概括
酵母mRNA拼接涉及一个保存的TACTAAC序列. 研究人员发现,一种特定的RNA中间体,主要是,表明早期拼接步骤和酵母和哺乳动物mRNA处理之间的相似之处.
科学领域:
- 分子生物学分子生物学
- 在RNA分离过程中.
- 酵母遗传学 酵母遗传学
背景情况:
- 酵母mRNA内基具有保存的TACTAAC序列,对于剪接至关重要.
- 之前的研究发现,在野生类型的rp51A内核拼接中间体中,TACTAAC盒中出现逆转录酶停止.
研究的目的:
- 为了调查逆转录酶在酵母mRNA拼接中的TACTAAC盒停留的性质.
- 描述假定拼接中间体的组成和结构.
- 为了比较酵母和哺乳动物mRNA拼接的早期步骤.
主要方法:
- 反转录酶停止分析在酵母内部的TACTAAC盒子 (rp51A和actin).
- 拼接中间体的RNA特征,包括拉里亚特形成和外子组成.
主要成果:
- 逆转录酶停止发生在野生类型rp51A和actin内部的TACTAAC盒中的分支核酸上.
- 确定了一种关键的中间体,含有完整的内子和3'外子,缺少5'外子,主要以拉里亚特结构存在.
- 检测到其他中间体,包括切除的内子形式和自由的5'外子.
结论:
- 拉里亚特结构的形成和5'结处的切割代表了酵母mRNA拼接的早期事件.
- 在酵母和哺乳动物的mRNA拼接机制之间存在显著的相似之处.
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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...
Pre-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...
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Pre-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...
mRNA Stability and Gene Expression
The structure and stability of mRNA molecules regulates gene expression, as mRNAs are a key step in the pathway from gene to protein. In eukaryotes, the half-life of mRNA varies from a few minutes up to several days. mRNA stability is essential in growth and development. The absence of the proteins regulating its stability, such as tristetraprolin in mice, can cause systemic issues, including bone marrow overgrowth, inflammation, and autoimmunity.
Cis-acting Elements involved in mRNA stability
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