RNAヘリケーズAは,CBPとRNAポリメラーゼIIとの結合を媒介する
T Nakajima1, C Uchida, S F Anderson
1Department of Cell Biology, Harvard Medical School, Boston, Massachusetts 02115, USA.
Cell
|October 10, 1997
まとめ
RNAヘリケーズA (RHA) は,共活性化剤CBPが信号依存遺伝子発現を活性化するために不可欠です. ラ・ラ・ラ・ラ (ラ・ラ・ラ) とは
科学分野:
- 分子生物学は分子生物学である.
- 遺伝子規制 遺伝子規制
- クロマチンの構造 クロマチンの構造
背景:
- 同活性化剤CBPは,RNAポリメラーゼIIとの関連を通して,信号依存遺伝子発現に作用する.
- RNAヘリコラーゼA (RHA) は核DNA/RNAヘリコラーゼで,ドロソフィラの雄性用量補償因子,mle.mle.に同質性がある.
研究 の 目的:
- CBPが遺伝子発現を刺激するメカニズムにおけるRNAヘリカーゼA (RHA) の役割を調査する.
- CBPとRNAポリメラーゼII複合体の結合にRHAが必要かどうかを判断する.
主な方法:
- 遺伝子の活性化を調べるために,一時的なトランスフェクションアッセイが使用されました.
- CREBによる標的遺伝子の活性化を媒介するRHAの機能を評価した.
- RHAのヘリカーゼ活性に影響する突然変異がCREB依存転写に与える影響を評価した.
主要な成果:
- CBPとRNAポリメラーゼIIの間の複合形成は,RHAを必要とすることが示されました.
- RHAは,CREBによって媒介される標的遺伝子発現を活性化するためにCBPと協力することが判明しました.
- RHAのヘリカーゼ活性を低下させたRHAの変異は,CREB依存転写を著しく低下させた.
結論:
- RHAは,シグナル応答性遺伝子のCBP媒介による転写活性化の重要な構成要素である.
- RHAのヘリカーゼ活動は,CREB依存遺伝子発現におけるその機能のために必要である.
- RHAは,プロモーターの転写機構の組み立てを強化するクロマチンの構造的変化を誘導することによって,遺伝子活性化を促進する可能性が高い.
関連する概念動画
Bacterial RNA Polymerase
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...
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...
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...
Bacterial RNA Polymerase
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...
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...
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...


