定义一种支持RNA聚合酶II促进体转录的染色质结构
Michael J Fisher1, Donal S Luse1
1Department of Cardiovascular and Metabolic Sciences, Lerner Research Institute, Cleveland Clinic, Cleveland, Ohio, USA.
The Journal of biological chemistry
|June 30, 2024
概括
基因组H3氨酸4三甲基化 (H3K4me3) 通过使TFIID与+1核细胞相互作用来促进转录. 这种修改克服了核酶抑制,特别是对于TATA-less促进体.
科学领域:
- 分子生物学分子生物学
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
- 基因规则 基因规则
背景情况:
- 哺乳动物RNA聚合酶II预启动复合体聚集在+1核素体附近,通常在转录开始地点的下游40-50bp.
- 活性促进体在+1核酶上具有H3K4me3修饰,该修饰与TFIID (转录因子II D) 相互作用.
研究的目的:
- 调查 +1 核细胞位和 H3K4me3 修饰在 TFIID 调节转录启动中的作用.
- 确定远端核细胞体上的H3K4me3修饰是否可以支持转录.
主要方法:
- 在体外转录试验中,使用具有不同近接边缘位置 (NPE) 和H3K4me3修改的核体模板进行了转录试验.
- 在含有TATA和没有TATA的促进剂之间对转录活性进行比较.
- 对具有保留核因子的转录反应进行分析,以评估早期终止.
主要成果:
- 修改H3K4me3减轻了TFIID对+51 NPEs模板的转录抑制,特别是对于TATA-less促进器.
- 当H3K4me3存在时,具有+35 NPEs的模板与TFIID一起活跃.
- 双核模板显示转录时,只有远端核是H3K4me3修饰的,表明TFIID相互作用不仅限于+1核.
结论:
- +1核细胞体的H3K4me3修饰对于TFIID介导的转录启动至关重要,克服了核细胞体近位抑制.
- TFIID-H3K4me3相互作用可以发生,即使修饰是在远端核细胞体上.
- 在保留多个核因子的反应中,+1核酶似乎不是早期转录终止的重要障碍.
相关概念视频
Transcription Initiation
16.4K
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...
16.4K
RNA Polymerase II Accessory Proteins
9.2K
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...
9.2K
The Eukaryotic Promoter Region
16.2K
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...
16.2K
Chromatin Structure Regulates pre-mRNA Processing
7.0K
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...
7.0K
Eukaryotic Transcription Activators
11.0K
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...
The binding domains are capable of recognizing and interacting with regulatory sequences on the DNA. These...
11.0K
General Transcription Factors
5.2K
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...
5.2K


