The N-terminal domain of Nup159 forms a beta-propeller that functions in mRNA export by tethering the helicase Dbp5 to the nuclear pore

Mol Cell. 2004 Dec 3;16(5):749-60. doi: 10.1016/j.molcel.2004.10.032.

Abstract

Nuclear export of mRNA in eukaryotic cells is mediated by soluble transport factors and components of the nuclear pore complex (NPC). The cytoplasmically oriented nuclear pore protein Nup159 plays a critical role in mRNA export through its conserved N-terminal domain (NTD). Here, we report the crystal structure of the Nup159 NTD, refined to 2.5 A. The structure reveals an unusually asymmetric seven-bladed beta-propeller that is structurally conserved throughout eukarya. Using structure-based conservation analysis, we have targeted specific surface residues for mutagenesis. Residue substitutions in a conserved loop of the NTD abolish in vitro binding to Dbp5, a DEAD box helicase required for mRNA export. In vivo, these mutations cause Dbp5 mislocalization and block mRNA export. These findings suggest that the Nup159 NTD functions in mRNA export as a binding platform, tethering shuttling Dbp5 molecules at the nuclear periphery and locally concentrating this mRNA remodeling factor at the cytoplasmic face of the NPC.

Publication types

  • Research Support, Non-U.S. Gov't
  • Research Support, U.S. Gov't, Non-P.H.S.
  • Research Support, U.S. Gov't, P.H.S.

MeSH terms

  • Adenosine Triphosphatases / chemistry
  • Biological Transport
  • Cell Nucleus / metabolism
  • Chromatography, Gel
  • Crystallography, X-Ray
  • Cytoplasm / metabolism
  • DEAD-box RNA Helicases
  • In Situ Hybridization
  • Mutagenesis, Site-Directed
  • Mutation
  • Nuclear Pore / metabolism
  • Nuclear Pore Complex Proteins / chemistry*
  • Nuclear Pore Complex Proteins / genetics
  • Nuclear Pore Complex Proteins / physiology*
  • Nucleocytoplasmic Transport Proteins / chemistry*
  • Nucleocytoplasmic Transport Proteins / metabolism*
  • Plasmids / metabolism
  • Protein Conformation
  • Protein Structure, Secondary
  • Protein Structure, Tertiary
  • RNA Helicases / chemistry*
  • RNA Helicases / metabolism*
  • RNA, Messenger / metabolism
  • Recombinant Proteins / chemistry
  • Saccharomyces cerevisiae / metabolism
  • Saccharomyces cerevisiae Proteins / chemistry*
  • Saccharomyces cerevisiae Proteins / genetics
  • Saccharomyces cerevisiae Proteins / metabolism*
  • Saccharomyces cerevisiae Proteins / physiology*

Substances

  • NUP159 protein, S cerevisiae
  • Nuclear Pore Complex Proteins
  • Nucleocytoplasmic Transport Proteins
  • RNA, Messenger
  • Recombinant Proteins
  • Saccharomyces cerevisiae Proteins
  • Adenosine Triphosphatases
  • DBP5 protein, S cerevisiae
  • DEAD-box RNA Helicases
  • RNA Helicases