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HIV-1 Vpr interacts with the nuclear transport pathway to promote macrophage infection

M A Vodicka1, D M Koepp, P A Silver

  • 1Divisions of Molecular Medicine and Basic Science, Fred Hutchinson Cancer Research Center, Seattle, Washington 98109 USA.

Genes & Development
|March 7, 1998
PubMed

Insights

The HIV-1 Vpr protein aids viral nucleic acid entry into macrophages and cell cycle arrest. Its nuclear import function, essential for macrophage infection, is separable from its cell cycle arrest role.

Area of Science:

  • Molecular Biology
  • Virology
  • Cell Biology

Background:

  • The human immunodeficiency virus type 1 (HIV-1) Vpr protein is crucial for viral replication.
  • Vpr is known to promote nuclear entry of viral genetic material in non-dividing cells and induce cell cycle arrest.
  • Understanding Vpr's molecular mechanisms is key to developing antiviral strategies.

Purpose of the Study:

  • To investigate the role of HIV-1 Vpr in nuclear transport and cell cycle regulation.
  • To determine the functional domains of Vpr responsible for its distinct activities.
  • To elucidate the interaction of Vpr with host cell nuclear import machinery.

Main Methods:

  • Localization studies of Vpr in human and yeast cells.
  • Analysis of Vpr interactions with importin-alpha and nucleoporins.
  • Functional assays using wild-type and mutant Vpr (Vpr F34I) in HIV-1 infection models and yeast systems.

Main Results:

  • Vpr localizes to the nuclear envelope and interacts with importin-alpha and nucleoporins, similar to importin-beta.
  • Overexpression of Vpr or importin-beta in yeast inhibits mRNA nuclear export.
  • A Vpr mutant (Vpr F34I) defective in nuclear envelope localization and binding to importin-alpha/nucleoporins impairs HIV-1 macrophage infection but retains G2 arrest capability.

Conclusions:

  • HIV-1 Vpr's function in nuclear import resembles that of importin-beta.
  • The nuclear import function of Vpr is essential for efficient HIV-1 infection of macrophages.
  • The G2 cell cycle arrest function of Vpr is independent of its nuclear import role, indicating functional separability.

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