U snRNA遺伝子プロモーターのRNAポリメラーゼ特異性を変化させる
I W Mattaj1, N A Dathan, H D Parry
1European Molecular Biology Laboratory, Heidelberg, Federal Republic of Germany.
Cell
|November 4, 1988
まとめ
研究者らは,RNAポリメラーゼIIIが直接転写開始部位を認識することを発見した. この発見により,XenopusにおけるRNAポリメラーゼIIおよびIIIの特定のU6およびU2遺伝子プロモーターの作成が可能になった.
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
- バイオケミストリー バイオケミストリー
背景:
- Xenopus tropicalis U6遺伝子プロモーターは,RNAポリメラーゼIIとIIIの両方で転写されていることが知られている.
- ポリメラーゼの特異性を支配する異なる規制要素を理解することは,遺伝子発現の研究にとって極めて重要です.
研究 の 目的:
- U6プロモーターのRNAポリメラーゼII対RNAポリメラーゼIII転写を決定する特定のDNA要素を解明する.
- 転写開始部位の認識におけるRNAポリメラーゼIIIの潜在的な直接的役割を調査する.
- 変化したポリメラーゼ特異性を持つ新しいプロモーターを設計する.
主な方法:
- サイト指向型変異遺伝を用いたU6プロモーター構造と機能の分析.
- RNAポリメラーゼIIおよびIIIによる比較トランスクリプションアッセイ.
- 改造されたU6およびU2遺伝子プロモーターの工学.
主要な成果:
- U6プロモーターには,RNAポリメラーゼIII (TATAのような配列,イニシアーション領域) の異なる要素と,両方のポリメラーゼに共通する要素が含まれています.
- 転写開始部位での厳格なピューリン要求は,RNAポリメラーゼIIIによる直接認識を示唆する.
- ミュータント分析は,RNAポリメラーゼIIIがプロモーターの選択に関与するという仮説を裏付けている.
- RNAポリメラーゼII特異的なU6プロモーターを成功裏に生成し,U2プロモーターをRNAポリメラーゼIII特異性へと変換した.
結論:
- RNAポリメラーゼIIIは,おそらく直接に転写開始部位を認識し,プロモーターの選択に重要な役割を果たします.
- この研究は,微分ポリメラーゼ募集のメカニズムについての洞察を提供します.
- エンジニアリングされたプロモーターは,Xenopusにおける特定の遺伝子発現の研究のための貴重なツールを提供します.
関連する概念動画
00:43Bacterial 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
00:58Eukaryotic 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
02:36RNA Polymerase II Accessory Proteins
8.9K
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...
8.9K
02:41Chromatin Structure Regulates pre-mRNA Processing
6.6K
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...
6.6K
02:23RNA Editing
8.3K
RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...
8.3K
01:53Bacterial 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