一个统一的模型,用于mTORC1-介导的mRNA翻译调节
Carson C Thoreen1, Lynne Chantranupong, Heather R Keys
1Department of Cancer Biology, Dana Farber Cancer Institute, 250 Longwood Avenue, Boston, Massachusetts 02115, USA.
Nature
|May 4, 2012
概括
猛素复合体1 (mTORC1) 的哺乳动物标选择性地控制了具有5'终端寡聚胺 (TOP) 基因的信使RNA (mRNA) 的翻译. 这种调节由4E结合蛋白 (4E-BPs) 和eIF4G1调节,影响细胞生长.
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 生物化学
背景情况:
- 拉巴胺素 (mTOR) 复合体1 (mTORC1) 途径的机械性标对细胞生长和增殖至关重要.
- mTORC1调节信使RNA (mRNA) 的翻译,但具体的机制和mRNA的目标仍然不完全理解.
- 现有的模型还不能完全解释mTORC1如何差别控制特定mRNA的翻译.
研究的目的:
- 定义mTORC1-依赖的翻译控制背后的mRNA特征和机制.
- 阐明翻译调节剂在mTORC1控制mRNA翻译中的作用.
- 建立一个统一的模型,用于mTORC1对翻译程序的调节.
主要方法:
- 在小鼠细胞中使用了高分辨率的转录基因组规模的核糖体概况.
- 细胞被急性治疗Torin 1,一个强大的mTORC1抑制剂.
- 在受调节的mRNA上识别5'终端寡聚胺 (TOP) 和TOP类图案.
主要成果:
- mTORC1有选择性地调节具有5'终端寡聚胺 (TOP) 基因或以前未被识别的TOP类基因的mRNA.
- 没有发现证据支持基于5'未翻译区域长度或复杂性的监管.
- 4E结合蛋白 (4E-BPs) 的损失使TOP和TOP样mRNA的翻译对mTORC1的抑制产生了抵抗力.
- 4E-BPs通过破坏eIF4E-eIF4G1相互作用来抑制翻译启动,选择性地影响TOP mRNA结合.
结论:
- mTORC1的翻译控制主要针对具有TOP或TOP类动因的mRNA.
- 翻译抑制剂的4E-BP家族是mTORC1在调节TOP mRNA翻译中的关键作用体.
- 4E-BPs和eIF4G1之间的相互作用对于mTORC1选择性抑制TOP mRNA翻译至关重要.
相关概念视频
Regulation of Expression Occurs at Multiple Steps
Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence.
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Regulated mRNA Transport
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing specific...
mTOR Signaling and Cancer Progression
The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
The mTOR pathway or the...
Regulation of Expression Occurs at Multiple Steps
Gene expression can be regulated at almost every step from gene to protein. Transcription is the step that is most commonly regulated. This involves the binding of proteins to short regulatory sequences on the DNA. This association can either promote or inhibit the transcription of a gene associated with the respective sequence.
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
Transcription results in the generation of precursor (pre-mRNA) that consists of both exons and introns, which needs further processing before being translated to a...
mTOR Signaling and Cancer Progression
The mammalian target of rapamycin or mTOR protein was discovered in 1994 due to its direct interaction with rapamycin. The protein gets its name from a yeast homolog called TOR. The mTOR protein complex in mammalian cells plays a major role in balancing anabolic processes such as the synthesis of proteins, lipids, and nucleotides and catabolic processes, such as autophagy in response to environmental cues, such as availability of nutrients and growth factors.
The mTOR pathway or the...
The mTOR pathway or the...
Regulation of Expression at Multiple Steps
The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the addition of a...


