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Updated: Aug 18, 2026

Analysis of mRNA Nuclear Export Kinetics in Mammalian Cells by Microinjection
11:32

Analysis of mRNA Nuclear Export Kinetics in Mammalian Cells by Microinjection

Published on: December 4, 2010

REF proteins mediate the export of spliced and unspliced mRNAs from the nucleus

J P Rodrigues1, M Rode, D Gatfield

  • 1European Molecular Biology Laboratory, Meyerhofstrasse 1, 69117 Heidelberg, Germany.

Proceedings of the National Academy of Sciences of the United States of America
|February 7, 2001
PubMed

Insights

REF proteins are crucial for exporting messenger RNA (mRNA) from the nucleus. These proteins bind to RNA and facilitate the nuclear export of both spliced and unspliced mRNAs.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Genetics

Background:

  • The REF (heterogeneous ribonucleoprotein-like) protein family possesses a conserved RNA-binding domain and Arg-Gly-rich regions.
  • REFs are known to interact with RNA and the mRNA export factor TAP/Mex67p.
  • It is hypothesized that REFs assist in recruiting TAP/Mex67p to messenger ribonucleoprotein complexes (mRNPs).

Purpose of the Study:

  • To investigate the role of REF proteins in mRNA nuclear export.
  • To determine the functional significance of the variable regions in REFs for RNA and TAP binding.
  • To elucidate the precise step at which REFs act in the mRNA export pathway.

Main Methods:

  • Antibody production against REF proteins.
  • In vitro binding assays to assess REF interaction with RNA and TAP.
  • Microinjection of antibodies into Xenopus oocytes to study effects on mRNA export.
  • Analysis of pre-mRNA splicing and constitutive transport element (CTE)-mediated RNA export.

Main Results:

  • The variable regions of REFs are essential for their binding to both RNA and TAP.
  • Antibodies against REFs inhibit mRNA nuclear export in Xenopus oocytes, regardless of splicing status.
  • REF proteins act downstream of splicing but upstream of TAP/Mex67p in the mRNA export pathway.
  • Recombinant REFs enhance the export efficiency of poorly exported mRNAs.

Conclusions:

  • REF proteins play a critical and direct role in the nuclear export of mRNAs.
  • Both spliced and unspliced mRNAs utilize common export factors, including REFs, to reach the cytoplasm.
  • These findings highlight REFs as key mediators in the fundamental process of mRNA transport from the nucleus.

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