通过RNA干扰导向的染色质修饰与RNA聚合酶II转录相结合
Vera Schramke1, Daniel M Sheedy, Ahmet M Denli
1Wellcome Trust Centre for Cell Biology, Institute of Cell and Molecular Biology, King's Buildings, University of Edinburgh, Edinburgh EH9 3JR, UK.
Nature
|June 21, 2005
概括
裂变酵母中的RNA干扰 (RNAi) 需要对同源DNA序列的转录来修改色素. 这一过程与RNA聚合酶II活性相结合,突出显示了转录的活性.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
背景情况:
- RNA干扰 (RNAi) 是一种保存的生物过程,它使用小干扰RNA (siRNAs) 调节基因表达.
- 在真核生物中,siRNAs可以导致信使RNA降解或在同源基因组位点发生表观遗传修饰.
- siRNAs诱导DNA或染色质修饰的精确机制尚未完全理解.
研究的目的:
- 为了研究转录在RNAi导向的染色质修饰在裂变酵母 (Schizosaccharomyces pombe) 中的作用.
- 为了确定外源转录是否足以触发RNAi介导的表观遗传变化.
- 阐明RNA聚合酶II及其调节域在这个过程中的参与.
主要方法:
- 使用裂变酵母 (Schizosaccharomyces pombe) 作为一个模型生物.
- 研究在RNAi导向的染色体修饰中对同源DNA序列转录的要求.
- 评估外源转录 (T7聚合酶) 对RNAi介导沉默的影响.
- 检查Ago1,一个关键的RNAi效应蛋白,与目标转录和RNA聚合酶II的关联.
- 分析切断RNA聚合酶II的碳氧终端域 (CTD) 对转录沉默的影响.
主要成果:
- 在裂变酵母中由RNAi指导的染色质修饰仅在转录同源DNA序列时才会发生.
- 通过T7聚合酶的外部转录不足以诱导这些染色质修饰.
- 阿戈1与目标转录和RNA聚合酶II.都结合在一起.
- 破坏RNA聚合酶II CTD会损害RNAi导向的转录沉默.
结论:
- 在裂变酵母中,转录活性对于RNAi介导的染色质修饰至关重要.
- 由RNAi导向的表观遗传变化与内源转录机制相结合,特别是涉及RNA聚合酶II.
- 这些发现表明,siRNA引导的RNA聚合酶II对新生转录的向导致染色质改变和转录沉默的机制.
相关概念视频
Types of RNA
Overview
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
Chromatin Structure Regulates pre-mRNA Processing
In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell.
The chromatin structure, especially...
The chromatin structure, especially...
Transcription Initiation
Initiation is the first step of transcription in eukaryotes. Prokaryotic RNA Polymerase (RNAP) can bind to the template DNA and start transcribing. On the other hand, transcription in eukaryotes requires additional proteins, called transcription factors, to first bind to the promoter region in the DNA template. This binding helps recruit the specific RNAP that can assemble on the DNA and start transcription.
The promoters and enhancers and their accessory proteins allow tight regulation of...
The promoters and enhancers and their accessory proteins allow tight regulation of...
Types of RNA
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in regulating gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA Performs Diverse...
RNA Performs Diverse...
RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...


