相关实验视频
Updated: Jul 31, 2026
11:22
Measuring the Kinetics of mRNA Transcription in Single Living Cells
Published on: August 25, 2011
在新生mRNA的延长和封闭过程中对真核细胞转录的冷图像
Science (New York, N.Y.)
|February 21, 1992
概括
使者RNA (mRNA) 的身份是在转录过程中确立的. 疫苗RNA聚合酶结合了一个18核酸RNA段,在较长的新生链上发生了5'封闭,这表明一种配转录机制.
科学领域:
- 分子生物学分子生物学
- 生物化学 生物化学
- 病毒学 病毒学
背景情况:
- 使者RNA (mRNA) 经历了对功能至关重要的修改.
- 这些转录过程中的修改的精确时间和机制是基因表达的关键.
研究的目的:
- 为了研究疫苗RNA聚合酶的RNA结合部位.
- 确定新生的mRNA的5'封闭的时间和要求.
- 阐明在真核生物中共同转录的mRNA身份确定的机制.
主要方法:
- 核糖核酶足迹绘制以映射RNA-蛋白相互作用.
- 对疫苗RNA聚合酶三元复合物的分析.
- 用纯化的封闭酶进行生物化学测试.
主要成果:
- 在疫苗RNA聚合酶上确定了一个18核酸RNA结合部位.
- 在聚合酶转位过程中,结合部位的尺寸保持不变.
- 5'封闭是共转录的,发生在新生的RNA链≥31个核酸上.
- 封闭酶与RNA聚合酶形成一个双复合体,独立于核酸.
结论:
- 疫苗RNA聚合酶具有定义的RNA结合部位,对转录至关重要.
- 5'封闭被整合到转录过程中,发生在足够长的新生RNA上.
- 这些发现提出了一个模型,用于如何在真核细胞的转录过程中建立mRNA身份.
相关概念视频
02:01pre-mRNA Processing
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl guanosine). This 5’ cap helps the...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl guanosine). This 5’ cap helps the...
02:35Transcription 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...
02:01Pre-mRNA Processing
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl guanosine). This 5’ cap helps the...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a “cap” to the 5’ end of the growing transcript. In this process, a 5’ phosphate is replaced by modified guanosine that has a methyl group attached to it (7-Methyl guanosine). This 5’ cap helps the...
01:53Bacterial 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:
02:35Transcription 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...
01:35Pre-mRNA Processing: Modification of pre-mRNA Ends
In eukaryotic cells, transcripts made by RNA polymerase are modified and processed before exiting the nucleus. Unprocessed RNA is called precursor mRNA or pre-mRNA to distinguish it from mature mRNA.
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps the cell...
Once about 20-40 ribonucleotides have been joined together by RNA polymerase, a group of enzymes adds a cap to the 5' end of the growing transcript. In this process, a 5' phosphate is replaced by modified guanosine that has a methyl group attached (7-methyl guanosine). This 5' cap helps the cell...