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Adenovirus core protein pVII is translocated into the nucleus by multiple import receptor pathways

Harald Wodrich1, Aurelia Cassany, Maximiliano A D'Angelo

  • 1Institut de Génétique Moléculaire de Montpellier, UMR 5535 CNRS, 1919 Route de Mende, 34293 Montpellier Cedex 05, France. harald.wodrich@igmm.cnrs.fr

Journal of Virology
|September 16, 2006
PubMed

Insights

Adenovirus protein VII facilitates viral DNA import into the nucleus. This protein utilizes multiple nuclear import pathways, acting as a key adaptor for receptor-mediated entry of the viral genome.

Area of Science:

  • Virology
  • Molecular Biology
  • Cell Biology

Background:

  • Adenoviruses are nonenveloped viruses with double-stranded DNA genomes that replicate in the nucleus.
  • Protein VII is a major structural component of the adenovirus core, closely associated with viral DNA.
  • Protein VII is imported into the nucleus concurrently with the viral genome post-infection, potentially aiding DNA import.

Purpose of the Study:

  • To investigate if adenovirus protein VII employs specific receptor-mediated mechanisms for nuclear import.
  • To identify the nuclear localization signals (NLS) within protein VII and the cellular import receptors involved.

Main Methods:

  • Transfection of cultured cells with protein VII fusion constructs.
  • Microinjection of cells with recombinant protein VII fusions.
  • Deletion mapping and site-specific mutagenesis to identify NLS regions and residues.
  • In vitro binding assays with purified import receptors and permeabilized cells.

Main Results:

  • Protein VII exhibits potent nuclear localization signal (NLS) activity.
  • Three distinct NLS-containing regions were identified within protein VII.
  • Protein VII and its NLS domains bind strongly and specifically to importin alpha, importin beta, importin 7, and transportin.
  • These cellular import receptors mediate the nuclear import of protein VII fusions in vitro.

Conclusions:

  • Adenovirus protein VII functions as a crucial NLS-containing adaptor for receptor-mediated import of adenovirus DNA.
  • Multiple import pathways, involving various cellular nuclear import receptors, are utilized for efficient viral genome entry into the nucleus.

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