関連する実験動画
Updated: Jul 30, 2026

13:34
Gene Trapping Using Gal4 in Zebrafish
Published on: September 29, 2013
転写活性化剤GAL4のネガティブな効果
1Department of Biochemistry and Molecular Biology, Harvard University, Cambridge, Massachusetts 02138.
Nature
|August 25, 1988
まとめ
酵母 GAL4 アクティベーター誘導体の高いレベルは,転写を阻害し,スキャッチングと呼ばれる現象を防ぐことができます. この効果は,アクティベーターがアクティベーターを起動したときに発生します.
科学分野:
- 分子生物学は分子生物学である.
- イースト遺伝学 イースト遺伝学
- トランスクリプションに関する規則
背景:
- イーストの転写活性化剤であるGAL4はDNAを結合させ,遺伝子転写を開始する.
- GAL4の酸性活性化領域は,転写機構の構成要素と相互作用すると仮定されています.
- DNA結合ドメインは,遺伝子の活性化のための活性化領域を配置します.
研究 の 目的:
- 酵母におけるGAL4誘導体の転写への影響を調査する.
- GAL4による転写抑制のメカニズムを特徴づける.
主な方法:
- 酵母における高濃度の様々なGAL4誘導体の発現.
- GAL4結合部位が欠けている遺伝子の転写への影響を評価する.
- 観察された抑制におけるDNA結合ドメインの役割を分析する.
主要な成果:
- GAL4誘導体は,GAL4結合部位が欠けている特定の遺伝子の転写を抑制する.
- より強力な活性化剤は,より強い抑制効果を示します.
- 転写抑制は,GAL4 DNA結合ドメインとは独立しています.
結論:
- GAL4誘導体が転写を阻害する"スキャッチング"と呼ばれる新しい現象が記述されています.
- 抑制は,GAL4の活性化領域による重要な転写因子の定位に起因する.
- これは,遺伝子発現における自己調節またはクロス調節のためのメカニズムを示唆しています.
関連する概念動画
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...
Co-activators and Co-repressors
Gene transcription is regulated by the synergistic action of several proteins that form a complex at a gene regulatory site. This is observed in eukaryotes, where the regulation of gene expression is a complex process. Regulatory proteins in eukaryotes can broadly be classified into two types – regulators that bind directly to specific DNA sequences and co-regulators that associate with regulatory proteins but cannot directly bind to the DNA. These co-regulators are further divided into...
Eukaryotic Transcription Activators
Transcription activators are proteins that promote the transcription of genes from DNA to RNA. In most cases, these proteins contain two separate domains ‒ a domain that binds to DNA and a domain for activating transcription; however, in some cases, a single domain is responsible for both binding and activation of transcription, as seen in the glucocorticoid receptor and MyoD.
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are...
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These domains are...
Eukaryotic Transcription Inhibitors
Certain biochemical processes, such as embryonic development and cell growth regulation, depend on the repression of specific genes. DNA binding proteins known as eukaryotic transcription inhibitors regulate the repression of gene expression in eukaryotes. The presence of these inhibitors at the required location and time in the cell is triggered by the presence of hormones and additional signals from other cells.
Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...
Eukaryotic transcription inhibitors usually contain two distinct domains, a DNA...
Combinatorial Gene Control
Combinatorial gene control is the synergistic action of several transcriptional factors to regulate the expression of a single gene. The absence of one or more of these factors may lead to a significant difference in the level of gene expression or repression.
The expression of more than 30,000 genes is controlled by approximately 2000-3000 transcription factors. This is possible because a single transcription factor can recognize more than one regulatory sequence. The specificity in gene...
The expression of more than 30,000 genes is controlled by approximately 2000-3000 transcription factors. This is possible because a single transcription factor can recognize more than one regulatory sequence. The specificity in gene...
General Transcription Factors
Tissue-specific transcription factors contribute to diverse cellular functions in mammals. For example, the gene for beta globin, a major component of hemoglobin, is present in all cells of the body. However, it is only expressed in red blood cells because the transcription factors that can bind to the promoter sequences of the beta globin gene are only expressed in these cells. Tissue-specific transcription factors also ensure that mutations in these factors may impair only the function of...

