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HnRNP proteins and the nuclear export of mRNA

S Piñol-Roma1

  • 1Department of Cell Biology and Anatomy, Mount Sinai School of Medicine, Box 1007, One Gustave L. Levy Place, New York, NY 10029-6574, USA.

Seminars in Cell & Developmental Biology
|February 1, 1997
PubMed

Insights

Heterogeneous nuclear ribonucleoprotein (hnRNP) proteins bind pre-mRNAs for processing. This review highlights how nuclear export sequences (NESs) in shuttling hnRNPs mediate mRNA export from the nucleus.

Area of Science:

  • Molecular Biology
  • Cell Biology
  • Gene Expression

Background:

  • Pre-messenger RNAs (pre-mRNAs) in the nucleus form heterogeneous nuclear ribonucleoprotein (hnRNP) complexes with RNA-binding proteins.
  • hnRNP proteins are crucial for pre-mRNA processing into mature messenger RNAs (mRNAs).
  • Some hnRNP proteins exhibit continuous shuttling between the nucleus and cytoplasm.

Purpose of the Study:

  • To review the role of hnRNP proteins in mRNA processing and nuclear export.
  • To elucidate the mechanism of nuclear export mediated by shuttling hnRNPs.

Main Methods:

  • Review of recent studies on hnRNP protein function.
  • Analysis of nuclear export sequences (NESs) in shuttling hnRNPs.
  • Examination of hnRNP-mRNA interactions during nuclear export.

Main Results:

  • Shuttling hnRNP proteins possess specific nuclear export sequences (NESs).
  • These hnRNPs remain bound to mRNAs during their transit through nuclear pores.
  • Nuclear export of mRNAs appears to be facilitated by the export of bound hnRNPs.

Conclusions:

  • The export of NES-containing hnRNP proteins is a key mechanism for mRNA nuclear export.
  • hnRNP proteins play a dual role in mRNA processing and export.
  • Understanding hnRNP function provides insights into gene expression regulation.

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