洛卡格拉特将DEAD盒蛋白eIF4A转化为一个序列选择性转化抑制剂
Shintaro Iwasaki1, Stephen N Floor1, Nicholas T Ingolia1
1Department of Molecular and Cell Biology, Center for RNA Systems Biology, University of California, Berkeley, California 94720, USA.
Nature
|June 17, 2016
概括
洛卡胺A (RocA) 通过向真核细胞启动因子4A (eIF4A) 来选择性杀死癌细胞. 这种药物将eIF4A结到特定的RNA序列上,破坏蛋白质合成并减少癌细胞的表达.
科学领域:
- 分子生物学
- 生物化学
- 癌症研究
背景情况:
- 洛卡胺A (RocA) 抑制蛋白质合成,并选择性地向形瘤细胞.
- RocA的向是真核启动因子4A (eIF4A),一种依赖ATP的RNA基酶,具有针对结构化mRNA5'未翻译区域的选择性.
- 之前的假设表明RocA通过减少eIF4A可用性或向结构化的mRNA区域来抑制翻译.
研究的目的:
- 阐明RocA选择性抑制翻译的确切机制.
- 研究mRNA二次结构和eIF4A在RocA作用机制中的作用.
- 确定RocA如何在针对特定的信使RNA方面实现选择性.
主要方法:
- 在体外生化测定以研究eIF4A-RNA相互作用.
- 基于细胞的实验来评估翻译抑制和蛋白质表达.
- 分析RocA对eIF4A结合亲和力和RNA酶活性的影响.
主要成果:
- RocA的选择性并不是主要由mRNA 5' 未翻译区域的二次结构决定的.
- 通过减少eIF4A的可用性,RocA不会抑制翻译.
- RocA 的作用是将 eIF4A 粘合到多氨酸序列上,不依赖 ATP,阻断 43S 扫描并导致过早的翻译启动.
结论:
- 通过稳定eIF4A和多氨酸序列之间的特定相互作用,RocA可以选择性地抑制翻译.
- 这种机制导致上游翻译启动和向转录的蛋白质表达减少.
- 这项研究提供了药物稳定序列选择性RNA蛋白相互作用的新例.
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