促发元件调节细胞质mRNA衰变的发生
Almog Bregman1, Moran Avraham-Kelbert, Oren Barkai
1Department of Molecular Microbiology, Technion-Israel Institute of Technology, Haifa 31096, Israel.
Cell
|December 27, 2011
概括
酵母促进体,特别是上游激活序列 (UAS) 和Rap1p蛋白,可以控制转录后的信使RNA (mRNA) 衰变率. 这一发现揭示了促进体在转录后调节基因表达中的新作用.
科学领域:
- 分子生物学分子生物学
- 酵母遗传学 酵母遗传学
- 基因规则 基因规则
背景情况:
- 促进体是DNA序列,对启动转录至关重要,并由转基因作用因子调节.
- 对于促进体的传统理解仅限于它们在基因合成中的作用,而不是转录后调节.
研究的目的:
- 调查酵母促进体是否影响转录后的mRNA衰变率.
- 为了确定特定的促进子元素和参与调节mRNA稳定性的因素.
主要方法:
- 利用酵母中的记者基因系统来评估mRNA衰变动力学.
- 操纵了记者基因的上游激活序列 (UAS).
- 研究了Rap1p结合部位和Rap1p蛋白在mRNA衰变中的作用.
主要成果:
- 改变记者基因的UAS序列,而不改变转录,修改了它的衰变速率.
- 一个具有两个Rap1p结合位点的特定cis元素,以及Rap1p,足以增强mRNA衰变.
- 发现Rap1p可以刺激某些内源mRNA的合成和衰变.
结论:
- 酵母促进体,通过UAS等元素和Rap1p等蛋白质,可以调节细胞质中的mRNA衰变.
- 促成因子可能会影响信使核糖蛋白 (mRNP) 的组成,影响mRNA的稳定性.
- 促进者在协调mRNA合成和衰变方面发挥双重作用,影响整体mRNA水平.
相关概念视频
02:31Nuclear 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...
02:24Regulation 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...
02:51mRNA Stability and Gene Expression
The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity.
Cis-acting Elements involved in mRNA stability
Cis-acting Elements involved in mRNA stability
02:31Nuclear 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...
02:51mRNA Stability and Gene Expression
The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity.
Cis-acting Elements involved in mRNA stability
Cis-acting Elements involved in mRNA stability
01:23Regulation 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...