在CAP-依赖的II类促进体中转录激活:CAP和RNA聚合酶之间的两个相互作用
1Department of Chemistry and Waksman Institute, Rutgers University, New Brunswick, New Jersey 08855, USA.
Cell
|December 13, 1996
概括
催化剂激活蛋白 (CAP) 使用两种不同的相互作用来激活II类促进体的转录. 这些相互作用涉及RNA聚合酶α子单元的不同域,影响转录启动中的单独步骤.
科学领域:
- 分子生物学分子生物学
- 基因规则 基因规则
- 蛋白质-DNA相互作用
背景情况:
- 二类催化剂激活蛋白 (CAP) 依赖的促进剂涉及CAP与重叠RNA聚合酶的DNA部位的结合.
- 之前的研究发现了CAP的激活区域与RNA聚合酶α子单元C端域之间的一种相互作用.
研究的目的:
- 阐明转录激活在II类CAP依赖促进体中的完整机制.
- 确定CAP和转录机制之间的所有关键相互作用.
主要方法:
- 使用分子生物学技术研究蛋白质-蛋白质相互作用.
- 分析了特定的CAP域在转录激活中的作用.
- 研究了这些相互作用对转录启动步骤的影响.
主要成果:
- 在II类CAP-依赖的促进体中转录激活需要两个不同的CAP-RNA聚合酶α子单元相互作用.
- 第二种促进体类特异性相互作用涉及RNA聚合酶α子单元N-终端域.
- 这两种相互作用影响着转录启动的不同阶段.
结论:
- 在II类促进体中,CAP的转录激活是通过双重相互作用介导的多步骤过程.
- 这为了解激活剂如何使用多个相互作用来调节转录机制提供了一个模型.
- 强调了特定蛋白质域相互作用在基因调节中的重要性.
相关概念视频
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...
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...
Transcription Initiation
Initiation is the first step of transcription in eukaryotes. Prokaryotic RNA Polymerase (RNAP) can bind to the template DNA and start transcribing. On the other hand, transcription in eukaryotes requires additional proteins, called transcription factors, to first bind to the promoter region in the DNA template. This binding helps recruit the specific RNAP that can assemble on the DNA and start transcription.
The promoters and enhancers and their accessory proteins allow tight regulation of...
The promoters and enhancers and their accessory proteins allow tight regulation of...
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...
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...


