Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Division of Hematology, Department of Medicine, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
Sylvester Comprehensive Cancer Center, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Medical Scientist Training Program, University of Miami Miller School of Medicine, Miami, FL 33136, USA; Molecular and Cellular Pharmacology Graduate Program, University of Miami Miller School of Medicine, Miami, FL 33136, USA.
Cell Rep. 2021 Oct 12;37(2):109806. doi: 10.1016/j.celrep.2021.109806.
Tactical disruption of protein synthesis is an attractive therapeutic strategy, with the first-in-class eIF4A-targeting compound zotatifin in clinical evaluation for cancer and COVID-19. The full cellular impact and mechanisms of these potent molecules are undefined at a proteomic level. Here, we report mass spectrometry analysis of translational reprogramming by rocaglates, cap-dependent initiation disruptors that include zotatifin. We find effects to be far more complex than simple "translational inhibition" as currently defined. Translatome analysis by TMT-pSILAC (tandem mass tag-pulse stable isotope labeling with amino acids in cell culture mass spectrometry) reveals myriad upregulated proteins that drive hitherto unrecognized cytotoxic mechanisms, including GEF-H1-mediated anti-survival RHOA/JNK activation. Surprisingly, these responses are not replicated by eIF4A silencing, indicating a broader translational adaptation than currently understood. Translation machinery analysis by MATRIX (mass spectrometry analysis of active translation factors using ribosome density fractionation and isotopic labeling experiments) identifies rocaglate-specific dependence on specific translation factors including eEF1ε1 that drive translatome remodeling. Our proteome-level interrogation reveals that the complete cellular response to these historical "translation inhibitors" is mediated by comprehensive translational landscape remodeling.
靶向蛋白合成的调控是一种有吸引力的治疗策略，首个 eIF4A 靶向化合物 zotatifin 正在临床评估用于癌症和 COVID-19。这些强效分子在蛋白质组水平上的全面细胞影响和机制尚未确定。在这里，我们报告了 rocaglates （包括 zotatifin）引起的帽依赖性起始抑制剂对翻译重编程的质谱分析。我们发现其作用远比目前定义的“翻译抑制”要复杂得多。通过 TMT-pSILAC（串联质量标签-脉冲稳定同位素标记与细胞培养质谱中的氨基酸）进行的翻译组分析揭示了众多上调的蛋白质，这些蛋白质驱动了迄今为止尚未被识别的细胞毒性机制，包括 GEF-H1 介导的抗生存 RHOA/JNK 激活。令人惊讶的是，这些反应不能被 eIF4A 沉默所复制，表明存在比目前理解的更广泛的翻译适应性。通过 MATRIX（使用核糖体密度分级和同位素标记实验对活跃翻译因子的质谱分析）进行的翻译机制分析表明，rocaglates 特异性依赖于特定的翻译因子，包括驱动翻译组重塑的 eEF1ε1。我们的蛋白质组水平研究表明，这些历史上的“翻译抑制剂”对这些细胞的全面反应是由全面的翻译景观重塑介导的。
Zotero 插件
