Intermolecular interactions between retroviral gag proteins in the nucleus

Scott P. Kenney, Timothy L. Lochmann, Cullen L. Schmid, Leslie J. Parent

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

The retroviral Gag polyprotein directs virus particle assembly, resulting in the release of virions from the plasma membranes of infected cells. The earliest steps in assembly, those immediately following Gag synthesis, are very poorly understood. For Rous sarcoma virus (RSV), Gag proteins are synthesized in the cytoplasm and then undergo transient nuclear trafficking before returning to the cytoplasm for transport to the plasma membrane. Thus, RSV provides a useful model to study the initial steps in assembly because the early and later stages are spatially separated by the nuclear envelope. We previously described mutants of RSV Gag that are defective in nuclear export, thereby isolating these "trapped" Gag proteins at an early assembly step. Using the nuclear export mutants, we asked whether Gag protein-protein interactions occur within the nucleus. Complementation experiments revealed that the wild-type Gag protein could partially rescue export-defective Gag mutants into virus-like particles (VLPs). Additionally, the export mutants had a frans-dominant negative effect on wild-type Gag, interfering with its release into VLPs. Confocal imaging of wild-type and mutant Gag proteins bearing different fluorescent tags suggested that complementation between Gag proteins occurred in the nucleus. Additional evidence for nuclear Gag-Gag interactions was obtained using fluorescence resonance energy transfer, and we found that the formation of intranuclear Gag complexes was dependent on the NC domain. Bimolecular fluorescence complementation allowed the direct visualization of intranuclear Gag-Gag dimers. Together, these experimental results strongly suggest that RSV Gag proteins are capable of interacting within the nucleus.

Original languageEnglish (US)
Pages (from-to)683-691
Number of pages9
JournalJournal of virology
Volume82
Issue number2
DOIs
StatePublished - Jan 1 2008

Fingerprint

gag Gene Products
Rous sarcoma virus
mutants
Virion
virus-like particles
proteins
virion
Cell Nucleus Active Transport
plasma membrane
cytoplasm
fluorescence
Cytoplasm
Cell Membrane
nuclear membrane
protein-protein interactions
energy transfer
Virus Assembly
Fluorescence Resonance Energy Transfer
Nuclear Envelope
Mutant Proteins

All Science Journal Classification (ASJC) codes

  • Microbiology
  • Immunology
  • Insect Science
  • Virology

Cite this

Kenney, Scott P. ; Lochmann, Timothy L. ; Schmid, Cullen L. ; Parent, Leslie J. / Intermolecular interactions between retroviral gag proteins in the nucleus. In: Journal of virology. 2008 ; Vol. 82, No. 2. pp. 683-691.
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Intermolecular interactions between retroviral gag proteins in the nucleus. / Kenney, Scott P.; Lochmann, Timothy L.; Schmid, Cullen L.; Parent, Leslie J.

In: Journal of virology, Vol. 82, No. 2, 01.01.2008, p. 683-691.

Research output: Contribution to journalArticle

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