一个核帽结合蛋白质复合体,参与了mRNA前拼接
E Izaurralde1, J Lewis, C McGuigan
1European Molecular Biology Laboratory, Heidelberg, Federal Republic of Germany.
Cell
|August 26, 1994
概括
由CBP80和CBP20组成的盖结合蛋白复合体 (CBC) 在核前mRNA拼接中起着至关重要的作用. 这个复合体对于识别前mRNA和促进拼接复合体形成的早期步骤至关重要.
科学领域:
- 分子生物学分子生物学
- 细胞生物学 细胞生物学
- 生物化学 生物化学
背景情况:
- 盖结合蛋白复合体 (CBC) 存在于HeLa细胞的细胞核中.
- CBC包括两个已知的蛋白质:CBP80和CBP20.
研究的目的:
- 描述结蛋白复合体 (CBC) 并阐明其在mRNA前处理中的功能.
- 研究CBC在核前mRNA拼接途径中的作用.
主要方法:
- 从HeLa细胞核中净化CBC.
- 同分离和共免疫沉试验以确认CBC组成.
- 在体外和体外拼接试验中使用修改后的帽子类似物.
- 在CBC-depleted提取物中对mRNA前拼接的分析.
主要成果:
- 纯化CBC由CBP80和CBP20组成,CBP80和CBP20是共分离的,并且是共免疫可接受的.
- 修改后的盖子类似物抑制拼接并与CBC结合,这表明它在拼接中发挥了作用.
- 从提取物中消耗的CBC阻断了与腺病毒前mRNA结合复合形成的早期步骤.
结论:
- 结蛋白复合体 (CBC) 是一个功能实体,参与了mRNA前拼接.
- CBC可能在识别前mRNA中发挥着关键作用.
- 在mRNA前处理过程中,CBC对于高效的拼接复合体组装至关重要.
相关概念视频
RNA Splicing
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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...
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...
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...
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...
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Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...
Nuclear Export of mRNA
Before mRNAs are exported to the cytoplasm, it is crucial to check each mRNA for structural and functional integrity. Eukaryotic cells use several different mechanisms, collectively known as mRNA surveillance, to look for irregularities in mRNAs. Irregular or aberrant mRNA are rapidly degraded by various enzymes. If a defective mRNA escapes the surveillance, it would be translated into a protein which would either be non-functional or not function properly. One of the primary irregularities in...


