相关实验视频
Updated: May 10, 2026

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Using Caco-2 Cells to Study Lipid Transport by the Intestine
Published on: August 20, 2015
概括
一个新的机制解释了肠道Apo-B48的产生方式,与肝脏Apo-B100不同. 这涉及肠道中特定的mRNA修饰,从一个基因中创建两个蛋白质.
科学领域:
- 生物化学 生物化学
- 分子生物学分子生物学
- 遗传学 是一个遗传学.
背景情况:
- 阿波脂蛋白B (apo-B) 对于脂蛋白组装和运输至关重要.
- 肠道的apo-B48和肝脏的apo-B100是相关的,但不同的异型.
- 阿波-B48生产的确切机制尚不清楚.
研究的目的:
- 阐明导致肠道apo-B48.B48产生的分子机制.
- 为了研究肠道和肝脏apo-B生产之间的遗传和mRNA差异.
主要方法:
- 来自人类和子小肠的cDNA克隆的分析.
- 聚合酶链反应 (PCR) 放大来自各种组织和细胞系 (人/子肠,子肝,HepG2) 的cDNA.
- 肠道和肝脏的Apo-B序列和基因组DNA的比较.
主要成果:
- 所有肠道cDNA克隆都表现出C-to-T基变化,在2153位置创建了一个过早的停止编码子.
- 这种停止编码子仅在肠道mRNA中发现,而不是在肠细胞基因组DNA中.
- 在子肝和HepG2细胞系mRNA中缺少停止.
结论:
- 在肠道中,mRNA的组织特异性协同或后转录修饰 (C-to-U变化) 会产生apo-B48.8.
- Apo-B48 代表了 apo-B100 的 N-终端 2152 个氨基酸.
- 这代表了首次记录的单个mRNA核酸修饰的实例,从单个初级转录中产生了两个不同的蛋白质.
相关概念视频
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...
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...
Ribosomal RNA Synthesis
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.
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,...
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,...
RNA Editing
RNA editing is a post-transcriptional modification where a precursor mRNA (pre-mRNA) nucleotide sequence is changed by base insertion, deletion, or modification. The extent of RNA editing varies from a few hundred bases, in mitochondrial DNA of trypanosomes, to a just single base, in nuclear genes of mammals. Even a single base change in the pre-mRNA can convert a codon for one amino acid into the codon for another amino acid or a stop codon. This type of re-coding can significantly affect the...
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...

