Requirement of DDX3 DEAD box RNA helicase for HIV-1 Rev-RRE export function

Cell. 2004 Oct 29;119(3):381-92. doi: 10.1016/j.cell.2004.09.029.

Abstract

A single transcript in its unspliced and spliced forms directs the synthesis of all HIV-1 proteins. Although nuclear export of intron-containing cellular transcripts is restricted in mammalian cells, HIV-1 has evolved the viral Rev protein to overcome this restriction for viral transcripts. Previously, CRM1 was identified as a cellular cofactor for Rev-dependent export of intron-containing HIV-1 RNA. Here, we present evidence that Rev/CRM1 activity utilizes the ATP-dependent DEAD box RNA helicase, DDX3. We show that DDX3 is a nucleo-cytoplasmic shuttling protein, which binds CRM1 and localizes to nuclear membrane pores. Knockdown of DDX3 using either antisense vector or dominant-negative mutants suppressed Rev-RRE-function in the export of incompletely spliced HIV-1 RNAs. Plausibly, DDX3 is the human RNA helicase which functions in the CRM1 RNA export pathway analogously to the postulated role for Dbp5p in yeast mRNA export.

MeSH terms

  • Amino Acid Sequence
  • Cytoplasm / metabolism
  • DEAD-box RNA Helicases
  • Genes, env / physiology*
  • HIV Infections / enzymology
  • HIV Infections / metabolism*
  • HIV-1 / genetics
  • HIV-1 / metabolism*
  • Humans
  • Karyopherins / metabolism
  • Molecular Sequence Data
  • Nuclear Pore / metabolism
  • RNA Helicases / metabolism*
  • RNA, Viral / metabolism
  • Receptors, Cytoplasmic and Nuclear / metabolism
  • Virus Replication / physiology

Substances

  • Karyopherins
  • RNA, Viral
  • Receptors, Cytoplasmic and Nuclear
  • exportin 1 protein
  • DDX3X protein, human
  • DEAD-box RNA Helicases
  • RNA Helicases