相关实验视频
Updated: Jul 18, 2026

15:33
Adenoviral Transduction of Naive CD4 T Cells to Study Treg Differentiation
Published on: August 13, 2013
概括
腺病毒E1a蛋白调节基因转录. 突变者表明,转录抑制,而不是激活,是腺病毒转变的关键,为病毒瘤发生提供了新的见解.
科学领域:
- 分子生物学分子生物学
- 病毒学 病毒学
- 癌症研究 癌症研究
背景情况:
- 腺病毒利用E1a蛋白进行细胞转化.
- 有两个主要的E1a蛋白,243和289氨基酸,具有不同的功能.
- 这些蛋白质具有高序列同质性,但有46个氨基酸的区别.
研究的目的:
- 为了确定腺病毒E1a蛋白质内的功能区域.
- 研究转录激活和抑制在病毒转化中的作用.
- 描述一种新的变形缺陷突变物种类型.
主要方法:
- 在腺病毒E1a区域构建单基替代突变.
- 对突变E1a蛋白的转录激活和抑制活动的分析.
- 评估突变E1a蛋白的病毒转化能力.
主要成果:
- 在E1a蛋白中定位了两个不同的功能区域:一个用于转录激活,一个用于抑制.
- 289个氨基酸蛋白质拥有这两个区域,主要作为激活剂.
- 243氨基酸蛋白质缺乏激活域,主要作为抑制剂起作用.
- 保存区域中的突变产生了转换缺陷的突变,这些突变保留了转录激活,但失去了抑制.
- 这些发现表明,转录抑制对于腺病毒介导的细胞转化至关重要.
结论:
- 腺病毒E1a蛋白具有不同的功能域,用于转录激活和抑制.
- 通过E1a蛋白质进行转录抑制对于腺病毒诱导的细胞转化至关重要.
- 这项研究为腺病毒瘤发生的分子机制提供了新的见解.
相关概念视频
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...
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...
Leaky Scanning
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for...

