概括
研究人员发现了两个转录因子,Sp1和Sp2,对于精确的体外转录至关重要. Sp1是促进子特异性的,而Sp2是一般的转录因子,表明Sp1是促进子特异性的.
科学领域:
- 分子生物学分子生物学
- 基因规则 基因规则
背景情况:
- 精确的基因转录对于细胞功能至关重要.
- 了解转录因子的作用是解读基因调节的关键.
研究的目的:
- 识别和描述涉及精确体外转录的因素.
- 阐明促进体特异性和一般转录因子的特定作用.
主要方法:
- 全细胞HeLa提取物的分化.
- 采用各种DNA模板 (SV40,腺病毒,β-环球蛋白,ASV) 的体外转录试验.
- 对转录启动的因子要求的分析.
主要成果:
- 一种新的分离程序产生了体外转录的三个必不可少的组件:Sp1,Sp2和RNA聚合酶II.
- Sp1 显示出促进体特异性,增强 SV40 早期促进体转录,同时抑制腺病毒主要晚期促进体转录.
- Sp2作为一种通用转录因子,对多个促进体有必要.
结论:
- 在促进子选择中,Sp1起着至关重要的作用,而不仅仅是一般的转录.
- 这些发现区分了促进体特异性 (Sp1) 和一般性 (Sp2) 转录因子的功能.
- 这项研究提供了关于真核细胞转录启动的复杂机制的见解.
相关概念视频
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...
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...
The Eukaryotic Promoter Region
The eukaryotic promoter region is a segment of DNA located upstream of a gene. It contains an RNA polymerase binding site, a transcription start site, and several cis-regulatory sequences. The proximal promoter region is located in the vicinity of the gene and has cis-regulatory sequences and the core promoter. The core promoter is the binding site for RNA polymerase and is usually located between -35 and +35 nucleotides from the transcription start site. The distal promoter regions 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...


