RT Journal Article SR Electronic T1 microRNAs slow translating ribosomes to prevent protein misfolding JF bioRxiv FD Cold Spring Harbor Laboratory SP 2020.12.08.417139 DO 10.1101/2020.12.08.417139 A1 Sako, Hiroaki A1 Akimoto, Takayuki A1 Suzuki, Katsuhiko A1 Ushida, Takashi A1 Yamamoto, Tadashi YR 2020 UL http://biorxiv.org/content/early/2020/12/09/2020.12.08.417139.abstract AB An evolutionarily conserved mechanism, use of non-optimal codons, slows ribosomes during translation to allow proper folding of nascent polypeptides. However, until now, it was unknown whether any eukaryote-specific mechanisms exist for this purpose. Here, we propose that miRNAs slow translating ribosomes to prevent protein misfolding, with little negative effect on protein abundance. To prove this, we bioinformatically analyze ribosome profiling and miRNA binding sites and biochemically confirm that miRNA deficiency causes severe misfolding, which is rescued by slowing translating ribosomes. We demonstrate that non-cleaving shRNAs, targeting regions where elongation rates become faster in miRNA-deficient cells, improve protein folding with minimal effects on protein abundance. These results reveal broader functionality of miRNAs and a previously unknown mechanism to prevent protein misfolding.One Sentence Summary Eukaryote use of miRNAs prevents protein misfolding in a target-specific manner.Competing Interest StatementPatent application (2020-134520) covers the concept that miRNAs and shRNAs slow translating ribosomes to prevent protein misfolding.