艾滋病毒-1 Tat蛋白增加了转录启动,并稳定了延长
M F Laspia1, A P Rice, M B Mathews
1Cold Spring Harbor Laboratory, New York 11724.
Cell
|October 20, 1989
概括
人类免疫缺陷病毒-1 (HIV-1) Tat蛋白独特地增强了全长病毒RNA的产生,并抑制了转录暂停. 腺病毒E1A蛋白广泛增加病毒RNA合成,但不影响暂停.
科学领域:
- 分子生物学分子生物学
- 病毒学 病毒学
- 基因规则 基因规则
背景情况:
- 人类免疫缺陷病毒-1 (HIV-1) 转录受到病毒和细胞因素的严格调节.
- 艾滋病毒-1 Tat 蛋白质是有效病毒基因表达所必需的关键病毒转激活剂.
- 腺病毒E1A蛋白作为研究病毒转激活机制的比较模型.
研究的目的:
- 研究和比较HIV-1 Tat和腺病毒E1A调节HIV-1转录的不同机制.
- 阐明这些转激活剂在控制病毒RNA合成,转录延长和促进器-近位暂停中的作用.
主要方法:
- 对细胞质RNA类的分析,包括全长和截断的转录.
- 测量RNA合成速率以评估转录活性.
- 针对HIV-1 TAR元素的局部定向突变发生,以评估其在转激活中的作用.
主要成果:
- 塔特选择性地增加了全长的HIV-1RNA,而E1A则促进了全长和截断的转录.
- 泰特和E1A都提高了促进者近端转录率.
- 塔特,但不是E1A,抑制了转录极性 (暂停).
- 在 TAR 元素的突变取消了Tat介导的转激活,但没有影响E1A的响应性.
结论:
- 它通过 TAR 元素作用,增强转录启动复合体的形成,稳定延长复合体.
- E1A通过TAR独立的机制影响HIV-1转录,主要是促进启动.
- 这些发现突出了病毒转激活剂用来调节宿主基因表达和病毒复制的独特策略.
更多相关视频
13:47Lentiviral Vector Platform for the Efficient Delivery of Epigenome-editing Tools into Human Induced Pluripotent Stem Cell-derived Disease Models
Published on: March 29, 2019
09:38Identification of Nucleolar Factors During HIV-1 Replication Through Rev Immunoprecipitation and Mass Spectrometry
Published on: June 26, 2019
相关概念视频
Transcription Elongation Factors
Transcription elongation is a dynamic process that alters depending upon the sequence heterogeneity of the DNA being transcribed. Hence, it is not surprising that the elongation complex's composition also varies along the way while transcribing a gene.
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA into a...
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA into a...
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...
Bacterial Transcription
RNA polymerase (RNAP) carries out DNA-dependent RNA synthesis in both bacteria and eukaryotes. Bacteria do not have a membrane-bound nucleus. So, transcription and translation occur simultaneously, on the same DNA template.
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These are:
Transcription can be divided into three main stages, each involving distinct DNA sequences to guide the polymerase. These 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...
Transcription Elongation Factors
Transcription elongation is a dynamic process that alters depending upon the sequence heterogeneity of the DNA being transcribed. Hence, it is not surprising that the elongation complex's composition also varies along the way while transcribing a gene.
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA into a...
The transcription elongation is regulated via pausing of RNA polymerase on several occasions during transcription. In bacteria, these halts are necessary because the transcription of DNA into mRNA is coupled to the translation of that mRNA into a...
