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Yeast Upf1 CH domain interacts with Rps26 of the 40S ribosomal subunit

Ei Ei Min1, Bijoyita Roy, Nadia Amrani

  • 1Department of Microbiology and Physiological Systems, University of Massachusetts Medical School, Worcester, Massachusetts 01655, USA.

RNA (New York, N.Y.)
|June 27, 2013
PubMed

Insights

The nonsense-mediated mRNA decay (NMD) regulator Upf1 specifically binds to 40S ribosomal subunits, interacting with Rps26. This interaction, dependent on ATP and Upf1

Area of Science:

  • Molecular Biology
  • RNA Biology
  • Gene Regulation

Background:

  • Nonsense-mediated mRNA decay (NMD) is a crucial surveillance pathway that degrades aberrant mRNAs containing premature stop codons.
  • Upf1 is a central regulator of NMD, but the precise mechanism of its selective association with NMD target mRNAs remains unclear.
  • Previous studies indicated Upf1 associates with 40S ribosomal subunits, a key component of the translation machinery.

Purpose of the Study:

  • To elucidate the specific nature of the interaction between Upf1 and 40S ribosomal subunits.
  • To identify ribosomal proteins that directly interact with Upf1.
  • To understand the functional and regulatory aspects of Upf1's association with the 40S subunit.

Main Methods:

  • Co-immunoprecipitation of epitope-tagged 40S ribosomal subunits.
  • Purification of ribosomal subunits under various conditions (high-salt wash, puromycin release).
  • Yeast two-hybrid screening to identify Upf1-interacting proteins.
  • In vitro binding assays and mutational analysis of UPF1 domains.

Main Results:

  • Upf1 specifically co-immunoprecipitated with 40S ribosomal subunits, independent of other NMD factors (eRF1, eRF3, Upf2, Upf3).
  • A direct interaction between Upf1 and the ribosomal protein Rps26 was identified.
  • Upf1:40S subunit association is modulated by ATP, and the Upf1:Rps26 interaction requires the N-terminal CH domain of Upf1.

Conclusions:

  • Upf1's specific association with the 40S ribosomal subunit is a key feature of its function in NMD.
  • The interaction with Rps26 likely mediates Upf1's recruitment to target mRNAs.
  • Upf1 may play a role in the dissociation of premature termination complexes, contributing to mRNA degradation.
Keywords:
NMDRNA helicaseribosomal proteins

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