Mapping interactions between mRNA export factors in living cells

PLoS One. 2013 Jun 24;8(6):e67676. doi: 10.1371/journal.pone.0067676. Print 2013.

Abstract

The TREX complex couples nuclear mRNA processing events with subsequent export to the cytoplasm. TREX also acts as a binding platform for the mRNA export receptor Nxf1. The sites of mRNA transcription and processing within the nucleus have been studied extensively. However, little is known about where TREX assembly takes place and where Nxf1 is recruited to TREX to form the export competent mRNP. Here we have used sensitized emission Förster resonance energy transfer (FRET) and fluorescence lifetime imaging (FLIM)-FRET, to produce a spatial map in living cells of the sites for the interaction of two TREX subunits, Alyref and Chtop, with Nxf1. Prominent assembly sites for export factors are found in the vicinity of nuclear speckles in regions known to be involved in transcription, splicing and exon junction complex formation highlighting the close coupling of mRNA export with mRNP biogenesis.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Cell Nucleus / metabolism
  • Cell Survival
  • Fluorescence Recovery After Photobleaching
  • Fluorescence Resonance Energy Transfer
  • HeLa Cells
  • Humans
  • Nuclear Proteins / metabolism*
  • Nucleocytoplasmic Transport Proteins / metabolism*
  • Protein Binding
  • Protein Interaction Mapping*
  • Protein Transport
  • RNA Transport*
  • RNA-Binding Proteins / metabolism*
  • Transcription Factors / metabolism*
  • Transcription, Genetic

Substances

  • ALYREF protein, human
  • CHTOP protein, human
  • NXF1 protein, human
  • Nuclear Proteins
  • Nucleocytoplasmic Transport Proteins
  • RNA-Binding Proteins
  • Transcription Factors