Department of Molecular & Cell Biology, University of California, Berkeley, CA, 94720, USA.
Innovative Genomics Institute, University of California, Berkeley, CA, 94720, USA.
Nat Commun. 2020 Oct 2;11(1):4941. doi: 10.1038/s41467-020-18765-2.
Methods to directly inhibit gene expression using small molecules hold promise for the development of new therapeutics targeting proteins that have evaded previous attempts at drug discovery. Among these, small molecules including the drug-like compound PF-06446846 (PF846) selectively inhibit the synthesis of specific proteins, by stalling translation elongation. These molecules also inhibit translation termination by an unknown mechanism. Using cryo-electron microscopy (cryo-EM) and biochemical approaches, we show that PF846 inhibits translation termination by arresting the nascent chain (NC) in the ribosome exit tunnel. The arrested NC adopts a compact α-helical conformation that induces 28 S rRNA nucleotide rearrangements that suppress the peptidyl transferase center (PTC) catalytic activity stimulated by eukaryotic release factor 1 (eRF1). These data support a mechanism of action for a small molecule targeting translation that suppresses peptidyl-tRNA hydrolysis promoted by eRF1, revealing principles of eukaryotic translation termination and laying the foundation for new therapeutic strategies.
方法使用小分子直接抑制基因表达，为开发针对先前药物发现尝试中逃避的蛋白质的新疗法提供了希望。在这些方法中，包括类似药物的化合物 PF-06446846（PF846）在内的小分子通过阻止翻译延伸，选择性地抑制特定蛋白质的合成。这些分子还通过未知机制抑制翻译终止。通过使用冷冻电子显微镜（cryo-EM）和生化方法，我们表明 PF846 通过阻止新生链（NC）在核糖体出口隧道中，抑制翻译终止。被捕获的 NC 采用紧凑的α-螺旋构象，诱导 28 S rRNA 核苷酸重排，抑制由真核释放因子 1（eRF1）刺激的肽酰转移酶中心（PTC）催化活性。这些数据支持了一种针对抑制由 eRF1 促进的肽酰-tRNA 水解的翻译小分子的作用机制，揭示了真核翻译终止的原则，并为新的治疗策略奠定了基础。
Zotero 插件
