting mechanistic information such as the critical nucleus size or the time to assemble an individual capsid has been challenging. In this article, we theoretically examine two models for capsid assembly kinetics to show that these properties can be determined from the concentration dependence of median assembly times and the la...

  7. Ma Ying-jeou’s Presidential Discourse

    Directory of Open Access Journals (Sweden)

    Jonathan Sullivan

    2012-01-01

    Full Text Available Despite the substantial advances made in cross-Strait relations during Ma Ying-jeou’s (Ma Yingjiu first term, the ROC president’s rhetoric varied considerably as he grappled with the difficult reality of implementing campaign and inauguration pledges to establish better relations with China while striving to maintain national respect and sovereignty. In this article, we put forward a framework for measuring, analysing and explaining this variation in President Ma’s first-term discourse. Analysing a very large number of Ma’s speeches, addresses, etc., we provide empirical assessments of how the content of Ma’s public pronouncements has developed over time, how his rhetoric varies according to the strategic context and timing of a speech, and how his discourse compares to that of his predecessor, Chen Shui-bian (Chen Shuibian. In addressing these questions, the article contributes a quantitative perspective to existing work on political discourse in Taiwan and to the growing methodological and applied literature on how to systematically analyse Chinese political text.

  8. MaNGA: Target selection and Optimization

    Science.gov (United States)

    Wake, David

    2016-01-01

    The 6-year SDSS-IV MaNGA survey will measure spatially resolved spectroscopy for 10,000 nearby galaxies using the Sloan 2.5m telescope and the BOSS spectrographs with a new fiber arrangement consisting of 17 individually deployable IFUs. We present the simultaneous design of the target selection and IFU size distribution to optimally meet our targeting requirements. The requirements for the main samples were to use simple cuts in redshift and magnitude to produce an approximately flat number density of targets as a function of stellar mass, ranging from 1x109 to 1x1011 M⊙, and radial coverage to either 1.5 (Primary sample) or 2.5 (Secondary sample) effective radii, while maximizing S/N and spatial resolution. In addition we constructed a "Color-Enhanced" sample where we required 25% of the targets to have an approximately flat number density in the color and mass plane. We show how these requirements are met using simple absolute magnitude (and color) dependent redshift cuts applied to an extended version of the NASA Sloan Atlas (NSA), how this determines the distribution of IFU sizes and the resulting properties of the MaNGA sample.

  9. Roadmap to MaRIE March 2015

    Energy Technology Data Exchange (ETDEWEB)

    Barnes, Cris William [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2015-03-30

    Los Alamos National Laboratory’s proposed MaRIE facility is slated to introduce the world’s highest energy hard x-ray free electron laser (XFEL). As the light source for the Matter-Radiation Interactions in Extremes experimental facility (MaRIE), the 42-keV XFEL, with bursts of x-ray pulses at gigahertz repetition for studying fast dynamical processes, will help accelerate discovery and design of the advanced materials needed to meet 21st-century national security and energy security challenges. Yet the science of free-electron lasers has a long and distinguished history at Los Alamos National Laboratory (LANL), where for nearly four decades Los Alamos scientists have been performing research, design, development, and collaboration work in FEL science. The work at Los Alamos has evolved from low-gain amplifier and oscillator FEL development to highbrightness photoinjector development, and later, self-amplified spontaneous emission (SASE) and high-gain amplifier FEL development.

  10. Was there a super-eruption on the Gondwanan coast 477 Ma ago?

    Science.gov (United States)

    Gutiérrez-Alonso, G.; Gutiérrez-Marco, J. C.; Fernández-Suárez, J.; Bernárdez, E.; Corfu, F.

    2016-06-01

    Precise zircon and monazite ID-TIMS U-Pb dating of three Lower Ordovician altered ash-fall tuff beds (K-bentonites) in the Cantabrian Zone of NW Iberia yielded coeval ages together with an equivalent previously studied sample (477.5 ± 1 (Gutierrez-Alonso et al., 2007)), of 477 ± 1.3 Ma, 477.2 ± 1.1 Ma and 477.3 ± 1 Ma, with a pooled concordia age (all analyses in the four samples) of 477.2 ± 0.74 Ma. A conservative estimation of the volume and mass of the studied K-bentonite beds (using exclusively the CZ data) yields a volume for the preserved deposits of ca. 37.5 km3 (Volcanic Explosivity Index - VEI = 6, Colossal). When considering other putative equivalent beds in Iberia and neighboring realms (i.e. Armorica, Sardinia) the volume of ejecta associated to this event would make it reach the Supervolcanic-Apocalyptic status (VEI = 8, > 1000 km3). At variance with most known cases of this kind of gigantic eruption events, geological observations indicate that the studied magmatic event was related to continental margin extension and thinning and not to plate convergence. We speculate that a geochronologically equivalent large caldera event recognized in the geological record of NW Iberia could be ground zero of this super-eruption.

  11. Analogs of LDL Receptor Ligand Motifs in Dengue Envelope and Capsid Proteins as Potential Codes for Cell Entry

    OpenAIRE

    Juan Guevara; Jaime Romo; Troy McWhorter; Natalia Valentinova Guevara

    2015-01-01

    It is established that cell entry of low density lipoprotein particles (LLPs) containing Apo B100 and Apo E is mediated by receptors and GAGs. Receptor ligand motifs, XBBBXXBX, XBBXBX, and ΨBΨXB, and mono- and bipartite NLS sequences are abundant in Apo E and Apo B100 as well as in envelope and capsid proteins of Dengue viruses 1–4 (DENV1–4). Synthetic, fluorescence-labeled peptides of sequences in DENV2 envelope protein, and DENV3 capsid that include these motifs were used to conduct a quali...

  12. Structural Basis for the Development of Avian Virus Capsids That Display Influenza Virus Proteins and Induce Protective Immunity

    OpenAIRE

    Pascual, Elena; Mata, Carlos P.; Gómez-Blanco, Josué; Moreno, Noelia; Bárcena, Juan; Blanco, Esther; Rodríguez-Frandsen, Ariel; Nieto, Amelia; Carrascosa, José L.; Castón, José R.

    2014-01-01

    Bioengineering of viruses and virus-like particles (VLPs) is a well-established approach in the development of new and improved vaccines against viral and bacterial pathogens. We report here that the capsid of a major avian pathogen, infectious bursal disease virus (IBDV), can accommodate heterologous proteins to induce protective immunity. The structural units of the ∼70-nm-diameter T=13 IBDV capsid are trimers of VP2, which is made as a precursor (pVP2). The pVP2 C-terminal domain has an am...

  13. Genetically Thermo-Stabilised, Immunogenic Poliovirus Empty Capsids; a Strategy for Non-replicating Vaccines

    Science.gov (United States)

    Fox, Helen; Minor, Philip D.

    2017-01-01

    While wild type polio has been nearly eradicated there will be a need to continue immunisation programmes for some time because of the possibility of re-emergence and the existence of long term excreters of poliovirus. All vaccines in current use depend on growth of virus and most of the non-replicating (inactivated) vaccines involve wild type viruses known to cause poliomyelitis. The attenuated vaccine strains involved in the eradication programme have been used to develop new inactivated vaccines as production is thought safer. However it is known that the Sabin vaccine strains are genetically unstable and can revert to a virulent transmissible form. A possible solution to the need for virus growth would be to generate empty viral capsids by recombinant technology, but hitherto such particles are so unstable as to be unusable. We report here the genetic manipulation of the virus to generate stable empty capsids for all three serotypes. The particles are shown to be extremely stable and to generate high levels of protective antibodies in animal models. PMID:28103317

  14. RNase P Ribozymes Inhibit the Replication of Human Cytomegalovirus by Targeting Essential Viral Capsid Proteins.

    Science.gov (United States)

    Yang, Zhu; Reeves, Michael; Ye, Jun; Trang, Phong; Zhu, Li; Sheng, Jingxue; Wang, Yu; Zen, Ke; Wu, Jianguo; Liu, Fenyong

    2015-06-24

    An engineered RNase P-based ribozyme variant, which was generated using the in vitro selection procedure, was used to target the overlapping mRNA region of two proteins essential for human cytomegalovirus (HCMV) replication: capsid assembly protein (AP) and protease (PR). In vitro studies showed that the generated variant, V718-A, cleaved the target AP mRNA sequence efficiently and its activity was about 60-fold higher than that of wild type ribozyme M1-A. Furthermore, we observed a reduction of 98%-99% in AP/PR expression and an inhibition of 50,000 fold in viral growth in cells with V718-A, while a 75% reduction in AP/PR expression and a 500-fold inhibition in viral growth was found in cells with M1-A. Examination of the antiviral effects of the generated ribozyme on the HCMV replication cycle suggested that viral DNA encapsidation was inhibited and as a consequence, viral capsid assembly was blocked when the expression of AP and PR was inhibited by the ribozyme. Thus, our study indicates that the generated ribozyme variant is highly effective in inhibiting HCMV gene expression and blocking viral replication, and suggests that engineered RNase P ribozyme can be potentially developed as a promising gene-targeting agent for anti-HCMV therapy.

  15. Cross-serotype immunity induced by immunization with a conserved rhinovirus capsid protein.

    Directory of Open Access Journals (Sweden)

    Nicholas Glanville

    Full Text Available Human rhinovirus (RV infections are the principle cause of common colds and precipitate asthma and COPD exacerbations. There is currently no RV vaccine, largely due to the existence of ∼150 strains. We aimed to define highly conserved areas of the RV proteome and test their usefulness as candidate antigens for a broadly cross-reactive vaccine, using a mouse infection model. Regions of the VP0 (VP4+VP2 capsid protein were identified as having high homology across RVs. Immunization with a recombinant VP0 combined with a Th1 promoting adjuvant induced systemic, antigen specific, cross-serotype, cellular and humoral immune responses. Similar cross-reactive responses were observed in the lungs of immunized mice after infection with heterologous RV strains. Immunization enhanced the generation of heterosubtypic neutralizing antibodies and lung memory T cells, and caused more rapid virus clearance. Conserved domains of the RV capsid therefore induce cross-reactive immune responses and represent candidates for a subunit RV vaccine.

  16. 3D reconstruction and capsid protein characterization of grass carp reovirus

    Institute of Scientific and Technical Information of China (English)

    FANG; Qin; Shah; Sanket; LIANG; Yuyao; Z.; H.; ZHOU

    2005-01-01

    Grass carp reovirus (GCRV) is a relatively new virus first isolated in China and is a member of the Aquareovirus genus of the Reoviridae family. Recent report of genomic sequencing showed that GCRV shared high degree of homology with mammalian reovirus (MRV). As a step of our effort to understand the structural basis of GCRV pathogenesis, we determined the three-dimensional (3D) structure of GCRV capsid at 17 (A) resolution by electron cryomicroscopy. Each GCRV capsid has a multilayered organization, consisting of an RNA core, an inner, middle and outer protein layer. The outer layer is made up of 200 trimers that are arranged on an incomplete T=13 icosahedral lattice. A characteristic feature of this layer is the depression resulting from the absence of trimers around the peripentonal positions, revealing the underlying trimers on the middle layer. There are 120 subunits in the inner layer arranged with T=1 symmetry. These structural features are common to other members of the Reoviridae. Moreover, SDS-PAGE analysis showed that GCRV virions contain seven structural proteins (VP1-VP7). These structural proteins have a high degree of sequence homology to MRV, consistent with the structural similarities observed in our study. The high structural similarities of isolated GCRV and MRV suggest that future structural studies focusing on GCRV entering into and replicating within its host cell are necessary in order to fully understand the structural basis of GCRV pathogenesis.

  17. Critical Role of Autophagy in the Processing of Adenovirus Capsid-Incorporated Cancer-Specific Antigens.

    Directory of Open Access Journals (Sweden)

    Sarah R Klein

    Full Text Available Adenoviruses are highly immunogenic and are being examined as potential vectors for immunotherapy. Infection by oncolytic adenovirus is followed by massive autophagy in cancer cells. Here, we hypothesize that autophagy regulates the processing of adenoviral proteins for antigen presentation. To test this hypothesis, we first examined the presentation of viral antigens by infected cells using an antibody cocktail of viral capsid proteins. We found that viral antigens were processed by JNK-mediated autophagy, and that autophagy was required for their presentation. Consistent with these results, splenocytes isolated from virus-immunized mice were activated by infected cells in an MHC II-dependent manner. We then hypothesize that this mechanism can be utilized to generate an efficient cancer vaccine. To this end, we constructed an oncolytic virus encompassing an EGFRvIII cancer-specific epitope in the adenoviral fiber. Infection of cancer cells with this fiber-modified adenovirus resulted in recognition of infected cancer cells by a specific anti-EGFRvIII antibody. However, inhibition of autophagy drastically decreased the capability of the specific antibody to detect the cancer-related epitope in infected cells. Our data suggest that combination of adenoviruses with autophagy inducers may enhance the processing and presentation of cancer-specific antigens incorporated into capsid proteins.

  18. Sequence analysis and location of capsid proteins within RNA 2 of strawberry latent ringspot virus.

    Science.gov (United States)

    Kreiah, S; Strunk, G; Cooper, J I

    1994-09-01

    The nucleotide sequence of the RNA 2 of a strawberry isolate (H) of strawberry latent ringspot virus (SLRSV) comprised 3824 nucleotides and contained one long open reading frame with a theoretical coding capacity of 890 amino acids equivalent to a protein of 98.8K. The N-terminal amino acid sequences of virion-derived proteins were determined by Edman degradation allowing the capsid coding regions to be located and serine/glycine cleavage sites to be identified within the polyprotein. The amino acid sequence in the capsid coding region of an isolate of SLRSV from flowering cherry in New Zealand was 97% identical to that of SLRSV-H. Except in the 3' and 5' terminal non-coding sequences, computer-based alignment and comparison algorithms did not reveal any substantial homologies between RNA 2 of SLRSV-H and the equivalent genomic segments in the nepoviruses arabis mosaic, cherry leaf roll, grapevine fanleaf, raspberry ringspot, grapevine hungarian chrome mosaic, tomato blackring, tomato ringspot, tobacco ringspot, or in the comoviruses cowpea mosaic and red clover mottle. Despite the similarities in overall genome organization, data from RNA 2 remain insufficient for unambiguous positioning of SLRSV in relation to species/genera in the Comoviridae.

  19. Uniform description of polymer ejection dynamics from capsid with and without hydrodynamics

    Science.gov (United States)

    Piili, J.; Suhonen, P. M.; Linna, R. P.

    2017-05-01

    We use stochastic rotation dynamics (SRD) to examine the dynamics of the ejection of an initially strongly confined flexible polymer from a spherical capsid with and without hydrodynamics. The results obtained using stochastic rotation dynamics (SRD) are compared to similar Langevin simulations. Inclusion of hydrodynamic modes speeds up the ejection but also allows the part of the polymer outside the capsid to expand closer to equilibrium. This shows as higher values of radius of gyration when hydrodynamics are enabled. By examining the waiting times of individual polymer beads, we find that the waiting time tw grows with the number of ejected monomers s as a sum of two exponents. When ≈63 % of the polymer has ejected, the ejection enters the regime of slower dynamics. The functional form of tw versus s is universal for all ejection processes starting from the same initial monomer densities. Inclusion of hydrodynamics only reduces its magnitude. Consequently, we define a universal scaling function h such that the cumulative waiting time t =N0h (s /N0) for large N0. Our unprecedentedly precise measurements of force indicate that this form for tw(s ) originates from the corresponding force toward the pore decreasing superexponentially at the end of the ejection. Our measured tw(s ) explains the apparent superlinear scaling of the ejection time with the polymer length for short polymers. However, for asymptotically long polymers, tw(s ) predicts linear scaling.

  20. Dissociation of an antiviral compound from the internal pocket of human rhinovirus 14 capsid.

    Science.gov (United States)

    Li, Yumin; Zhou, Zhigang; Post, Carol Beth

    2005-05-24

    WIN antiviral compounds bind human rhinovirus, as well as enterovirus and parechovirus, in an internal cavity located within the viral protein capsid. Access to the buried pocket necessitates deviation from the average viral protein structure identified by crystallography. We investigated the dissociation of WIN 52084 from the pocket in human rhinovirus 14 by using an adiabatic, biased molecular dynamics simulation method. Multiple dissociation trajectories are used to characterize the pathway. WIN 52084 exits between the polypeptide chain near the ends of betaC and betaH in a series of steps. Small, transient packing defects in the protein are sufficient for dissociation. A number of torsion-angle transitions of the antiviral compound are involved, which suggests that flexibility in antiviral compounds is important for binding. It is interesting to note that dissociation is associated with an increase in the conformational fluctuations of residues never in direct contact with WIN 52084 over the course of dissociation. These residues are N-terminal residues in the viral proteins VP3 and VP4 and are located in the interior of the capsid near the icosahedral 5-fold axis. The observed changes in dynamics may be relevant to structural changes associated with virion uncoating and its inhibition by antiviral compounds.

  1. Controlled immobilisation of active enzymes on the cowpea mosaic virus capsid

    Science.gov (United States)

    Aljabali, Alaa A. A.; Barclay, J. Elaine; Steinmetz, Nicole F.; Lomonossoff, George P.; Evans, David J.

    2012-08-01

    Immobilisation of horseradish peroxidase (HRP) and glucose oxidase (GOX) via covalent attachment of modified enzyme carbohydrate to the exterior of the cowpea mosaic virus (CPMV) capsid gave high retention of enzymatic activity. The number of enzymes bound per virus was determined to be about eleven for HRP and 2-3 for GOX. This illustrates that relatively large biomacromolecules can be readily coupled to the virus surface using simple conjugation strategies. Virus-biomacromolecule hybrids have great potential for uses in catalysis, diagnostic assays or biosensors.Immobilisation of horseradish peroxidase (HRP) and glucose oxidase (GOX) via covalent attachment of modified enzyme carbohydrate to the exterior of the cowpea mosaic virus (CPMV) capsid gave high retention of enzymatic activity. The number of enzymes bound per virus was determined to be about eleven for HRP and 2-3 for GOX. This illustrates that relatively large biomacromolecules can be readily coupled to the virus surface using simple conjugation strategies. Virus-biomacromolecule hybrids have great potential for uses in catalysis, diagnostic assays or biosensors. Electronic supplementary information (ESI) available: Alternative conjugation strategies, agarose gel electrophoresis of CPMV and CPMV-HRP conjugates, UV-vis spectrum of HRP-ADHCPMV, agarose gel electrophoresis of GOX-ADHCPMV particles and corresponding TEM image, calibration curves for HRP-ADHCPMV and GOX-ADHCPMV, DLS data for GOX-ADHCPMV are made available. See DOI: 10.1039/c2nr31485a

  2. Immunochemical assessment of p16 and HPV L1 capsid protein in cervical squamous intraepithelial lesions.

    Science.gov (United States)

    Balan, Raluca; Giuşcă, Simona; Căruntu, Irina Draga; Gheorghiţă, V; Neacşu, D; Amălinei, Cornelia

    2010-01-01

    The behavior of the cervical squamous intraepithelial lesions cannot be predicted, many of them, particularly of the low grade type, may disappear without treatment. Invasive cervical carcinoma occurs in approximately 10% of the intraepithelial precursor lesions, being strongly associated with HPV infection. The aim of this study was to make a comparative assessment between immunohistochemical and immunocytochemical expression of p16 and L1 HPV capsid protein respectively, in low grade and high grade cervical squamous intraepithelial lesions. The study involved 20 patients with cytological diagnosis of LSIL/CIN1 (low grade squamous intraepithelial lesion/cervical intraepithelial neoplasia) and HSIL (CIN2 and CIN3) (high grade squamous intraepithelial lesion), which underwent a subsequent cervical biopsy. The conventional smears were evaluated for the immunoexpression of L1HPV protein and the corresponding biopsies for the immunoexpression of p16. The HPV L1 capsid protein was expressed in 46% of LSIL and 24% of HSIL. P16 was positive in 68% of LSIL, 84% of CIN2 and 100% of CIN3. The correlative analysis of p16 status and protein L1HPV expression can be very useful in the assessment of progression risk of cervical squamous intraepithelial lesions.

  3. Engineering Virus Capsids Into Biomedical Delivery Vehicles: Structural Engineering Problems in Nanoscale.

    Science.gov (United States)

    Bajaj, Saumya; Banerjee, Manidipa

    2015-01-01

    Virus capsids have evolved to protect the genome sequestered in their interior from harsh environmental conditions, and to deliver it safely and precisely to the host cell of choice. This characteristic makes them naturally perfect containers for delivering therapeutic molecules to specific locations. Development of an ideal virus-based nano-container for medical usage requires that the capsid be converted into a targetable protein cage which retains the original stability, flexibility and host cell penetrating properties of the native particles, without the associated immunogenicity, and is able to encapsulate large quantities of therapeutic or diagnostic material. In the last few years, several icosahedral, non-enveloped viruses, with a diameter of 25-90 nm-a size which conveniently falls within the 10-100 nm range desirable for biomedical nanoparticles-have been chemically or genetically engineered towards partial fulfilment of the above criteria. This review summarizes the approaches taken towards engineering viruses into biomedical delivery devices and discusses the challenges involved in achieving this goal.

  4. EST Table: CA946121 [KAIKOcDNA[Archive

    Lifescience Database Archive (English)

    Full Text Available CA946121 KI000181 10/09/28 67 %/199 aa ref|XP_001607023.1| PREDICTED: similar to ma...0308|ref|XP_972041.1| PREDICTED: similar to mandelate racemase [Tribolium castaneum] CK507909 L9 ...

  5. Tremendous change of the earth surface system and tectonic setting of salt-lake formation in Yuncheng Basin since 7.1 Ma

    Institute of Scientific and Technical Information of China (English)

    王强; 李彩光; 田国强; 张文治; 刘椿; 宁联元; 岳军; 程自刚; 何翠英

    2002-01-01

    The Yuncheng salt lake has formed under the setting of stepped subsidence of fault-blocks from the north to the south in Yuncheng Basin. In the phase of red clay accumulation during 7.1-3.6 Ma, the size of palaeo-lake was larger than the present salt lake, and palaeo-monsoon had formed. At 3.6 Ma, the northern basement in the basin raised abruptly due to the radiative effect of Qinghai-Tibet Plateau uplifting, and palaeo-lake was contracting southwards. At ca. 2.6 Ma ancient river flowed into the northern part of the basin. During ca. 2.0-1.9 Ma aerolian effect strengthened and loess started to accumulate on the most part of the basin. Since ca. 1.8-1.0 Ma the subsidence of the lake fault-block has been speeding up abruptly. As under the natural hydrogradient the salt lake received enough groundwater supply, and the rate of loess accumulation in the lake area was lower than that of subsidence of the lake fault-block, the lake could be preserved and becomes the only modern lake on Chinese Loess Plateau. Four large strengthening change records of the monsoon were found in the lake sequence of 5.8-1.9 Ma B.P.

  6. Development of Viral Capsid DNA Aptamer Conjugates as Cell-Targeted Delivery Vehicles

    Science.gov (United States)

    Tong, Gary Jen-Wei

    The ability to generate semi-synthetic DNA-protein conjugates has become increasingly important in the fields of chemical biology and nanobiotechnology. As applications in these fields become more complex, there is also an increased need for methods of attaching synthetic DNA to protein substrates in a well-defined manner. This work outlines the development of new methods for site-specific DNA-protein bioconjugation, as well as the development of novel viral capsid DNA aptamer conjugates for cell-targeting purposes. In order to generate DNA-protein conjugates in a site-specific manner, chemistries orthogonal to native functional groups present on DNA and proteins were exploited. In one method, the attachment of DNA to proteins was achieved via oxime formation. This strategy involved the in situ deprotection of an allyloxycarbonyl-protected alkoxyamine-bearing DNA in the presence of a protein containing a single ketone group. The utility of this approach was demonstrated in the synthesis of a DNA-GFP conjugate. In addition to the oxime formation route, two oxidative coupling methods were also developed for DNA-protein bioconjugation. The first reaction coupled phenylenediamine-containing DNA to anilines, which had been site-specifically incorporated into proteins, in the presence of NaIO4. These reaction conditions were demonstrated on the proteins bacteriophage MS2 and GFP, and were mild enough for the components to retain both protein structure and DNA base-pairing capabilities. The second oxidative coupling reaction conjugated aniline-containing proteins to DNA bearing an o-aminophenol moiety. This reaction occurred under similarly mild conditions; however, higher coupling yields were achieved on MS2 at shorter reaction times by using this strategy. In all three of these methods, the generation of a singly-modified product was achieved. Using one of our oxidative coupling strategies, MS2-DNA aptamer conjugates were synthesized for the development of multivalent

  7. Identification and characterization of novel NuMA isoforms

    Energy Technology Data Exchange (ETDEWEB)

    Wu, Jin, E-mail: petersdu2112@hotmail.com [Key Laboratory for Cell Proliferation and Regulation of the Ministry of Education, Beijing Normal University, Beijing (China); Xu, Zhe [Department of Clinical Laboratory Diagnosis, Beijing Tiantan Hospital, Capital Medical University, Beijing (China); Core Laboratory for Clinical Medical Research, Beijing Tiantan Hospital, Capital Medical University, Beijing (China); He, Dacheng [Key Laboratory for Cell Proliferation and Regulation of the Ministry of Education, Beijing Normal University, Beijing (China); Lu, Guanting, E-mail: guantlv@126.com [Beijing DnaLead Science and Technology Co., LTD, Beijing (China)

    2014-11-21

    Highlights: • Seven NuMA isoforms generated by alternative splicing were categorized into 3 groups: long, middle and short. • Both exons 15 and 16 in long NuMA were “hotspot” for alternative splicing. • Lower expression of short NuMA was observed in cancer cells compared with nonneoplastic controls. • Distinct localization pattern of short isoforms indicated different function from that of long and middle NuMA. - Abstract: The large nuclear mitotic apparatus (NuMA) has been investigated for over 30 years with functions related to the formation and maintenance of mitotic spindle poles during mitosis. However, the existence and functions of NuMA isoforms generated by alternative splicing remains unclear. In the present work, we show that at least seven NuMA isoforms (categorized into long, middle and short groups) generated by alternative splicing from a common NuMA mRNA precursor were discovered in HeLa cells and these isoforms differ mainly at the carboxyl terminus and the coiled-coil domains. Two “hotspot” exons with molecular mass of 3366-nt and 42-nt tend to be spliced during alternative splicing in long and middle groups. Furthermore, full-length coding sequences of long and middle NuMA obtained by using fusion PCR were constructed into GFP-tagged vector to illustrate their cellular localization. Long NuMA mainly localized in the nucleus with absence from nucleoli during interphase and translocated to the spindle poles in mitosis. Middle NuMA displayed the similar cell cycle-dependent distribution pattern as long NuMA. However, expression of NuMA short isoforms revealed a distinct subcellular localization. Short NuMA were present in the cytosol during the whole cycle, without colocalization with mitotic apparatus. These results have allowed us tentatively to explore a new research direction for NuMA’s various functions.

  8. Gondwanaland from 650-500 Ma assembly through 320 Ma merger in Pangea to 185-100 Ma breakup: supercontinental tectonics via stratigraphy and radiometric dating

    Science.gov (United States)

    Veevers, J. J.

    2004-12-01

    Gondwanaland lasted from the 650-500 Ma (late Neoproterozoic-Cambrian) amalgamation of African and South American terranes to Antarctica-Australia-India through 320 Ma (mid-Carboniferous) merging with Laurussia in Pangea to breakup from 185 to 100 Ma (Jurassic and Early Cretaceous). Gondwanaland straddled the equator at 540 Ma, lay wholly in the Southern Hemisphere by 350 Ma, and then rotated clockwise so that at 250 Ma Australia reached the S pole and Africa the equator. By initial breakup of Pangea at 185 Ma, Gondwanaland had moved northward such that North Africa reached 35°N. The first clear picture of Gondwanaland, in the Cambrian, shows the assembly of continents with later Laurentian, European and Asian terranes along the "northern" margin, and with a trench along the "western" and "southern" margins, reflected by a 10,000-km-long chain of 530-500 Ma granites. The interior was crossed by the Prydz-Leeuwin and Mozambique Orogenic Belts. The shoreline lapped the flanks of uplifts generated during this complex terminal Pan-Gondwanaland (650-500 Ma) deformation, which endowed Gondwanaland with a thick, buoyant crust and lithosphere and a nonmarine siliciclastic facies. During the Ordovician, terranes drifted from Africa as the first of many transfers of material to the "northern" continents. Central Australia was crossed by the sea, and the eastern margin and ocean floor were flooded by grains of quartz (and 600-500 Ma zircon) from Antarctica. Ice centres in North Africa and southern South America/Africa waxed and waned in the latest Ordovician, Early Silurian, latest Devonian, and Early Carboniferous. In the mid-Carboniferous, Laurussia and Gondwanaland merged in the composite called Pangea by definitive right-lateral contact along the Variscan suture, with collisional stress and subsequent uplift felt as far afield as Australia. Ice sheets developed on the tectonic uplands of Gondwanaland south of 30°S. In the Early Permian, the self-induced heat beneath

  9. 40 Ma years of hydrothermal W mineralization during the Variscan orogenic evolution of the French Massif Central revealed by U-Pb dating of wolframite

    Science.gov (United States)

    Harlaux, Matthieu; Romer, Rolf L.; Mercadier, Julien; Morlot, Christophe; Marignac, Christian; Cuney, Michel

    2017-03-01

    We present U-Pb thermal ionization mass spectrometer (TIMS) ages of wolframite from several granite-related hydrothermal W±Sn deposits in the French Massif Central (FMC) located in the internal zone of the Variscan belt. The studied wolframite samples are characterized by variable U and Pb contents (typically <10 ppm) and show significant variations in their radiogenic Pb isotopic compositions. The obtained U-Pb ages define three distinct geochronological groups related to three contrasting geodynamic settings: (i) Visean to Namurian mineralization (333-327 Ma) coeval with syn-orogenic compression and emplacement of large peraluminous leucogranites (ca. 335-325 Ma), (ii) Namurian to Westphalian mineralization (317-315 Ma) synchronous with the onset of late-orogenic extension and emplacement of syn-tectonic granites (ca. 315-310 Ma) and (iii) Stephanian to Permian mineralization (298-274 Ma) formed during post-orogenic extension contemporaneous with the Permian volcanism in the entire Variscan belt. The youngest ages (276-274 Ma) likely reflect the reopening of the U-Pb isotopic system after wolframite crystallization and may correspond to late hydrothermal alteration (e.g. ferberitization). Our results demonstrate that W(±Sn) mineralization in the FMC formed during at least three distinct hydrothermal events in different tectono-metamorphic settings over a time range of 40 Ma.

  10. Phylogenetic diversity of marine cyanophage isolates and natural virus communities as revealed by sequences of viral capsid assembly protein gene g20.

    Science.gov (United States)

    Zhong, Yan; Chen, Feng; Wilhelm, Steven W; Poorvin, Leo; Hodson, Robert E

    2002-04-01

    In order to characterize the genetic diversity and phylogenetic affiliations of marine cyanophage isolates and natural cyanophage assemblages, oligonucleotide primers CPS1 and CPS8 were designed to specifically amplify ca. 592-bp fragments of the gene for viral capsid assembly protein g20. Phylogenetic analysis of isolated cyanophages revealed that the marine cyanophages were highly diverse yet more closely related to each other than to enteric coliphage T4. Genetically related marine cyanophage isolates were widely distributed without significant geographic segregation (i.e., no correlation between genetic variation and geographic distance). Cloning and sequencing analysis of six natural virus concentrates from estuarine and oligotrophic offshore environments revealed nine phylogenetic groups in a total of 114 different g20 homologs, with up to six clusters and 29 genotypes encountered in a single sample. The composition and structure of natural cyanophage communities in the estuary and open-ocean samples were different from each other, with unique phylogenetic clusters found for each environment. Changes in clonal diversity were also observed from the surface waters to the deep chlorophyll maximum layer in the open ocean. Only three clusters contained known cyanophage isolates, while the identities of the other six clusters remain unknown. Whether or not these unidentified groups are composed of bacteriophages that infect different Synechococcus groups or other closely related cyanobacteria remains to be determined. The high genetic diversity of marine cyanophage assemblages revealed by the g20 sequences suggests that marine viruses can potentially play important roles in regulating microbial genetic diversity.

  11. Tectonic forcing of early to middle jurassic seawater Sr/Ca

    DEFF Research Database (Denmark)

    Ullmann, Clemens Vinzenz; Hesselbo, Stephen P.; Korte, Christoph

    2013-01-01

    The Jurassic Period (ca. 201–145 Ma) is marked by fundamental reorganizations of paleogeography, paleoceanography, ecosystems, and the progressive shift from aragonite to calcite as the favored marine biogenic carbonate polymorph. Sr/Ca ratios of well-preserved Jurassic oysters and belemnites from...

  12. Protection of chickens against avian hepatitis E virus (avian HEV) infection by immunization with recombinant avian HEV capsid protein.

    Science.gov (United States)

    Guo, H; Zhou, E M; Sun, Z F; Meng, X J

    2007-04-12

    Avian hepatitis E virus (avian HEV) is an emerging virus associated with hepatitis-splenomegaly syndrome in chickens in North America. Avian HEV is genetically and antigenically related to human HEV, the causative agent of hepatitis E in humans. In the lack of a practical animal model, avian HEV infection in chickens has been used as a model to study human HEV replication and pathogenesis. A 32 kDa recombinant ORF2 capsid protein of avian HEV expressed in Escherichia coli was found having similar antigenic structure as that of human HEV containing major neutralizing epitopes. To determine if the capsid protein of avian HEV can be used as a vaccine, 20 chickens were immunized with purified avian HEV recombinant protein with aluminum as adjuvant and another 20 chickens were mock immunized with KLH precipitated in aluminum as controls. Both groups of chickens were subsequently challenged with avian HEV. All the tested mock-immunized control chickens developed typical avian HEV infection characterized by viremia, fecal virus shedding and seroconversion to avian HEV antibodies. Gross hepatic lesions were also found in portion of these chickens. In contrast, none of the tested chickens immunized with avian HEV capsid protein had detectable viremia, fecal virus shedding or observable gross hepatitis lesions. The results from this study suggested that immunization of chickens with avian HEV recombinant ORF2 capsid protein with aluminum as adjuvant can induce protective immunity against avian HEV infection. Chickens are a useful small animal model to study anti-HEV immunity and pathogenesis.

  13. α-Defensin HD5 Inhibits Human Papillomavirus 16 Infection via Capsid Stabilization and Redirection to the Lysosome

    Directory of Open Access Journals (Sweden)

    Mayim E. Wiens

    2017-01-01

    Full Text Available α-Defensins are an important class of abundant innate immune effectors that are potently antiviral against a number of nonenveloped viral pathogens; however, a common mechanism to explain their ability to block infection by these unrelated viruses is lacking. We previously found that human defensin 5 (HD5 blocks a critical host-mediated proteolytic processing step required for human papillomavirus (HPV infection. Here, we show that bypassing the requirement for this cleavage failed to abrogate HD5 inhibition. Instead, HD5 altered HPV trafficking in the cell. In the presence of an inhibitory concentration of HD5, HPV was internalized and reached the early endosome. The internalized capsid became permeable to antibodies and proteases; however, HD5 prevented dissociation of the viral capsid from the genome, reduced viral trafficking to the trans-Golgi network, redirected the incoming viral particle to the lysosome, and accelerated the degradation of internalized capsid proteins. This mechanism is equivalent to the mechanism by which HD5 inhibits human adenovirus. Thus, our data support capsid stabilization and redirection to the lysosome during infection as a general antiviral mechanism of α-defensins against nonenveloped viruses.

  14. X-ray structure of Triatoma virus empty capsid: insights into the mechanism of uncoating and RNA release in dicistroviruses.

    Science.gov (United States)

    Sánchez-Eugenia, Rubén; Durana, Aritz; López-Marijuan, Ibai; Marti, Gerardo A; Guérin, Diego M A

    2016-10-01

    In viruses, uncoating and RNA release are two key steps of successfully infecting a target cell. During these steps, the capsid must undergo the necessary conformational changes to allow RNA egress. Despite their importance, these processes are poorly understood in the family Dicistroviridae. Here, we used X-ray crystallography to solve the atomic structure of a Triatoma virus(TrV) empty particle (Protein Data Bank ID 5L7O), which is the resulting capsid after RNA release. It is observed that the overall shape of the capsid and of the three individual proteins is maintained in comparison with the mature virion. Furthermore, no channels indicative of RNA release are formed in the TrV empty particle. However, the most prominent change in the empty particle when compared with the mature virion is the loss of order in the N-terminal domain of the VP2 protein. In mature virions, the VP2 N-terminal domain of one pentamer is swapped with its twofold related copy in an adjacent pentamer, thereby stabilizing the binding between the pentamers. The loss of these interactions allows us to propose that RNA release may take place through transient flipping-out of pentameric subunits. The lower number of stabilizing interactions between the pentamers and the lack of formation of new holes support this model. This model differs from the currently accepted model for rhinoviruses and enteroviruses, in which genome externalization occurs by extrusion of the RNA through capsid channels.

  15. α-Defensin HD5 Inhibits Human Papillomavirus 16 Infection via Capsid Stabilization and Redirection to the Lysosome

    Science.gov (United States)

    Wiens, Mayim E.

    2017-01-01

    ABSTRACT α-Defensins are an important class of abundant innate immune effectors that are potently antiviral against a number of nonenveloped viral pathogens; however, a common mechanism to explain their ability to block infection by these unrelated viruses is lacking. We previously found that human defensin 5 (HD5) blocks a critical host-mediated proteolytic processing step required for human papillomavirus (HPV) infection. Here, we show that bypassing the requirement for this cleavage failed to abrogate HD5 inhibition. Instead, HD5 altered HPV trafficking in the cell. In the presence of an inhibitory concentration of HD5, HPV was internalized and reached the early endosome. The internalized capsid became permeable to antibodies and proteases; however, HD5 prevented dissociation of the viral capsid from the genome, reduced viral trafficking to the trans-Golgi network, redirected the incoming viral particle to the lysosome, and accelerated the degradation of internalized capsid proteins. This mechanism is equivalent to the mechanism by which HD5 inhibits human adenovirus. Thus, our data support capsid stabilization and redirection to the lysosome during infection as a general antiviral mechanism of α-defensins against nonenveloped viruses. PMID:28119475

  16. Theory of morphological transformation of viral capsid shell during the maturation process in the HK97 bacteriophage and similar viruses.

    Science.gov (United States)

    Konevtsova, O V; Lorman, V L; Rochal, S B

    2016-05-01

    We consider the symmetry and physical origin of collective displacement modes playing a crucial role in the morphological transformation during the maturation of the HK97 bacteriophage and similar viruses. It is shown that the experimentally observed hexamer deformation and pentamer twist in the HK97 procapsid correspond to the simplest irreducible shear strain mode of a spherical shell. We also show that the icosahedral faceting of the bacteriophage capsid shell is driven by the simplest irreducible radial displacement field. The shear field has the rotational icosahedral symmetry group I while the radial field has the full icosahedral symmetry I_{h}. This difference makes their actions independent. The radial field sign discriminates between the icosahedral and the dodecahedral shapes of the faceted capsid shell, thus making the approach relevant not only for the HK97-like viruses but also for the parvovirus family. In the frame of the Landau-Ginzburg formalism we propose a simple phenomenological model valid for the first reversible step of the HK97 maturation process. The calculated phase diagram illustrates the discontinuous character of the virus shape transformation. The characteristics of the virus shell faceting and expansion obtained in the in vitro and in vivo experiments are related to the decrease in the capsid shell thickness and to the increase of the internal capsid pressure.

  17. Theory of morphological transformation of viral capsid shell during the maturation process in the HK97 bacteriophage and similar viruses

    Science.gov (United States)

    Konevtsova, O. V.; Lorman, V. L.; Rochal, S. B.

    2016-05-01

    We consider the symmetry and physical origin of collective displacement modes playing a crucial role in the morphological transformation during the maturation of the HK97 bacteriophage and similar viruses. It is shown that the experimentally observed hexamer deformation and pentamer twist in the HK97 procapsid correspond to the simplest irreducible shear strain mode of a spherical shell. We also show that the icosahedral faceting of the bacteriophage capsid shell is driven by the simplest irreducible radial displacement field. The shear field has the rotational icosahedral symmetry group I while the radial field has the full icosahedral symmetry Ih. This difference makes their actions independent. The radial field sign discriminates between the icosahedral and the dodecahedral shapes of the faceted capsid shell, thus making the approach relevant not only for the HK97-like viruses but also for the parvovirus family. In the frame of the Landau-Ginzburg formalism we propose a simple phenomenological model valid for the first reversible step of the HK97 maturation process. The calculated phase diagram illustrates the discontinuous character of the virus shape transformation. The characteristics of the virus shell faceting and expansion obtained in the in vitro and in vivo experiments are related to the decrease in the capsid shell thickness and to the increase of the internal capsid pressure.

  18. Insights into minor group rhinovirus uncoating: the X-ray structure of the HRV2 empty capsid.

    Directory of Open Access Journals (Sweden)

    Damià Garriga

    2012-01-01

    Full Text Available Upon attachment to their respective receptor, human rhinoviruses (HRVs are internalized into the host cell via different pathways but undergo similar structural changes. This ultimately results in the delivery of the viral RNA into the cytoplasm for replication. To improve our understanding of the conformational modifications associated with the release of the viral genome, we have determined the X-ray structure at 3.0 Å resolution of the end-stage of HRV2 uncoating, the empty capsid. The structure shows important conformational changes in the capsid protomer. In particular, a hinge movement around the hydrophobic pocket of VP1 allows a coordinated shift of VP2 and VP3. This overall displacement forces a reorganization of the inter-protomer interfaces, resulting in a particle expansion and in the opening of new channels in the capsid core. These new breaches in the capsid, opening one at the base of the canyon and the second at the particle two-fold axes, might act as gates for the externalization of the VP1 N-terminus and the extrusion of the viral RNA, respectively. The structural comparison between native and empty HRV2 particles unveils a number of pH-sensitive amino acid residues, conserved in rhinoviruses, which participate in the structural rearrangements involved in the uncoating process.

  19. Insights into minor group rhinovirus uncoating: the X-ray structure of the HRV2 empty capsid.

    Science.gov (United States)

    Garriga, Damià; Pickl-Herk, Angela; Luque, Daniel; Wruss, Jürgen; Castón, José R; Blaas, Dieter; Verdaguer, Núria

    2012-01-01

    Upon attachment to their respective receptor, human rhinoviruses (HRVs) are internalized into the host cell via different pathways but undergo similar structural changes. This ultimately results in the delivery of the viral RNA into the cytoplasm for replication. To improve our understanding of the conformational modifications associated with the release of the viral genome, we have determined the X-ray structure at 3.0 Å resolution of the end-stage of HRV2 uncoating, the empty capsid. The structure shows important conformational changes in the capsid protomer. In particular, a hinge movement around the hydrophobic pocket of VP1 allows a coordinated shift of VP2 and VP3. This overall displacement forces a reorganization of the inter-protomer interfaces, resulting in a particle expansion and in the opening of new channels in the capsid core. These new breaches in the capsid, opening one at the base of the canyon and the second at the particle two-fold axes, might act as gates for the externalization of the VP1 N-terminus and the extrusion of the viral RNA, respectively. The structural comparison between native and empty HRV2 particles unveils a number of pH-sensitive amino acid residues, conserved in rhinoviruses, which participate in the structural rearrangements involved in the uncoating process.

  20. Cell culture adaptation mutations in foot-and-mouth disease virus serotype A capsid proteins: implications for receptor interactions

    Science.gov (United States)

    In this study we describe the adaptive changes fixed on the capsid of several foot-and-mouth disease virus serotype A strains during propagation in cell monolayers. Viruses passaged extensively in three cell lines (BHK-21, LFBK and IB-RS-2), consistently gained several positively charged amino acids...

  1. Interaction between Bluetongue virus outer capsid protein VP2 and vimentin is necessary for virus egress

    Directory of Open Access Journals (Sweden)

    Roy Polly

    2007-01-01

    Full Text Available Abstract Background The VP2 outer capsid protein Bluetongue Virus (BTV is responsible for receptor binding, haemagglutination and eliciting host-specific immunity. However, the assembly of this outer capsid protein on the transcriptionally active viral core would block transcription of the virus. Thus assembly of the outer capsid on the core particle must be a tightly controlled process during virus maturation. Earlier studies have detected mature virus particles associated with intermediate filaments in virus infected cells but the viral determinant for this association and the effect of disrupting intermediate filaments on virus assembly and release are unknown. Results In this study it is demonstrated that BTV VP2 associates with vimentin in both virus infected cells and in the absence of other viral proteins. Further, the determinants of vimentin localisation are mapped to the N-terminus of the protein and deletions of aminio acids between residues 65 and 114 are shown to disrupt VP2-vimentin association. Site directed mutation also reveals that amino acid residues Gly 70 and Val 72 are important in the VP2-vimentin association. Mutation of these amino acids resulted in a soluble VP2 capable of forming trimeric structures similar to unmodified protein that no longer associated with vimentin. Furthermore, pharmacological disruption of intermediate filaments, either directly or indirectly through the disruption of the microtubule network, inhibited virus release from BTV infected cells. Conclusion The principal findings of the research are that the association of mature BTV particles with intermediate filaments are driven by the interaction of VP2 with vimentin and that this interaction contributes to virus egress. Furthermore, i the N-terminal 118 amino acids of VP2 are sufficient to confer vimentin interaction. ii Deletion of amino acids 65–114 or mutation of amino acids 70–72 to DVD abrogates vimentin association. iii Finally

  2. Characterization of neutralizing epitopes within the major capsid protein of human papillomavirus type 33

    Directory of Open Access Journals (Sweden)

    Sapp Martin

    2006-10-01

    Full Text Available Abstract Background Infections with papillomaviruses induce type-specific immune responses, mainly directed against the major capsid protein, L1. Based on the propensity of the L1 protein to self-assemble into virus-like particles (VLPs, type-specific vaccines have already been developed. In order to generate vaccines that target a broader spectrum of HPV types, extended knowledge of neutralizing epitopes is required. Despite the association of human papillomavirus type 33 (HPV33 with cervical carcinomas, fine mapping of neutralizing conformational epitopes on HPV33 has not been reported yet. By loop swapping between HPV33 and HPV16 capsid proteins, we have identified amino acid sequences critical for the binding of conformation-dependent type-specific neutralizing antibodies to surface-exposed hyper variable loops of HPV33 capsid protein L1. Results Reactivities of monoclonal antibodies (mAbs H33.B6, H33.E12, H33.J3 and H16.56E with HPV16:33 and HPV33:16 hybrid L1 VLPs revealed the complex structures of their conformational epitopes as well as the major residues contributing to their binding sites. Whereas the epitope of mAb H33.J3 was determined by amino acids (aa 51–58 in the BC loop of HPV33 L1, sequences of at least two hyper variable loops, DE (aa 132–140 and FGb (aa 282–291, were found to be essential for binding of H33.B6. The epitope of H33.E12 was even more complex, requiring sequences of the FGa loop (aa 260–270, in addition to loops DE and FGb. Conclusion These data demonstrate that neutralizing epitopes in HPV33 L1 are mainly located on the tip of the capsomere and that several hyper variable loops contribute to form these conformational epitopes. Knowledge of the antigenic structure of HPV is crucial for designing hybrid particles as a basis for intertypic HPV vaccines.

  3. Structural Transitions and Energy Landscape for Cowpea Chlorotic Mottle Virus Capsid Mechanics from Nanomanipulation in Vitro and in Silico

    Science.gov (United States)

    Kononova, Olga; Snijder, Joost; Brasch, Melanie; Cornelissen, Jeroen; Dima, Ruxandra I.; Marx, Kenneth A.; Wuite, Gijs J.L.; Roos, Wouter H.; Barsegov, Valeri

    2013-01-01

    Physical properties of capsids of plant and animal viruses are important factors in capsid self-assembly, survival of viruses in the extracellular environment, and their cell infectivity. Combined AFM experiments and computational modeling on subsecond timescales of the indentation nanomechanics of Cowpea Chlorotic Mottle Virus capsid show that the capsid’s physical properties are dynamic and local characteristics of the structure, which change with the depth of indentation and depend on the magnitude and geometry of mechanical input. Under large deformations, the Cowpea Chlorotic Mottle Virus capsid transitions to the collapsed state without substantial local structural alterations. The enthalpy change in this deformation state ΔHind = 11.5–12.8 MJ/mol is mostly due to large-amplitude out-of-plane excitations, which contribute to the capsid bending; the entropy change TΔSind = 5.1–5.8 MJ/mol is due to coherent in-plane rearrangements of protein chains, which mediate the capsid stiffening. Direct coupling of these modes defines the extent of (ir)reversibility of capsid indentation dynamics correlated with its (in)elastic mechanical response to the compressive force. This emerging picture illuminates how unique physico-chemical properties of protein nanoshells help define their structure and morphology, and determine their viruses’ biological function. PMID:24138865

  4. Location of the bacteriophage P22 coat protein C-terminus provides opportunities for the design of capsid-based materials.

    Science.gov (United States)

    Servid, Amy; Jordan, Paul; O'Neil, Alison; Prevelige, Peter; Douglas, Trevor

    2013-09-01

    Rational design of modifications to the interior and exterior surfaces of virus-like particles (VLPs) for future therapeutic and materials applications is based on structural information about the capsid. Existing cryo-electron microscopy-based models suggest that the C-terminus of the bacteriophage P22 coat protein (CP) extends toward the capsid exterior. Our biochemical analysis through genetic manipulations of the C-terminus supports the model where the CP C-terminus is exposed on the exterior of the P22 capsid. Capsids displaying a 6xHis tag appended to the CP C-terminus bind to a Ni affinity column, and the addition of positively or negatively charged coiled coil peptides to the capsid results in association of these capsids upon mixing. Additionally, a single cysteine appended to the CP C-terminus results in the formation of intercapsid disulfide bonds and can serve as a site for chemical modifications. Thus, the C-terminus is a powerful location for multivalent display of peptides that facilitate nanoscale assembly and capsid modification.

  5. Earliest human occupations at Dmanisi (Georgian Caucasus) dated to 1.85–1.78 Ma

    Science.gov (United States)

    Ferring, Reid; Oms, Oriol; Agustí, Jordi; Berna, Francesco; Nioradze, Medea; Shelia, Teona; Tappen, Martha; Vekua, Abesalom; Zhvania, David; Lordkipanidze, David

    2011-01-01

    The early Pleistocene colonization of temperate Eurasia by Homo erectus was not only a significant biogeographic event but also a major evolutionary threshold. Dmanisi's rich collection of hominin fossils, revealing a population that was small-brained with both primitive and derived skeletal traits, has been dated to the earliest Upper Matuyama chron (ca. 1.77 Ma). Here we present archaeological and geologic evidence that push back Dmanisi's first occupations to shortly after 1.85 Ma and document repeated use of the site over the last half of the Olduvai subchron, 1.85–1.78 Ma. These discoveries show that the southern Caucasus was occupied repeatedly before Dmanisi's hominin fossil assemblage accumulated, strengthening the probability that this was part of a core area for the colonization of Eurasia. The secure age for Dmanisi's first occupations reveals that Eurasia was probably occupied before Homo erectus appears in the East African fossil record. PMID:21646521

  6. 论维吾尔语否定成分-ma-/-ma-的句法特性

    Institute of Scientific and Technical Information of China (English)

    力提甫·托乎提

    2011-01-01

    本文在乔姆斯基最简方案理论的启发下,首先肯定维吾尔语否定成分-ma-/-ma-可以构成否定短语(NEGP=negation phrase)。在此基础上,探讨-ma-/-ma-的否定范围,包括无标记否定结构、用音强缩小或转移否定范围、否定焦点的选定、否定意义的强化、否定结构的歧义以及句子的否定、复杂结构中的否定和双否定等问题,揭示-ma-/-ma-的句法特性。%The Chomskyan theory of generative syntax, especially the Minimalist Program, enables us to rethink on Uyghur inflectional suffixes. Guided by this theory, this paper first confirms that the Uyghur negative suffix -ma-/-ma-can form its own NEGP (negation phrase). Then it explores the scope of negation, including the unmarked negation structure, reduced or transferred negation, focus of negation, intensified negation, ambiguity of negation, sentential negation, and complex and double negation, attempting to explain the syntactic property of the negative suffix-ma-/-ma-.

  7. Retargeting of rat parvovirus H-1PV to cancer cells through genetic engineering of the viral capsid.

    Science.gov (United States)

    Allaume, Xavier; El-Andaloussi, Nazim; Leuchs, Barbara; Bonifati, Serena; Kulkarni, Amit; Marttila, Tiina; Kaufmann, Johanna K; Nettelbeck, Dirk M; Kleinschmidt, Jürgen; Rommelaere, Jean; Marchini, Antonio

    2012-04-01

    The rat parvovirus H-1PV is a promising anticancer agent given its oncosuppressive properties and the absence of known side effects in humans. H-1PV replicates preferentially in transformed cells, but the virus can enter both normal and cancer cells. Uptake by normal cells sequesters a significant portion of the administered viral dose away from the tumor target. Hence, targeting H-1PV entry specifically to tumor cells is important to increase the efficacy of parvovirus-based treatments. In this study, we first found that sialic acid plays a key role in H-1PV entry. We then genetically engineered the H-1PV capsid to improve its affinity for human tumor cells. By analogy with the resolved crystal structure of the closely related parvovirus minute virus of mice, we developed an in silico three-dimensional (3D) model of the H-1PV wild-type capsid. Based on this model, we identified putative amino acids involved in cell membrane recognition and virus entry at the level of the 2-fold axis of symmetry of the capsid, within the so-called dimple region. In situ mutagenesis of these residues significantly reduced the binding and entry of H-1PV into permissive cells. We then engineered an entry-deficient viral capsid and inserted a cyclic RGD-4C peptide at the level of its 3-fold axis spike. This peptide binds α(v)β(3) and α(v)β(5) integrins, which are overexpressed in cancer cells and growing blood vessels. The insertion of the peptide rescued viral infectivity toward cells overexpressing α(v)β(5) integrins, resulting in the efficient killing of these cells by the reengineered virus. This work demonstrates that H-1PV can be genetically retargeted through the modification of its capsid, showing great promise for a more efficient use of this virus in cancer therapy.

  8. Chasing the Origin of Viruses: Capsid-Forming Genes as a Life-Saving Preadaptation within a Community of Early Replicators.

    Science.gov (United States)

    Jalasvuori, Matti; Mattila, Sari; Hoikkala, Ville

    2015-01-01

    Virus capsids mediate the transfer of viral genetic information from one cell to another, thus the origin of the first viruses arguably coincides with the origin of the viral capsid. Capsid genes are evolutionarily ancient and their emergence potentially predated even the origin of first free-living cells. But does the origin of the capsid coincide with the origin of viruses, or is it possible that capsid-like functionalities emerged before the appearance of true viral entities? We set to investigate this question by using a computational simulator comprising primitive replicators and replication parasites within a compartment matrix. We observe that systems with no horizontal gene transfer between compartments collapse due to the rapidly emerging replication parasites. However, introduction of capsid-like genes that induce the movement of randomly selected genes from one compartment to another rescues life by providing the non-parasitic replicators a mean to escape their current compartments before the emergence of replication parasites. Capsid-forming genes can mediate the establishment of a stable meta-population where parasites cause only local tragedies but cannot overtake the whole community. The long-term survival of replicators is dependent on the frequency of horizontal transfer events, as systems with either too much or too little genetic exchange are doomed to succumb to replication-parasites. This study provides a possible scenario for explaining the origin of viral capsids before the emergence of genuine viruses: in the absence of other means of horizontal gene transfer between compartments, evolution of capsid-like functionalities may have been necessary for early life to prevail.

  9. Changing the S and MA [Safety and Mission Assurance] Paradigm

    Science.gov (United States)

    Malone, Roy W., Jr.

    2010-01-01

    Objectives: 1) Optimize S&MA organization to best facilitate Shuttle transition in 2010, successfully support Ares developmental responsibilities, and minimize the impacts of the gap between last Shuttle flight and start of Ares V Project. 2) Improve leveraging of critical skills and experience between Shuttle and Ares. 3) Split technical and supervisory functions to facilitate technical penetration. 4) Create Chief Safety and Mission Assurance Officer (CSO) stand-alone position for successfully implementation of S&MA Technical Authority. 5) Minimize disruption to customers. 6) Provide early involvement of S&MA leadership team and frequent/open communications with S&MA team members and steak-holders.

  10. Nucleotide sequence of maize dwarf mosaic virus capsid protein gene and its expression in Escherichia coli

    Institute of Scientific and Technical Information of China (English)

    赛吉庆; 康良仪; 黄忠; 史春霖; 田波; 谢友菊

    1995-01-01

    The 3’-terminal 1 279 nucleotide sequence of maize dwarf mosaic virus (MDMV) genome has been determined. This sequence contains an open reading frame of 1023 nudeotides and a 3’ -non-coding region of 256 nucleotides. The open reading frame includes all of the coding regions for the viral capsid protein (CP) and part of the viral nuclear inclusion protein (Nib). The predicted viral CP consists of 313 amino acid residues with a calculated molecular weight of 35400. The amino acid sequence of the viral CP derived from MDMV cDNA shows about 47%-54% homology to that of 4 other potyviruses. The viral CP gene was constructed in frame with the lacZ gene in pUC19 plasmid and expressed in E. coli cells. The fusion polypeptide positively reacted in Western blot with an antiserum prepared against the native viral CP.

  11. Identification of two functional nuclear localization signals in the capsid protein of duck circovirus

    Energy Technology Data Exchange (ETDEWEB)

    Xiang, Qi-Wang; Zou, Jin-Feng; Wang, Xin [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Shandong, Taian 271018 (China); Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong, Taian 271018 (China); Sun, Ya-Ni [College of Veterinary Medicine, Northwest A and F University, Shanxi, Yangling 712100 (China); Gao, Ji-Ming; Xie, Zhi-Jing [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Shandong, Taian 271018 (China); Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong, Taian 271018 (China); Wang, Yu [Department of Basic Medical Sciences, Taishan Medical College, Shandong, Taian 271000 (China); Zhu, Yan-Li [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Shandong, Taian 271018 (China); Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong, Taian 271018 (China); Jiang, Shi-Jin, E-mail: sjjiang@sdau.edu.cn [Department of Preventive Veterinary Medicine, College of Veterinary Medicine, Shandong Agricultural University, Shandong, Taian 271018 (China); Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong, Taian 271018 (China)

    2013-02-05

    The capsid protein (CP) of duck circovirus (DuCV) is the major immunogenic protein and has a high proportion of arginine residues concentrated at the N terminus of the protein, which inhibits efficient mRNA translation in prokaryotic expression systems. In this study, we investigated the subcellular distribution of DuCV CP expressed via recombinant baculoviruses in Sf9 cells and the DNA binding activities of the truncated recombinant DuCV CPs. The results showed that two independent bipartite nuclear localization signals (NLSs) situated at N-terminal 1-17 and 18-36 amino acid residue of the CP. Moreover, two expression level regulatory signals (ELRSs) and two DNA binding signals (DBSs) were also mapped to the N terminus of the protein and overlapped with the two NLSs. The ability of CP to bind DNA, coupled with the karyophilic nature of this protein, strongly suggests that it may be responsible for nuclear targeting of the viral genome.

  12. Analysis of epitopes in the capsid protein of avian hepatitis E virus by using monoclonal antibodies.

    Science.gov (United States)

    Dong, Shiwei; Zhao, Qin; Lu, Mingzhe; Sun, Peiming; Qiu, Hongkai; Zhang, Lu; Lv, Junhua; Zhou, En-Min

    2011-02-01

    Avian hepatitis E virus (HEV) is related genetically and antigenically to human and swine HEVs and capsid protein of avian HEV shares approximately 48-49% amino acid sequence identities with those of human and swine HEVs. Six monoclonal antibodies (MAbs) were produced and used to locate different epitopes in the ORF2 region of aa 339-570 of avian HEV Chinese isolate. The results showed that five epitopes were located in the aa 339-414 region and one in the aa 510-515 region. Two epitopes located in aa 339-355 and aa 384-414 regions are the immunodominant epitopes on the surface of the avian HEV particles as demonstrated by immune capture of viral particles and immunohistochemical detection of the ORF2 antigens with two MAbs.

  13. Kinetics of the association of dengue virus capsid protein with the granular component of nucleolus.

    Science.gov (United States)

    Tiwary, Ashish Kumar; Cecilia, D

    2017-02-01

    Dengue virus (DENV) replicates in the cytoplasm but translocation of the capsid protein (C) to the nucleoli of infected cells has been shown to facilitate virus multiplication for DENV-2. This study demonstrates that the nucleolar localization of C occurs with all four serotypes of DENV. The interaction of C with the nucleolus was found to be dynamic with a mobile fraction of 66% by FRAP. That the C shuttled between the nucleus and cytoplasm was suggested by FLIP and translation inhibition experiments. Colocalization with B23 indicated that DENV C targeted the granular component (GC) of the nucleolus. Presence of DENV C in the nucleolus affected the recovery kinetics of B23 in infected and transfected cells. Sub-nucleolar localization of DENV C of all serotypes to the GC, its mobility in and out of the nucleolus and its affect on the dynamics of B23 is being shown for the first time. Copyright © 2016 Elsevier Inc. All rights reserved.

  14. Three-dimensional structure of the Epstein-Barr virus capsid.

    Science.gov (United States)

    Germi, Raphaele; Effantin, Gregory; Grossi, Laurence; Ruigrok, Rob W H; Morand, Patrice; Schoehn, Guy

    2012-08-01

    Epstein-Barr virus (EBV), a gammaherpesvirus, infects >90 % of the world's population. Primary infection by EBV can lead to infectious mononucleosis, and EBV persistence is associated with several malignancies. Despite its importance for human health, little structural information is available on EBV. Here we report the purification of the EBV capsid by CsCl- or sucrose density-gradient centrifugation. Cryo-electron microscopy and image analysis resulted in two slightly different three-dimensional structures at about 20 Å resolution. These structures were compared with that of human herpesvirus 8, another gammaherpesvirus. CsCl-gradient purification leads to the removal of part of the triplex complex around the fivefold axes, whereas the complexes between hexons remained in place. This may be due to local differences in stability resulting from variation in quasi-equivalent interactions between pentons and hexons compared with those between hexons only.

  15. Multiple functions of capsid proteins in (+) stranded RNA viruses during plant-virus interactions.

    Science.gov (United States)

    Weber, Philipp H; Bujarski, Jozef J

    2015-01-22

    In addition to providing a protective shell for genomic RNA(s), the coat (capsid) proteins (CPs) of plus-stranded RNA viruses play a variety of other functions that condition the plant-virus relationship. In this review we outline the extensive research progress that has been made within the last decade on those CP characteristics that relate to virus infectivity, pathogenicity, symptom expression, interactions with host factors, virus movement, vector transmission, host range, as well as those used to study virus evolution. By discussing the examples among a variety of plant RNA viruses we show that in addition to general features and pathways, the involvement of CPs may assume very distinct tasks that depend on the particular virus life style. Research perspectives and potential applications are discussed at the end.

  16. Specific interaction of capsid protein and importin-{alpha}/{beta} influences West Nile virus production

    Energy Technology Data Exchange (ETDEWEB)

    Bhuvanakantham, Raghavan; Chong, Mun-Keat [Flavivirology Laboratory, Department of Microbiology, 5 Science Drive 2, National University of Singapore, Singapore 117597 (Singapore); Ng, Mah-Lee, E-mail: micngml@nus.edu.sg [Flavivirology Laboratory, Department of Microbiology, 5 Science Drive 2, National University of Singapore, Singapore 117597 (Singapore)

    2009-11-06

    West Nile virus (WNV) capsid (C) protein has been shown to enter the nucleus of infected cells. However, the mechanism by which C protein enters the nucleus is unknown. In this study, we have unveiled for the first time that nuclear transport of WNV and Dengue virus C protein is mediated by their direct association with importin-{alpha}. This interplay is mediated by the consensus sequences of bipartite nuclear localization signal located between amino acid residues 85-101 together with amino acid residues 42 and 43 of C protein. Elucidation of biological significance of importin-{alpha}/C protein interaction demonstrated that the binding efficiency of this association influenced the nuclear entry of C protein and virus production. Collectively, this study illustrated the molecular mechanism by which the C protein of arthropod-borne flavivirus enters the nucleus and showed the importance of importin-{alpha}/C protein interaction in the context of flavivirus life-cycle.

  17. Adaptive mutations in the JC virus protein capsid are associated with progressive multifocal leukoencephalopathy (PML.

    Directory of Open Access Journals (Sweden)

    Shamil R Sunyaev

    2009-02-01

    Full Text Available PML is a progressive and mostly fatal demyelinating disease caused by JC virus infection and destruction of infected oligodendrocytes in multiple brain foci of susceptible individuals. While JC virus is highly prevalent in the human population, PML is a rare disease that exclusively afflicts only a small percentage of immunocompromised individuals including those affected by HIV (AIDS or immunosuppressive drugs. Viral- and/or host-specific factors, and not simply immune status, must be at play to account for the very large discrepancy between viral prevalence and low disease incidence. Here, we show that several amino acids on the surface of the JC virus capsid protein VP1 display accelerated evolution in viral sequences isolated from PML patients but not in sequences isolated from healthy subjects. We provide strong evidence that at least some of these mutations are involved in binding of sialic acid, a known receptor for the JC virus. Using statistical methods of molecular evolution, we performed a comprehensive analysis of JC virus VP1 sequences isolated from 55 PML patients and 253 sequences isolated from the urine of healthy individuals and found that a subset of amino acids found exclusively among PML VP1 sequences is acquired via adaptive evolution. By modeling of the 3-D structure of the JC virus capsid, we showed that these residues are located within the sialic acid binding site, a JC virus receptor for cell infection. Finally, we go on to demonstrate the involvement of some of these sites in receptor binding by demonstrating a profound reduction in hemagglutination properties of viral-like particles made of the VP1 protein carrying these mutations. Collectively, these results suggest that a more virulent PML causing phenotype of JC virus is acquired via adaptive evolution that changes viral specificity for its cellular receptor(s.

  18. Identification, expression, and immunogenicity of Kaposi's sarcoma-associated herpesvirus-encoded small viral capsid antigen.

    Science.gov (United States)

    Lin, S F; Sun, R; Heston, L; Gradoville, L; Shedd, D; Haglund, K; Rigsby, M; Miller, G

    1997-04-01

    We describe a recombinant antigen for use in serologic tests for antibodies to Kaposi's sarcoma (KS)-associated herpesvirus (KSHV). The cDNA for a small viral capsid antigen (sVCA) was identified by immunoscreening of a library prepared from the BC-1 body cavity lymphoma cell line induced into KSHV lytic gene expression by sodium butyrate. The cDNA specified a 170-amino-acid peptide with homology to small viral capsid proteins encoded by the BFRF3 gene of Epstein-Barr virus and the ORF65 gene of herpesvirus saimiri. KSHV sVCA was expressed from a 0.85-kb mRNA present late in lytic KSHV replication in BC-1 cells. This transcript was sensitive to phosphonoacetic acid and phosphonoformic acid, inhibitors of herpesvirus DNA replication. KSHV sVCA expressed in mammalian cells or Escherichia coli or translated in vitro was recognized as an antigen by antisera from KS patients. Rabbit antisera raised to KSHV sVCA expressed in E. coli detected a 22-kDa protein in KSHV-infected human B cells. Overexpressed KSHV sVCA purified from E. coli and used as an antigen in immunoblot screening assay did not cross-react with EBV BFRF3. Antibodies to sVCA were present in 89% of 47 human immunodeficiency virus (HIV)-positive patients with KS, in 20% of 54 HIV-positive patients without KS, but in none of 122 other patients including children born to HIV-seropositive mothers and patients with hemophilia, autoimmune disease, or nasopharyngeal carcinoma. Low-titer antibody was detected in three sera from 28 healthy subjects. Antibodies to recombinant sVCA correlate with KS in high-risk populations. Recombinant sVCA can be used to examine the seroepidemiology of infection with KSHV in the general population.

  19. The C Terminus of the Herpes Simplex Virus UL25 Protein Is Required for Release of Viral Genomes from Capsids Bound to Nuclear Pores.

    Science.gov (United States)

    Huffman, Jamie B; Daniel, Gina R; Falck-Pedersen, Erik; Huet, Alexis; Smith, Greg A; Conway, James F; Homa, Fred L

    2017-08-01

    The herpes simplex virus (HSV) capsid is released into the cytoplasm after fusion of viral and host membranes, whereupon dynein-dependent trafficking along microtubules targets it to the nuclear envelope. Binding of the capsid to the nuclear pore complex (NPC) is mediated by the capsid protein pUL25 and the capsid-tethered tegument protein pUL36. Temperature-sensitive mutants in both pUL25 and pUL36 dock at the NPC but fail to release DNA. The uncoating reaction has been difficult to study due to the rapid release of the genome once the capsid interacts with the nuclear pore. In this study, we describe the isolation and characterization of a truncation mutant of pUL25. Live-cell imaging and immunofluorescence studies demonstrated that the mutant was not impaired in penetration of the host cell or in trafficking of the capsid to the nuclear membrane. However, expression of viral proteins was absent or significantly delayed in cells infected with the pUL25 mutant virus. Transmission electron microscopy revealed capsids accumulated at nuclear pores that retained the viral genome for at least 4 h postinfection. In addition, cryoelectron microscopy (cryo-EM) reconstructions of virion capsids did not detect any obvious differences in the location or structural organization for the pUL25 or pUL36 proteins on the pUL25 mutant capsids. Further, in contrast to wild-type virus, the antiviral response mediated by the viral DNA-sensing cyclic guanine adenine synthase (cGAS) was severely compromised for the pUL25 mutant. These results demonstrate that the pUL25 capsid protein has a critical role in releasing viral DNA from NPC-bound capsids.IMPORTANCE Herpes simplex virus 1 (HSV-1) is the causative agent of several pathologies ranging in severity from the common cold sore to life-threatening encephalitic infection. Early steps in infection include release of the capsid into the cytoplasm, docking of the capsid at a nuclear pore, and release of the viral genome into the nucleus

  20. X-Ray Data on Extraterrestrial CA Dialuminate (CaAl4O7)

    Science.gov (United States)

    Weber, D.; Ross, C. R., II; Bischoff, A.

    1993-07-01

    volume, are slightly higher in Ca-dialuminate from Acfer 182 than from synthetic CaAl4O7. This may be due to the incorporation of traces of refractory elements (REE) with large ionic radii, which were analyzed within inclusion 022/9 [10]. With the determination of the cell constants of natural Ca-dialuminate combined with data on synthetic CaAl4O7, sufficient X-ray data should be available required to nominate this mineral. References: [1] Christophe Michel-Levy M. et al. (1982) EPSL, 61, 13-22. [2] Kimura M. et al. (1993) GCA, in press. [3] Weber D. and Bischoff A. (1992) Meteoritics, 27, 304-305. [4] Weber D. and Bischoff A. (1993) GCA, submitted. [5] Boyko E. R. and Wisnyi L. G. (1958) Acta Cryst., 11, 444-445. [6] Goodwin D. W. and Lindop A. J. (1970) Acta Cryst., B26, 1230-1235. [7] Baldock P. J. et al. (1970) J. Appl. Cryst., 3, 188-191. [8] Geiger C. A. et al. (1988) GCA, 52, 1729-1736. [9] Gross S. (1977) Geol. Surv. Israel Bull. 70, 1-80. [10] Bischoff A. et al. (1992) Meteoritics, 27, 204. Table 1, which appears in the hard copy, shows unit-cell constants of Ca- dialuminate (monocline; space group C2/c) and X-ray powder diffraction data (CrK-alpha (Ni-beta), 45 kV, 30 mA) on extraterrestrial CaAl4O7 in comparison to JCPDS data [7]. Numbers in parentheses are uncertainties in last significant figures.

  1. 42 CFR 422.50 - Eligibility to elect an MA plan.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Eligibility to elect an MA plan. 422.50 Section 422... Eligibility to elect an MA plan. For this subpart, all references to an MA plan include MA-PD and both MA local and MA regional plans, as defined in § 422.2 unless specifically noted otherwise. (a)...

  2. 42 CFR 422.103 - Benefits under an MA MSA plan.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Benefits under an MA MSA plan. 422.103 Section 422... Benefits under an MA MSA plan. (a) General rule. An MA organization offering an MA MSA plan must make...) Countable expenses. An MA organization offering an MA MSA plan must count toward the annual deductible...

  3. MaROS: Information Management Service

    Science.gov (United States)

    Allard, Daniel A.; Gladden, Roy E.; Wright, Jesse J.; Hy, Franklin H.; Rabideau, Gregg R.; Wallick, Michael N.

    2011-01-01

    This software is provided by the Mars Relay Operations Service (MaROS) task to a variety of Mars projects for the purpose of coordinating communications sessions between landed spacecraft assets and orbiting spacecraft assets at Mars. The Information Management Service centralizes a set of functions previously distributed across multiple spacecraft operations teams, and as such, greatly improves visibility into the end-to-end strategic coordination process. Most of the process revolves around the scheduling of communications sessions between the spacecraft during periods of time when a landed asset on Mars is geometrically visible by an orbiting spacecraft. These relay sessions are used to transfer data both to and from the landed asset via the orbiting asset on behalf of Earth-based spacecraft operators. This software component is an application process running as a Java virtual machine. The component provides all service interfaces via a Representational State Transfer (REST) protocol over https to external clients. There are two general interaction modes with the service: upload and download of data. For data upload, the service must execute logic specific to the upload data type and trigger any applicable calculations including pass delivery latencies and overflight conflicts. For data download, the software must retrieve and correlate requested information and deliver to the requesting client. The provision of this service enables several key advancements over legacy processes and systems. For one, this service represents the first time that end-to-end relay information is correlated into a single shared repository. The software also provides the first multimission latency calculator; previous latency calculations had been performed on a mission-by-mission basis.

  4. 人物专栏:马军%Personage Column: MA Jun

    Institute of Scientific and Technical Information of China (English)

    2006-01-01

    @@ Ma Jun is the Head of Harbin Institute of Hematology & Oncology that serves as a teaching, research and medical center of hematology and oncology in China. Dr. Ma is a very famous professor of Hematology and Oncology in the county and abroad now.

  5. Van maïsstengel tot ethanol, eiwitten en energie

    NARCIS (Netherlands)

    Laar, E.; Sanders, J.P.M.

    2010-01-01

    Maïs wordt in een bioethanolinstallatie in Lelystad verwerkt voor de productie van ethanol, eiwitten en energie. ZeaFuels heeft een methode ontwikkeld waarmee direct bij de boerderij via de vergisting van maïs het maximale uit de grondstof kan worden gehaald

  6. 77 FR 1503 - Massasoit National Wildlife Refuge, Plymouth, MA

    Science.gov (United States)

    2012-01-10

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF THE INTERIOR Fish and Wildlife Service Massasoit National Wildlife Refuge, Plymouth, MA AGENCY: Fish and Wildlife... Hill Road, Sudbury, MA 01776. In-Person Drop-off: You may drop off comments during regular...

  7. "Sel kevadel olen ma eriti ilus..." : [luuletused] / Triin Soomets

    Index Scriptorium Estoniae

    Soomets, Triin

    2003-01-01

    Sisu: "Sel kevadel olen ma eriti ilus..." ; "Tahaksin teha midagi tõelist; midagi suurt..." ; "veebruaris on keha nii valge et syda läheb pahaks..." ; "kõige kohutavamad lepingud..." ; "Igal loojangul kutsun sind ja igal koidikul tõukan su ära..." ; "need hakid..." ; "Põhja vajudes on viimane asi, mida ma näen, rohelised sähvatused..."

  8. Human papillomavirus major capsid protein L1 remains associated with the incoming viral genome throughout the entry process.

    Science.gov (United States)

    DiGiuseppe, Stephen; Bienkowska-Haba, Malgorzata; Guion, Lucile G M; Keiffer, Timothy R; Sapp, Martin

    2017-05-31

    During infectious entry, acidification within the endosome triggers uncoating of the HPV capsid whereupon host cyclophilins facilitate the release of most of the major capsid protein, L1, from the minor capsid protein L2 and the viral genome. The L2/DNA complex traffics to the trans-Golgi network (TGN). Following the onset of mitosis, HPV-harboring transport vesicles bud from the TGN followed by association with mitotic chromosomes. During this time, the HPV genome remains in a vesicular compartment until the nucleus has completely reformed. Recent data suggests that while most of L1 protein dissociates and is degraded in the endosome, some L1 protein remains associated with the viral genome. The L1 protein has DNA binding activity and L2 protein has multiple domains capable of interacting with L1 capsomeres. In this study, we report that some L1 protein traffics with L2 and viral genome to the nucleus. The accompanying L1 protein is mostly full-length and retains conformation-dependent epitopes, which are recognized by neutralizing antibodies. Since more than one L1 molecule contributes to these epitopes and require assembly into capsomeres, we propose that L1 protein is present in form of pentamers. Furthermore, we provide evidence that L1 protein interacts directly with viral DNA within the capsid. Based on our findings, we propose that the L1 protein, likely arranged as capsomeres, stabilizes the viral genome within the subviral complex during intracellular trafficking.IMPORTANCE After internalization, the non-enveloped human papillomavirus virion uncoats in the endosome whereupon conformational changes result in a dissociation of a subset of the major capsid protein L1 from the minor capsid protein L2, which remains in complex with the viral DNA. Recent data suggests that some L1 protein may accompany the viral genome beyond the endosomal compartment. Herein, we demonstrate that conformationally intact L1 protein, likely still arranged as capsomeres, remains

  9. Identification of an antigenic domain in the N-terminal region of avian hepatitis E virus (HEV) capsid protein that is not common to swine and human HEVs.

    Science.gov (United States)

    Wang, Lizhen; Sun, Yani; Du, Taofeng; Wang, Chengbao; Xiao, Shuqi; Mu, Yang; Zhang, Gaiping; Liu, Lihong; Widén, Frederik; Hsu, Walter H; Zhao, Qin; Zhou, En-Min

    2014-12-01

    The antigenic domains located in the C-terminal 268 amino acid residues of avian hepatitis E virus (HEV) capsid protein have been characterized. This region shares common epitopes with swine and human HEVs. However, epitopes in the N-terminal 338 amino acid residues have never been reported. In this study, an antigenic domain located between amino acids 23 and 85 was identified by indirect ELISA using the truncated recombinant capsid proteins as coating antigens and anti-avian HEV chicken sera as primary antibodies. In addition, this domain did not react with anti-swine and human HEV sera. These results indicated that the N-terminal 338 amino acid residues of avian HEV capsid protein do not share common epitopes with swine and human HEVs. This finding is important for our understanding of the antigenicity of the avian HEV capsid protein. Furthermore, it has important implications in the selection of viral antigens for serological diagnosis.

  10. Structural polymorphism of the major capsid protein of a double-stranded RNA virus: an amphipathic alpha helix as a molecular switch.

    Science.gov (United States)

    Saugar, Irene; Luque, Daniel; Oña, Ana; Rodríguez, José F; Carrascosa, José L; Trus, Benes L; Castón, José R

    2005-07-01

    The infectious bursal disease virus T=13 viral particle is composed of two major proteins, VP2 and VP3. Here, we show that the molecular basis of the conformational flexibility of the major capsid protein precursor, pVP2, is an amphipatic alpha helix formed by the sequence GFKDIIRAIR. VP2 containing this alpha helix is able to assemble into the T=13 capsid only when expressed as a chimeric protein with an N-terminal His tag. An amphiphilic alpha helix, which acts as a conformational switch, is thus responsible for the inherent structural polymorphism of VP2. The His tag mimics the VP3 C-terminal region closely and acts as a molecular triggering factor. Using cryo-electron microscopy difference imaging, both polypeptide elements were detected on the capsid inner surface. We propose that electrostatic interactions between these two morphogenic elements are transmitted to VP2 to acquire the competent conformations for capsid assembly.

  11. Proceedings of the Aircraft Wake Vortices Conference, March 15-17, 1977, held at the Transportation Systems Center, Kendall Square, Cambridge, MA

    Science.gov (United States)

    1977-06-01

    CA. Jan. 1977. 309 -1.A IM ASSESSMENT OF ATMOSPHERIC EFFECTS ON THE BEHAVIOR OF AIRCRAFT WAKE VORTICES PAUL B. MACCREADY. JR. AND PETER B.S. LISSAMAN...Transportation Systems Center Civil Aviation Authority Kendall Square London Space House Cambridge MA 02142 Kingsway WC2 England Pitchford . Lynn D. Lockheed

  12. MaMiCo: Software design for parallel molecular-continuum flow simulations

    KAUST Repository

    Neumann, Philipp

    2015-11-19

    The macro-micro-coupling tool (MaMiCo) was developed to ease the development of and modularize molecular-continuum simulations, retaining sequential and parallel performance. We demonstrate the functionality and performance of MaMiCo by coupling the spatially adaptive Lattice Boltzmann framework waLBerla with four molecular dynamics (MD) codes: the light-weight Lennard-Jones-based implementation SimpleMD, the node-level optimized software ls1 mardyn, and the community codes ESPResSo and LAMMPS. We detail interface implementations to connect each solver with MaMiCo. The coupling for each waLBerla-MD setup is validated in three-dimensional channel flow simulations which are solved by means of a state-based coupling method. We provide sequential and strong scaling measurements for the four molecular-continuum simulations. The overhead of MaMiCo is found to come at 10%-20% of the total (MD) runtime. The measurements further show that scalability of the hybrid simulations is reached on up to 500 Intel SandyBridge, and more than 1000 AMD Bulldozer compute cores. Program summary: Program title: MaMiCo. Catalogue identifier: AEYW_v1_0. Program summary URL: http://cpc.cs.qub.ac.uk/summaries/AEYW_v1_0.html Program obtainable from: CPC Program Library, Queen\\'s University, Belfast, N. Ireland. Licensing provisions: BSD License. No. of lines in distributed program, including test data, etc.: 67905. No. of bytes in distributed program, including test data, etc.: 1757334. Distribution format: tar.gz. Programming language: C, C++II. Computer: Standard PCs, compute clusters. Operating system: Unix/Linux. RAM: Test cases consume ca. 30-50 MB. Classification: 7.7. External routines: Scons (http:www.scons.org), ESPResSo, LAMMPS, ls1 mardyn, waLBerla. Nature of problem: Coupled molecular-continuum simulation for multi-resolution fluid dynamics: parts of the domain are resolved by molecular dynamics whereas large parts are covered by a CFD solver, e.g. a lattice Boltzmann automaton

  13. The Herpes Simplex Virus 1 UL17 Protein Is the Second Constituent of the Capsid Vertex-Specific Component Required for DNA Packaging and Retention▿

    Science.gov (United States)

    Toropova, Katerina; Huffman, Jamie B.; Homa, Fred L.; Conway, James F.

    2011-01-01

    The herpes simplex virus (HSV) UL17 and UL25 minor capsid proteins are essential for DNA packaging. They are thought to comprise a molecule arrayed in five copies around each of the capsid vertices. This molecule was initially termed the “C-capsid-specific component” (CCSC) (B. L. Trus et al., Mol. Cell 26:479-489, 2007), but as we have subsequently observed this feature on reconstructions of A, B, and C capsids, we now refer to it more generally as the “capsid vertex-specific component” (CVSC) (S. K. Cockrell et al., J. Virol. 85:4875-4887, 2011). We previously confirmed that UL25 occupies the vertex-distal region of the CVSC density by visualizing a large UL25-specific tag in reconstructions calculated from cryo-electron microscopy (cryo-EM) images. We have pursued the same strategy to determine the capsid location of the UL17 protein. Recombinant viruses were generated that contained either a small tandem affinity purification (TAP) tag or the green fluorescent protein (GFP) attached to the C terminus of UL17. Purification of the TAP-tagged UL17 or a similarly TAP-tagged UL25 protein clearly demonstrated that the two proteins interact. A cryo-EM reconstruction of capsids containing the UL17-GFP protein reveals that UL17 is the second component of the CVSC and suggests that UL17 interfaces with the other CVSC component, UL25, through its C terminus. The portion of UL17 nearest the vertex appears to be poorly constrained, which may provide flexibility in interacting with tegument proteins or the DNA-packaging machinery at the portal vertex. The exposed locations of the UL17 and UL25 proteins on the HSV-1 capsid exterior suggest that they may be attractive targets for highly specific antivirals. PMID:21632758

  14. The herpes simplex virus 1 UL17 protein is the second constituent of the capsid vertex-specific component required for DNA packaging and retention.

    Science.gov (United States)

    Toropova, Katerina; Huffman, Jamie B; Homa, Fred L; Conway, James F

    2011-08-01

    The herpes simplex virus (HSV) UL17 and UL25 minor capsid proteins are essential for DNA packaging. They are thought to comprise a molecule arrayed in five copies around each of the capsid vertices. This molecule was initially termed the "C-capsid-specific component" (CCSC) (B. L. Trus et al., Mol. Cell 26:479-489, 2007), but as we have subsequently observed this feature on reconstructions of A, B, and C capsids, we now refer to it more generally as the "capsid vertex-specific component" (CVSC) (S. K. Cockrell et al., J. Virol. 85:4875-4887, 2011). We previously confirmed that UL25 occupies the vertex-distal region of the CVSC density by visualizing a large UL25-specific tag in reconstructions calculated from cryo-electron microscopy (cryo-EM) images. We have pursued the same strategy to determine the capsid location of the UL17 protein. Recombinant viruses were generated that contained either a small tandem affinity purification (TAP) tag or the green fluorescent protein (GFP) attached to the C terminus of UL17. Purification of the TAP-tagged UL17 or a similarly TAP-tagged UL25 protein clearly demonstrated that the two proteins interact. A cryo-EM reconstruction of capsids containing the UL17-GFP protein reveals that UL17 is the second component of the CVSC and suggests that UL17 interfaces with the other CVSC component, UL25, through its C terminus. The portion of UL17 nearest the vertex appears to be poorly constrained, which may provide flexibility in interacting with tegument proteins or the DNA-packaging machinery at the portal vertex. The exposed locations of the UL17 and UL25 proteins on the HSV-1 capsid exterior suggest that they may be attractive targets for highly specific antivirals.

  15. Production and Application of Polyclonal Antibodies Against Recombinant Capsid Protein of Extra Small Virus of Macrobrachium rosenbergii.

    Science.gov (United States)

    Neethi, V; Sivakumar, N; Kumar, Kundan; Rajendran, K V; Makesh, M

    2012-12-01

    Macrobrachium rosenbergii nodavirus along with a satellite virus, extra small virus (XSV) causes white tail disease (WTD) in the giant freshwater prawn M. rosenbergii. Infected M. rosenbergii postlarvae were collected from a hatchery in Kakinada, Andhra Pradesh. The gene coding the capsid protein of XSV was cloned in a bacterial expression vector pRSET A and the recombinant protein was expressed in Escherichia coli BL21(DE3)pLysS cells. The recombinant protein was purified by Nickel affinity chromatography. Polyclonal antibodies were produced in mice against the recombinant protein and the antibodies reacted specifically with the recombinant protein and XSV in WTD-infected tissues. This is the first report of detection of XSV using antibodies against recombinant capsid protein.

  16. Fusion calculations for 40Ca+40Ca, 48Ca+48Ca, 40Ca+48Ca and p+208Pb systems

    Science.gov (United States)

    Gao, Jie; Zhang, Haifei; Bao, Xiaojun; Li, Junqing; Zhang, Hongfei

    2014-09-01

    The fusion cross sections of calcium isotopes and proton induced fusion have been calculated in terms of a coupled-channels formulation. Results indicated that there are big differences between the two fusion types. In the calculations of calcium isotopes fusion, the pair-transfer coupling has been applied in addition to the vibrational coupling, the combined effects showed that pair-transfer has played a significant role in the fusion process for the asymmetric 40Ca+48Ca system. The result of proton induced fusion for p+208Pb system successfully presents the fusion oscillation, which agrees with the experimental data rather well.

  17. A single amino acid of human immunodeficiency virus type 2 capsid protein affects conformation of two external loops and viral sensitivity to TRIM5α.

    Directory of Open Access Journals (Sweden)

    Tadashi Miyamoto

    Full Text Available We previously reported that human immunodeficiency virus type 2 (HIV-2 carrying alanine or glutamine but not proline at position 120 of the capsid protein (CA could grow in the presence of anti-viral factor TRIM5α of cynomolgus monkey (CM. To elucidate details of the interaction between the CA and TRIM5α, we generated mutant HIV-2 viruses, each carrying one of the remaining 17 possible amino acid residues, and examined their sensitivity to CM TRIM5α-mediated restriction. Results showed that hydrophobic residues or those with ring structures were associated with sensitivity, while those with small side chains or amide groups conferred resistance. Molecular dynamics simulation study revealed a structural basis for the differential TRIM5α sensitivities. The mutations at position 120 in the loop between helices 6 and 7 (L6/7 affected conformation of the neighboring loop between helices 4 and 5 (L4/5, and sensitive viruses had a common L4/5 conformation. In addition, the common L4/5 structures of the sensitive viruses were associated with a decreased probability of hydrogen bond formation between the 97th aspartic acid in L4/5 and the 119th arginine in L6/7. When we introduced aspartic acid-to-alanine substitution at position 97 (D97A of the resistant virus carrying glutamine at position 120 to disrupt hydrogen bond formation, the resultant virus became moderately sensitive. Interestingly, the virus carrying glutamic acid at position 120 showed resistance, while its predicted L4/5 conformation was similar to those of sensitive viruses. The D97A substitution failed to alter the resistance of this particular virus, indicating that the 120th amino acid residue itself is also involved in sensitivity regardless of the L4/5 conformation. These results suggested that a hydrogen bond between the L4/5 and L6/7 modulates the overall structure of the exposed surface of the CA, but the amino acid residue at position 120 is also directly involved in CM TRIM5

  18. Characterization and expression profiles of MaACS and MaACO genes from mulberry (Morus alba L.)%桑树MaACS和MaACO基因的鉴定和表达模式研究

    Institute of Scientific and Technical Information of China (English)

    Chang-ying LIU; Shu-mei HAN; Cheng LU; Mao-de YU; Rui-hua LÜ; Jun LI; Ai-chun ZHAO; Xi-ling WANG; Umuhoza DIANE; Xiao-hong WANG; Chuan-hong WANG; Ya-sheng YU

    2014-01-01

    研究目的:分离和鉴定桑树中参与乙烯生物合成的酶的编码基因MaACS 和MaACO,研究其表达模式。创新要点:基于最新公布的桑树基因组数据库数据,获得5个MaACS 基因和2个MaACO 基因,对其进行了生物信息分析,同时鉴定了其在不同桑树组织中、不同发育时期桑椹中和不同激素作用下的表达模式。研究方法:通过生物信息学方法筛选和鉴定基因,利用荧光定量逆转录聚合酶链式反应(qRT-PCR)分析基因的表达量。重要结论:MaACS 和MaACO 基因在根、茎、叶等不同组织中呈现出不同的表达模式,在桑椹发育过程中呈现出两种表达模式,其表达量被脱落酸和乙烯利上调。%1-Aminocyclopropane-1-carboxylic acid synthase (ACS) and 1-aminocyclopropane-1-carboxylic acid oxidase (ACO) are encoded by multigene families and are involved in fruit ripening by catalyzing the production of ethylene throughout the development of fruit. However, there are no reports on ACS or ACO genes in mulberry, partly because of the limited molecular research background. In this study, we have obtained five ACS gene sequences and two ACO gene sequences from Morus Genome Database. Sequence alignment and phylogenetic analysis of MaACO1 and MaACO2 showed that their amino acids are conserved compared with ACO proteins from other species. MaACS1 and MaACS2 are type I, MaACS3 and MaACS4 are type II, and MaACS5 is type III, with different C-terminal se-quences. Quantitative reverse transcriptase polymerase chain reaction (qRT-PCR) expression analysis showed that the transcripts of MaACS genes were strongly expressed in fruit, and more weakly in other tissues. The expression of MaACO1 and MaACO2 showed different patterns in various mulberry tissues. MaACS and MaACO genes demon-strated two patterns throughout the development of mulberry fruit, and both of them were strongly up-regulated by abscisic acid (ABA) and ethephon.

  19. Detention of HPV L1 Capsid Protein and hTERC Gene in Screening of Cervical Cancer

    Directory of Open Access Journals (Sweden)

    Huang Bin

    2013-06-01

    Full Text Available   Objective(s: To investigate the expression of human papilloma virus (HPV L1 capsid protein, and human telomerase RNA component (hTERC in cervical cancer and the role of detection of both genes in screening of cervical cancer.   Materials and Methods: A total of 309 patients were recruited and cervical exfoliated cells were collected. Immunocytochemistry was employed to detect HPV L1 capsid protein, and fluorescent in situ hybridization (FISH was performed to detect the hTERC. Results: The expression of HPV L1 capsid protein reduced with the increase of the histological grade of cervical cells and was negatively related to the grade of cervical lesions. However, the expression of hTERC increased with the increase of the histological grade and positively associated with the grade of cervical lesions. The proportion of patients with L1(-/hTERC(+ was higher in patients with histological grade of CIN2 or higher than that in those with histological grade of CIN1. The L1(+/hTERC(- and L1(-/hTERC(- were negatively related to the grade of cervical lesions. L1(-/hTERC(+ was positively associated with the grade of cervical lesions. The L1/hTERC ratio increased. The negative predictive value of both HPV L1 and hTERC was higher than that of HPV L1 or hTERC, but there was no marked difference in the screening efficacy of cervical cancer among HPV L1, hTERC and HPV L1+hTERC. Conclusion: HPV L1 capsid protein and hTERC gene may serve as markers for the early diagnosis and prediction of cervical lesions. The increase in L1/hTERC ratio reflects the progression of cervical lesions to a certain extent.

  20. Potential recombinant vaccine against influenza A virus based on M2e displayed on nodaviral capsid nanoparticles

    Directory of Open Access Journals (Sweden)

    Yong CY

    2015-04-01

    Full Text Available Chean Yeah Yong,1 Swee Keong Yeap,2 Kok Lian Ho,3 Abdul Rahman Omar,2,4 Wen Siang Tan1,2 1Department of Microbiology, Faculty of Biotechnology and Biomolecular Sciences, 2Institute of Bioscience, 3Department of Pathology, Faculty of Medicine and Health Sciences, 4Department of Veterinary Pathology and Microbiology, Faculty of Veterinary Medicine, Universiti Putra Malaysia, Selangor, Malaysia Abstract: Influenza A virus poses a major threat to human health, causing outbreaks from time to time. Currently available vaccines employ inactivated viruses of different strains to provide protection against influenza virus infection. However, high mutation rates of influenza virus hemagglutinin (H and neuraminidase (N glycoproteins give rise to vaccine escape mutants. Thus, an effective vaccine providing protection against all strains of influenza virus would be a valuable asset. The ectodomain of matrix 2 protein (M2e was found to be highly conserved despite mutations of the H and N glycoproteins. Hence, one to five copies of M2e were fused to the carboxyl-terminal end of the recombinant nodavirus capsid protein derived from Macrobrachium rosenbergii. The chimeric proteins harboring up to five copies of M2e formed nanosized virus-like particles approximately 30 nm in diameter, which could be purified easily by immobilized metal affinity chromatography. BALB/c mice immunized subcutaneously with these chimeric proteins developed antibodies specifically against M2e, and the titer was proportional to the copy numbers of M2e displayed on the nodavirus capsid nanoparticles. The fusion proteins also induced a type 1 T helper immune response. Collectively, M2e displayed on the nodavirus capsid nanoparticles could provide an alternative solution to a possible influenza pandemic in the future. Keywords: matrix 2 ectodomain, nodavirus capsid, virus-like particle, fusion protein, subunit vaccine, immunogenicity

  1. Protection against myxomatosis and rabbit viral hemorrhagic disease with recombinant myxoma viruses expressing rabbit hemorrhagic disease virus capsid protein.

    OpenAIRE

    Bertagnoli, Stéphane; Gelfi, Jacqueline; Le Gall, Ghislaine; Boilletot, Eric; Vautherot, Jean-François; Rasschaert, Denis; Laurent, Sylvie; Petit, Frédérique; Boucraut-Baralon, Corine; Milon, Alain

    1996-01-01

    Two myxoma virus-rabbit hemorrhagic disease virus (RHDV) recombinant viruses were constructed with the SG33 strain of myxoma virus to protect rabbits against myxomatosis and rabbit viral hemorrhagic disease. These recombinant viruses expressed the RHDV capsid protein (VP60). The recombinant protein, which is 60 kDa in size, was antigenic, as revealed by its reaction in immunoprecipitation with antibodies raised against RHDV. Both recombinant viruses induced high levels of RHDV- and myxoma vir...

  2. Antigenic relationships among human rotaviruses as determined by outer capsid protein VP4.

    Science.gov (United States)

    Gorziglia, M; Larralde, G; Kapikian, A Z; Chanock, R M

    1990-01-01

    cDNA clones representing the VP4 gene of symptomatic human rotavirus strain KU (VP7 serotype 1) or DS-1 (VP7 serotype 2) or asymptomatic human rotavirus strain 1076 (VP7 serotype 2) were constructed and inserted into a baculovirus expression vector under the control of the polyhedrin promoter. The resulting recombinants expressed the appropriate authentic VP4 rotavirus outer capsid protein. Guinea pigs immunized with these VP4 proteins developed antibodies that neutralized infectivity of the rotavirus from which the immunizing VP4 was derived. These antisera were then used in neutralization tests to define the extent and distribution of VP4 antigenic polymorphism among human rotaviruses. Three distinct serotypes and one subtype of the VP4 outer capsid protein were identified among 17 human rotavirus strains that had previously been assigned to five distinct VP7 serotypes. For the most part, VP4 serotype segregated independently of VP7 serotype. Ten strains of human rotavirus that were associated with symptomatic infection and that exhibited VP7 serotype 1, 3, 4, or 9 specificity, each possessed a VP4 of the same serotype and subtype, designated VP4 serotype 1A. Both symptomatic human rotavirus strains with VP7 serotype 2 specificity were related by neutralization to the VP4 serotype 1A strains and were classified as a subtype of VP4 serotype 1--i.e., serotype 1B--since viruses of serotype 1A appeared to be prime strains. Four human rotavirus strains that were recovered from healthy infants in newborn nurseries in which virus transmission persisted over a long interval, belonged to VP7 serotype 1, 2, 3, or 4, but each strain possessed the same VP4 antigenic specificity that was designated VP4 serotype 2. Finally, a single strain of symptomatic human rotavirus of VP7 serotype 1 specificity possessed a unique VP4 that was provisionally classified as VP4 serotype 3 but this remains to be confirmed because neutralization tests were performed in only one direction. Among

  3. Structure of the immature HIV-1 capsid in intact virus particles at 8.8 Å resolution

    Science.gov (United States)

    Schur, Florian K. M.; Hagen, Wim J. H.; Rumlová, Michaela; Ruml, Tomáš; Müller, Barbara; Kräusslich, Hans-Georg; Briggs, John A. G.

    2015-01-01

    Human immunodeficiency virus type 1 (HIV-1) assembly proceeds in two stages. First, the 55 kilodalton viral Gag polyprotein assembles into a hexameric protein lattice at the plasma membrane of the infected cell, inducing budding and release of an immature particle. Second, Gag is cleaved by the viral protease, leading to internal rearrangement of the virus into the mature, infectious form. Immature and mature HIV-1 particles are heterogeneous in size and morphology, preventing high-resolution analysis of their protein arrangement in situ by conventional structural biology methods. Here we apply cryo-electron tomography and sub-tomogram averaging methods to resolve the structure of the capsid lattice within intact immature HIV-1 particles at subnanometre resolution, allowing unambiguous positioning of all α-helices. The resulting model reveals tertiary and quaternary structural interactions that mediate HIV-1 assembly. Strikingly, these interactions differ from those predicted by the current model based on in vitro-assembled arrays of Gag-derived proteins from Mason-Pfizer monkey virus. To validate this difference, we solve the structure of the capsid lattice within intact immature Mason-Pfizer monkey virus particles. Comparison with the immature HIV-1 structure reveals that retroviral capsid proteins, while having conserved tertiary structures, adopt different quaternary arrangements during virus assembly. The approach demonstrated here should be applicable to determine structures of other proteins at subnanometre resolution within heterogeneous environments.

  4. Multiple capsid-stabilizing interactions revealed in a high-resolution structure of an emerging picornavirus causing neonatal sepsis

    Science.gov (United States)

    Shakeel, Shabih; Westerhuis, Brenda M.; Domanska, Ausra; Koning, Roman I.; Matadeen, Rishi; Koster, Abraham J.; Bakker, Arjen Q.; Beaumont, Tim; Wolthers, Katja C.; Butcher, Sarah J.

    2016-07-01

    The poorly studied picornavirus, human parechovirus 3 (HPeV3) causes neonatal sepsis with no therapies available. Our 4.3-Å resolution structure of HPeV3 on its own and at 15 Å resolution in complex with human monoclonal antibody Fabs demonstrates the expected picornavirus capsid structure with three distinct features. First, 25% of the HPeV3 RNA genome in 60 sites is highly ordered as confirmed by asymmetric reconstruction, and interacts with conserved regions of the capsid proteins VP1 and VP3. Second, the VP0 N terminus stabilizes the capsid inner surface, in contrast to other picornaviruses where on expulsion as VP4, it forms an RNA translocation channel. Last, VP1's hydrophobic pocket, the binding site for the antipicornaviral drug, pleconaril, is blocked and thus inappropriate for antiviral development. Together, these results suggest a direction for development of neutralizing antibodies, antiviral drugs based on targeting the RNA-protein interactions and dissection of virus assembly on the basis of RNA nucleation.

  5. VP2 capsid domain of the H-1 parvovirus determines susceptibility of human cancer cells to H-1 viral infection.

    Science.gov (United States)

    Cho, I-R; Kaowinn, S; Song, J; Kim, S; Koh, S S; Kang, H-Y; Ha, N-C; Lee, K H; Jun, H-S; Chung, Y-H

    2015-05-01

    Although H-1 parvovirus is used as an antitumor agent, not much is known about the relationship between its specific tropism and oncolytic activity. We hypothesize that VP2, a major capsid protein of H-1 virus, determines H-1-specific tropism. To assess this, we constructed chimeric H-1 viruses expressing Kilham rat virus (KRV) capsid proteins, in their complete or partial forms. Chimeric H-1 viruses (CH1, CH2 and CH3) containing the whole KRV VP2 domain could not induce cytolysis in HeLa, A549 and Panc-1 cells. However, the other chimeric H-1 viruses (CH4 and CH5) expressing a partial KRV VP2 domain induced cytolysis. Additionally, the significant cytopathic effect caused by CH4 and CH5 infection in HeLa cells resulted from preferential viral amplification via DNA replication, RNA transcription and protein synthesis. Modeling of VP2 capsid protein showed that two variable regions (VRs) (VR0 and VR2) of H-1 VP2 protein protrude outward, because of the insertion of extra amino-acid residues, as compared with those of KRV VP2 protein. This might explain the precedence of H-1 VP2 protein over KRV in determining oncolytic activity in human cancer cells. Taking these results together, we propose that the VP2 protein of oncolytic H-1 parvovirus determines its specific tropism in human cancer cells.

  6. Structural determination of importin alpha in complex with beak and feather disease virus capsid nuclear localization signal

    Energy Technology Data Exchange (ETDEWEB)

    Patterson, Edward I. [Charles Sturt University, School of Animal and Veterinary Sciences, Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); EH Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); Dombrovski, Andrew K. [Charles Sturt University, School of Biomedical Sciences, Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); Swarbrick, Crystall M.D. [Charles Sturt University, School of Biomedical Sciences, Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); EH Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); Raidal, Shane R. [Charles Sturt University, School of Animal and Veterinary Sciences, Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); EH Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); Forwood, Jade K., E-mail: jforwood@csu.edu.au [Charles Sturt University, School of Biomedical Sciences, Boorooma St., Wagga Wagga, New South Wales 2678 (Australia); EH Graham Centre for Agricultural Innovation (NSW Department of Primary Industries and Charles Sturt University), Boorooma St., Wagga Wagga, New South Wales 2678 (Australia)

    2013-09-06

    Highlights: •Circovirus capsid proteins contain large nuclear localization signals (NLS). •A method of nuclear import has not been elucidated. •Beak and feather disease virus (BFDV) capsid NLS was crystallized with importin α. •The structure showed BFDV NLS binding to the major site of importin α. •Result shows implications for mechanism of nuclear transport for all circoviruses. -- Abstract: Circoviruses represent a rapidly increasing genus of viruses that infect a variety of vertebrates. Replication requires shuttling viral molecules into the host cell nucleus, a process facilitated by capsid-associated protein (Cap). Whilst a nuclear localization signal (NLS) has been shown to mediate nuclear translocation, the mode of nuclear transport remains to be elucidated. To better understand this process, beak and feather disease virus (BFDV) Cap NLS was crystallized with nuclear import receptor importin-α (Impα). Diffraction yielded structural data to 2.9 Å resolution, and the binding site on both Impα and BFDV Cap NLS were well resolved. The binding mechanism for the major site is likely conserved across circoviruses as supported by the similarity of NLSs in circovirus Caps. This finding illuminates a crucial step for infection of host cells by this viral family, and provides a platform for rational drug design against the binding interface.

  7. Effects of capsid-modified oncolytic adenoviruses and their combinations with gemcitabine or silica gel on pancreatic cancer.

    Science.gov (United States)

    Kangasniemi, Lotta; Parviainen, Suvi; Pisto, Tommi; Koskinen, Mika; Jokinen, Mika; Kiviluoto, Tuula; Cerullo, Vincenzo; Jalonen, Harry; Koski, Anniina; Kangasniemi, Anna; Kanerva, Anna; Pesonen, Sari; Hemminki, Akseli

    2012-07-01

    Conventional cancer treatments often have little impact on the course of advanced pancreatic cancer. Although cancer gene therapy with adenoviruses is a promising developmental approach, the primary receptor is poorly expressed in pancreatic cancers which might compromise efficacy and thus targeting to other receptors could be beneficial. Extended stealth delivery, combination with standard chemotherapy or circumvention of host antiadenoviral immune response might improve efficacy further. In this work, capsid-modified adenoviruses were studied for transduction of cell lines and clinical normal and tumor tissue samples. The respective oncolytic viruses were tested for oncolytic activity in vitro and in vivo. Survival was studied in a peritoneally disseminated pancreas cancer model, with or without concurrent gemcitabine while silica implants were utilized for extended intraperitoneal virus delivery. Immunocompetent mice and Syrian hamsters were used to study the effect of silica mediated delivery on antiviral immune responses and subsequent in vivo gene delivery. Capsid modifications selectively enhanced gene transfer to malignant pancreatic cancer cell lines and clinical samples. The respective oncolytic viruses resulted in increased cell killing in vitro, which translated into a survival benefit in mice. Early proinfammatory cytokine responses and formation of antiviral neutralizing antibodies was partially avoided with silica implants. The implant also shielded the virus from pre-existing neutralizing antibodies, while increasing the pancreas/liver gene delivery ratio six-fold. In conclusion, capsid modified adenoviruses would be useful for testing in pancreatic cancer trials. Silica implants might increase the safety and efficacy of the approach.

  8. Heat-shock protein 90 promotes nuclear transport of herpes simplex virus 1 capsid protein by interacting with acetylated tubulin.

    Directory of Open Access Journals (Sweden)

    Meigong Zhong

    Full Text Available Although it is known that inhibitors of heat shock protein 90 (Hsp90 can inhibit herpes simplex virus type 1 (HSV-1 infection, the role of Hsp90 in HSV-1 entry and the antiviral mechanisms of Hsp90 inhibitors remain unclear. In this study, we found that Hsp90 inhibitors have potent antiviral activity against standard or drug-resistant HSV-1 strains and viral gene and protein synthesis are inhibited in an early phase. More detailed studies demonstrated that Hsp90 is upregulated by virus entry and it interacts with virus. Hsp90 knockdown by siRNA or treatment with Hsp90 inhibitors significantly inhibited the nuclear transport of viral capsid protein (ICP5 at the early stage of HSV-1 infection. In contrast, overexpression of Hsp90 restored the nuclear transport that was prevented by the Hsp90 inhibitors, suggesting that Hsp90 is required for nuclear transport of viral capsid protein. Furthermore, HSV-1 infection enhanced acetylation of α-tubulin and Hsp90 interacted with the acetylated α-tubulin, which is suppressed by Hsp90 inhibition. These results demonstrate that Hsp90, by interacting with acetylated α-tubulin, plays a crucial role in viral capsid protein nuclear transport and may provide novel insight into the role of Hsp90 in HSV-1 infection and offer a promising strategy to overcome drug-resistance.

  9. Specificity of an anti-capsid antibody associated with Hepatitis B Virus-related acute liver failure.

    Science.gov (United States)

    Wu, Weimin; Chen, Zhaochun; Cheng, Naiqian; Watts, Norman R; Stahl, Stephen J; Farci, Patrizia; Purcell, Robert H; Wingfield, Paul T; Steven, Alasdair C

    2013-01-01

    Previously, the livers of patients suffering from acute liver failure (ALF), a potentially fatal syndrome arising from infection by Hepatitis B Virus (HBV), were found to contain massive amounts of an antibody specific for the core antigen (HBcAg) capsid. We have used cryo-electron microscopy and molecular modeling to define its epitope. HBV capsids are icosahedral shells with 25Å-long dimeric spikes, each a 4-helix bundle, protruding from the contiguous "floor". Of the anti-HBcAg antibodies previously characterized, most bind around the spike tip while one binds to the floor. The ALF-associated antibody binds tangentially to a novel site on the side of the spike. This epitope is conformational. The Fab binds with high affinity to its principal determinants but has lower affinities for quasi-equivalent variants. The highest occupancy site is on one side of a spike, with no detectable binding to the corresponding site on the other side. Binding of one Fab per dimer was also observed by analytical ultracentrifugation. The Fab did not bind to the e-antigen dimer, a non-assembling variant of capsid protein. These findings support the propositions that antibodies with particular specificities may correlate with different clinical expressions of HBV infection and that antibodies directed to particular HBcAg epitopes may be involved in ALF pathogenesis.

  10. An alternative model for CaCO3 over-shooting during the PETM : Biological carbonate compensation

    NARCIS (Netherlands)

    Luo, Yiming; Boudreau, Bernard P.; Dickens, Gerald R.; Sluijs, Appy; Middelburg, Jack J.

    2016-01-01

    Decreased CaCO3 content of deep-sea sediments argues for rapid and massive acidification of the oceans during the Paleocene–Eocene Thermal Maximum (PETM, ∼56 Ma BP). In the course of the subsequent recovery from this acidification, sediment CaCO3 content came to exceed pre-PETM levels, known as over

  11. Development of chitosan nanoparticles as drug delivery system for a prototype capsid inhibitor.

    Science.gov (United States)

    Xue, Meiyan; Hu, Steven; Lu, Yifei; Zhang, Yu; Jiang, Xutao; An, Sai; Guo, Yubo; Zhou, Xue; Hou, Huimin; Jiang, Chen

    2015-11-30

    Oral delivery of biopharmaceutics drug disposition classification system (BDDCS) Class II or IV drugs with poor aqueous solubility and poor enzymatic and/or metabolic stability is very challenging. Bay41-4109, a member of the heteroaryldihydropyrimidine (HAP) family, inhibits HBV replication by destabilizing capsid assembly. It pertains to class II of the BDDCS which has a practically insoluble solubility which is 38 μg/mL (LYSA) and the oral delivery resulted in low bioavailability. The purpose of the current research work was to develop and evaluate Bay41-4109 loaded chitosan nanoparticles to increase the solubility and bioavailability for treatment of HBV. The Bay41-4109 nanoparticles were prepared by gelation of chitosan with tripolyphosphate (TPP) through ionic cross-linking. A three-factor three-level central composite design (CCD) was introduced to perform the experiments. A quadratic polynomial model was generated to predict and evaluate the independent variables with respect to the dependent variables. Bay41-4109 was encapsulated in the chitosan nanoparticles were demonstrated by PLM, FTIR, DSC, XRD and TEM etc. The in vivo results suggest that Bay41-4109 nanoparticles have better bioavailability and would be a promising approach for oral delivery of Bay41-4109 for the treatment of HBV.

  12. Molecular variability analyses of Apple chlorotic leaf spot virus capsid protein

    Indian Academy of Sciences (India)

    T Rana; V Chandel; Y Kumar; R Ram; V Hallan; A A Zaidi

    2010-12-01

    The complete sequences of the coat protein (CP) gene of 26 isolates of Apple chlorotic leaf spot virus (ACLSV) from India were determined. The isolates were obtained from various pome (apple, pear and quince) and stone (plum, peach, apricot, almond and wild Himalayan cherry) fruit trees. Other previously characterized ACLSV isolates and Trichoviruses were used for comparative analysis. Indian ACLSV isolates among themselves and with isolates from elsewhere in the world shared 91–100% and 70–98% sequence identities at the amino acid and nucleotide levels, respectively. The highest degree of variability was observed in the middle portion with 9 amino acid substitutions in contrast to the N-terminal and C-terminal ends, which were maximally conserved with only 4 amino acid substitutions. In phylogenetic analysis no reasonable correlation between host species and/or geographic origin of the isolates was observed. Alignment with capsid protein genes of other Trichoviruses revealed the TaTao ACLSV peach isolate to be phylogenetically closest to Peach mosaic virus, Apricot pseudo chlorotic leaf spot virus and Cherry mottle leaf virus. Recombination analysis (RDP3 ver.2.6) done for all the available ACLSV complete CP sequences of the world and Indian isolates indicate no significant evidence of recombination. However, one recombination event among Indian ACLSV-CP isolates was detected. To the best of our knowledge, this is the first report of complete CP sequence variability study from India and also the first evidence of homologous recombination in ACLSV.

  13. Several recombinant capsid proteins of equine rhinitis a virus show potential as diagnostic antigens.

    Science.gov (United States)

    Li, Fan; Stevenson, Rachel A; Crabb, Brendan S; Studdert, Michael J; Hartley, Carol A

    2005-06-01

    Equine rhinitis A virus (ERAV) is a significant pathogen of horses and is also closely related to Foot-and-mouth disease virus (FMDV). Despite these facts, knowledge of the prevalence and importance of ERAV infections remains limited, largely due to the absence of a simple, robust diagnostic assay. In this study, we compared the antigenicities of recombinant full-length and fragmented ERAV capsid proteins expressed in Escherichia coli by using sera from experimentally infected and naturally exposed horses. We found that, from the range of antigens tested, recombinant proteins encompassing the C-terminal region of VP1, full-length VP2, and the N-terminal region of VP2 reacted specifically with antibodies present in sera from each of the five experimentally infected horses examined. Antibodies to epitopes on VP2 (both native and recombinant forms) persisted longer postinfection (>105 days) than antibodies specific for epitopes on other fragments. Our data also suggest that B-cell epitopes within the C terminus of VP1 and N terminus of VP2 contribute to a large proportion of the total reactivity of recombinant VP1 and VP2, respectively. Importantly, the reactivity of these VP1 and VP2 recombinant proteins in enzyme-linked immunosorbent assays (ELISAs) correlated well with the results from a range of native antigen-based serological assays using sera from 12 field horses. This study provides promising candidates for development of a diagnostic ERAV ELISA.

  14. Subcellular localization and rearrangement of endoplasmic reticulum by Brome mosaic virus capsid protein.

    Science.gov (United States)

    Bamunusinghe, Devinka; Seo, Jang-Kyun; Rao, A L N

    2011-03-01

    Genome packaging in the plant-infecting Brome mosaic virus (BMV), a member of the alphavirus-like superfamily, as well as in other positive-strand RNA viruses pathogenic to humans (e.g., poliovirus) and animals (e.g., Flock House virus), is functionally coupled to replication. Although the subcellular localization site of BMV replication has been identified, that of the capsid protein (CP) has remained elusive. In this study, the application of immunofluorescence confocal microscopy to Nicotiana benthamiana leaves expressing replication-derived BMV CP as a green fluorescent protein (GFP) fusion, in conjunction with antibodies to the CP and double-stranded RNA, a presumed marker of RNA replication, revealed that the subcellular localization sites of replication and CP overlap. Our temporal analysis by transmission electron microscopy of ultrastructural modifications induced in BMV-infected N. benthamiana leaves revealed a reticulovesicular network of modified endoplasmic reticulum (ER) incorporating large assemblies of vesicles derived from ER accumulated in the cytoplasm during BMV infection. Additionally, for the first time, we have found by ectopic expression experiments that BMV CP itself has the intrinsic property of modifying ER to induce vesicles similar to those present in BMV infections. The significance of CP-induced vesicles in relation to CP-organized viral functions that are linked to replication-coupled packaging is discussed.

  15. Self-assembly of nanoparticles into biomimetic capsid-like nanoshells

    Science.gov (United States)

    Yang, Ming; Chan, Henry; Zhao, Gongpu; Bahng, Joong Hwan; Zhang, Peijun; Král, Petr; Kotov, Nicholas A.

    2017-03-01

    Nanoscale compartments are one of the foundational elements of living systems. Capsids, carboxysomes, exosomes, vacuoles and other nanoshells easily self-assemble from biomolecules such as lipids or proteins, but not from inorganic nanomaterials because of difficulties with the replication of spherical tiling. Here we show that stabilizer-free polydispersed inorganic nanoparticles (NPs) can spontaneously organize into porous nanoshells. The association of water-soluble CdS NPs into self-limited spherical capsules is the result of scale-modified electrostatic, dispersion and other colloidal forces. They cannot be accurately described by the Derjaguin-Landau-Vervey-Overbeek theory, whereas molecular-dynamics simulations with combined atomistic and coarse-grained description of NPs reveal the emergence of nanoshells and some of their stabilization mechanisms. Morphology of the simulated assemblies formed under different conditions matched nearly perfectly the transmission electron microscopy tomography data. This study bridges the gap between biological and inorganic self-assembling nanosystems and conceptualizes a new pathway to spontaneous compartmentalization for a wide range of inorganic NPs including those existing on prebiotic Earth.

  16. A Novel Pharmacophore Model Derived from a Class of Capsid Protein Enterovirus 71 Inhibitors

    Institute of Scientific and Technical Information of China (English)

    DUAN Hong-Xia; YANG Xin-Ling; WANG Dao-Quan; NING Jun; MEI Xiang-Dong; ZHANG Jian

    2012-01-01

    Capsid protein enterovirus 71 (EV71) is one of the major viruses that cause the severe encephalitis and thus result in a high mortality in children less than 5 years of age.In an effort to discover new potent inhibitors against EV71,a novel three-dimensional pharmacophore model was developed on 24 inhibitors with different molecular structures and bioactivities.The best hypothesis (Hypo1) has a high predictive power and consists of four features,namely,one hydrophobic point (HY) and three hydrogen-bond acceptors (HA).Two key features of the best Hypo1,HY1 and HA3 match well with an important narrow hydrophobic canyon and with the surface of LYS274 in the target EV71 active site,respectively.The more versatile feature,HA1,is firstly found to be very influential on these compounds’ bioactivities,which may interact with the other side of the active site in the EV71 receptor.The application of the model is successful in predicting the activities of 30 known EV71 inhibitors with a correlation coefficient of 0.831.Furthermore,Hypo1 demonstrates a superior screening capability for retrieving inhibitors from the database with a high enrichment factor of 70.This study provides some important clues in search for more potent inhibitors against EV71 infection.

  17. Human serum antibodies to a major defined epitope of human herpesvirus 8 small viral capsid antigen.

    Science.gov (United States)

    Tedeschi, R; De Paoli, P; Schulz, T F; Dillner, J

    1999-04-01

    The major antibody-reactive epitope of the small viral capsid antigen (sVCA) of human herpesvirus 8 (HHV-8) was defined by use of overlapping peptides. Strong IgG reactivity was found among approximately 50% of 44 human immunodeficiency virus-positive or -negative patients with Kaposi's sarcoma and 13 subjects who were seropositive by immunofluorescence assay (IFA) for the latent HHV-8 nuclear antigen. Only 1 of 106 subjects seronegative for both lytic and latent HHV-8 antigens and 10 of 81 subjects IFA-seropositive only for the lytic HHV-8 antigen had strong IgG reactivity to this epitope. Among 534 healthy Swedish women, only 1.3% were strongly seropositive. Comparison of the peptide-based and purified sVCA protein-based ELISAs found 55% sensitivity and 98% specificity. However, only 1 of 452 serum samples from healthy women was positive in both tests. In conclusion, the defined sVCA epitope was a specific, but not very sensitive, serologic marker of active HHV-8 infection. Such infection appears to be rare among Swedish women, even with sexual risk-taking behavior.

  18. Maize rayado fino virus capsid proteins assemble into virus-like particles in Escherichia coli.

    Science.gov (United States)

    Hammond, Rosemarie W; Hammond, John

    2010-02-01

    Maize rayado fino virus (MRFV; genus Marafivirus; family Tymoviridae) is an isometric plant virus of 30 nm containing two components: empty shells and complete virus particles (encapsidating the 6.3 kb genomic RNA). Both particles are composed of two serologically related, carboxy co-terminal, coat proteins (CP) of apparent molecular mass 21-22 kDa (CP2) and 24-28 kDa (CP1) in a molar ratio of 3:1, respectively; CP1 contains a 37 amino acid amino terminal extension of CP2. In our study, expression of CP1 or CP2 in Escherichia coli resulted in assembly of each capsid protein into virus-like particles (VLPs), appearing in electron microscopy as stain-permeable (CP2) or stain-impermeable particles (CP1). CP1 VLPs encapsidated bacterial 16S ribosomal RNA, but not CP mRNA, while CP2 VLPs encapsidated neither CP mRNA nor 16S ribosomal RNA. Expression of CP1 and CP2 in E. coli using a co-expression vector resulted in the assembly of VLPs which were stain-impermeable and encapsidated CP mRNA. These results suggest that the N-terminal 37 amino acid residues of CP1, although not required for particle formation, may be involved in the assembly of complete virions and that the presence of both CP1 and CP2 in the particle is required for specific encapsidation of MRFV CP mRNA.

  19. Mechanical and assembly units of viral capsids identified via quasi-rigid domain decomposition.

    Directory of Open Access Journals (Sweden)

    Guido Polles

    Full Text Available Key steps in a viral life-cycle, such as self-assembly of a protective protein container or in some cases also subsequent maturation events, are governed by the interplay of physico-chemical mechanisms involving various spatial and temporal scales. These salient aspects of a viral life cycle are hence well described and rationalised from a mesoscopic perspective. Accordingly, various experimental and computational efforts have been directed towards identifying the fundamental building blocks that are instrumental for the mechanical response, or constitute the assembly units, of a few specific viral shells. Motivated by these earlier studies we introduce and apply a general and efficient computational scheme for identifying the stable domains of a given viral capsid. The method is based on elastic network models and quasi-rigid domain decomposition. It is first applied to a heterogeneous set of well-characterized viruses (CCMV, MS2, STNV, STMV for which the known mechanical or assembly domains are correctly identified. The validated method is next applied to other viral particles such as L-A, Pariacoto and polyoma viruses, whose fundamental functional domains are still unknown or debated and for which we formulate verifiable predictions. The numerical code implementing the domain decomposition strategy is made freely available.

  20. Engineering bacterial surface displayed human norovirus capsid proteins: A novel system to explore interaction between norovirus and ligands

    Directory of Open Access Journals (Sweden)

    Mengya eNiu

    2015-12-01

    Full Text Available Human noroviruses (HuNoVs are major contributors to acute nonbacterial gastroenteritis outbreaks. Many aspects of HuNoVs are poorly understood due to both the current inability to culture HuNoVs, and the lack of efficient small animal models. Surrogates for HuNoVs, such as recombinant viral like particles (VLPs expressed in eukaryotic system or P particles expressed in prokaryotic system, have been used for studies in immunology and interaction between the virus and its receptors. However, it is difficult to use VLPs or P particles to collect or isolate potential ligands binding to these recombinant capsid proteins. In this study, a new strategy was used to collect HuNoVs binding ligands through the use of ice nucleation protein (INP to display recombinant capsid proteins of HuNoVs on bacterial surfaces. The viral protein-ligand complex could be easily separated by a low speed centrifugation step. This system was also used to explore interaction between recombinant capsid proteins of HuNoVs and their receptors. In this system, the VP1 capsid encoding gene (ORF2 and the protruding domain (P domain encoding gene (3’ terminal fragment of ORF2 of HuNoVs GI.1 and GII.4 were fused with 5’ terminal fragment of ice nucleation protein encoding gene (inaQn. The results demonstrated that the recombinant VP1 and P domains of HuNoVs were expressed and anchored on the surface of Escherichia coli BL21 cells after the bacteria were transformed with the corresponding plasmids. Both cell surface displayed VP1 and P domains could be recognized by HuNoVs specific antibodies and interact with the viral histo-blood group antigens receptors. In both cases, displayed P domains had better binding abilities than VP1. This new strategy of using displayed HuNoVs capsid proteins on the bacterial surface could be utilized to separate HuNoVs binding components from complex samples, to investigate interaction between the virus and its receptors, as well as to develop an

  1. Contact Aligner 2 (Front Side): Suss Microtec MA8

    Data.gov (United States)

    Federal Laboratory Consortium — Description:CORAL Name: SussMA8This system utilizes 1X contact lithography to transfer photomask patterns onto substrates Specifications / Capabilities:UV broadband...

  2. 76 FR 19911 - Drawbridge Operation Regulations; Apponagansett River, Dartmouth, MA

    Science.gov (United States)

    2011-04-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Apponagansett River, Dartmouth, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The...

  3. 76 FR 37041 - Drawbridge Operation Regulation; Apponagansett River, Dartmouth, MA

    Science.gov (United States)

    2011-06-24

    ..., issue of the Federal Register (73 FR 3316). Public Meeting We do not now plan to hold a public meeting..., Dartmouth, MA AGENCY: Coast Guard, DHS. ACTION: Notice of proposed rulemaking. SUMMARY: The Coast...

  4. 77 FR 25890 - Drawbridge Operation Regulations; Manchester Harbor, Manchester, MA

    Science.gov (United States)

    2012-05-02

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Manchester Harbor, Manchester, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The...

  5. Zhi Liao:Ma Liang Solo Visual Exhibition

    Institute of Scientific and Technical Information of China (English)

    Jade; Franklin

    2007-01-01

    can prove to be simultaneously amusing and macabre, as if to him there is no distinction between the two. Prior to focusing on photography Ma Liang worked as a short-film director and cinematographer. The evidence of this is

  6. 1420 Ma diabasic intrusives from the Mesoproterozoic Singhora Group, Chhattisgarh Supergroup, India: Implications towards non-plume intrusive activity

    Indian Academy of Sciences (India)

    Priyabrata Das; Kaushik Das; Partha Pratim Chakraborty; S Balakrishnan

    2011-04-01

    Besides offering significant clues towards tracking the geochemical evolution of the mantle and architectural reconstruction of different ‘supercontinent’, geochronological and geochemical appraisal of igneous inputs are also important to bracket the depositional time frame of any lithopackage, particularly, the unfossiliferous sedimentary successions. The present study deals with diabasic intrusive within Mesoproterozoic Saraipalli Formation, which is an argillaceous constituent present at the basal part of nearly 400 m thick four-tiered unmetamorphosed but deformed sedimentary succession of Singhora Group, Chhattisgarh Supergroup, central India. The SE–NW trending intrusive comprises mainly of plagioclase and augite together with minor orthopyroxene, biotite and opaque minerals. Though some plagioclase laths are partially sericitized, the ophitic-to-subophitic texture of the rock is well preserved. Major and trace element geochemical data indicate that this intrusive is basalt-to-basaltic andesite in character and of subalkaline basalt affinity. Multi-element plot shows overall LILE-enrichment and enrichment of Pb and slight depletion of Nb and P, coupled with moderate La/Nb and Th/Nb ratios. Zr, Y and Nb ternary diagrams plot in the fields of within plate basalt. Selected HFSE ratios indicate a non-plume source with crustal assimilation/sediment mixing. Sm–Nd and Rb–Sr isotope data show that the intrusive has Srinitial and Ndinitial of 0.709377–0.706672 and 0.510919–0.510815, respectively. Positive tNd [t = 1420 Ma] values (+0.3 to + 2.3) indicate depleted isotopic nature of their protolith. The calculated DM age is 1.7–1.9 Ga. The mineral-whole rock isochron data (Sm–Nd systematics) of the intrusive implies an emplacement age of ca. 1420 Ma. Considering synchronous terrain boundary shear zone development in Bastar craton on the southeastern part of the Singhora basin, mafic magmatism in Eastern Ghats and large-scale basic intrusion in Sausar

  7. MaNGA: Mapping Nearby Galaxies at Apache Point Observatory

    CERN Document Server

    Weijmans, Anne-Marie

    2015-01-01

    MaNGA (Mapping Nearby Galaxies at APO) is a galaxy integral-field spectroscopic survey within the fourth generation Sloan Digital Sky Survey (SDSS-IV). It will be mapping the composition and kinematics of gas and stars in 10,000 nearby galaxies, using 17 differently sized fiber bundles. MaNGA's goal is to provide new insights in galaxy formation and evolution, and to deliver a local benchmark for current and future high-redshift studies.

  8. 46 CFR 7.15 - Massachusetts Bay, MA.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 1 2010-10-01 2010-10-01 false Massachusetts Bay, MA. 7.15 Section 7.15 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY PROCEDURES APPLICABLE TO THE PUBLIC BOUNDARY LINES Atlantic Coast § 7.15 Massachusetts Bay, MA. A line drawn from latitude 42°37.9′ N. longitude 70°31.2′ W. (Cape...

  9. A new 40 MA ranchero explosive pulsed power system

    Energy Technology Data Exchange (ETDEWEB)

    Goforth, James [Los Alamos National Laboratory; Herrera, Dennis [Los Alamos National Laboratory; Oona, Hank [Los Alamos National Laboratory; Torres, David [Los Alamos National Laboratory; Atchison, W L [Los Alamos National Laboratory; Colgate, S A [Los Alamos National Laboratory; Griego, J R [Los Alamos National Laboratory; Guzik, J [Los Alamos National Laboratory; Holtkamp, D B [Los Alamos National Laboratory; Idzorek, G [Los Alamos National Laboratory; Kaul, A [Los Alamos National Laboratory; Kirkpatrick, R C [Los Alamos National Laboratory; Menikoff, R [Los Alamos National Laboratory; Reardon, P T [Los Alamos National Laboratory; Reinovsky, R E [Los Alamos National Laboratory; Rousculp, C L [Los Alamos National Laboratory; Sgro, A G [Los Alamos National Laboratory; Tabaka, L J [Los Alamos National Laboratory; Tierney, T E [Los Alamos National Laboratory; Watt, R G [Los Alamos National Laboratory

    2009-01-01

    We are developing a new high explosive pulsed power (HEPP) system based on the 1.4 m long Ranchero generator which was developed in 1999 for driving solid density z-pinch loads. The new application requires approximately 40 MA to implode similar liners, but the liners cannot tolerate the 65 {micro}s, 3 MA current pulse associated with delivering the initial magnetic flux to the 200 nH generator. To circumvent this problem, we have designed a system with an internal start switch and four explosively formed fuse (EFF) opening switches. The integral start switch is installed between the output glide plane and the armature. It functions in the same manner as a standard input crowbar switch when armature motion begins, but initially isolates the load. The circuit is completed during the flux loading phase using post hole convolutes. Each convolute attaches the inner (coaxial) output transmission line to the outside of the outer coax through a penetration of the outer coaxial line. The attachment is made with the conductor of an EFF at each location. The EFFs conduct 0.75 MA each, and are actuated just after the internal start switch connects to the load. EFFs operating at these parameters have been tested in the past. The post hole convolutes must withstand as much as 80 kV at peak dl/dt during the Ranchero load current pulse. We describe the design of this new HEPP system in detail, and give the experimental results available at conference time. In addition, we discuss the work we are doing to test the upper current limits of a single standard size Ranchero module. Calculations have suggested that the generator could function at up to {approx}120 MA, the rule of thumb we follow (1 MA/cm) suggests 90 MA, and simple flux compression calculations, along with the {approx}4 MA seed current available from our capacitor bank, suggests 118 MA is the currently available upper limit.

  10. MaNGA: Mapping Nearby Galaxies at Apache Point Observatory

    Science.gov (United States)

    Weijmans, A.-M.; MaNGA Team

    2016-10-01

    MaNGA (Mapping Nearby Galaxies at APO) is a galaxy integral-field spectroscopic survey within the fourth generation Sloan Digital Sky Survey (SDSS-IV). It will be mapping the composition and kinematics of gas and stars in 10,000 nearby galaxies, using 17 differently sized fiber bundles. MaNGA's goal is to provide new insights in galaxy formation and evolution, and to deliver a local benchmark for current and future high-redshift studies.

  11. SDSS-IV MaNGA: Project Overview

    Science.gov (United States)

    Bundy, Kevin; MaNGA Team

    2016-01-01

    I present an overview of the scientific motivation and basic design of the Sloan Digital Sky Survey-IV program, MaNGA: Mapping Nearby Galaxies at Apache Point Observatory. MaNGA is currently in its second year of operations with roughly 2000 galaxies now observed, already the largest integral field spectroscopic survey of galaxies ever conducted. By combining the wealth of information made available by resolved spectroscopy with the statistical power of a sample of 10,000 galaxies, MaNGA is providing transformative insights on key questions about the life history of galaxies. These questions range from the nature of growth of star-forming disks and stellar spheroidals, to the physical origin of star formation quenching, to the ways in which the different mass components in galaxies interact and assemble over time. MaNGA's success owes to a dedicated team of scientists, engineers, and observers working to optimize the survey operations and develop advanced data processing, analysis, and interface tools in order to fully realize MaNGA's exciting potential. Continuing in the Sloan tradition, MaNGA data products will be made publicly available, with the first release scheduled for Summer 2016.

  12. A Mason-Pfizer Monkey virus Gag-GFP fusion vector allows visualization of capsid transport in live cells and demonstrates a role for microtubules.

    Directory of Open Access Journals (Sweden)

    Jasmine Clark

    Full Text Available Immature capsids of the Betaretrovirus, Mason-Pfizer Monkey virus (M-PMV, are assembled in the pericentriolar region of the cell, and are then transported to the plasma membrane for budding. Although several studies, utilizing mutagenesis, biochemistry, and immunofluorescence, have defined the role of some viral and host cells factors involved in these processes, they have the disadvantage of population analysis, rather than analyzing individual capsid movement in real time. In this study, we created an M-PMV vector in which the enhanced green fluorescent protein, eGFP, was fused to the carboxyl-terminus of the M-PMV Gag polyprotein, to create a Gag-GFP fusion that could be visualized in live cells. In order to express this fusion protein in the context of an M-PMV proviral backbone, it was necessary to codon-optimize gag, optimize the Kozak sequence preceding the initiating methionine, and mutate an internal methionine codon to one for alanine (M100A to prevent internal initiation of translation. Co-expression of this pSARM-Gag-GFP-M100A vector with a WT M-PMV provirus resulted in efficient assembly and release of capsids. Results from fixed-cell immunofluorescence and pulse-chase analyses of wild type and mutant Gag-GFP constructs demonstrated comparable intracellular localization and release of capsids to untagged counterparts. Real-time, live-cell visualization and analysis of the GFP-tagged capsids provided strong evidence for a role for microtubules in the intracellular transport of M-PMV capsids. Thus, this M-PMV Gag-GFP vector is a useful tool for identifying novel virus-cell interactions involved in intracellular M-PMV capsid transport in a dynamic, real-time system.

  13. Increase in physical activities in kindergarten children with cerebral palsy by employing MaKey-MaKey-based task systems.

    Science.gov (United States)

    Lin, Chien-Yu; Chang, Yu-Ming

    2014-09-01

    In this study, we employed Flash- and Scratch-based multimedia by using a MaKey-MaKey-based task system to increase the motivation level of children with cerebral palsy to perform physical activities. MaKey MaKey is a circuit board that converts physical touch to a digital signal, which is interpreted by a computer as a keyboard message. In this study, we used conductive materials to control this interaction. This study followed single-case design using ABAB models in which A indicated the baseline and B indicated the intervention. The experiment period comprised 1 month and a half. The experimental results demonstrated that in the case of two kindergarten children with cerebral palsy, their scores were considerably increased during the intervention phrases. The developmental applications of the results are also discussed.

  14. 75 FR 38128 - Sensata Technologies MA, Inc., Power Controls Division, Formerly Known As Airpax Corp., Cambridge...

    Science.gov (United States)

    2010-07-01

    ... Employment and Training Administration Sensata Technologies MA, Inc., Power Controls Division, Formerly Known..., 2010, applicable to workers of Sansata Technologies MA, Incorporated, Power Controls Division, formerly... under the control of the Cambridge, Maryland location of Sensata Technologies MA, Incorporated,...

  15. The Ca(2+)/Calmodulin/CaMKK2 Axis: Nature's Metabolic CaMshaft.

    Science.gov (United States)

    Marcelo, Kathrina L; Means, Anthony R; York, Brian

    2016-10-01

    Calcium (Ca(2+)) is an essential ligand that binds its primary intracellular receptor calmodulin (CaM) to trigger a variety of downstream processes and pathways. Central to the actions of Ca(2+)/CaM is the activation of a highly conserved Ca(2+)/CaM kinase (CaMK) cascade that amplifies Ca(2+) signals through a series of subsequent phosphorylation events. Proper regulation of Ca(2+) flux is necessary for whole-body metabolism and disruption of Ca(2+) homeostasis has been linked to various metabolic diseases. Here we provide a synthesis of recent advances that highlight the roles of the Ca(2+)/CaMK axis in key metabolic tissues. An appreciation of this information is critical to understanding the mechanisms by which Ca(2+)/CaM-dependent signaling contributes to metabolic homeostasis and disease.

  16. Conserved Tryptophan Motifs in the Large Tegument Protein pUL36 Are Required for Efficient Secondary Envelopment of Herpes Simplex Virus Capsids

    Science.gov (United States)

    Ivanova, Lyudmila; Buch, Anna; Döhner, Katinka; Pohlmann, Anja; Binz, Anne; Prank, Ute; Sandbaumhüter, Malte

    2016-01-01

    ABSTRACT Herpes simplex virus (HSV) replicates in the skin and mucous membranes, and initiates lytic or latent infections in sensory neurons. Assembly of progeny virions depends on the essential large tegument protein pUL36 of 3,164 amino acid residues that links the capsids to the tegument proteins pUL37 and VP16. Of the 32 tryptophans of HSV-1-pUL36, the tryptophan-acidic motifs 1766WD1767 and 1862WE1863 are conserved in all HSV-1 and HSV-2 isolates. Here, we characterized the role of these motifs in the HSV life cycle since the rare tryptophans often have unique roles in protein function due to their large hydrophobic surface. The infectivity of the mutants HSV-1(17+)Lox-pUL36-WD/AA-WE/AA and HSV-1(17+)Lox-CheVP26-pUL36-WD/AA-WE/AA, in which the capsid has been tagged with the fluorescent protein Cherry, was significantly reduced. Quantitative electron microscopy shows that there were a larger number of cytosolic capsids and fewer enveloped virions compared to their respective parental strains, indicating a severe impairment in secondary capsid envelopment. The capsids of the mutant viruses accumulated in the perinuclear region around the microtubule-organizing center and were not dispersed to the cell periphery but still acquired the inner tegument proteins pUL36 and pUL37. Furthermore, cytoplasmic capsids colocalized with tegument protein VP16 and, to some extent, with tegument protein VP22 but not with the envelope glycoprotein gD. These results indicate that the unique conserved tryptophan-acidic motifs in the central region of pUL36 are required for efficient targeting of progeny capsids to the membranes of secondary capsid envelopment and for efficient virion assembly. IMPORTANCE Herpesvirus infections give rise to severe animal and human diseases, especially in young, immunocompromised, and elderly individuals. The structural hallmark of herpesvirus virions is the tegument, which contains evolutionarily conserved proteins that are essential for several

  17. Antigenic and Cryo-Electron Microscopy Structure Analysis of a Chimeric Sapovirus Capsid.

    Science.gov (United States)

    Miyazaki, Naoyuki; Taylor, David W; Hansman, Grant S; Murata, Kazuyoshi

    2015-12-23

    The capsid protein (VP1) of all caliciviruses forms an icosahedral particle with two principal domains, shell (S) and protruding (P) domains, which are connected via a flexible hinge region. The S domain forms a scaffold surrounding the nucleic acid, while the P domains form a homodimer that interacts with receptors. The P domain is further subdivided into two subdomains, termed P1 and P2. The P2 subdomain is likely an insertion in the P1 subdomain; consequently, the P domain is divided into the P1-1, P2, and P1-2 subdomains. In order to investigate capsid antigenicity, N-terminal (N-term)/S/P1-1 and P2/P1-2 were switched between two sapovirus genotypes GI.1 and GI.5. The chimeric VP1 constructs were expressed in insect cells and were shown to self-assemble into virus-like particles (VLPs) morphologically similar to the parental VLPs. Interestingly, the chimeric VLPs had higher levels of cross-reactivities to heterogeneous antisera than the parental VLPs. In order to better understand the antigenicity from a structural perspective, we determined an intermediate-resolution (8.5-Å) cryo-electron microscopy (cryo-EM) structure of a chimeric VLP and developed a VP1 homology model. The cryo-EM structure revealed that the P domain dimers were raised slightly (∼5 Å) above the S domain. The VP1 homology model allowed us predict the S domain (67-229) and P1-1 (229-280), P2 (281-447), and P1-2 (448-567) subdomains. Our results suggested that the raised P dimers might expose immunoreactive S/P1-1 subdomain epitopes. Consequently, the higher levels of cross-reactivities with the chimeric VLPs resulted from a combination of GI.1 and GI.5 epitopes. We developed sapovirus chimeric VP1 constructs and produced the chimeric VLPs in insect cells. We found that both chimeric VLPs had a higher level of cross-reactivity against heterogeneous VLP antisera than the parental VLPs. The cryo-EM structure of one chimeric VLP (Yokote/Mc114) was solved to 8.5-Å resolution. A homology model

  18. Geochemistry of Late Cretaceous (60- 67 Ma) igneous activities in the Hebrides Terrace seamount (guyot) area, Scotland

    Institute of Scientific and Technical Information of China (English)

    M. El-Tokhi; M. Omran; A. El-Muslem

    2005-01-01

    Tholeiitic basalts in various stages of alteration were dredged from Late Cretaceous volcanic rocks (60 -67 Ma) in the Hebrides Terrace seamount area in the Atlantic Ocean. These rocks are extrusive olivine basalts, including high- and low-Al basalts. High-Al basalts are depleted in MgO, CaO, Cr,Sc, V, Sr, Zr and enriched in TiO2, Na2 O, Nb, Rb as compared with low-Al basalts. Petrography and bulk-rock composition (major, trace and rare-earth elements) data defined clear tholeiitic suites displaying possible liquid lines of descent related to different degrees of crystal fractionation and partial melting.Isotopic dating of dredged samples gave the guyot an age of 60 - 67 Ma, in support of the assumption that it was formed during the Late Cretaceous.

  19. Identification of two neutralization epitopes on the capsid protein of avian hepatitis E virus.

    Science.gov (United States)

    Zhou, E-M; Guo, H; Huang, F F; Sun, Z F; Meng, X J

    2008-02-01

    Avian hepatitis E virus (avian HEV) is genetically and antigenically related to human HEV, the causative agent of hepatitis E. To identify the neutralizing epitopes on the capsid (ORF2) protein of avian HEV, four mAbs (7B2, 1E11, 10A2 and 5G10) against recombinant avian HEV ORF2 protein were generated. mAbs 7B2, 1E11 and 10A2 blocked each other for binding to avian HEV ORF2 protein in a competitive ELISA, whereas 5G10 did not block the other mAbs, suggesting that 7B2, 1E11 and 10A2 recognize the same or overlapping epitopes and 5G10 recognizes a different one. The epitopes recognized by 7B2, 1E11 and 10A2, and by 5G10 were mapped by Western blotting between aa 513 and 570, and between aa 476 and 513, respectively. mAbs 1E11, 10A2 and 5G10 were shown to bind to avian HEV particles in vitro, although only 5G10 reacted to viral antigens in transfected LMH cells. To assess the neutralizing activities of the mAbs, avian HEV was incubated in vitro with each mAb before inoculation into specific-pathogen-free chickens. Both viraemia and faecal virus shedding were delayed in chickens inoculated with the mixtures of avian HEV and 1E11, 10A2 or 5G10, suggesting that these three mAbs partially neutralize avian HEV.

  20. A replicating adenovirus capsid display recombinant elicits antibodies against Plasmodium falciparum sporozoites in Aotus nancymaae monkeys.

    Science.gov (United States)

    Karen, Kasey A; Deal, Cailin; Adams, Robert J; Nielsen, Carolyn; Ward, Cameron; Espinosa, Diego A; Xie, Jane; Zavala, Fidel; Ketner, Gary

    2015-01-01

    Decades of success with live adenovirus vaccines suggest that replication-competent recombinant adenoviruses (rAds) could serve as effective vectors for immunization against other pathogens. To explore the potential of a live rAd vaccine against malaria, we prepared a viable adenovirus 5 (Ad5) recombinant that displays a B-cell epitope from the circumsporozoite protein (CSP) of Plasmodium falciparum on the virion surface. The recombinant induced P. falciparum sporozoite-neutralizing antibodies in mice. Human adenoviruses do not replicate in mice. Therefore, to examine immunogenicity in a system in which, as in humans, the recombinant replicates, we constructed a similar recombinant in an adenovirus mutant that replicates in monkey cells and immunized four Aotus nancymaae monkeys. The recombinant replicated in the monkeys after intratracheal instillation, the first demonstration of replication of human adenoviruses in New World monkeys. Immunization elicited antibodies both to the Plasmodium epitope and the Ad5 vector. Antibodies from all four monkeys recognized CSP on intact parasites, and plasma from one monkey neutralized sporozoites in vitro and conferred partial protection against P. falciparum sporozoite infection after passive transfer to mice. Prior enteric inoculation of two animals with antigenically wild-type adenovirus primed a response to the subsequent intratracheal inoculation, suggesting a route to optimizing performance. A vaccine is not yet available against P. falciparum, which induces the deadliest form of malaria and kills approximately one million children each year. The live capsid display recombinant described here may constitute an early step in a critically needed novel approach to malaria immunization. Copyright © 2015, American Society for Microbiology. All Rights Reserved.

  1. Characterization of virus-like particles and identification of capsid proteins in Xanthophyllomyces dendrorhous.

    Science.gov (United States)

    Flores, Oriana; Alcaíno, Jennifer; Fernandez-Lobato, María; Cifuentes, Víctor; Baeza, Marcelo

    2015-04-01

    Two dsRNAs of estimated lengths of 5 (L1) and 3.7 (L2) kpb are commonly found in strains of the basidiomycetous yeast Xanthophyllomyces dendrorhous, and the presence of virus-like particles (VLPs) have been described in some strains. Recently, two putative totiviruses (XdV-L1A and XdV-L1B) were identified from L1 dsRNA and one (XdV-L2) from L2 dsRNA in the strain UCD 67-385. In some strains, there are smaller dsRNAs (0.9-1.4 kb) that probable are satellite elements. In this work, the VLPs from several strains of X. dendrorhous, which differ in their dsRNAs content, were separated by sucrose gradient and characterized in relation to the dsRNAs and proteins that compose them. It was found that all types of dsRNAs were encapsidated into VLPs, supporting the hypothesis that the smaller dsRNAs are satellite molecules. A main protein of approx. 76 or 37 kDa composed the virions that only have the L1-dsRNA or L2-dsRNA, respectively. In the strain UCD 67-385, these both proteins were identified as viral capsid protein (CP), allow to confirm the gag predicted ORFs in XdV-L1A, XdV-L1B, and XdV-L2, with CPs of 76.6, 76.2, and 38.8 kDa, respectively. Analysis of predicted structures of CPs of XdV-L1A and XdV-L1B, showed high similitudes with the CPs of ScV-L-A and other totiviruses.

  2. Molecular evolution of the Sorghum Maturity Gene Ma3.

    Science.gov (United States)

    Wang, Yan; Tan, Lubin; Fu, Yongcai; Zhu, Zuofeng; Liu, Fengxia; Sun, Chuanqing; Cai, Hongwei

    2015-01-01

    Time to maturity is a critical trait in sorghum (Sorghum bicolor) breeding, as it determines whether a variety can be grown in a particular cropping system or ecosystem. Understanding the nucleotide variation and the mechanisms of molecular evolution of the maturity genes would be helpful for breeding programs. In this study, we analyzed the nucleotide diversity of Ma3, an important maturity gene in sorghum, using 252 cultivated and wild sorghum materials from all over the world. The nucleotide variation and diversity were analyzed based both on race- and usage-based groups. We also sequenced 12 genes around the Ma3 gene in 185 of these materials to search for a selective sweep and found that purifying selection was the strongest force on Ma3, as low nucleotide diversity and low-frequency amino acid variants were observed. However, a very special mutation, described as ma3R, seemed to be under positive selection, as indicated by dramatically reduced nucleotide variation not only at the loci but also in the surrounding regions among individuals carrying the mutations. In addition, in an association study using the Ma3 nucleotide variations, we detected 3 significant SNPs for the heading date at a high-latitude environment (Beijing) and 17 at a low-latitude environment (Hainan). The results of this study increases our understanding of the evolutionary mechanisms of the maturity genes in sorghum and will be useful in sorghum breeding.

  3. A Middle Miocene (13.5-12 Ma) deformational event constrained by volcanism along the Puna-Eastern Cordillera border, NW Argentina

    Science.gov (United States)

    Aramayo, Alejandro; Guzmán, Silvina; Hongn, Fernando; del Papa, Cecilia; Montero-López, Carolina; Sudo, Masafumi

    2017-04-01

    The features of Middle Miocene deposits in the Puna-Eastern Cordillera transition (Valles Calchaquíes) indicate that Cenozoic deformation, sedimentation and volcanism follow a complex spatiotemporal relationship. The intense volcanic activity recorded in the eastern Puna border between 14 and 11.5 Ma coincides with the occurrence of one of the most important deformation events of the Neogene tectonic evolution in the region. Studies performed across the Puna-Eastern Cordillera transition show different relationships between volcanic deposits of ca. 13.5-12.1 Ma and the Oligocene-Miocene Angastaco Formation. In this paper we describe the ash-flow tuff deposits which are the first of this type found concordant in the sedimentary fill of Valles Calchaquíes. Several analyses performed on these pyroclastic deposits allow a correlation to be made with the Alto de Las Lagunas Ignimbrite (ca. 13.5 Ma) of the Pucarilla-Cerro Tipillas Volcanic Complex located in the Puna. Outcrops of the ca. 13.5 Ma pyroclastic deposits are recognised within the Puna and the Valle Calchaquí. However, in the southern prolongation of the Valle de Hualfín (Tiopampa-Pucarilla depression) that separates the Puna from the Valle Calchaquí at these latitudes, these deposits are partially eroded and buried, and thus their occurrence is recorded only by abundant volcanic clasts included in conglomerates of the Angastaco Formation. The sedimentation of the Angastaco Formation was aborted at ca. 12 Ma in the Tiopampa-Pucarilla depression by the Pucarilla Ignimbrite, which unconformably covers the synorogenic units. On the contrary, in the Valle Calchaquí the sedimentation of the Angastaco Formation continued until the Late Miocene. The different relationships between the Miocene Angastaco Formation and the ignimbrites with ages of ca. 13.5 and ca. 12 Ma reveal that in this short period ( 1.5 m.y.) a significant deformation event took place and resulted in marked palaeogeographic changes, as

  4. Further evidence of 777 Ma subduction-related continental arc magmatism in Eastern Dom Feliciano Belt, southern Brazil: The Chácara das Pedras Orthogneiss

    Science.gov (United States)

    Koester, E.; Porcher, C. C.; Pimentel, M. M.; Fernandes, L. A. D.; Vignol-Lelarge, M. L.; Oliveira, L. D.; Ramos, R. C.

    2016-07-01

    In this study new SHRIMP U-Pb zircon data for the Chácara das Pedras Gneiss in Porto Alegre, southern Brazil are presented. They represent a small exposure of the crust which was intruded by a large volume of orogenic to anorogenic granitoids at ca. 618-562 m.y. in the Eastern Domain of the Dom Feliciano Belt. The Chácara das Pedras tonalitic orthogneiss has geochemical similarities with subduction-related magmatic rocks of continental arcs. They present high Sr initial ratios (∼0.712), negative ɛNd(t = 777) values (∼-6), TDM varying from 1.8 to 2.0 Ga. The igneous protoliths of these orthogneisses were previously considered to be Paleoproterozoic based on an upper intercept age of discordant zircon analyses. In the present study these orthogneisses were re-sampled and re-analyzed in an attempt to obtain more concordant analytical data. The U-Pb zircon analyses were carried out using the SHRIMP IIe at the Laboratório de Geocronologia de Alta Resolução of the Universidade de São Paulo. The U-Pb concordia age obtained for igneous textural domains of the zircon grains is 777 ± 4 Ma. A few analyses on zircon overgrowths give poorly defined late Cryogenian ages of ca. 650 Ma. Older ages, mostly discordant, were obtained in a few zircon cores, showing an upper intercept age of ca. 1.9 Ga. One sample of the Três Figueiras Granodiorite, which crosscut the orthogneiss in the same outcrop, was also investigated. The zircons of this granodiorite are, however, mostly metamitic, preventing the determination of a reliable age. Some concordant analyses from a few grains define ages ranging in the interval between ca. 603 and 1022 Ma. The youngest (ca. 603 Ma) may represent a maximum age for the granodiorite crystallization. Older ages, with discordance Plata and Kalahari cratons.

  5. Genome sequence, structural proteins, and capsid organization of the cyanophage Syn5: a "horned" bacteriophage of marine synechococcus.

    Science.gov (United States)

    Pope, Welkin H; Weigele, Peter R; Chang, Juan; Pedulla, Marisa L; Ford, Michael E; Houtz, Jennifer M; Jiang, Wen; Chiu, Wah; Hatfull, Graham F; Hendrix, Roger W; King, Jonathan

    2007-05-11

    Marine Synechococcus spp and marine Prochlorococcus spp are numerically dominant photoautotrophs in the open oceans and contributors to the global carbon cycle. Syn5 is a short-tailed cyanophage isolated from the Sargasso Sea on Synechococcus strain WH8109. Syn5 has been grown in WH8109 to high titer in the laboratory and purified and concentrated retaining infectivity. Genome sequencing and annotation of Syn5 revealed that the linear genome is 46,214 bp with a 237 bp terminal direct repeat. Sixty-one open reading frames (ORFs) were identified. Based on genomic organization and sequence similarity to known protein sequences within GenBank, Syn5 shares features with T7-like phages. The presence of a putative integrase suggests access to a temperate life cycle. Assignment of 11 ORFs to structural proteins found within the phage virion was confirmed by mass-spectrometry and N-terminal sequencing. Eight of these identified structural proteins exhibited amino acid sequence similarity to enteric phage proteins. The remaining three virion proteins did not resemble any known phage sequences in GenBank as of August 2006. Cryo-electron micrographs of purified Syn5 virions revealed that the capsid has a single "horn", a novel fibrous structure protruding from the opposing end of the capsid from the tail of the virion. The tail appendage displayed an apparent 3-fold rather than 6-fold symmetry. An 18 A resolution icosahedral reconstruction of the capsid revealed a T=7 lattice, but with an unusual pattern of surface knobs. This phage/host system should allow detailed investigation of the physiology and biochemistry of phage propagation in marine photosynthetic bacteria.

  6. L'espace des francs-maçons

    OpenAIRE

    2015-01-01

    À l’heure où l’on commémore avec faste les 275 ans de la franc-maçonnerie en France, ce livre est né d’un constat inquiétant et d’un espoir. Longtemps pionnière dans l’observation des formes de sociabilité, l’histoire de la franc-maçonnerie peine aujourd’hui à trouver un second souffle. Elle est même menacée de marginalisation universitaire et scientifique. Paradoxalement, la situation n’a sans doute jamais été aussi propice à une relance de la recherche : l’ouverture des fonds maçonniques de...

  7. Atmel maXTouch控制器支持Windows 8

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    爱特梅尔公司(Atmel Corporation)宣布,爱特梅尔maXTouch mXT1386率先成为能够支持微软(Microsoft)公司全新的以触摸为中心的Windows 8操作系统的触摸控制器,此前mXT1386控制器已经用于三星(Samsung)公司的Windows Developer Preview(开发者预览版)PC。mXT1386控制器利用爱特梅尔获得验证的maXTouch技术,是爱特梅尔maXTouch系列中首款支持Windows8操作系统的产品,适用于多种尺寸的触摸屏。

  8. Examples for Clinical Use of Ma Zi Ren Wan

    Institute of Scientific and Technical Information of China (English)

    张书文

    2002-01-01

    @@ Ma Zi Ren Wan (麻子仁丸), originally recorded in Treatise on Febrile Diseases (伤寒论), is composed of Ma Zi Ren (麻子仁Fructus Cannabis), Bai Shao (白芍Radix Paeoniae Alba), Zhi Shi (枳实Fructus Aurantii Immaturus), Da Huang (大黄Radix etRhizoma Rhei), Hou Po (厚朴cortex Magnoliae Officinalis) and Xing Ren (杏仁Semen Armeniacae Amarum). Good therapeutic results have been achieved by using Ma ZiRen Wan in treatment of febrile disease at the restoring stage, chronic consumptive diseases, hemorrhoid, disorders in women after delivery, chronic kidney disease, senile constipation, pulmonary heart disease, diabetes, coronary heart disease and hypertension. Some illustrative cases are introduced below.

  9. Changing the Safety and Mission Assurance (S and MA) Paradigm

    Science.gov (United States)

    Malone, Roy W.; Safie, Fayssal M.

    2010-01-01

    This slide presentation reviews the change in the work and impact of the Safety and Mission Assurance directorate at Marshall Space Flight Center. It reviews the background and the reasons given for a strong Safety & Mission Assurance presence in all planning for space flight. This was pointed out by the Rogers Commission Report after the Space Challenger accident, by the Columbia Accident Investigation Board (CAIB) and by a 2006 NASA Exploration Safety Study (NESS) Team. The overall objective of the work in this area was to improve and maintain S&MA expertise and skills. Training for this work was improved and the S&MA organization was reorganized. This has resulted in a paradigm shift for NASA's safety efforts, which is described. The presentation then reviews the impact of the new S&MA work in the Ares I design and development.

  10. Alternative Polyadenylation of Human Bocavirus at Its 3′ End Is Regulated by Multiple Elements and Affects Capsid Expression

    Science.gov (United States)

    Hao, Sujuan; Zhang, Junmei; Chen, Zhen; Xu, Huanzhou; Wang, Hanzhong

    2016-01-01

    ABSTRACT Alternative processing of human bocavirus (HBoV) P5 promoter-transcribed RNA is critical for generating the structural and nonstructural protein-encoding mRNA transcripts. The regulatory mechanism by which HBoV RNA transcripts are polyadenylated at proximal [(pA)p] or distal [(pA)d] polyadenylation sites is still unclear. We constructed a recombinant HBoV infectious clone to study the alternative polyadenylation regulation of HBoV. Surprisingly, in addition to the reported distal polyadenylation site, (pA)d, a novel distal polyadenylation site, (pA)d2, which is located in the right-end hairpin (REH), was identified during infectious clone transfection or recombinant virus infection. (pA)d2 does not contain typical hexanucleotide polyadenylation signal, upstream elements (USE), or downstream elements (DSE) according to sequence analysis. Further study showed that HBoV nonstructural protein NS1, REH, and cis elements of (pA)d were necessary and sufficient for efficient polyadenylation at (pA)d2. The distance and sequences between (pA)d and (pA)d2 also played a key role in the regulation of polyadenylation at (pA)d2. Finally, we demonstrated that efficient polyadenylation at (pA)d2 resulted in increased HBoV capsid mRNA transcripts and protein translation. Thus, our study revealed that all the bocaviruses have distal poly(A) signals on the right-end palindromic terminus, and alternative polyadenylation at the HBoV 3′ end regulates its capsid expression. IMPORTANCE The distal polyadenylation site, (pA)d, of HBoV is located about 400 nucleotides (nt) from the right-end palindromic terminus, which is different from those of bovine parvovirus (BPV) and canine minute virus (MVC) in the same genus whose distal polyadenylation is located in the right-end stem-loop structure. A novel polyadenylation site, (pA)d2, was identified in the right-end hairpin of HBoV during infectious clone transfection or recombinant virus infection. Sequence analysis showed that (pA)d2

  11. Crystal structure of a human rhinovirus neutralizing antibody complexed with a peptide derived from viral capsid protein VP2.

    OpenAIRE

    1994-01-01

    The three-dimensional structure of the complex between the Fab fragment of an anti-human rhinovirus neutralizing antibody (8F5) and a cross-reactive synthetic peptide from the viral capsid protein VP2 has been determined at 2.5 A resolution by crystallographic methods. The refinement is presently at an R factor of 0.18 and the antigen-binding site and viral peptide are well defined. The peptide antigen adopts a compact fold by two tight turns and interacts through hydrogen bonds, some with io...

  12. Protection against myxomatosis and rabbit viral hemorrhagic disease with recombinant myxoma viruses expressing rabbit hemorrhagic disease virus capsid protein.

    Science.gov (United States)

    Bertagnoli, S; Gelfi, J; Le Gall, G; Boilletot, E; Vautherot, J F; Rasschaert, D; Laurent, S; Petit, F; Boucraut-Baralon, C; Milon, A

    1996-08-01

    Two myxoma virus-rabbit hemorrhagic disease virus (RHDV) recombinant viruses were constructed with the SG33 strain of myxoma virus to protect rabbits against myxomatosis and rabbit viral hemorrhagic disease. These recombinant viruses expressed the RHDV capsid protein (VP60). The recombinant protein, which is 60 kDa in size, was antigenic, as revealed by its reaction in immunoprecipitation with antibodies raised against RHDV. Both recombinant viruses induced high levels of RHDV- and myxoma virus-specific antibodies in rabbits after immunization. Inoculations by the intradermal route protected animals against virulent RHDV and myxoma virus challenges.

  13. Structure of the Three N-Terminal Immunoglobulin Domains of the Highly Immunogenic Outer Capsid Protein from a T4-Like Bacteriophage

    Energy Technology Data Exchange (ETDEWEB)

    Fokine, Andrei; Islam, Mohammad Z.; Zhang, Zhihong; Bowman, Valorie D.; Rao, Venigalla B.; Rossmann, Michael G. (CUA); (Purdue)

    2011-09-16

    The head of bacteriophage T4 is decorated with 155 copies of the highly antigenic outer capsid protein (Hoc). One Hoc molecule binds near the center of each hexameric capsomer. Hoc is dispensable for capsid assembly and has been used to display pathogenic antigens on the surface of T4. Here we report the crystal structure of a protein containing the first three of four domains of Hoc from bacteriophage RB49, a close relative of T4. The structure shows an approximately linear arrangement of the protein domains. Each of these domains has an immunoglobulin-like fold, frequently found in cell attachment molecules. In addition, we report biochemical data suggesting that Hoc can bind to Escherichia coli, supporting the hypothesis that Hoc could attach the phage capsids to bacterial surfaces and perhaps also to other organisms. The capacity for such reversible adhesion probably provides survival advantages to the bacteriophage.

  14. Prognostic relevance of human papillomavirus L1 capsid protein detection within mild and moderate dysplastic lesions of the cervix uteri in combination with p16 biomarker

    DEFF Research Database (Denmark)

    Hilfrich, Ralf; Hariri, Jalil

    2008-01-01

    OBJECTIVE: To proof the prognostic relevance of HPV L1 capsid protein detection on colposcopically-guided punch biopsies in combination with p16. STUDY DESIGN: Sections of colposcopically-guided punch biopsies from 191 consecutive cases with at least 5 years of follow-up were stained with HPV L1...... capsid protein antibodies (Cytoactiv screening antibody) and a monoclonal anti-p16 antibody. Fifty sections were derived from a benign group, 91 from low-grade (cervical intraepithelial neoplasia [CIN 1]) lesions and 50 from high-grade (CIN 2 and 3) lesions. RESULTS: Overall only 16.1% of the 87 L1......-negative, p16-positive CIN lesions showed remission of the lesion compared to 72.4% of the double positive cases. None of the L1/p16 double negative CIN lesions progressed. CONCLUSION: HPV L1 capsid protein detection with Cytoactiv screening antibody seems to be a promising new tool to predict the behavior...

  15. Akuntansi dalam Penetapan Sĩma Masa Jawa Kuno

    Directory of Open Access Journals (Sweden)

    Novrida Qudsi Lutfillah

    2014-08-01

    Full Text Available This article aims to uncover the accounting practices of Sĩma. The archaeological context is used as a research method to collect data, to interpret and to understand a culture. The results concluded that the accounting practices of sima had purposes to: (1 give privileges to certain areas; (2 establish and balanced the powers of social religious institution. The accounting practices and the role of the accountant (called Citralekha are visible on the ritual ceremonies of Sĩma. The values reflected in the accounting practice were the blessings and the peace of life, as well as the self purity.

  16. Stratigraphic-structural characteristics of Mačva basin

    Directory of Open Access Journals (Sweden)

    Carević Ivana

    2009-01-01

    Full Text Available The analysis of stratigraphic-structural features of Mačva basin had been conducted in this paper on the basis of data obtained with deep exploratory boring performed for the needs of hydrogeothermal research project for the purpose of identifying the reserves of geothermal energy of Mačva. The research has been carried out with the aim of finding out the relation between the Tertiary and its Triassic bedrock (Ladinian and Carnian stages in which process the considerable realistic image of paleorelief (the bedrock of Tertiary deposits was obtained.

  17. CPAPD Vice President Mr. Ma Biao Visits Morocco and Greece

    Institute of Scientific and Technical Information of China (English)

    2015-01-01

    At the respective invitation of the Amadeus Institute and the World Peace Council(WPC),Mr.Ma Biao,Vice Chairman of the National Committee of the Chinese People’s Political Consultative Conference(CPPCC)and Vice President of the Chinese People’s Association for Peace and Disarmament(CPAPD)led a CPAPD delegation on a good-will visit to Morocco and Greece during November 10 to 19,2015.During the stay in Morocco,Mr.Ma Biao respectively met with Moroccan Senate Vice

  18. Specific interaction between hnRNP H and HPV16 L1 proteins: Implications for late gene auto-regulation enabling rapid viral capsid protein production

    Energy Technology Data Exchange (ETDEWEB)

    Zheng, Zi-Zheng; Sun, Yuan-Yuan; Zhao, Min; Huang, Hui [National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, Fujian 361005 (China); School of Life Sciences, Xiamen University, Xiamen, Fujian 361005 (China); Zhang, Jun; Xia, Ning-Shao [National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, Fujian 361005 (China); School of Life Sciences, Xiamen University, Xiamen, Fujian 361005 (China); School of Public Health, Xiamen University, Xiamen, Fujian 361005 (China); Miao, Ji, E-mail: jmiao@xmu.edu.cn [National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, Fujian 361005 (China); School of Life Sciences, Xiamen University, Xiamen, Fujian 361005 (China); Zhao, Qinjian, E-mail: qinjian_zhao@xmu.edu.cn [National Institute of Diagnostics and Vaccine Development in Infectious Diseases, Xiamen University, Xiamen, Fujian 361005 (China); School of Public Health, Xiamen University, Xiamen, Fujian 361005 (China)

    2013-01-18

    Highlights: ► The RNA-binding hnRNP H regulates late viral gene expression. ► hnRNP H activity was inhibited by a late viral protein. ► Specific interaction between HPV L1 and hnRNP H was demonstrated. ► Co-localization of HPV L1 and hnRNP H inside cells was observed. ► Viral capsid protein production, enabling rapid capsid assembly, was implicated. -- Abstract: Heterogeneous nuclear ribonucleoproteins (hnRNPs), including hnRNP H, are RNA-binding proteins that function as splicing factors and are involved in downstream gene regulation. hnRNP H, which binds to G triplet regions in RNA, has been shown to play an important role in regulating the staged expression of late proteins in viral systems. Here, we report that the specific association between hnRNP H and a late viral capsid protein, human papillomavirus (HPV) L1 protein, leads to the suppressed function of hnRNP H in the presence of the L1 protein. The direct interaction between the L1 protein and hnRNP H was demonstrated by complex formation in solution and intracellularly using a variety of biochemical and immunochemical methods, including peptide mapping, specific co-immunoprecipitation and confocal fluorescence microscopy. These results support a working hypothesis that a late viral protein HPV16 L1, which is down regulated by hnRNP H early in the viral life cycle may provide an auto-regulatory positive feedback loop that allows the rapid production of HPV capsid proteins through suppression of the function of hnRNP H at the late stage of the viral life cycle. In this positive feedback loop, the late viral gene products that were down regulated earlier themselves disable their suppressors, and this feedback mechanism could facilitate the rapid production of capsid proteins, allowing staged and efficient viral capsid assembly.

  19. Peptide ligands incorporated into the threefold spike capsid domain to re-direct gene transduction of AAV8 and AAV9 in vivo.

    Directory of Open Access Journals (Sweden)

    Stefan Michelfelder

    Full Text Available Efficiency and specificity of viral vectors are vital issues in gene therapy. Insertion of peptide ligands into the adeno-associated viral (AAV capsid at receptor binding sites can re-target AAV2-derived vectors to alternative cell types. Also, the use of serotypes AAV8 and -9 is more efficient than AAV2 for gene transfer to certain tissues in vivo. Consequently, re-targeting of these serotypes by ligand insertion could be a promising approach but has not been explored so far. Here, we generated AAV8 and -9 vectors displaying peptides in the threefold spike capsid domain. These peptides had been selected from peptide libraries displayed on capsids of AAV serotype 2 to optimize systemic gene delivery to murine lung tissue and to breast cancer tissue in PymT transgenic mice (PymT. Such peptide insertions at position 590 of the AAV8 capsid and position 589 of the AAV9 capsid changed the transduction properties of both serotypes. However, both peptides inserted in AAV8 did not result in the same changes of tissue tropism as they did in AAV2. While the AAV2 peptides selected on murine lung tissue did not alter tropism of serotypes 8 and -9, insertion of the AAV2-derived peptide selected on breast cancer tissue augmented tumor gene delivery in both serotypes. Further, this peptide mediated a strong but unspecific in vivo gene transfer for AAV8 and abrogated transduction of various control tissues for AAV9. Our findings indicate that peptide insertion into defined sites of AAV8 and -9 capsids can change and improve their efficiency and specificity compared to their wild type variants and to AAV2, making these insertion sites attractive for the generation of novel targeted vectors in these serotypes.

  20. Lethal mutations in the major homology region and their suppressors act by modulating the dimerization of the rous sarcoma virus capsid protein C-terminal domain.

    Science.gov (United States)

    Dalessio, Paula M; Craven, Rebecca C; Lokhandwala, Parvez M; Ropson, Ira J

    2013-02-01

    An infective retrovirus requires a mature capsid shell around the viral replication complex. This shell is formed by about 1500 capsid protein monomers, organized into hexamer and pentamer rings that are linked to each other by the dimerization of the C-terminal domain (CTD). The major homology region (MHR), the most highly conserved protein sequence across retroviral genomes, is part of the CTD. Several mutations in the MHR appear to block infectivity by preventing capsid formation. Suppressor mutations have been identified that are distant in sequence and structure from the MHR and restore capsid formation. The effects of two lethal and two suppressor mutations on the stability and function of the CTD were examined. No correlation with infectivity was found for the stability of the lethal mutations (D155Y-CTD, F167Y-CTD) and suppressor mutations (R185W-CTD, I190V-CTD). The stabilities of three double mutant proteins (D155Y/R185W-CTD, F167Y/R185W-CTD, and F167Y/I190V-CTD) were additive. However, the dimerization affinity of the mutant proteins correlated strongly with biological function. The CTD proteins with lethal mutations did not dimerize, while those with suppressor mutations had greater dimerization affinity than WT-CTD. The suppressor mutations were able to partially correct the dimerization defect caused by the lethal MHR mutations in double mutant proteins. Despite their dramatic effects on dimerization, none of these residues participate directly in the proposed dimerization interface in a mature capsid. These findings suggest that the conserved sequence of the MHR has critical roles in the conformation(s) of the CTD that are required for dimerization and correct capsid maturation. Copyright © 2012 Wiley Periodicals, Inc.

  1. Helical Conformation in the CA-SP1 Junction of the Immature HIV-1 Lattice Determined from Solid-State NMR of Virus-like Particles.

    Science.gov (United States)

    Bayro, Marvin J; Ganser-Pornillos, Barbie K; Zadrozny, Kaneil K; Yeager, Mark; Tycko, Robert

    2016-09-21

    Maturation of HIV-1 requires disassembly of the Gag polyprotein lattice, which lines the viral membrane in the immature state, and subsequent assembly of the mature capsid protein lattice, which encloses viral RNA in the mature state. Metastability of the immature lattice has been proposed to depend on the existence of a structurally ordered, α-helical segment spanning the junction between capsid (CA) and spacer peptide 1 (SP1) subunits of Gag, a segment that is dynamically disordered in the mature capsid lattice. We report solid state nuclear magnetic resonance (ssNMR) measurements on the immature lattice in noncrystalline, spherical virus-like particles (VLPs) derived from Gag. The ssNMR data provide definitive evidence for this critical α-helical segment in the VLPs. Differences in ssNMR chemical shifts and signal intensities between immature and mature lattice assemblies also support a major rearrangement of intermolecular interactions in the maturation process, consistent with recent models from electron cryomicroscopy and X-ray crystallography.

  2. 人乳头瘤病毒衣壳蛋白与宫颈病变%Human Papillomavirus′ Capsid Proteins and Cervical Lesions

    Institute of Scientific and Technical Information of China (English)

    黄成琳; 张淑兰

    2014-01-01

    Cervical cancer seriously endangers women′s health,and human papillomavirus (HPV) is considered to be the primary cause. Doctors have been striving to find an effective diagnostic method for judging cervical lesions level and predicting its prognosis. HPV capsid proteins comprise the major capsid protein (L1 capsid protein) and the minor capsid protein (L2 capsid protein),and these two proteins play an important role in assembling into virus particles,trafficking HPV to the cell,and causing the host′s immune reactions. In recent years,studies have shown that the L1 capsid protein can be used to predict the progress and subsidence of cervical lesions. HPV prophylactic vaccines ,which are exploited on the basis of the L1 and L2 capsid protein,are proved to get a good preventive effect in clinical trials. This paper reviews the biological characteristics of HPV and researches progress on HPV capsid protein in cervical lesions in recent years.%宫颈癌严重危害妇女健康,人乳头瘤病毒(HPV)感染是其首要病因。临床医师一直致力于寻找一种能有效判断宫颈病变级别及预测预后的诊断方法。 HPV衣壳蛋白包括主要衣壳蛋白(L1壳蛋白)和次要衣壳蛋白(L2壳蛋白),这两种蛋白在组装成病毒颗粒、协助病毒入胞及引起机体免疫反应等多个方面发挥重要作用。近年研究表明, L1壳蛋白可用于预测宫颈病变的进展与消退。以L1及L2壳蛋白为基础研发的HPV预防性疫苗在临床试验中得到了很好的预防效果。综述HPV生物学特点及近年来有关HPV衣壳蛋白在宫颈病变的研究进展。

  3. Synthesis and characterization of different immunogenic viral nanoconstructs from rotavirus VP6 inner capsid protein

    Directory of Open Access Journals (Sweden)

    Bugli F

    2014-05-01

    Full Text Available Francesca Bugli,1 Valeria Caprettini,2 Margherita Cacaci,1 Cecilia Martini,1 Francesco Paroni Sterbini,1 Riccardo Torelli,1 Stefano Della Longa,3 Massimiliano Papi,4 Valentina Palmieri,4 Bruno Giardina,5 Brunella Posteraro,1 Maurizio Sanguinetti,1 Alessandro Arcovito5 1Istituto di Microbiologia, Università Cattolica del Sacro Cuore, 2Dipartimento di Fisica, Sapienza Università di Roma, Rome, 3Dipartimento di Medicina Clinica, Sanità Pubblica, Scienze della Vita e dell’Ambiente, Università dell’Aquila, L’Aquila, 4Istituto di Fisica, 5Istituto di Biochimica e Biochimica Clinica, Università Cattolica del Sacro Cuore, Rome, Italy Abstract: In order to deliver low-cost viral capsomeres from a large amount of soluble viral VP6 protein from human rotavirus, we developed and optimized a biotechnological platform in Escherichia coli. Specifically, three different expression protocols were compared, differing in their genetic constructs, ie, a simple native histidine-tagged VP6 sequence, VP6 fused to thioredoxin, and VP6 obtained with the newly described small ubiquitin-like modifier (SUMO fusion system. Our results demonstrate that the histidine-tagged protein does not escape the accumulation in the inclusion bodies, and that SUMO is largely superior to the thioredoxin-fusion tag in enhancing the expression and solubility of VP6 protein. Moreover, the VP6 protein produced according to the SUMO fusion tag displays well-known assembly properties, as observed in both transmission electron microscopy and atomic force microscopy images, giving rise to either VP6 trimers, 60 nm spherical virus-like particles, or nanotubes a few micron long. This different quaternary organization of VP6 shows a higher level of immunogenicity for the elongated structures with respect to the spheres or the protein trimers. Therefore, the expression and purification strategy presented here – providing a large amount of the viral capsid protein in the native

  4. Mg/Ca and ?18O in the brackish shallow-water benthic foraminifer Ammonia 'beccarii'

    NARCIS (Netherlands)

    Toyofuku, T.; Suzuki, M.; Suga, H.; Sakai, S.; Suzuki, A.; Ishikawa, T.; Nooijer, L.J. de; Schiebel, R.; Kawahata, H.; Kitazato, H.

    2011-01-01

    Specimens of the benthic foraminifer Ammonia beccarii were cultured in the laboratory in order to determine the relation between temperature and Mg/Ca and oxygen isotope values in their tests. Asexual reproduction in this species provides a large number of juveniles that were allowed to grow into ma

  5. DVD-d. Shrek Kolmas; Ma olen legend / Andres Laasik

    Index Scriptorium Estoniae

    Laasik, Andres, 1960-2016

    2008-01-01

    Lühiarvustused USA 2007.a. filmidele : animafilm "Shrek Kolmas" ("Shrek the Third", režissöörid Chris Miller, Raman Hui) ja ulmefilm "Ma olen legend" ("I Am Legend"; režissöör Francis Lawrence)

  6. Thesis Writing Challenges for Non-Native MA Students

    Science.gov (United States)

    Sadeghi, Karim; Shirzad Khajepasha, Arash

    2015-01-01

    Writing in a second (L2)/foreign language is generally a challenging activity, and writing an MA thesis, as an example of academic enterprise, can be daunting when done in a language in which the writer is not fully competent. The challenge such a genre of writing poses for L2 writers has not been properly addressed. To fill in the gap in this…

  7. Ma Shi Wen Tong and its Theory of Language

    Institute of Scientific and Technical Information of China (English)

    2007-01-01

    <正>Ma Shi Wen Tong is a very influential book in the field of linguistics.Its theory of language is closely related to the social background of China at that time.The paper will deal with concept of language in this book from a cultural and historical perspective.

  8. China's Overseas M&A in Global Economic Crisis

    Institute of Scientific and Technical Information of China (English)

    Han Kang

    2009-01-01

    @@ verseas Merger and Acquisition (M&A) is not only the major means for the enterprises to expand rapid-ly and operate globally, but also the significant stra-tegic tools for acquiring advanced technotegy from other companies and seizing the market and other resources.

  9. Ma Junren’s Track Team Stuns the World

    Institute of Scientific and Technical Information of China (English)

    1994-01-01

    At the Fourth World Athletics Championships in Stuttgart, Germany, Chinese runners, most Ma Junren’s, triumphed. They won the gold in the 1,500, gold and silver in the 10,000 and swept the 3,000. Twenty-four days later at the National Games in Beijing, Ma’s team broke many world records.

  10. Organisational Learning through International M&A Integration Strategies

    Science.gov (United States)

    Holland, Wayne; Salama, Alzira

    2010-01-01

    Purpose: The purpose of this research paper is to explore the learning process associated with international mergers and acquisitions (M&A) integration strategies. Design/methodology/approach: The paper employs a comparative case study methodology, utilising qualitative data through in-depth interviews with top management responsible for…

  11. 75 FR 65567 - Drawbridge Operation Regulations; Mystic River, Charlestown, MA

    Science.gov (United States)

    2010-10-26

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Mystic River, Charlestown, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The Commander,...

  12. 75 FR 25305 - Massachusetts Disaster Number MA-00027

    Science.gov (United States)

    2010-05-07

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster Number MA-00027 AGENCY: U.S. Small Business Administration. ACTION: Amendment 1. SUMMARY: This is an amendment of the Presidential declaration of a major disaster for...

  13. 75 FR 25305 - Massachusetts Disaster Number MA-00025

    Science.gov (United States)

    2010-05-07

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster Number MA-00025 AGENCY: U.S. Small Business Administration. ACTION: Amendment 1. SUMMARY: This is an amendment of the Presidential declaration of a major disaster for...

  14. 76 FR 58558 - Massachusetts Disaster Number MA-00040

    Science.gov (United States)

    2011-09-21

    ... From the Federal Register Online via the Government Publishing Office ] SMALL BUSINESS ADMINISTRATION Massachusetts Disaster Number MA-00040 AGENCY: U.S. Small Business Administration. ACTION: Amendment 1. SUMMARY: This is an amendment of the Presidential declaration of a major disaster for...

  15. 78 FR 37455 - Drawbridge Operation Regulations; Charles River, Boston, MA

    Science.gov (United States)

    2013-06-21

    ... regulation was published in the Federal Register (78 FR 35756) under the same name and docket number. This... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Charles River, Boston, MA...

  16. 77 FR 6963 - Drawbridge Operation Regulations; Merrimack River, Amesbury, MA

    Science.gov (United States)

    2012-02-10

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Merrimack River, Amesbury, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The Commander,...

  17. 46 CFR 308.544 - Facultative binder, Form MA-315.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Facultative binder, Form MA-315. 308.544 Section 308.544 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Iii-Facultative War Risk Cargo Insurance § 308.544 Facultative binder, Form...

  18. 46 CFR 308.533 - Closing report, Form MA-313.

    Science.gov (United States)

    2010-10-01

    ... 46 Shipping 8 2010-10-01 2010-10-01 false Closing report, Form MA-313. 308.533 Section 308.533 Shipping MARITIME ADMINISTRATION, DEPARTMENT OF TRANSPORTATION EMERGENCY OPERATIONS WAR RISK INSURANCE War Risk Cargo Insurance Ii-Open Policy War Risk Cargo Insurance § 308.533 Closing report, Form...

  19. 76 FR 67245 - Massachusetts Disaster Number MA-00040

    Science.gov (United States)

    2011-10-31

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Disaster Declaration 12803 and 12804 Massachusetts Disaster Number MA-00040 AGENCY: U.S. Small Business Administration. ACTION: Amendment 2. SUMMARY: This is an amendment of the Presidential...

  20. 77 FR 65619 - Drawbridge Operation Regulations; Taunton River, MA

    Science.gov (United States)

    2012-10-30

    ... Federal Register (73 FR 3316). 4. Public Meeting We do not now plan to hold a public meeting. But you may... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Taunton River, MA AGENCY:...

  1. 76 FR 45644 - Massachusetts Disaster Number MA-00037

    Science.gov (United States)

    2011-07-29

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster Number MA-00037 AGENCY: U.S. Small Business Administration. ] ACTION: Amendment 1. SUMMARY: This is an amendment of the Presidential declaration of a major disaster for...

  2. 78 FR 35756 - Drawbridge Operation Regulations; Charles River, Boston, MA

    Science.gov (United States)

    2013-06-14

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; Charles River, Boston, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulations. SUMMARY: The Commander,...

  3. 76 FR 53019 - Massachusetts Disaster Number MA-00036

    Science.gov (United States)

    2011-08-24

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster Number MA-00036 AGENCY: U.S. Small Business Administration. ACTION: Amendment 1. SUMMARY: This is an amendment of the Presidential declaration of a major disaster for the...

  4. 75 FR 30872 - Massachusetts Disaster Number MA-00025

    Science.gov (United States)

    2010-06-02

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster Number MA-00025 AGENCY: U.S. Small Business Administration. ACTION: Amendment 2. SUMMARY: This is an amendment of the Presidential declaration of a major disaster for the...

  5. 78 FR 15292 - Drawbridge Operation Regulations; West Bay, Osterville, MA

    Science.gov (United States)

    2013-03-11

    ... From the Federal Register Online via the Government Publishing Office DEPARTMENT OF HOMELAND SECURITY Coast Guard 33 CFR Part 117 Drawbridge Operation Regulations; West Bay, Osterville, MA AGENCY: Coast Guard, DHS. ACTION: Notice of temporary deviation from regulation. SUMMARY: The Coast Guard...

  6. 75 FR 39059 - Massachusetts Disaster Number MA-00025

    Science.gov (United States)

    2010-07-07

    ... From the Federal Register Online via the Government Publishing Office SMALL BUSINESS ADMINISTRATION Massachusetts Disaster Number MA-00025 AGENCY: U.S. Small Business Administration. ACTION: Amendment 3. SUMMARY: This is an amendment of the Presidential declaration of a major disaster for...

  7. DVD-d. Shrek Kolmas; Ma olen legend / Andres Laasik

    Index Scriptorium Estoniae

    Laasik, Andres, 1960-2016

    2008-01-01

    Lühiarvustused USA 2007.a. filmidele : animafilm "Shrek Kolmas" ("Shrek the Third", režissöörid Chris Miller, Raman Hui) ja ulmefilm "Ma olen legend" ("I Am Legend"; režissöör Francis Lawrence)

  8. Thesis Writing Challenges for Non-Native MA Students

    Science.gov (United States)

    Sadeghi, Karim; Shirzad Khajepasha, Arash

    2015-01-01

    Writing in a second (L2)/foreign language is generally a challenging activity, and writing an MA thesis, as an example of academic enterprise, can be daunting when done in a language in which the writer is not fully competent. The challenge such a genre of writing poses for L2 writers has not been properly addressed. To fill in the gap in this…

  9. MaRGEE: Move and Rotate Google Earth Elements

    Science.gov (United States)

    Dordevic, Mladen M.; Whitmeyer, Steven J.

    2015-12-01

    Google Earth is recognized as a highly effective visualization tool for geospatial information. However, there remain serious limitations that have hindered its acceptance as a tool for research and education in the geosciences. One significant limitation is the inability to translate or rotate geometrical elements on the Google Earth virtual globe. Here we present a new JavaScript web application to "Move and Rotate Google Earth Elements" (MaRGEE). MaRGEE includes tools to simplify, translate, and rotate elements, add intermediate steps to a transposition, and batch process multiple transpositions. The transposition algorithm uses spherical geometry calculations, such as the haversine formula, to accurately reposition groups of points, paths, and polygons on the Google Earth globe without distortion. Due to the imminent deprecation of the Google Earth API and browser plugin, MaRGEE uses a Google Maps interface to facilitate and illustrate the transpositions. However, the inherent spatial distortions that result from the Google Maps Web Mercator projection are not apparent once the transposed elements are saved as a KML file and opened in Google Earth. Potential applications of the MaRGEE toolkit include tectonic reconstructions, the movements of glaciers or thrust sheets, and time-based animations of other large- and small-scale geologic processes.

  10. BioMaPS: A Roadmap for Success

    Science.gov (United States)

    McCarthy, Maeve L.; Fister, K. Renee

    2010-01-01

    The manuscript outlines the impact that our National Science Foundation Interdisciplinary Training for Undergraduates in Biological and Mathematical Sciences program, BioMaPS, has had on the students and faculty at Murray State University. This interdisciplinary program teams mathematics and biology undergraduate students with mathematics and…

  11. 42 CFR 422.74 - Disenrollment by the MA organization.

    Science.gov (United States)

    2010-10-01

    ...) Basis of disenrollment for disruptive behavior. An organization may disenroll an individual whose... MA organization has fulfilled the requirements to request disenrollment for disruptive behavior. If... established under paragraph (d)(1) of this section. (ii) The individual has engaged in disruptive...

  12. The Authority and Charismas of Jack Ma's Leadership

    Institute of Scientific and Technical Information of China (English)

    陈希

    2014-01-01

    Jack Ma is the top manager of Ali Baba group, with a strong leadership. He mixes autocratic leadership and charismatic leadership together. The powers he used are from his position, the reward system of the company and the charismas to gain his leading power. In addition, he uses his charismas and his achievements to win the trust of the employees, which develop his leadership.

  13. M&A New Rules May Trigger Merger Wave

    Institute of Scientific and Technical Information of China (English)

    HUBERT TSE

    2006-01-01

    @@ The Chinese government issued a series of new M&A and takeover rules in July and August 2006 to further regulate and facilitate foreign investors' acquisition activities in China.The new rules are aimed at offering more flexibility, reducing costs and increasing takeover efficiencies for foreign-funded M&As in the world's fastest-growing major economy.

  14. 42 CFR 422.104 - Special rules on supplemental benefits for MA MSA plans.

    Science.gov (United States)

    2010-10-01

    ... 42 Public Health 3 2010-10-01 2010-10-01 false Special rules on supplemental benefits for MA MSA... Beneficiary Protections § 422.104 Special rules on supplemental benefits for MA MSA plans. (a) An MA organization offering an MA MSA plan may not provide supplemental benefits that cover expenses that...

  15. Capsid protein: evidences about the partial protective role of neutralizing antibody-independent immunity against dengue in monkeys.

    Science.gov (United States)

    Gil, Lázaro; Izquierdo, Alienys; Lazo, Laura; Valdés, Iris; Ambala, Peris; Ochola, Lucy; Marcos, Ernesto; Suzarte, Edith; Kariuki, Thomas; Guzmán, Guadalupe; Guillén, Gerardo; Hermida, Lisset

    2014-05-01

    The role of cellular immune response in dengue virus infection is not yet fully understood. Only few studies in murine models propose that CD8(+) T-cells are associated with protection from infection and disease. At the light of recent reports about the protective role of CD8(+) T-cells in humans and the no correlation between neutralizing antibodies and protection observed in several studies, a vaccine based on cell-mediated immunity constitute an attractive approach. Our group has developed a capsid-based vaccine as nucleocpasid-like particles from dengue-2 virus, which induced a protective CD4(+) and CD8(+) cell-mediated immunity in mice, without the contribution of neutralizing antibodies. Herein we evaluated the immunogenicity and protective efficacy of this molecule in monkeys. Neither IgG antibodies against the whole virus nor neutralizing antibodies were elicited after the antigen inoculation. However, animals developed a cell-mediated immunity, measured by gamma interferon secretion and cytotoxic capacity. Although only one out of three vaccinated animals was fully protected against viral challenge, a viral load reduction was observed in this group compared with the placebo one, suggesting that capsid could be the base on an attractive vaccine against dengue.

  16. Expression of viral polymerase and phosphorylation of core protein determine core and capsid localization of the human hepatitis B virus.

    Science.gov (United States)

    Deroubaix, Aurélie; Osseman, Quentin; Cassany, Aurélia; Bégu, Dominique; Ragues, Jessica; Kassab, Somar; Lainé, Sébastien; Kann, Michael

    2015-01-01

    Biopsies from patients show that hepadnaviral core proteins and capsids - collectively called core - are found in the nucleus and cytoplasm of infected hepatocytes. In the majority of studies, cytoplasmic core localization is related to low viraemia while nuclear core localization is associated with high viral loads. In order to better understand the molecular interactions leading to core localization, we analysed transfected hepatoma cells using immune fluorescence microscopy. We observed that expression of core protein in the absence of other viral proteins led to nuclear localization of core protein and capsids, while expression of core in the context of the other viral proteins resulted in a predominantly cytoplasmic localization. Analysis of which viral partner was responsible for cytoplasmic retention indicated that the HBx, surface proteins and HBeAg had no impact but that the viral polymerase was the major determinant. Further analysis revealed that ϵ, an RNA structure to which the viral polymerase binds, was essential for cytoplasmic retention. Furthermore, we showed that core protein phosphorylation at Ser 164 was essential for the cytoplasmic core localization phenotype, which is likely to explain differences observed between individual cells.

  17. EPIDERMAL GROWTH FACTOR RECEPTOR (EGFR AND HUMAN PAPILLOMAVIRUS (HPV L1 CAPSID PROTEIN IN CERVICAL SQUAMOUS INTRAEPITHELIAL LESIONS

    Directory of Open Access Journals (Sweden)

    Balan Raluca

    2010-09-01

    Full Text Available We analyzed the immunohistochemical pattern of epidermal growth factor receptor (EGFR in cervical squamous intraepithelial lesions (SILs in correlation with L1 HPV capsid protein, in order to determine the relationship between EGFR expression and the infection status of human papillomavirus (HPV. The study included 40 cases, 24 LSIL (low grade SIL (CIN1, cervical intraepithelial neoplasia and 16 HSIL (high grade SIL (6 cases of CIN2 and 10 cases of CIN3. The immunoexpression of L1 HPV protein was assessed on conventional cervico-vaginal smears and EGFR was immunohistochemically evaluated on the corresponding cervical biopsies. The HPV L1 capsid protein was expressed in 45.83% of LSIL and 25% of HSIL. EGFR was overexpressed in 62,4% of HSIL (58,4% CIN2 and 41,6% CIN3 and 37,6% LSIL. The immunoexpression of L1 HPV has clinical application in the progression assessment of the cervical precancerous lesions without a correlation to the grade of the cervical SIL. EGFR is expressed by all proliferating squamous epithelial cells, thus corresponding with the grade of SIL. The evaluation of EGFR status, correlated with L1 HPV protein expression, can provide useful data of progression risk of cervical squamous intraepithelial lesions

  18. African Swine Fever Virus Undergoes Outer Envelope Disruption, Capsid Disassembly and Inner Envelope Fusion before Core Release from Multivesicular Endosomes.

    Directory of Open Access Journals (Sweden)

    Bruno Hernáez

    2016-04-01

    Full Text Available African swine fever virus (ASFV is a nucleocytoplasmic large DNA virus (NCLDV that causes a highly lethal disease in domestic pigs. As other NCLDVs, the extracellular form of ASFV possesses a multilayered structure consisting of a genome-containing nucleoid successively wrapped by a thick protein core shell, an inner lipid membrane, an icosahedral protein capsid and an outer lipid envelope. This structural complexity suggests an intricate mechanism of internalization in order to deliver the virus genome into the cytoplasm. By using flow cytometry in combination with pharmacological entry inhibitors, as well as fluorescence and electron microscopy approaches, we have dissected the entry and uncoating pathway used by ASFV to infect the macrophage, its natural host cell. We found that purified extracellular ASFV is internalized by both constitutive macropinocytosis and clathrin-mediated endocytosis. Once inside the cell, ASFV particles move from early endosomes or macropinosomes to late, multivesicular endosomes where they become uncoated. Virus uncoating requires acidic pH and involves the disruption of the outer membrane as well as of the protein capsid. As a consequence, the inner viral membrane becomes exposed and fuses with the limiting endosomal membrane to release the viral core into the cytosol. Interestingly, virus fusion is dependent on virus protein pE248R, a transmembrane polypeptide of the inner envelope that shares sequence similarity with some members of the poxviral entry/fusion complex. Collective evidence supports an entry model for ASFV that might also explain the uncoating of other multienveloped icosahedral NCLDVs.

  19. Specific recognition of the major capsid protein of Acanthamoeba polyphaga mimivirus by sera of patients infected by Francisella tularensis.

    Science.gov (United States)

    Pelletier, Nicolas; Raoult, Didier; La Scola, Bernard

    2009-08-01

    Francisella tularensis, a Gram-negative cocobacillus responsible for tularemia, especially severe pneumonia, is a facultative intracellular bacterium classified as a biological agent of category A. Acanthamoeba polyphaga mimivirus (APM) is a recently discovered giant virus suspected to be an agent of both community- and hospital-acquired pneumonia. During specificity testing of antibody to APM detection, it was observed that nearly all patients infected by F. tularensis had elevated antibody titers to APM. In the present study, we investigated this cross-reactivity by immunoproteomics. Apart from the detection of antibodies reactive to new immunoreactive proteins in patients infected by F. tularensis, we showed that the sera of those patients recognize specifically two proteins of APM: the capsid protein and another protein of unknown function. No common protein motif can be detected in silico based on genome analysis of the involved protein. Furthermore, this cross-reactivity was confirmed with the recombinant capsid protein expressed in Escherichia coli. This emphasizes the pitfalls of a serological diagnosis of pneumonia.

  20. The VPS4 component of the ESCRT machinery plays an essential role in HPV infectious entry and capsid disassembly

    Science.gov (United States)

    Broniarczyk, Justyna; Pim, David; Massimi, Paola; Bergant, Martina; Goździcka-Józefiak, Anna; Crump, Colin; Banks, Lawrence

    2017-01-01

    Human Papillomavirus (HPV) infection involves multiple steps, from cell attachment, through endocytic trafficking towards the trans-Golgi network, and, ultimately, the entry into the nucleus during mitosis. An essential viral protein in infectious entry is the minor capsid protein L2, which engages different components of the endocytic sorting machinery during this process. The ESCRT machinery is one such component that seems to play an important role in the early stages of infection. Here we have analysed the role of specific ESCRT components in HPV infection, and we find an essential role for VPS4. Loss of VPS4 blocks infection with multiple PV types, suggesting an evolutionarily conserved critical step in infectious entry. Intriguingly, both L1 and L2 can interact with VPS4, and appear to be in complex with VPS4 during the early stages of virus infection. By using cell lines stably expressing a dominant-negative mutant form of VPS4, we also show that loss of VPS4 ATPase activity results in a marked delay in capsid uncoating, resulting in a defect in the endocytic transport of incoming PsVs. These results demonstrate that the ESCRT machinery, and in particular VPS4, plays a critical role in the early stages of PV infection.