RT Journal Article
SR Electronic
T1 Multi-protein Bridging Factor 1(Mbf1), Rps3 and Asc1 prevent stalled ribosomes from frameshifting
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 366344
DO 10.1101/366344
A1 Jiyu Wang
A1 Jie Zhou
A1 Qidi Yang
A1 Elizabeth J. Grayhack
YR 2018
UL http://biorxiv.org/content/early/2018/07/10/366344.abstract
AB Stalled ribosomes in bacteria frameshift, but stalled ribosomes in eukaryotes do not frameshift and abort translation, suggesting that eukaryote-specific mechanisms might prevent frameshifting. We show that the conserved eukaryotic/archaeal protein Mbf1 acts with ribosomal proteins Rps3/uS3 and eukaryotic Asc1/RACK1 to prevent frameshifting at inhibitory CGA-CGA codon pairs in Saccharomyces cerevisiae. Mutations in RPS3 that allow frameshifting implicate eukaryotic conserved residues near the mRNA entry site. Mbf1 and Rps3 cooperate to maintain the reading frame of stalled ribosomes, while Asc1 mediates distinct events that result in aborted translation. Frameshifting occurs through a +1 shift with a CGA codon in the P site and involves competition between codons entering the A site, implying that the wobble interaction of the P site codon destabilizes translation elongation. Thus, eukaryotes have evolved unique mechanisms involving both a universally conserved ribosome component and two eukaryotic-specific proteins to maintain the reading frame at ribosome stalls.