人間のβ-グロービンのプレ-mRNAにおける自己触媒RNAの分裂は,転写終結を促進する
Alexandre Teixeira1, Abdessamad Tahiri-Alaoui, Steve West
1Sir William Dunn School of Pathology, University of Oxford, South Parks Road, Oxford OX1 3RE, UK.
Nature
|November 27, 2004
まとめ
研究者らは,RNAの自己分裂が,ヒトのβ-グロービン遺伝子の転写終止を誘導することを発見した. この共同転写分裂 (CoTC) メカニズムは霊長類にわたって保存されており,遺伝子調節における一般的なプロセスである可能性があります.
科学分野:
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
- バイオケミストリー バイオケミストリー
背景:
- 転写終結は遺伝子発現の重要な規制ステップですが,そのメカニズムは依然としてほとんど不明です.
- 最近の研究では,ヒトβ-グロービン遺伝子の転写の終結における重要なイベントとして,共転写割れ (Co-transcriptional cleavage, CoTC) を特定しました.
研究 の 目的:
- 人間のβ-グロービン遺伝子終結における共転写分裂 (CoTC) の基礎となる分子機構を調査する.
- CoTC に関するRNAの自己分裂活動と,その in vivo の機能的意義を特徴づける.
- CoTCの進化的保存と遺伝子調節における潜在的より広範な影響を調査する.
主な方法:
- 人間のβ-グロービン遺伝子における転写終結のインビボ分析.
- CoTCリボ酵素のオートカタリティックコアの特徴.
- 類人猿のβ-グロービン遺伝子の3'側面領域の比較配列解析.
主要な成果:
- ヒトのβ-グロービン前伝達 RNAにおけるCoTCプロセスは,固有のRNAの自己切断活動を伴う.
- CoTCリボ酵素の自己触媒的核が特定され,効率的なin vivo終了におけるその機能的役割が確認されました.
- 特定されたCoTC核は,他の霊長類のβ-グロービン遺伝子の3'側面領域で高い保全を示しています.
結論:
- RNAの自己分裂によって媒介される共転写分裂 (CoTC) は,ヒトβ-グロービン遺伝子の効率的な転写終結に不可欠です.
- このオートカタリティック・クリバージ・メカニズムは,霊長類のベータ・グロービン遺伝子に進化的に保存されており,根本的な役割を果たしていることを示唆している.
- プレ-mRNAにおける制御されたオートカタリティック・クリバージ・エレメントは,mRNAの処理と転写の終結のための一般的なメカニズムを表す可能性があります.
関連する概念動画
Bacterial RNA Polymerase
20.0K
Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
20.0K
Eukaryotic RNA Polymerases
17.3K
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...
17.3K
Transcription Attenuation in Prokaryotes
14.6K
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...
14.6K
Bacterial Transcription
25.6K
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:
25.6K
Pre-mRNA Processing: Modification of pre-mRNA Ends
14.2K
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps...
14.2K
Transcription in Prokaryotes
4.4K
Transcription is a highly regulated process that converts genetic information into RNA molecules. The transcription cycle is divided into three key stages: initiation, elongation, and termination, each driven by specific molecular mechanisms.Initiation of TranscriptionIn bacteria, transcription begins when the RNA polymerase core enzyme associates with a sigma factor to form a holoenzyme. For example, the E. coli sigma factor called σ70 forms a holoenzyme, which recognizes the -10 (Pribnow...
4.4K


