イーストRat1エクソヌクレアゼは,RNAポリメラーゼIIによる転写終了を促進する
Minkyu Kim1, Nevan J Krogan, Lidia Vasiljeva
1Department of Biological Chemistry and Molecular Pharmacology, Harvard Medical School, 240 Longwood Avenue, Boston, Massachusetts 02115, USA.
Nature
|November 27, 2004
まとめ
RNAポリメラーゼIIカーボキシ末端ドメインのリン酸化はmRNA処理を調節する. Rat1/Rai1外核酵素は3RNAを分解し,ポリアデニレーション部位で転写終了を誘発する.
科学分野:
- 分子生物学は分子生物学である.
- 遺伝子発現の表現について
- RNA 処理 RNA 処理
背景:
- RNAポリメラーゼII (RNApII) のカルボキシ末端領域 (CTD) は,リン酸化パターンを介してmRNA処理と転写を調整する.
- セリン2のような特定のCTDリン酸化は,mRNA処理と転写終止の両方に不可欠なポリアデニレーション因子を採用します.
研究 の 目的:
- 転写終結におけるRtt103とラット1/Rai1エクソヌクレアスの役割を調査する.
- ポリアデニレーション部位の割れとRNAポリメラーゼIIの転写終結を結びつけるメカニズムを解明する.
主な方法:
- Rtt103とRat1/Rai1の3'遺伝子末端における局所化に関する研究.
- 変異細胞 (rat1-1, rai1Delta) でのRNAの安定性と転写終了の分析.
主要な成果:
- Rtt103とRat1/Rai1は,タンパク質をコードする遺伝子の3'端に定着する.
- Rat1またはRai1の変異は,ポリアデニレーション部位を下流のRNAの安定化につながります.
- 終結欠陥は,機能的なRat1/Rai1.1が存在しない多くの遺伝子で観察されています.
結論:
- ポリアデニレーション部位の割れは,Rat1/Rai1エクソヌクレアゼによる下流RNAの分解の前提条件である.
- Rat1/Rai1による3'-下流RNAの分解は,転写終了を誘発する重要なイベントです.
関連する概念動画
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...
Transcription Attenuation in Prokaryotes
Transcriptional attenuation occurs when RNA transcription is prematurely terminated due to the formation of a terminator mRNA hairpin structure. Bacteria use these hairpins to regulate the transcription process and control the synthesis of several amino acids including histidine, lysine, threonine, and phenylalanine. Transcription attenuation takes place in the non-coding regions of mRNA.
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
There are several different mechanisms used to attenuate transcription. In ribosome mediated...
Bacterial Transcription
RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, transcription and translation occur simultaneously, on the same DNA template.
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
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...
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...
Transcriptional Regulation: Riboswitches
Riboswitches are RNA elements that regulate gene expression by altering their secondary structures in response to specific effector molecules. These elements, located in the leader regions of certain mRNAs, act as transcriptional regulators by toggling between alternative conformations to control downstream gene expression. Riboswitch-mediated regulation is a precise mechanism for modulating biosynthetic pathways, as exemplified by the riboflavin biosynthesis pathway in Bacillus...


