一个TRF1:BRF复合体指导DrosophilaRNA聚合酶III转录
1Department of Molecular and Cell Biology, Howard Hughes Medical Institute, University of California, Berkeley, 94720, USA.
Cell
|June 13, 2000
概括
在Drosophila中,与TBP而不是BRF复合的TATA结合蛋白相关因子1 (TRF1) 中介于RNA聚合酶III转录. 这一发现挑战了TBP在转录中的普遍作用.
科学领域:
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
- 生物化学 生物化学
背景情况:
- 传统上,TATA结合蛋白 (TBP) 被认为是RNA聚合酶I,II和III的通用转录因子.
- 在Drosophila中RNA聚合酶III (Pol III) 转录启动的精确机制尚未完全阐明.
研究的目的:
- 调查TBP相关因素在DrosophilaRNA聚合酶III转录中的作用.
- 在这个模型生物体中确定负责Pol III转录的特定蛋白质复合体.
主要方法:
- 免疫沉测试以确定蛋白质相互作用.
- 在体外转录试验中,使用免疫缺陷提取物和重组蛋白进行了转录试验.
- 使用体内方法分析聚烯染色体位点的蛋白质同位素化.
主要成果:
- 与TBP相关的1因子 (TRF1),而不是TBP,对于Drosophila.的RNA聚合酶III转录至关重要.
- 需要一个TRF1和BRF复合体来重建tRNA,5S和U6RNA基因的转录.
- 发现TRF1和BRF在体内主要复杂化,并在聚烯染色体上的Pol III基因位点同位.
结论:
- 与BRF复合的TRF1在Drosophila的RNA聚合酶III转录中发挥着关键作用,取代了TBP普遍接受的作用.
- 这项研究重新定义了Drosophila中Pol III转录启动的因素,突出了TRF1.1的重要性.
相关概念视频
Bacterial RNA Polymerase
20.0K
Unlike eukaryotes, bacteria use a single RNA Polymerase (RNAP) to transcribe all genes. The different subunits of bacterial RNAPhave distinct functions. The multisubunit structure of the bacterial RNAP helps the enzyme to maintain catalytic function, facilitate assembly, interact with DNA and RNA, and self-regulate its activity.
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
In most genes, the transcription site is a single base present upstream of the coding sequence. Though RNAP is a catalytically efficient enzyme, it does not recognize...
20.0K
Eukaryotic RNA Polymerases
17.3K
RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action.
All three eukaryotic RNAPs require specific transcription factors, of which the...
All three eukaryotic RNAPs require specific transcription factors, of which the...
17.3K
Transfer RNA Synthesis
10.3K
One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
10.3K
General Transcription Factors
5.9K
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...
5.9K
Transcriptional Regulation: Riboswitches
1.2K
Riboswitches are RNA elements that regulate gene expression by altering their secondary structures in response to specific effector molecules. These elements, located in the leader regions of certain mRNAs, act as transcriptional regulators by toggling between alternative conformations to control downstream gene expression. Riboswitch-mediated regulation is a precise mechanism for modulating biosynthetic pathways, as exemplified by the riboflavin biosynthesis pathway in Bacillus...
1.2K


