関連する実験動画
Updated: May 10, 2026

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Using Caco-2 Cells to Study Lipid Transport by the Intestine
Published on: August 20, 2015
まとめ
新しいメカニズムは,肝臓のApo-B100と異なる腸のApo-B48の生成方法を説明しています. これは腸内の特定のmRNAの改変を伴うもので,1つの遺伝子から2つのタンパク質を生成します.
科学分野:
- バイオケミストリー バイオケミストリー
- 分子生物学は分子生物学である.
- 遺伝学 遺伝学とは
背景:
- アポリポプロテインB (apo-B) は,リポプロテインの組立と輸送に不可欠です.
- 腸内アポ-B48と肝内アポ-B100は関連しているが,異なる異形である.
- アポ-B48の生産の正確なメカニズムは不明のままである.
研究 の 目的:
- 腸内アポ-B48.B48.の産生を支える分子メカニズムを解明する.
- 腸内および肝臓でのアポ-B生産の間の遺伝子およびmRNAの違いを調査する.
主な方法:
- 人間の小腸とウサギの小腸からのcDNAクローンの分析.
- ポリメラーゼ連鎖反応 (PCR) は,様々な組織や細胞系 (ヒト/ウサギの腸,ウサギの肝臓,HepG2) からcDNAを放大する.
- 腸と肝臓のアポB配列とゲノムDNAの比較.
主要な成果:
- すべての腸内cDNAクローンはCからTの塩基変化を示し,2153の位置で早期停止コドンを生み出しました.
- このストップコドンは腸内mRNAのみで発見され,腸細胞ゲノムDNAには含まれていません.
- ストップコドンはウサギの肝臓とHepG2細胞系mRNAに存在しなかった.
結論:
- 腸内のmRNAの組織特異的なコ-またはポストトランスクリプションによる改変 (C-to-U変化) はapo-B48.8.を生成する.
- Apo-B48は,apo-B100のN端の2152アミノ酸を表しています.
- これは,単一の mRNA 核酸変異が,単一のプライマリー トランスクリプトから 2 つの異なるタンパク質を生成する最初の文書化された事例を表しています.
関連する概念動画
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...

