酵母U6小核RNA的两个域对于核前体信使RNA拼接的两个步骤都需要
1California Institute of Technology, Division of Biology, Pasadena 91125.
Science (New York, N.Y.)
|October 19, 1990
概括
研究酵母U6RNA的研究.
科学领域:
- 分子生物学分子生物学
- 在RNA生物学,RNA生物学.
- 生物化学 生物化学
背景情况:
- 小核RNAs (snRNAs) 对于mRNA前拼接至关重要.
- U6RNA的保存序列表明它在拼接中起着催化作用.
- 了解U6RNA的功能是解读拼接机制的关键.
研究的目的:
- 阐明酵母U6RNA在mRNA前拼接中的功能.
- 在U6RNA中识别特定的域,对拼接至关重要.
- 为了研究U6RNA的催化作用.
主要方法:
- 在实验室中使用合成U6RNA复制功能性酵母U6小核核核蛋白蛋白 (snRNP).
- 针对U6RNA的局部导向突变发生,以创建单核酸替代.
- 使用U6RNA突变体对拼接中间体和拼接酶组件的分析.
主要成果:
- 在U6RNA中,有两个不同的域被确定为体外剪接必不可少.
- 这些领域的突变不同地影响了拼接的两个催化步骤.
- 阻断第一步的突变体未能进入结合体;阻断第二步的突变体形成了结合体,但阻止了结合.
- 影响第二阶段突变的位置与酵母U6基因中的内部插入位相关.
结论:
- 在mRNA前拼接的两个步骤中,U6RNA起着关键的,潜在的催化作用.
- 在U6RNA中的特定域对结合酶体功能和催化活性至关重要.
- 这些发现提供了对U6基因内内的进化起源的见解,并支持其在拼接中的催化作用.
相关概念视频
01:32RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
02:01pre-mRNA Processing
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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...
02:01Pre-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...
01:32RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...
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Ribosome synthesis is a highly complex and coordinated process involving more than 200 assembly factors. The synthesis and processing of ribosomal components occurs not only in the nucleolus but also in the nucleoplasm and the cytoplasm of eukaryotic cells.
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Ribosome biogenesis begins with the synthesis of 5S and 45S pre-rRNAs by distinct RNA polymerases. The primary transcripts are extensively processed and modified before they are bound and folded by ribosomal proteins and assembly factors,...
01:32Pre-mRNA Processing: RNA Splicing
Splicing is the process by which eukaryotic RNA is edited before its translation into protein. The RNA strand transcribed from eukaryotic DNA is called the primary transcript. The primary transcripts that become mRNAs are called precursor messenger RNAs (pre-mRNAs). Eukaryotic pre-mRNA contains alternating sequences of exons and introns. Exons are nucleotide sequences that code for proteins, whereas introns are the non-coding regions. In RNA splicing, introns are removed and exons are bonded...