核糖體碰撞觸發應激反應來調控細胞命運
作者:
小柯機器人發布時間:2020/7/2 13:21:56
美國約翰·霍普金斯大學醫學院Rachel Green研究組發現,核糖體碰撞觸發應激反應來調控細胞命運。相關論文於2020年6月30日在線發表在《細胞》雜誌上。
研究人員揭示了信號轉導中核糖體碰撞的功能。使用翻譯延長抑制劑和常見細胞應激條件,包括胺基酸飢餓和紫外線照射,研究人員發現核糖體碰撞激活了壓力激活蛋白激酶(SAPK)和GCN2介導的應激反應途徑。研究人員表明,MAPKKK ZAK充當核糖體碰撞的前哨,並且是SAPK(p38/JNK)和GCN2信號通路早期激活所必需的。選擇性核糖體譜分析和生物化學表明,儘管ZAK通常與多核體mRNA上的延伸核糖體結合,但它在碰撞核糖體的最小單位(二聚體)上特異性地自磷酸化。
總之,這些結果為了解翻譯動態平衡如何調節細胞命運提供了新的分子見解。
據悉,在mRNA的翻譯過程中出現的問題導致核糖體停頓和碰撞,從而引發一系列質量控制事件。然而,目前尚未探索對核糖體碰撞的整體細胞反應。
附:英文原文
Title: Ribosome Collisions Trigger General Stress Responses to Regulate Cell Fate
Author: Colin Chih-Chien Wu, Amy Peterson, Boris Zinshteyn, Sergi Regot, Rachel Green
Issue&Volume: 2020-06-30
Abstract: Problems arising during translation of mRNAs lead to ribosome stalling and collisions that trigger a series of quality control events. However, the global cellular response to ribosome collisions has not been explored. Here, we uncover a function for ribosome collisions in signal transduction. Using translation elongation inhibitors and general cellular stress conditions, including amino acid starvation and UV irradiation, we show that ribosome collisions activate the stress-activated protein kinase (SAPK) and GCN2-mediated stress response pathways. We show that the MAPKKK ZAK functions as the sentinel for ribosome collisions and is required for immediate early activation of both SAPK (p38/JNK) and GCN2 signaling pathways. Selective ribosome profiling and biochemistry demonstrate that although ZAK generally associates with elongating ribosomes on polysomal mRNAs, it specifically auto-phosphorylates on the minimal unit of colliding ribosomes, the disome. Together, these results provide molecular insights into how perturbation of translational homeostasis regulates cell fate.
DOI: 10.1016/j.cell.2020.06.006
Source: https://www.cell.com/cell/fulltext/S0092-8674(20)30693-0
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