Infectious entry pathway of adenovirus type 2

Varga, Mikael; Weibull, Claes; Everitt, Einar

doi:10.1128/jvi.65.11.6061-6070.1991

Cited by 108 publications

(40 citation statements)

References 50 publications

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“…The difference map gave the first clear view of the penton complex located on the capsid vertices. The penton complex is important structurally, as it completes the icosahedral capsid formed predominantly by hexons, and functionally, as it has been implicated in disruption of the endosomal membrane after receptor-mediated endocytosis (Seth et al, 1984;Varga at al., 1991). Penetration of the membrane and release of the virus into the cytoplasm is thought to involve a pH-dependent conformational change of the capsid within the acidic endosome (Wohlfart, 1988).…”

Section: Dissociation Of the Penton Complex During Cell Entrymentioning

confidence: 99%

Difference imaging of adenovirus: bridging the resolution gap between X-ray crystallography and electron microscopy.

1993

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While X‐ray crystallography provides atomic resolution structures of proteins and small viruses, electron microscopy provides complementary structural information on the organization of larger assemblies at lower resolution. A novel combination of these two techniques has bridged this resolution gap and revealed the various structural components forming the capsid of human type 2 adenovirus. An image reconstruction of the intact virus, derived from cryo‐electron micrographs, was deconvolved with an approximate contrast transfer function to mitigate microscope distortions. A model capsid was calculated from 240 copies of the crystallographic structure of the major capsid protein and filtered to the correct resolution. Subtraction of the calculated capsid from the corrected reconstruction gave a three‐dimensional difference map revealing the minor proteins that stabilize the virion. Elongated density penetrating the hexon capsid at the facet edges was ascribed to polypeptide IIIa, a component required for virion assembly. Density on the inner surface of the capsid, connecting the ring of peripentonal hexons, was assigned as polypeptide VI, a component that binds DNA. Identification of the regions of hexon that contact the penton base suggests a structural mechanism for previously proposed events during cell entry.

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Section: Dissociation Of the Penton Complex During Cell Entrymentioning

confidence: 99%

Difference imaging of adenovirus: bridging the resolution gap between X-ray crystallography and electron microscopy.

1993

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“…It is well established that morphologically unmodified infective viruses are adsorbed at the cell sur-face and subsequently migrate through the cytoplasm to the nuclear membrane. Only the viral nucleoids enter the nucleus, and their DNA becomes progressively uncoated (Varga et al, 1991; for a review, see Flint and Broker, 1980). However, no morphological evidence of parental DNA fibrils are found in the nuclei by conventional electron microscopy.…”

Section: Dna Detection By In Situ Hybridizationmentioning

confidence: 99%

Immunocytochemistry, autoradiography, in situ hybridization, selective stains: Complementary tools for ultrastructural study of structure‐function relationships in the nucleus. Applications to adenovirus‐infected cells

Puvion‐Dutilleul¹,

Puvion²

1995

Microscopy Res & Technique

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A significant amount of new information on structure-function relationships in nuclei of adenovirus-infected cells has accumulated during the last decade as a result of the combined use of several new cytochemical techniques. Localization of viral DNA on ultrathin sections of infected cells has been investigated at the ultrastructural level by using specific DNA staining and immunocytochemistry with monoclonal anti-DNA antibodies. Both techniques, however, concomitantly visualize cellular and viral DNA. The specific stain for DNA reveals the configuration of the DNA molecules in the different nuclear substructures, whatever their synthetic activities. The immunodetection of DNA reveals that specific antibodies strongly bind to DNA of condensed host chromatin and to both encapsidated and nonencapsidated inactive viral genomes. However, the observation of an abnormally low level of labeling over the substructures in which synthetic activities of viral genomes are known to be intense demonstrates a serious limitation of this technique for the detection of active DNA. Postembedding in situ hybridization is the most useful method for identifying with certainty the structures containing defined nucleic acid sequences. By using a biotinylated viral DNA probe, in situ hybridization provides specific identification of structures containing either viral DNA or viral RNA molecules. In addition, with appropriate pretreatment of the sections, it is possible to reveal either all the viral DNA--that is, both double- and single-stranded DNA molecules (dsDNA, ssDNA)--or more specific species such as only ssDNA or only dsDNA molecules. The replicative and transcriptional activities of viral genomes are determined by high-resolution autoradiography. Autoradiography after a short pulse incorporation of appropriate radioactive precursors by infected cells reveals the sites of cellular and viral DNA replication or transcription. A short pulse followed by chase periods of different durations reveals the progressive migration of the cellular and viral synthesized products. The in situ distribution of the viral 72 kDa DNA-binding protein, a highly phosphorylated protein which protects the viral ssDNA, is revealed either by immunocytochemistry with specific antibodies or by the bismuth staining method which stains all highly phosphorylated proteins, including both cellular and viral proteins. The combined results of all these cytochemical procedures reveal the composition and functions of some of the structures induced by adenovirus infection. They demonstrate that viral genomes engaged in replication lead to the formation of the replicative foci in which two compartments rapidly develop, one of which results from the aggregation of single strands of viral DNA and their accompanying 72 kDa protein.(ABSTRACT TRUNCATED AT 400 WORDS)

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“…Human adenovirus type 2 (Ad2) was propagated in HeLa cells, [3H]-thymidine-labelled and purified as described previously [19]. The specific radioactivity was 63000 cpm/10 m virions.…”

Section: Cells and Virusmentioning

confidence: 99%

Antibody-mediated uncoating of adenovirus in vitro

Everitt

Luca

Blixt

1992

FEMS Microbiology Letters

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In a virus destabilization assay in vitro it was demonstrated that exposure of adenovirus to proteins will non‐specifically protect the virus from being uncoated following transfer to low pH and hypotonic conditions. Such uncoating was also fully inhibited upon pretreatment of virus with 0.05% of the non‐ionic detergent polyxyethylene‐sorbitan monolaurate (Tween 20). However, in the presence of low concentrations of Tween 20 it was shown that monospecific immunoglobulins, directed against the fiber antigen and polyspecific antibodies produced in response to intact virions, were able to overcome the detergent‐protecting effect of uncoating. Immunoglobulins directed towards the remaining outer‐capsid components, the hexon, the penton base and the protein IIIa, revealed no such effects. The antifiber‐mediated uncoating was paralleled by an aggregation of the virions. The data suggest that the virion‐stabilizing effect of salt is enhanced by the hydrophobic action of a non‐ionic detergent. Under these conditions the interaction between antifiber antibodies and fibers of the virion will trigger a destabilization of the virion upon transfer to low pH and hypotonic conditions.

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Infectious entry pathway of adenovirus type 2

Cited by 108 publications

References 50 publications

Difference imaging of adenovirus: bridging the resolution gap between X-ray crystallography and electron microscopy.

Difference imaging of adenovirus: bridging the resolution gap between X-ray crystallography and electron microscopy.

Immunocytochemistry, autoradiography, in situ hybridization, selective stains: Complementary tools for ultrastructural study of structure‐function relationships in the nucleus. Applications to adenovirus‐infected cells

Antibody-mediated uncoating of adenovirus in vitro

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