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1.
Arch Virol ; 166(2): 403-411, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33392818

RESUMO

This study was conducted to investigate the genetic diversity of porcine circovirus type 2 (PCV2) and its coinfecting pathogens in pigs with respiratory disease in Vietnam. Samples from 127 clinical cases were obtained from different southern provinces of Vietnam from January 2018 to January 2020 for PCR and sequence analysis. The infection rate of PCV2 was 78.8%, and the major pathogens found in coinfections with PCV2 were porcine reproductive and respiratory syndrome virus, Mycoplasma hyopneumoniae, and Haemophilus parasuis. Forty-three PCV2-positive clinical samples were selected for amplification and sequencing of the ORF2 region. Phylogenetic analysis of PCV2 ORF2 showed that five of the sequences belonged to PCV2b (11.6%) and 38 belonged to PCV2d (88.4%), indicating that PCV2d strains were predominant in southern provinces of Vietnam. Alignment of the predicted amino acid sequences of the PCV2 capsid protein revealed polymorphic sites in the antibody recognition regions. This study demonstrates the prevalence of the PCV2d genotype in southern Vietnam and presents a comprehensive overview of the coinfecting pathogens associated with PCV2 in young pigs with respiratory disease.


Assuntos
Infecções por Circoviridae/virologia , Circovirus/genética , Coinfecção/virologia , Doenças Respiratórias/virologia , Doenças dos Suínos/virologia , Sequência de Aminoácidos , Animais , Proteínas do Capsídeo/genética , Genótipo , Prevalência , Suínos , Vietnã
2.
Arch Virol ; 166(2): 659-664, 2021 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-33404858

RESUMO

The bisegmented genome of a novel double-stranded (ds) RNA mycovirus, named "Aspergillus nidulans partitivirus 1" (AnPV1), isolated from the fungus Aspergillus nidulans strain HJ5-47, was sequenced and analyzed. AnPV1 contains two segments, AnPV1-1 and AnPV1-2. AnPV1-1 has 1837 bp with an open reading frame (ORF) that potentially encodes a putative RNA-dependent RNA polymerase (RdRp) of 572 amino acids (aa). AnPV1-2 has 1583 bp with an ORF encoding a putative capsid protein (CP) of 488 aa. Phylogenetic analyses indicated that AnPV1 and related viruses clustered in a group that could represent a new unclassified genus in the family Partitiviridae.


Assuntos
Aspergillus nidulans/virologia , Micovírus/genética , Genoma Viral/genética , Vírus de RNA/genética , Sequência de Aminoácidos , Sequência de Bases , Proteínas do Capsídeo/genética , Fases de Leitura Aberta/genética , Filogenia , RNA de Cadeia Dupla/genética , RNA Viral/genética , Análise de Sequência de DNA/métodos
3.
Nat Commun ; 12(1): 589, 2021 01 26.
Artigo em Inglês | MEDLINE | ID: mdl-33500404

RESUMO

Symmetrical protein complexes are ubiquitous in biology. Many have been re-engineered for chemical and medical applications. Viral capsids and their assembly are frequent platforms for these investigations. A means to create asymmetric capsids may expand applications. Here, starting with homodimeric Hepatitis B Virus capsid protein, we develop a heterodimer, design a hierarchical assembly pathway, and produce asymmetric capsids. In the heterodimer, the two halves have different growth potentials and assemble into hexamers. These preformed hexamers can nucleate co-assembly with other dimers, leading to Janus-like capsids with a small discrete hexamer patch. We can remove the patch specifically and observe asymmetric holey capsids by cryo-EM reconstruction. The resulting hole in the surface can be refilled with fluorescently labeled dimers to regenerate an intact capsid. In this study, we show how an asymmetric subunit can be used to generate an asymmetric particle, creating the potential for a capsid with different surface chemistries.


Assuntos
Proteínas do Capsídeo/metabolismo , Capsídeo/ultraestrutura , Vírus da Hepatite B/fisiologia , Modelos Moleculares , Montagem de Vírus , Capsídeo/metabolismo , Proteínas do Capsídeo/genética , Proteínas do Capsídeo/isolamento & purificação , Proteínas do Capsídeo/ultraestrutura , Microscopia Crioeletrônica , Vírus da Hepatite B/ultraestrutura , Multimerização Proteica/fisiologia , Proteínas Recombinantes/genética , Proteínas Recombinantes/isolamento & purificação , Proteínas Recombinantes/metabolismo , Proteínas Recombinantes/ultraestrutura
4.
BMC Infect Dis ; 21(1): 107, 2021 Jan 22.
Artigo em Inglês | MEDLINE | ID: mdl-33482744

RESUMO

BACKGROUND: G12 rotaviruses were first observed in sub-Saharan Africa in 2004 and since then have continued to emerge and spread across the continent and are reported as a significant human rotavirus genotype in several African countries, both prior to and after rotavirus vaccine introduction. This study investigated the genetic variability of 15 G12 rotavirus strains associated with either P[6] or P[8] identified between 2010 and 2014 from Ethiopia, Kenya, Rwanda, Tanzania, Togo and Zambia. METHODS: The investigation was carried out by comparing partial VP7 and partial VP4 sequences of the African G12P[6] and G12P[8] strains with the available GenBank sequences and exploring the recognized neutralization epitopes of these strains. Additionally, Bayesian evolutionary analysis was carried out using Markov Chain Monte Carlo (MCMC) implemented in BEAST to estimate the time to the most recent ancestor and evolutionary rate for these G12 rotavirus strains. RESULTS: The findings suggested that the VP7 and VP4 nucleotide and amino acid sequences of the G12 strains circulating in African countries are closely related, irrespective of country of origin and year of detection, with the exception of the Ethiopian strains that clustered distinctly. Neutralization epitope analysis revealed that rotavirus VP4 P[8] genes associated with G12 had amino acid sequences similar to those reported globally including the vaccine strains in RotaTeq and Rotarix. The estimated evolutionary rate of the G12 strains was 1.016 × 10- 3 substitutions/site/year and was comparable to what has been previously reported. Three sub-clusters formed within the current circulating lineage III shows the diversification of G12 from three independent ancestries within a similar time frame in the late 1990s. CONCLUSIONS: At present it appears to be unlikely that widespread vaccine use has driven the molecular evolution and sustainability of G12 strains in Africa. Continuous monitoring of rotavirus genotypes is recommended to assess the long-term impact of rotavirus vaccination on the dynamic nature of rotavirus evolution on the continent.


Assuntos
Infecções por Rotavirus/epidemiologia , Infecções por Rotavirus/virologia , Rotavirus/genética , África/epidemiologia , Antígenos Virais/genética , Proteínas do Capsídeo/genética , Epitopos/genética , Evolução Molecular , Genótipo , Humanos , Mutação , Filogenia , Rotavirus/classificação , Rotavirus/isolamento & purificação , Infecções por Rotavirus/prevenção & controle , Vacinas contra Rotavirus/administração & dosagem , Vacinas contra Rotavirus/genética
5.
Arch Virol ; 166(3): 767-778, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33420816

RESUMO

Complement component 1 Q subcomponent-binding protein (C1QBP) has been shown to interact with the porcine circovirus type 2 (PCV2) Cap protein. Here, using yeast two-hybrid (Y2H) and co-immunoprecipitation assays, as well as laser confocal microscopy, the interaction between C1QBP and Cap was confirmed. Furthermore, overexpression of C1QBP in cells altered the intracellular location of Cap, which was observed using confocal microscopy and verified by detection of Cap in nuclear protein extracts in a Western blot assay. By inhibiting nuclear transport of Cap, overexpression of C1QBP downregulated PCV2 proliferation in PK-15 cells, as determined by quantitative polymerase chain reaction (qPCR). As C1QBP plays a similar role in a fusion of green fluorescent protein (GFP) with the Cap nuclear localisation signal (NLS) sequence, (CapNLS-GFP), we propose that the target site for C1QBP in Cap is possibly located in the NLS region. Considering all the results together, this study demonstrated that C1QBP interacts with the Cap NLS region, resulting in changes in the intracellular localisation of the Cap protein. We confirmed that overexpression of C1QBP inhibits the proliferation of PCV2, and this is possibly related to the function of C1QBP in controlling nuclear transport of Cap.


Assuntos
Transporte Ativo do Núcleo Celular/fisiologia , Proteínas do Capsídeo/metabolismo , Circovirus/crescimento & desenvolvimento , Complemento C1q/metabolismo , Replicação Viral/fisiologia , Animais , Linhagem Celular , Chlorocebus aethiops , DNA Viral/metabolismo , Células HEK293 , Humanos , Domínios Proteicos/genética , Interferência de RNA , RNA Interferente Pequeno/genética , Reação em Cadeia da Polimerase em Tempo Real , Suínos , Células Vero
6.
Arch Virol ; 166(3): 967-972, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33420817

RESUMO

Neboviruses (NeVs) are important causative agents of calf diarrhea that belong to the family Caliciviridae. In this study, we investigated the genomic characteristics of a NeV strain from yaks that has a novel RdRp genotype. The complete genome of this strain (YAK/NRG-A9/19/CH) is 7454 nt in length and shares 68.3%-79.7% nt sequence identity with those of other NeVs. The RNA-dependent RNA polymerase (RdRp) gene of this strain shares 66.5%-78.5% nt sequence identity (74.0%-89.3% aa sequence identity) with the eight available complete NeV RdRp sequences, and a phylogenetic analysis based on these sequences showed that the new strain formed an independent branch, indicating that the RdRp of strain YAK/NRG-A9/19/CH may represent a novel RdRp genotype of NeV. These results contribute to a further understanding of the molecular characteristics and genetic evolution of NeVs.


Assuntos
Infecções por Caliciviridae/veterinária , Caliciviridae/genética , Proteínas do Capsídeo/genética , Genoma Viral/genética , /genética , Animais , Caliciviridae/isolamento & purificação , Bovinos , Doenças dos Bovinos/virologia , Evolução Molecular , Fezes/virologia , Genótipo , Filogenia , RNA Viral/genética
7.
Arch Virol ; 166(3): 973-976, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33427965

RESUMO

In this study, a new double-stranded RNA (dsRNA) virus, Alternaria tenuissima partitivirus 1 (AttPV1), was isolated from Alternaria tenuissima strain XJ-BZ-2-6, a phytopathogenic fungus infecting cotton in China. The genome of AttPV1 comprised three dsRNAs of 1,785 nt (dsRNA1), 1,545 nt (dsRNA2), and 1,537 nt (dsRNA3) in length, the nucleotide sequence of which was determined using reverse transcription polymerase chain reaction, random-primed clones, and RNA-ligase-mediated rapid amplification of cDNA ends. dsRNA1 had a single open reading frame encoding a putative 61.54-kDa RNA-dependent RNA polymerase (RdRp). dsRNA2 and dsRNA3 were predicted to encode putative coat proteins (CPs) of 47.90 kDa and 46.25 kDa, respectively. The RdRp domain shared 63.54-73.17% amino acid sequence identity with members of the genus Gammapartitivirus. Phylogenetic trees based on RdRp or CP sequences showed that AttPV1 clustered with members of the genus Gammapartitivirus. Hence, these results indicate that AttPV1 is a new gammapartitivirus from A. tenuissima.


Assuntos
Alternaria/virologia , Micovírus/genética , Genoma Viral/genética , Vírus de RNA/genética , RNA Viral/genética , Sequência de Aminoácidos , Sequência de Bases , Proteínas do Capsídeo/genética , China , Micovírus/classificação , Micovírus/isolamento & purificação , Gossypium/microbiologia , Fases de Leitura Aberta/genética , Doenças das Plantas/microbiologia , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação , RNA de Cadeia Dupla/genética , Alinhamento de Sequência , Proteínas Virais/genética
8.
Arch Virol ; 166(3): 977-981, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33427966

RESUMO

Here, we report a novel partitivirus infecting Metarhizium brunneum, which was designated "Metarhizium brunneum partitivirus 2" (MbPV2). The complete genome of MbPV2 consists of two segments, dsRNA1 and dsRNA2, with each dsRNA possessing a single open reading frame (ORF). dsRNA1 (1,775 bp) encodes a conserved RNA-dependent RNA polymerase (RdRp) with the highest sequence similarity to Plasmopara viticola associated partitivirus 1 (PvAPV1), while dsRNA2 (1,568 bp) encodes a coat protein (CP) with the highest sequence similarity to Colletotrichum partitivirus 1 (CtParV1). Phylogenetic analysis based on RdRp sequences showed that MbPV2 is a new member of the genus Gammapartitivirus, family Partitiviridae. This is the first report of a gammapartitivirus that infects the entomopathogenic fungus Metarhizium brunneum.


Assuntos
Micovírus/genética , Genoma Viral/genética , Metarhizium/virologia , Vírus de RNA/genética , RNA Viral/genética , Sequência de Aminoácidos , Proteínas do Capsídeo/genética , Micovírus/classificação , Micovírus/isolamento & purificação , Fases de Leitura Aberta/genética , Vírus de RNA/classificação , Vírus de RNA/isolamento & purificação , RNA de Cadeia Dupla/genética , Alinhamento de Sequência , Análise de Sequência de RNA
9.
Arch Virol ; 166(3): 983-986, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33439325

RESUMO

The complete genome sequence of a novel foveavirus identified in garlic (Allium sativum L.) in China was determined using RNA-seq, reverse transcription polymerase chain reaction (RT-PCR) and rapid amplification of cDNA ends (RACE) PCR. The entire genomic RNA (GenBank accession MT981417) is 8748 nucleotides long excluding the 3'-terminal poly(A) tail and contains five open reading frames (ORFs). These ORFs encode the viral replicase, a triple gene block, and a coat protein. The virus was tentatively named "garlic yellow stripe associated virus" (GarYSaV). Pairwise comparisons of protein sequences show that GarYSaV encodes proteins that share less than 47% identity with those of other foveaviruses, suggesting that it represents a new species in the genus. Phylogenetic analysis of amino acid sequences of the replicase and CP confirm that GarYSaV is a member of the genus Foveavirus. To our knowledge, this is the first report of a foveavirus in a monocot plant.


Assuntos
Flexiviridae/genética , Alho/virologia , Genoma Viral/genética , RNA Viral/genética , Sequência de Aminoácidos , Proteínas do Capsídeo/genética , China , Flexiviridae/classificação , Flexiviridae/isolamento & purificação , Fases de Leitura Aberta/genética , Filogenia , Doenças das Plantas/virologia , Sequenciamento Completo do Genoma/métodos
10.
Arch Virol ; 166(3): 991-994, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33492526

RESUMO

The 4704-nt genome sequence of Sikte waterborne virus (SWV), determined by fragmented and primer ligated dsRNA sequencing and by direct Sanger sequencing, is linear, nonsegmented and has the five ORFs of other tombusviruses. The 5' and 3' untranslated regions (UTRs) are 150 and 335 nt long, respectively. Phylogenetic analysis of the coat protein revealed that SWV is related to CymRSV and PNSV, but that of the SWV replicase protein, the p92 readthrough protein, indicated a close relationship to CNV. These phylogenetic analyses suggest the occurrence of recombination events in SWV, as reported previously for other tombusviruses.


Assuntos
Chenopodium quinoa/virologia , Genoma Viral/genética , RNA Viral/genética , Tombusvirus/classificação , Tombusvirus/genética , Sequência de Bases , Proteínas do Capsídeo/genética , Alemanha , Fases de Leitura Aberta/genética , Rios/virologia , Análise de Sequência de RNA , Sequenciamento Completo do Genoma
11.
Arch Virol ; 166(3): 863-870, 2021 Mar.
Artigo em Inglês | MEDLINE | ID: mdl-33495898

RESUMO

A dengue virus serotype 1 (DENV-1) epidemic occurred from October to December 2018 in Xishuangbanna, Yunnan, Southwest China, neighboring Myanmar, Laos, and Vietnam. In this study, we investigated the molecular characteristics, evolution, and potential source of DENV from Xishuangbanna. The C (capsid), prM (premembrane), and E (envelope) genes of DENV isolated from 87 serum samples obtained from local patients were amplified and sequenced, and the sequences were evaluated by identification of mutations, phylogenetic and homologous recombination analysis, and secondary structure prediction. Phylogenetic analysis showed that all of the epidemic DENV strains from Xishuangbanna could be grouped in a branch with DENV-1 isolates, and were most similar to the Fujian 2005 (China, DQ193572) and Singapore 2016 (MF314188) strains. When compared with DENV-1SS (the standard strain), there were 31 non-synonymous mutations, but no obvious homologous recombination signal was found. Secondary structure prediction showed that some changes had occurred in a helical region in proteins of the MN123849 and MN123854 strains, but there were few changes in the disordered region. This study reveals the molecular characteristics of the structural genes of the Xishuangbanna epidemic strains in 2018 and provides a reference for molecular epidemiology, infection, and pathogenicity research and vaccine development.


Assuntos
Proteínas do Capsídeo/genética , Vírus da Dengue/genética , Dengue/epidemiologia , Proteínas do Envelope Viral/genética , Sequência de Aminoácidos , China/epidemiologia , Vírus da Dengue/classificação , Vírus da Dengue/isolamento & purificação , Surtos de Doenças , Genótipo , Humanos , Epidemiologia Molecular , Filogenia , RNA Viral/genética , Alinhamento de Sequência , Análise de Sequência de RNA , Sorogrupo
12.
Viruses ; 13(1)2021 Jan 13.
Artigo em Inglês | MEDLINE | ID: mdl-33450892

RESUMO

The capsid structures of most Adeno-associated virus (AAV) serotypes, already assigned to an antigenic clade, have been previously determined. This study reports the remaining capsid structures of AAV7, AAV11, AAV12, and AAV13 determined by cryo-electron microscopy and three-dimensional image reconstruction to 2.96, 2.86, 2.54, and 2.76 Å resolution, respectively. These structures complete the structural atlas of the AAV serotype capsids. AAV7 represents the first clade D capsid structure; AAV11 and AAV12 are of a currently unassigned clade that would include AAV4; and AAV13 represents the first AAV2-AAV3 hybrid clade C capsid structure. These newly determined capsid structures all exhibit the AAV capsid features including 5-fold channels, 3-fold protrusions, 2-fold depressions, and a nucleotide binding pocket with an ordered nucleotide in genome-containing capsids. However, these structures have viral proteins that display clade-specific loop conformations. This structural characterization completes our three-dimensional library of the current AAV serotypes to provide an atlas of surface loop configurations compatible with capsid assembly and amenable for future vector engineering efforts. Derived vectors could improve gene delivery success with respect to specific tissue targeting, transduction efficiency, antigenicity or receptor retargeting.


Assuntos
Capsídeo/ultraestrutura , Dependovirus/classificação , Dependovirus/ultraestrutura , Modelos Moleculares , Vírion/ultraestrutura , Capsídeo/metabolismo , Proteínas do Capsídeo/química , Microscopia Crioeletrônica , Dependovirus/genética , Genoma Viral , Humanos , Processamento de Imagem Assistida por Computador , Imageamento Tridimensional , Sorogrupo
13.
Viruses ; 13(1)2021 Jan 15.
Artigo em Inglês | MEDLINE | ID: mdl-33467558

RESUMO

Adenovirus (AdV) infection elicits a strong immune response with the production of neutralizing antibodies and opsonization by complement and coagulation factors. One anti-hexon neutralizing antibody, called 9C12, is known to activate the complement cascade, resulting in the deposition of complement component C4b on the capsid, and the neutralization of the virus. The mechanism of AdV neutralization by C4b is independent of downstream complement proteins and involves the blockage of the release of protein VI, which is required for viral escape from the endosome. To investigate the structural basis underlying how C4b blocks the uncoating of AdV, we built a model for the complex of human adenovirus type-5 (HAdV5) with 9C12, together with complement components C1 and C4b. This model positions C4b near the Arg-Gly-Asp (RGD) loops of the penton base. There are multiple amino acids in the RGD loop that might serve as covalent binding sites for the reactive thioester of C4b. Molecular dynamics simulations with a multimeric penton base and C4b indicated that stabilizing interactions may form between C4b and multiple RGD loops. We propose that C4b deposition on one RGD loop leads to the entanglement of C4b with additional RGD loops on the same penton base multimer and that this entanglement blocks AdV uncoating.


Assuntos
Adenoviridae/imunologia , Complemento C4/química , Complemento C4/imunologia , Modelos Moleculares , Anticorpos Neutralizantes/química , Anticorpos Neutralizantes/imunologia , Anticorpos Antivirais/química , Anticorpos Antivirais/imunologia , Sítios de Ligação , Capsídeo/química , Capsídeo/metabolismo , Capsídeo/ultraestrutura , Proteínas do Capsídeo/química , Proteínas do Capsídeo/imunologia , Proteínas do Capsídeo/metabolismo , Proteínas do Capsídeo/ultraestrutura , Humanos , Imunoglobulina G/química , Imunoglobulina G/imunologia , Simulação de Acoplamento Molecular , Simulação de Dinâmica Molecular , Ligação Proteica , Conformação Proteica , Relação Estrutura-Atividade
14.
Viruses ; 13(1)2021 Jan 18.
Artigo em Inglês | MEDLINE | ID: mdl-33477441

RESUMO

Integration of retroviral reverse transcripts into the chromosomes of the cells that they infect is required for efficient viral gene expression and the inheritance of viral genomes to daughter cells. Before integration can occur, retroviral reverse transcription complexes (RTCs) must access the nuclear environment where the chromosomes reside. Retroviral integration is non-random, with different types of virus-host interactions impacting where in the host chromatin integration takes place. Lentiviruses such as HIV efficiently infect interphase cells because their RTCs have evolved to usurp cellular nuclear import transport mechanisms, and research over the past decade has revealed specific interactions between the HIV capsid protein and nucleoporin (Nup) proteins such as Nup358 and Nup153. The interaction of HIV capsid with cleavage and polyadenylation specificity factor 6 (CPSF6), which is a component of the cellular cleavage and polyadenylation complex, helps to dictate nuclear import as well as post-nuclear RTC invasion. In the absence of the capsid-CPSF6 interaction, RTCs are precluded from reaching nuclear speckles and gene-rich regions of chromatin known as speckle-associated domains, and instead mis-target lamina-associated domains out at the nuclear periphery. Highlighting this area of research, small molecules that inhibit capsid-host interactions important for integration site targeting are highly potent antiviral compounds.


Assuntos
Proteínas do Capsídeo/metabolismo , Capsídeo/metabolismo , Infecções por HIV/virologia , HIV-1/fisiologia , Interações Hospedeiro-Patógeno , Integração Viral , Transporte Ativo do Núcleo Celular , Proteínas do Capsídeo/química , Proteínas do Capsídeo/genética , Cromatina , Infecções por HIV/genética , Infecções por HIV/metabolismo , Humanos , Complexo de Proteínas Formadoras de Poros Nucleares/metabolismo , Ligação Proteica , Relação Estrutura-Atividade
15.
Viruses ; 13(1)2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33430521

RESUMO

We describe the complete capsid of a genotype C1-like Enterovirus A71 variant recovered from wastewater in a neighborhood in the greater Tempe, Arizona area (Southwest United States) in May 2020 using a pan-enterovirus amplicon-based high-throughput sequencing strategy. The variant seems to have been circulating for over two years, but its sequence has not been documented in that period. As the SARS-CoV-2 pandemic has resulted in changes in health-seeking behavior and overwhelmed pathogen diagnostics, our findings highlight the importance of wastewater-based epidemiology (WBE ) as an early warning system for virus surveillance.


Assuntos
Proteínas do Capsídeo/genética , Enterovirus Humano A/genética , Enterovirus Humano A/isolamento & purificação , Sequenciamento de Nucleotídeos em Larga Escala/métodos , Águas Residuárias/virologia , Vigilância Epidemiológica Baseada em Águas Residuárias , Arizona/epidemiologia , Capsídeo/química , Infecções por Enterovirus/epidemiologia , Infecções por Enterovirus/virologia , Humanos , Epidemiologia Molecular , Pandemias , Filogenia
16.
Vet Res ; 52(1): 4, 2021 Jan 07.
Artigo em Inglês | MEDLINE | ID: mdl-33413620

RESUMO

The transport of circovirus capsid protein into nucleus is essential for viral replication in infected cell. However, the role of nucleolar shuttle proteins during porcine circovirus 3 capsid protein (PCV3 Cap) import is still not understood. Here, we report a previously unidentified nucleolar localization signal (NoLS) of PCV3 Cap, which hijacks the nucleolar phosphoprotein nucleophosmin-1 (NPM1) to facilitate nucleolar localization of PCV3 Cap. The NoLS of PCV3 Cap and serine-48 residue of N-terminal oligomerization domain of NPM1 are essential for PCV3 Cap/NPM1 interaction. In addition, charge property of serine-48 residue of NPM1 is critical for nucleolar localization and interaction with PCV3 Cap. Taken together, our findings demonstrate for the first time that NPM1 interacts with PCV3 Cap and is responsible for its nucleolar localization.


Assuntos
Proteínas do Capsídeo/metabolismo , Circovirus/metabolismo , Proteínas Nucleares/metabolismo , Animais , Sítios de Ligação , Proteínas do Capsídeo/genética , Linhagem Celular , Circovirus/genética , Eletroforese em Gel de Poliacrilamida , Técnicas de Silenciamento de Genes , Immunoblotting , Microscopia Confocal , Serina , Suínos
17.
Proc Natl Acad Sci U S A ; 118(3)2021 01 19.
Artigo em Inglês | MEDLINE | ID: mdl-33384338

RESUMO

Human adenovirus species D (HAdV-D) types are currently being explored as vaccine vectors for coronavirus disease 2019 (COVID-19) and other severe infectious diseases. The efficacy of such vector-based vaccines depends on functional interactions with receptors on host cells. Adenoviruses of different species are assumed to enter host cells mainly by interactions between the knob domain of the protruding fiber capsid protein and cellular receptors. Using a cell-based receptor-screening assay, we identified CD46 as a receptor for HAdV-D56. The function of CD46 was validated in infection experiments using cells lacking and overexpressing CD46, and by competition infection experiments using soluble CD46. Remarkably, unlike HAdV-B types that engage CD46 through interactions with the knob domain of the fiber protein, HAdV-D types infect host cells through a direct interaction between CD46 and the hexon protein. Soluble hexon proteins (but not fiber knob) inhibited HAdV-D56 infection, and surface plasmon analyses demonstrated that CD46 binds to HAdV-D hexon (but not fiber knob) proteins. Cryoelectron microscopy analysis of the HAdV-D56 virion-CD46 complex confirmed the interaction and showed that CD46 binds to the central cavity of hexon trimers. Finally, soluble CD46 inhibited infection by 16 out of 17 investigated HAdV-D types, suggesting that CD46 is an important receptor for a large group of adenoviruses. In conclusion, this study identifies a noncanonical entry mechanism used by human adenoviruses, which adds to the knowledge of adenovirus biology and can also be useful for development of adenovirus-based vaccine vectors.


Assuntos
Adenovírus Humanos , Proteínas do Capsídeo , Regulação Viral da Expressão Gênica , Internalização do Vírus , Adenovírus Humanos/genética , Adenovírus Humanos/metabolismo , /metabolismo , Proteínas do Capsídeo/biossíntese , Proteínas do Capsídeo/genética , Linhagem Celular , Humanos
18.
Subcell Biochem ; 96: 451-470, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33252740

RESUMO

Non-enveloped Nackednaviridae and enveloped hepadnaviridae both have capsids that are formed by related small proteins which evolved more than 430 Mya. In Hepatitis B virus, which belongs to the enveloped hepadnaviridae, this small protein is termed Hepatitis B core protein (Hbc). Its function, as building block of a major human pathogen, triggered extensive research that elucidated the importance of almost every single amino acid for the structural integrity of the capsids and the orderly progression of the viral life cycle. In particular, encapsidation of the genome, envelopment of the capsid, uncoating of the genome and targeting of the different compartments during viral maturation have been a vivid focus of research. HBc has also been developed as a biotechnological tool for the design of nano-containers with tailored properties. These nano-containers can display foreign epitopes on their surfaces and induce a strong immune response, which is attractive for the development of vaccines against other pathogens. This chapter will discuss some of the unique properties of HBc and their significance for the formation of a functional macromolecular capsid.


Assuntos
Capsídeo/química , Vírus da Hepatite B/química , Proteínas do Core Viral/química , Proteínas do Capsídeo/química , Hepatite B/virologia , Humanos
19.
Subcell Biochem ; 96: 503-518, 2021.
Artigo em Inglês | MEDLINE | ID: mdl-33252742

RESUMO

Human adenoviruses (HAdVs) are large (150 MDa), complex, nonenveloped dsDNA viruses that cause self-limiting respiratory, ocular and enteric infections. They are significant health hazard in young, elderly and immuno-compromised populations. Moreover, various adenoviruses (AdVs) of mammalian origin are being used as vectors in gene, vaccine and cancer therapies. Multiple copies of at least 13 different proteins, all in all ~2800 protein molecules, come together to form an adenovirus virion packaging the ~36 Kbp geome. The details of structural organization of the adenovirus capsid and underlying network of protein-protein interactions provide clues into designing the modified and novel adenovirus vectors with desired functionalities and/or targeting specificities. The advancements in 3D structure determination by cryo-electron microscopy (cryo-EM) in the past decade have enabled unveiling of the complex organization of adenovirus architecture at near atomic resolution. Specifically, these studies revealed the structures and the network of interactions involving cement/minor proteins in stabilizing the AdV icosahedral architecture, which appear to be mostly conserved among human adenoviruses. In this chapter, we describe the current state of knowledge on the structure and organization of human adenoviruses.


Assuntos
Adenovírus Humanos/química , Proteínas do Capsídeo/química , Capsídeo/química , Adenovírus Humanos/ultraestrutura , Capsídeo/ultraestrutura , Proteínas do Capsídeo/ultraestrutura , Microscopia Crioeletrônica , Humanos , Modelos Moleculares , Ligação Proteica
20.
Gene ; 773: 145384, 2021 Mar 20.
Artigo em Inglês | MEDLINE | ID: mdl-33383119

RESUMO

Porcine circovirus type 4 (PCV4), a novel circovirus, was identified in pigs with serious symptoms, including porcine dermatitis and nephropathy syndrome (PDNS)-like signs, in China in 2019. This study investigated the prevalence and genome diversity of PCV4 in pigs from Guangxi Province, China, between 2015 and 2019. Thirteen of 257 (5.1%) samples were positive for PCV4, 9 of these (69.2%) PCV4-positive samples were coinfected with PCV2 or PCV3, and one PCV4-positive sample was coinfected with both PCV2 and PCV3. Three complete PCV4 genomes shared 36.9-73.8% nucleotide similarity with other representative circovirus genomes. Phylogenetic analysis indicated that PCV4 was most closely related to bat-associated circovirus and mink circovirus. In summary, this is the first epidemiological investigation and evolutionary analysis of PCV4 in Guangxi Province, China, and the results provide insight into the molecular epidemiology of PCV4.


Assuntos
Infecções por Circoviridae/genética , Circovirus/genética , Filogenia , Doenças dos Suínos/genética , Animais , Proteínas do Capsídeo/genética , China/epidemiologia , Infecções por Circoviridae/epidemiologia , Infecções por Circoviridae/patologia , Infecções por Circoviridae/veterinária , Circovirus/patogenicidade , Genoma Viral/genética , Humanos , Suínos/genética , Suínos/virologia , Doenças dos Suínos/epidemiologia , Proteínas Virais/genética
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