人类mRNA出口机器招募到mRNA的5'末端
Hong Cheng1, Kobina Dufu, Chung-Sheng Lee
1Department of Cell Biology, Harvard Medical School, Boston, MA 02115, USA.
Cell
|December 28, 2006
概括
该研究揭示了TREX复合物如何被招募到用于出口的信使RNA (mRNA) 中. 结蛋白CBP80和Aly在mRNA的5'端中介这种关键的相互作用.
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:
- 从核到细胞质的信使RNA (mRNA) 输出对基因表达至关重要.
- 保存的TREX (转录-外显子结合复合体) 机制在mRNA出口中起着至关重要的作用.
- 了解TREX复合体向mRNA招募的精确机制对于理解转录后基因调节至关重要.
研究的目的:
- 阐明TREX复合体被招募到mRNA的机制.
- 确定TREX招聘所涉及的关键组件和相互作用.
- 为了确定5'帽和拼接在这个过程中的作用.
主要方法:
- 通过生物化学分析研究了人类TREX复合物的对mRNA的招募.
- 分析了TREX成分,特别是Aly和5'盖结合蛋白CBP80.0之间的相互作用.
- 评估了TREX招募和mRNA出口对5'盖和拼接的依赖.
主要成果:
- 人类TREX复合体被招募到mRNA的5'端,Aly组件位于最接近5'盖的位置.
- 无论是TREX招募还是mRNA出口都取决于5'盖和拼接.
- CBP80与TREX直接关联,而Aly则调解了这种相互作用.
结论:
- CBP80-Aly相互作用是招募TREX复合体到mRNA的5'末端的主要机制.
- 这种招募对于通过核孔有效的mRNA出口至关重要.
- 这些发现支持mRNA出口的5'到3'方向性,与之前的观察相一致.
相关概念视频
Recombinant DNA
Overview
Nuclear Export of mRNA
Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...
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...
Nuclear Export
The nucleus restricts several proteins within and allows others to pass. The restricted proteins possess a nuclear retention sequence or NRS, anchoring them to the nuclear lamins and preventing their transport to the cytosol. The non-restricted proteins, after their synthesis, are transported to their site of action, such as the cytosol or other organelles, with the help of nuclear export signals or NES.
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
NES are of three types- the canonical 10-residue long leucine-rich signal and other...
Nuclear Export of mRNA
Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...
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...


