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Ribosome‐bound Pub1 modulates stop codon decoding during translation termination in yeast
Author(s) -
Urakov Valery N.,
Mitkevich Olga V.,
Safenkova Irina V.,
TerAvanesyan Michael D.
Publication year - 2017
Publication title -
the febs journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.981
H-Index - 204
eISSN - 1742-4658
pISSN - 1742-464X
DOI - 10.1111/febs.14099
Subject(s) - ribosome , polysome , release factor , stop codon , translation (biology) , ribosome profiling , stress granule , biology , microbiology and biotechnology , biochemistry , chemistry , genetics , messenger rna , gene , rna
In eukaryotes, termination of translation is controlled by polypeptide chain release factors eRF 1 and eRF 3, of which the former recognizes nonsense codons, while the latter interacts with eRF 1 and stimulates polypeptide release from the ribosome in a GTP ‐ dependent manner, and ABCE 1, which facilitates ribosome recycling. In this work, we demonstrate that Pub1, a yeast protein known to be involved in stress granule formation, regulation of gene expression, and organization of the tubulin cytoskeleton, also plays a role in translation termination. Pub1 was shown to bind to ribosomes independent of eRF 1 and eRF 3 and to interact with the N‐terminal glutamine‐/asparagine‐rich prion domain of eRF 3 via its short C‐terminal glutamine‐rich tract. High velocity sedimentation in sucrose gradient demonstrated that Pub1 was preferentially associated with heavy polysomes enriched with terminating ribosomes. Lack of Pub1 decreased efficiency of nonsense readthrough at a majority but not all tetranucleotide stop signals. This distinguishes Pub1 from most other known binding partners of the release factors which were shown to modulate readthrough of all nonsense codons uniformly. The obtained data show that Pub1 can act as an accessory translation factor involved in fine‐tuning of translation termination.