Nuclear Factor 90, a cellular dsRNA binding protein inhibits the HIV Rev-export function

Retrovirology. 2006 Nov 24;3:83. doi: 10.1186/1742-4690-3-83.

Abstract

Background: The HIV Rev protein is known to facilitate export of incompletely spliced and unspliced viral transcripts to the cytoplasm, a necessary step in virus life cycle. The Rev-mediated nucleo-cytoplasmic transport of nascent viral transcripts, dependents on interaction of Rev with the RRE RNA structural element present in the target RNAs. The C-terminal variant of dsRNA-binding nuclear protein 90 (NF90ctv) has been shown to markedly attenuate viral replication in stably transduced HIV-1 target cell line. Here we examined a mechanism of interference of viral life cycle involving Rev-NF90ctv interaction.

Results: Since Rev:RRE complex formations depend on protein:RNA and protein:protein interactions, we investigated whether the expression of NF90ctv might interfere with Rev-mediated export of RRE-containing transcripts. When HeLa cells expressed both NF90ctv and Rev protein, we observed that NF90ctv inhibited the Rev-mediated RNA transport. In particular, three regions of NF90ctv protein are involved in blocking Rev function. Moreover, interaction of NF90ctv with the RRE RNA resulted in the expression of a reporter protein coding sequences linked to the RRE structure. Moreover, Rev influenced the subcellular localization of NF90ctv, and this process is leptomycin B sensitive.

Conclusion: The dsRNA binding protein, NF90ctv competes with HIV Rev function at two levels, by competitive protein:protein interaction involving Rev binding to specific domains of NF90ctv, as well as by its binding to the RRE-RNA structure. Our results are consistent with a model of Rev-mediated HIV-1 RNA export that envisions Rev-multimerization, a process interrupted by NF90ctv.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Active Transport, Cell Nucleus
  • Cell Line
  • Cell Nucleus / metabolism
  • Gene Expression Regulation
  • Gene Products, rev / antagonists & inhibitors*
  • Gene Products, rev / metabolism
  • Genes, Reporter
  • HIV-1 / metabolism
  • HIV-1 / physiology*
  • Humans
  • Nuclear Factor 90 Proteins / chemistry
  • Nuclear Factor 90 Proteins / metabolism
  • Nuclear Factor 90 Proteins / physiology*
  • Protein Interaction Mapping
  • Protein Structure, Tertiary
  • RNA, Viral / metabolism*
  • Virus Replication / physiology
  • rev Gene Products, Human Immunodeficiency Virus

Substances

  • Gene Products, rev
  • ILF3 protein, human
  • Nuclear Factor 90 Proteins
  • RNA, Viral
  • rev Gene Products, Human Immunodeficiency Virus
  • rev protein, Human Immunodeficiency Virus-1