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Effect of human immunodeficiency virus type 1 protein R (vpr) gene expression on basic cellular function of fission

Y Zhao1, J Cao, M R O'Gorman

  • 1Section of Pediatric and Maternal Human Immunodeficiency Virus Infections, Children's Memorial Hospital, Illinois, USA. yzhao@nwu.edu

Journal of Virology
|September 1, 1996
PubMed

Insights

The human immunodeficiency virus type 1 (HIV-1) Vpr protein causes cell cycle G2 arrest in yeast, similar to its effects in human cells. This study demonstrates that fission yeast is a suitable model for investigating HIV-1 Vpr functions.

Area of Science:

  • Virology
  • Cell Biology
  • Molecular Biology

Background:

  • Human immunodeficiency virus type 1 (HIV-1) Vpr protein alters cell morphology and proliferation.
  • Vpr induces cell cycle G2 arrest in human cells.

Purpose of the Study:

  • Investigate the cellular effects of HIV-1 vpr gene expression using fission yeast (Schizosaccharomyces pombe) as a model.
  • Determine if Vpr-induced effects in yeast mirror those in human cells.

Main Methods:

  • Cloned the HIV-1 vpr gene into an inducible fission yeast expression vector.
  • Expressed the vpr gene in wild-type S. pombe cells.
  • Analyzed colonial, cellular, and molecular changes upon vpr gene induction and suppression.

Main Results:

  • HIV-1 Vpr expression induced small-colony formation, polymorphic cells, growth delay, and cell cycle G2 arrest in S. pombe.
  • Vpr-induced G2 arrest was independent of cell size and morphology.
  • G2 arrest correlated with increased p34cdc2 phosphorylation, suggesting negative mitotic regulation.
  • Okadaic acid (protein phosphatase inhibitor) transiently suppressed Vpr-induced arrest and morphological changes.

Conclusions:

  • HIV-1 Vpr induces cellular changes in S. pombe that are analogous to those observed in human cells.
  • The fission yeast S. pombe is a valuable model system for studying HIV-1 vpr gene functions.

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