関連する実験動画
Updated: May 11, 2026

09:59
Investigation of RNA Synthesis Using 5-Bromouridine Labelling and Immunoprecipitation
Published on: May 3, 2018
まとめ
中国ハムスター卵巣 (CHO) のハイブリッド細胞は,RNAポリメラーゼIIの規制メカニズムを示しています. アルファ-アマニチンへの曝露は,敏感なRNAポリメラーゼIIの無活性化につながり,抵抗性の形態が増加し,総活性が常に維持されます.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
- バイオケミストリー バイオケミストリー
背景:
- 中国ハムスター卵巣 (CHO) ハイブリッド細胞系は,アルファ-アマニチンに敏感な野生型の細胞と,アルファ-アマニチンに抵抗性のあるRNAポリメラーゼIIを持つ変異細胞を融合させることで作成されました.
- これらのハイブリッド細胞には,RNAポリメラーゼIIの感受性および耐性の両方が含まれており,微分酵素活性調節の研究を可能にします.
研究 の 目的:
- アルファ-アマニチンへの反応としてRNAポリメラーゼIIの細胞内レベルを制御する規制メカニズムを調査する.
- 酵素活性の変化が,酵素全体の質量変化と相関するかどうかを判断する.
主な方法:
- 微分酵素活性を引き起こすために,アルファ-アマニチンを含有する介質にCHOハイブリッド細胞を培養する.
- 敏感な放射性免疫測定法を使用して,RNAポリメラーゼII酵素の総質量を定量化します.
- 3H-アマニチン結合測定法を使用して,アルファ-アマニチン-無活性化RNAポリメラーゼIIの活性と結合能力を評価する.
主要な成果:
- アルファ-アマニチンで成長すると,敏感なRNAポリメラーゼIIは不活性化され,抵抗性RNAポリメラーゼIIの活動は比例して増加し,総活性が一定に維持されました.
- アルファアマニチンで治療された細胞における耐性酵素活性が2〜3倍増加したところ,放射性免疫測定法による総酵素質の有意な変化は示されなかった.
- 3H-アマニチン結合による不活性化された感受性ポリメラーゼIIの定量化により,酵素活性喪失と相関する結合能力の喪失が明らかになった.
結論:
- RNAポリメラーゼII.の細胞内濃度を制御するための規制メカニズムが存在します.
- この調節は,単なる翻訳後の修正や活性調節ではなく,酵素濃度の調整を伴う.
- 観察された調節はRNAポリメラーゼIの活動とは独立している.
関連する概念動画
Types of RNA
Overview
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
Three main types of RNA are involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). These RNAs perform diverse functions and can be broadly classified as protein-coding or non-coding RNA. Non-coding RNAs play important roles in the regulation of gene expression in response to developmental and environmental changes. Non-coding RNAs in prokaryotes can be manipulated to develop more effective antibacterial drugs for human or animal use.
RNA...
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...
Prokaryotic Transcriptional Activators and Repressors
The organization of prokaryotic genes in their genome is notably different from that of eukaryotes. Prokaryotic genes are organized, such that the genes for proteins involved in the same biochemical process or function are located together in groups. This group of genes, along with their regulatory elements, are collectively known as an operon. The functional genes in an operon are transcribed together to give a single strand of mRNA known as polycistronic mRNA.
Transcription of prokaryotic...
Transcription of prokaryotic...
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...
Regulation of Expression at Multiple Steps
The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the addition of a...
Stringent Response in E. coli
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...

