4E-BP1差异调节人类mRNAs的一个子集的翻译
Mehreen Mahbub1, Baishakhi Saha2, Dixie J Goss3
1Department of Chemistry, Hunter College, City University of New York, New York, USA; PhD. Program in Biochemistry, The Graduate Center of the City University of New York, New York, USA.
The Journal of biological chemistry
|November 27, 2025
概括
细胞启动因子4E结合蛋白1 (4E-BP1) 选择性地抑制特定mRNAs的独立转化. 这一规则通过控制非正典转化途径,影响应激反应和癌症的进展.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 生物化学 生化学
背景情况:
- 升高的真核启动因子4E结合蛋白1 (4E-BP1) 水平会通过eIF4E•4E-BP1复合体影响上限独立的翻译.
- 具有结构5'UTR的特定mRNA使用类似于CITE或类似于IRES的机制.
- 4E-BP1在调节这些上限独立的翻译机制中的确切作用仍然不完全理解.
研究的目的:
- 阐明4E-BP1调节CITE类和IRES类顶级独立翻译的机制.
- 为了研究4E-BP1对翻译的转录特异性影响.
- 确定eIF4GI和eIF4A在4E-BP1介导的转化控制中的作用.
主要方法:
- 基于光的异性质测试测量以测量结合亲和力.
- 路西法雷斯记者测定量化翻译效率.
- 通过特定蛋白质复合体对mRNA结合和翻译调节的分析.
主要成果:
- 与单独的eIF4E相比,eIF4E•4E-BP1复合体对目标mRNA的5' m7G-cap具有更高的结合亲和力.
- 4E-BP1比IRES类mRNA (FGF-9,p53B) 更有效地抑制了CITE类mRNA (HIF-1α,p53A) 的翻译.
- eIF4GI557-1599•eIF4A复合物选择性地克服了类似CITE的mRNA的4E-BP1抑制,而类似IRES的mRNA显示了最小的响应.
结论:
- 4E-BP1以一种特定于转录的方式选择性地抑制了独立于cap的翻译.
- 4E-BP1增强了eIF4GI557-1599对某些mRNA的招募,在细胞应激期间可能有助于43S PIC组装.
- 这些发现为选择性翻译控制提供了机制性的见解,这些见解与应激反应和通过非正典翻译的癌症进展有关.
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