関連する実験動画
Updated: Jul 20, 2026
14:40
Expression Analysis of Mammalian Linker-histone Subtypes
Published on: March 19, 2012
まとめ
マウスのL細胞の異質核RNA (hnRNA) には4つの5'末端型があります. ピューリンヌクレオチドはhNRNAの転写を開始し,ピリミジン末端のhNRNAは内部分裂イベントの結果である可能性が高い.
科学分野:
- 分子生物学は分子生物学である.
- RNA バイオケミストリー
- 遺伝子発現の表現について
背景:
- 異質な核RNA (hnRNA) は遺伝子発現において重要な役割を果たします.
- hnRNAの5'-端末構造を理解することは,転写開始と処理の解読の鍵です.
- カップ構造は,mRNAの安定性と翻訳のための重要な修正です.
研究 の 目的:
- マウス L 細胞 hnRNA.RNA のリン酸化され,封じられた 5' 端を分析する.
- 異なるhRNAの核酸組成を解明する.
- hnRNAとmRNAの前駆体関係のモデルを提案する.
主な方法:
- hnRNAのリン酸化および封じられた5'末端の分析.
- ヌクレオチド構造の識別 (pppXp,ppXp,pXp,m7/GpppXmp) について
- 異なるターミナルにおける核酸種の定量化.
主要な成果:
- マウスのL細胞 hnRNA.で4種類の5'末端が特定されました.
- トランスクリプションの開始は,純粋核酸 (GTP,ATP) のみに関係しています.
- ピリミジンを含む5'末端は,より大きなトランスクリプトの内部裂け目から生じる可能性が高い.
結論:
- hnRNAの誘発は,純粋核酸でのみ発生する.
- ピリミジン末端 hnRNAは,プライマリトランスクリプトの内部裂け方を示唆しています.
- mRNA配列が5'端とhnRNA前駆体の内部割れ部の両方から発生できるモデルが提案されています.
関連する概念動画
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...
00:58Eukaryotic RNA Polymerases
RNA Polymerase (RNAP) is conserved in all animals, with bacterial, archaeal, and eukaryotic RNAPs sharing significant sequence, structural, and functional similarities. Among the three eukaryotic RNAPs, RNA Polymerase II is most similar to bacterial RNAP in terms of both structural organization and folding topologies of the enzyme subunits. However, these similarities are not reflected in their mechanism of action.
All three eukaryotic RNAPs require specific transcription factors, of which the...
All three eukaryotic RNAPs require specific transcription factors, of which the...
02:41Chromatin Structure Regulates pre-mRNA Processing
In eukaryotic cells, nascent mRNA transcripts need to undergo many post-transcriptional modifications to reach the cell cytoplasm and translate into functional proteins. For a long time, transcription and pre-mRNA processing were considered two independent events that occur sequentially in the cell. However, it has now been well established that transcription and pre-mRNA processing are two simultaneous processes that are precisely regulated inside the cell.
The chromatin structure, especially...
The chromatin structure, especially...
02:36Transfer RNA Synthesis
One of the unique features of tRNA is the presence of modified bases. In some tRNAs, modified bases account for nearly 20% of the total bases in the molecule. Altogether, these unusual bases protect the tRNA from enzymatic degradation by RNases.
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
Each of these chemical modifications is carried by a specific enzyme, post-transcription. All of these enzymes have unique base and site-specificity. Methylation, the most common chemical modification, is carried by at least nine different enzymes, with...
02:51mRNA 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
Cis-acting Elements involved in mRNA stability
01:35Pre-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...