Search results for "capsid"

Seroepidemiology of porcine enteric sapovirus in pig farms in Venezuela

2010

Porcine enteric sapovirus (PES) has been shown to cause diarrhea under experimental conditions in gnotobiotic piglets. However, the role of PES as enteric pathogens in porcine farms remains unclear. To further understand the PES-host interactions under field conditions, a serological survey was carried out. To this end the capsid gene of a PES isolate was cloned in the baculovirus expression system and an ELISA was developed based on virus-like particles from the baculovirus-expressed PES capsid protein. A total of 85 serum samples collected from pigs ranging from 8 weeks to over 54 weeks of age were analyzed. An overall seroprevalence to PESs of 62% was found, with significant differences …

Dendritic cell aggresome-like-induced structure formation and delayed antigen presentation coincide in influenza virus-infected dendritic cells.

2005

Abstract Influenza virus infection induces maturation of murine dendritic cells (DCs), which is most important for the initiation of an immune response. However, in contrast to EL-4 and MC57 cells, DCs present viral CTL epitopes with a delay of up to 10 h. This delay in Ag presentation coincides with the up-regulation of MHC class I molecules as well as costimulatory molecules on the cell surface and the accumulation of newly synthesized ubiquitinated proteins in large cytosolic structures, called DC aggresome-like-induced structures (DALIS). These structures were observed previously after LPS-induced maturation of DCs, and it was speculated that they play a role in the regulation of MHC cl…

The Transcription Factors TBX2 and TBX3 Interact with Human Papillomavirus 16 (HPV16) L2 and Repress the Long Control Region of HPVs

2013

ABSTRACT The minor capsid protein L2 of human papillomaviruses (HPVs) has multiple functions during the viral life cycle. Although L2 is required for effective invasion and morphogenesis, only a few cellular interaction partners are known so far. Using yeast two-hybrid screening, we identified the transcription factor TBX2 as a novel interaction partner of HPV type 16 (HPV16) L2. Coimmunoprecipitations and immunofluorescence analyses confirmed the L2-TBX2 interaction and revealed that L2 also interacts with TBX3, another member of the T-box family. Transcription of the early genes during HPV infection is under the control of an upstream enhancer and early promoter region, the long control r…

Quasispecies dynamics and molecular evolution of human norovirus capsid P region during chronic infection.

2009

In this novel study, we have for the first time identified evolutionarily conserved capsid residues in an individual chronically infected with norovirus (GGII.3). From 2000 to 2003, a total of 147 P1-1 and P2 capsid sequences were sequenced and investigated for evolutionarily conserved and functionally important residues by the evolutionary trace (ET) algorithm. The ET algorithm revealed more absolutely conserved residues (ACR) in the P1-1 domain (47/53, 88 %) as compared with the P2 domain (86/133, 64 %). The capsid P1-1 and P2 domains evolved in time-dependent manner, with a distinct break point observed between autumn/winter of year 2000 (isolates P1, P3 and P5) and spring to autumn of y…

Nucleotide sequence of a ssRNA phage from Acinetobacter: kinship to coliphages.

2002

The complete nucleotide sequence of ssRNA phage AP205 propagating in Acinetobacter species is reported. The RNA has three large ORFs, which code for the following homologues of the RNA coliphage proteins: the maturation, coat and replicase proteins. Their gene order is the same as that in coliphages. RNA coliphages or Leviviridae fall into two genera: the alloleviviruses, like Qβ, which have a coat read-through protein, and the leviviruses, like MS2, which do not have this coat protein extension. AP205 has no read-through protein and may therefore be classified as a levivirus. A major digression from the known leviviruses is the apparent absence of a lysis gene in AP205 at the usual positio…

PML nuclear body-residing proteins sequentially associate with HPV genome after infectious nuclear delivery.

2019

Subnuclear promyelocytic leukemia (PML) nuclear bodies (NBs) are targeted by many DNA viruses after nuclear delivery. PML protein is essential for formation of PML NBs. Sp100 and Small Ubiquitin-Like Modifier (SUMO) are also permanently residing within PML NBs. Often, large DNA viruses disassemble and reorganize PML NBs to counteract their intrinsic antiviral activity and support establishment of infection. However, human papillomavirus (HPV) requires PML protein to retain incoming viral DNA in the nucleus for subsequent efficient transcription. In contrast, Sp100 was identified as a restriction factor for HPV. These findings suggested that PML NBs are important regulators of early stages o…

Purified Membrane-Containing Procapsids of Bacteriophage PRD1 Package the Viral Genome

2009

Icosahedral-tailed double-stranded DNA (dsDNA) bacteriophages and herpesviruses translocate viral DNA into a preformed procapsid in an ATP-driven reaction by a packaging complex that operates at a portal vertex. A similar packaging system operates in the tailless dsDNA phage PRD1 (Tectiviridae family), except that there is an internal membrane vesicle in the procapsid. The unit-length linear dsDNA genome with covalently linked 5'-terminal proteins enters the procapsid through a unique vertex. Two small integral membrane proteins, P20 and P22, provide a conduit for DNA translocation. The packaging machinery also contains the packaging ATPase P9 and the packaging efficiency factor P6. Here we…

Coxsackievirus B3-Induced Cellular Protrusions: Structural Characteristics and Functional Competence▿†

2011

ABSTRACT Virus-induced alterations in cell morphology play important roles in the viral life cycle. To examine the intracellular events of coxsackievirus B3 (CVB3) infection, green monkey kidney (GMK) cells were either inoculated with the virus or transfected with the viral RNA. Various microscopic and flow cytometric approaches demonstrated the emergence of CVB3 capsid proteins at 8 h posttransfection, followed by morphological transformation of the cells. The morphological changes included formation of membranous protrusions containing viral capsids, together with microtubules and actin. Translocation of viral capsids into these protrusions was sensitive to cytochalasin D, suggesting the …

Viral Entry and Receptors

2007

Killer toxin-secreting double-stranded RNA mycoviruses in the yeasts Hanseniaspora uvarum and Zygosaccharomyces bailii.

1994

Killer toxin-secreting strains of the yeasts Hanseniaspora uvarum and Zygosaccharomyces bailii were shown to contain linear double-stranded RNAs (dsRNAs) that persist within the cytoplasm of the infected host cell as encapsidated virus-like particles. In both yeasts, L- and M-dsRNAs were associated with 85-kDa major capsid protein, whereas the additional Z-dsRNA (2.8 kb), present only in the wild-type Z. bailii killer strain, was capsid protein, whereas the additional Z-dsRNA (2.8 kb), present only in the wild-type Z. bailii killer strain, was shown to be encapsidated by a 35-kDa coat protein. Although Northern (RNA) blot hybridizations indicated that L-dsRNA from Z. bailii is a LA species,…