Dissociation by Pelota, Hbs1 and ABCE1 of mammalian vacant 80S ribosomes and stalled elongation complexes

EMBO J. 2011 May 4;30(9):1804-17. doi: 10.1038/emboj.2011.93. Epub 2011 Mar 29.

Abstract

No-go decay (NGD) and non-stop decay (NSD) are eukaryotic surveillance mechanisms that target mRNAs on which elongation complexes (ECs) are stalled by, for example, stable secondary structures (NGD) or due to the absence of a stop codon (NSD). Two interacting proteins Dom34(yeast)/Pelota(mammals) and Hbs1, which are paralogues of eRF1 and eRF3, are implicated in these processes. Dom34/Hbs1 were shown to promote dissociation of stalled ECs and release of intact peptidyl-tRNA. Using an in vitro reconstitution approach, we investigated the activities of mammalian Pelota/Hbs1 and report that Pelota/Hbs1 also induced dissociation of ECs and release of peptidyl-tRNA, but only in the presence of ABCE1. Whereas Pelota and ABCE1 were essential, Hbs1 had a stimulatory effect. Importantly, ABCE1/Pelota/Hbs1 dissociated ECs containing only a limited number of mRNA nucleotides downstream of the P-site, which suggests that ABCE1/Pelota/Hbs1 would disassemble NSD complexes stalled at the 3'-end, but not pre-cleavage NGD complexes stalled in the middle of mRNA. ABCE1/Pelota/Hbs1 also dissociated vacant 80S ribosomes, which stimulated 48S complex formation, suggesting that Pelota/Hbs1 have an additional role outside of NGD.

Publication types

  • Comparative Study
  • Research Support, N.I.H., Extramural

MeSH terms

  • ATP-Binding Cassette Transporters / metabolism*
  • Animals
  • Electrophoresis
  • Endonucleases
  • Escherichia coli
  • Genetic Vectors / genetics
  • Humans
  • In Vitro Techniques
  • Microfilament Proteins / metabolism*
  • Nuclear Proteins
  • Peptide Termination Factors / metabolism*
  • RNA Stability / physiology*
  • RNA, Messenger / metabolism*
  • RNA, Transfer, Amino Acyl / metabolism*
  • Rabbits
  • Recombinant Proteins / metabolism
  • Ribosomes / metabolism*

Substances

  • ABCE1 protein, human
  • ATP-Binding Cassette Transporters
  • Microfilament Proteins
  • Nuclear Proteins
  • Peptide Termination Factors
  • RNA, Messenger
  • RNA, Transfer, Amino Acyl
  • Recombinant Proteins
  • peptide-chain-release factor 3
  • tRNA, peptidyl-
  • Endonucleases
  • pelo protein, human