核群の変動は,RNAポリメラーゼIIの転写ダイナミクスを支配する
Courtney Hodges1, Lacramioara Bintu, Lucyna Lubkowska
1Jason L. Choy Laboratory of Single-Molecule Biophysics and Biophysics Graduate Group, University of California, Berkeley, CA 94720, USA.
まとめ
RNAポリメラーゼII (Pol II) は,活性DNA分離によってではなく,その変動を修正することによって,核細胞を導航します. ヒストンは,ニュクレオソームを通して転写する際にDNAループを通じてポリメラーゼの後ろに転送されます.
科学分野:
- 分子生物学は分子生物学である.
- バイオフィジックス 生物物理学
- 遺伝学 遺伝学とは
背景:
- 核細胞は,真核生物のDNA包装の基本的な単位である.
- RNAポリメラーゼII (Pol II) による転写には,これらの核細胞構造をナビゲートする必要があります.
- Pol II-ニュクレオソームの相互作用を理解することは,遺伝子調節にとって極めて重要です.
研究 の 目的:
- Pol IIが核細胞を通して転写する物理的メカニズムを調査する.
- Pol IIと核細胞バリアの間のダイナミックな相互作用を特徴づける.
- 転写調節におけるヌクレオソームの変動の役割を明らかにする.
主な方法:
- 光学ピンチテストの開発と応用.
- 核細胞DNAを転写する個々のPol II複合体のリアルタイム観察.
- Pol IIのダイナミクスとパウスの行動の定量分析.
主要な成果:
- 核細胞は,波動する障壁として作用し,Pol IIの一時停止を増加させ,転写速度を低下させます.
- Pol IIは,DNAとヒストンを積極的に分離するのではなく,核細胞の変動を修正するラッチのように機能します.
- 転写ポリメラーゼの背後にあるヒストン移転の直接的な証拠は,一時的なDNAループを介して得られた.
結論:
- Pol IIと核細胞の間の物理的な相互作用は,転写調節の基礎を提供する.
- 核群の変動は,Pol IIのプロセシビティとパウズダイナミクスを著しく影響する.
- Pol IIのラッチのようなメカニズムは,クロマチンの障壁を通過する転写を促進します.
関連する概念動画
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...
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...
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...
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...
Eukaryotic RNA Polymerases
RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action.
All three eukaryotic RNAPs require specific transcription factors, of which the...
All three eukaryotic RNAPs require specific transcription factors, of which the...
Eukaryotic RNA Polymerases
RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action.
All three eukaryotic RNAPs require specific transcription factors, of which the...
All three eukaryotic RNAPs require specific transcription factors, of which the...


