Boric acid intercepts 80S ribosome migration from AUG-stop by stabilizing eRF1

翻訳での植物の無機栄養ホウ素の感知とそれに伴うタンパク質合成過程の変化を分子レベルで明らかにしました。これまで知られていなかった80Sリボソーム複合体がmRNA上を滑って移動するプロセスが翻訳制御に重要であることを明らかにしました。

Abstract:In response to environmental changes, cells flexibly and rapidly alter gene expression through translational controls. In plants, the translation of NIP5;1, a boric acid diffusion facilitator, is downregulated in response to an excess amount of boric acid in the environment through upstream open reading frames (uORFs) that consist of only AUG and stop codons. However, the molecular details of how this minimum uORF controls translation of the downstream main ORF in a boric acid-dependent manner have remained unclear. Here, by combining ribosome profiling, translation complex profile sequencing, structural analysis with cryo-electron microscopy and biochemical assays, we show that the 80S ribosome assembled at AUG-stop migrates into the subsequent RNA segment, followed by downstream translation initiation, and that boric acid impedes this process by the stable confinement of eukaryotic release factor 1 on the 80S ribosome on AUG-stop. Our results provide molecular insight into translation regulation by a minimum and environment-responsive uORF.

Authors: Mayuki Tanaka, Takeshi Yokoyama, Hironori Saito, Madoka Nishimoto, Kengo Tsuda, Naoyuki Sotta, Hideki Shigematsu, Mikako Shirouzu, Shintaro Iwasaki, Takuhiro Ito & Toru Fujiwara

Jouirnal: Nature Chemical Biology

DOI: https://doi.org/10.1038/s41589-023-01513-0