相关实验视频
Updated: May 31, 2026

11:39
Chromatin Immunoprecipitation (ChIP) in Mouse T-cell Lines
Published on: June 17, 2017
一个染色体标志和转录启动在大多数促进器在人类细胞中的标志
Matthew G Guenther1, Stuart S Levine, Laurie A Boyer
1Whitehead Institute for Biomedical Research, Cambridge, MA 02142, USA.
Cell
|July 17, 2007
概括
大多数人类基因都会启动转录,即使是以前认为不活跃的基因. 这种全基因组分析显示,转录启动是人类细胞中常见的事件,影响基因调节.
科学领域:
- 分子生物学分子生物学
- 基因组学就是基因组学.
- 表观遗传学 在表观遗传学中,表观遗传学是指表观遗传学.
背景情况:
- 了解基因调节对于细胞功能和发育至关重要.
- 以前的假设表明,许多编码蛋白质的基因在转录上是无声的.
- 转录启动在整体基因表达中的作用仍然不清楚.
研究的目的:
- 研究人类基因组中转录启动的程度.
- 确定在启动和延长阶段控制基因表达的调节机制.
- 为了表征被积极阻止启动转录的基因.
主要方法:
- 对人类胚胎干细胞和分化的细胞进行全基因组分析.
- 染色体免疫沉以检测基因组修饰 (H3K4me3,H3K9,14Ac,H3K36me3) 和RNA聚合酶II在基因促进者的占用.
- 对全长成绩单制作的分析.
主要成果:
- 大多数编码蛋白质的基因,包括那些被认为不活跃的基因,都显示出转录启动的证据.
- 具有特定基因子修饰的核细胞和RNA聚合酶II标志着大多数基因的促进者.
- 一个基因子集进行延长 (标记为H3K36me3),而另一个基因则启动但没有延长,这表明启动后的调节.
- 一个不同的基因类别在启动步骤中被积极抑制.
- 这些发现在干细胞和分化细胞中都是一致的.
结论:
- 转录启动是人类细胞中普遍存在的现象,在大多数蛋白质编码基因中发生.
- 基因表达通常在启动后的步骤中受到调节,特别是对于发育调节者.
- 防止转录启动的机制存在于基因的一个子集.
- 这项研究重新定义了我们对人类基因组基底转录活动的理解.
相关概念视频
Chromatin Position Affects Gene Expression
Chromatin is the massive complex of DNA and proteins packaged inside the nucleus. The complexity of chromatin folding and how it is packaged inside the nucleus greatly influences access to genetic information. Generally, the nucleus' periphery is considered transcriptionally repressive, while the cell's interior is considered a transcriptionally active area.
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the timing and level of...
Topologically Associated Domains (TADs)
The 3-dimensional positioning of chromatin in the nucleus influences the timing and level of...
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...
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...
Heterochromatin
The extent of chromatin compaction can be studied by staining chromatin using specific DNA binding dyes. Under the microscope, the dense-compacted regions that take up more dye are called heterochromatin. Heterochromatin is further classified into two forms – constitutive heterochromatin and facultative heterochromatin.
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
Constitutive heterochromatin: It is a highly compact region of chromatin that is mostly concentrated in the centromere and telomere. Unlike euchromatin, the amino acid at 9th...
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...
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...

