Dicerは,効率的かつ正確な処理のためにRNAの5'端を認識します
Jong-Eun Park1, Inha Heo, Yuan Tian
1School of Biological Sciences, Seoul National University, Seoul 151-742, Korea.
Nature
|July 15, 2011
まとめ
人間のDicer酵素は,正確なマイクロRNA (miRNA) 処理のために5'カウントルを使用して,二重鎖のRNA前駆体の両端を認識します. この発見は,RNAサイレンシングと小さなヘアピンRNA設計の理解に影響を与える.
科学分野:
- 分子生物学は分子生物学である.
- RNA 生物学 RNA 生物学
- バイオケミストリー バイオケミストリー
背景:
- RNAサイレンシングは,二重鎖RNAを小さなRNAに変換するDicer酵素の処理に依存しています.
- 正確なDicer処理は,機能的なマイクロRNA (miRNA) に不可欠である.
- 現在のモデルは,DicerがRNA前駆体3'端からの距離を測定することを示唆しています.
研究 の 目的:
- 二重鎖RNA前駆体処理におけるヒトDicerのメカニズムを調査する.
- Dicer cleavageサイト選択におけるRNA前駆体5'端の役割を特定する.
- Dicer.によって5'エンド認識の構造的基礎を探求する.
主な方法:
- ヒトDicerと二重鎖RNA基板を用いた生化学分析.
- ヒトDicerのサイト指向型変異により,主要残留物を特定する.
- Dicer-null 細胞を用いた in vitro 処理アッセイと in vivo 研究.
主要な成果:
- Human Dicerは,二重鎖のRNAの3'端と5'端の両方にアンカリングする.
- クリーバージ・サイトの選択は,主に5'カウントルール (5'端からの距離) によって決定されます.
- Dicerの新しい5'ポケットモチーフは,処理効率と精度にとって不可欠な5'-端末リン酸基を認識しています.
結論:
- Dicerによる5'-end認識は,正確で効率的なmiRNA生体生成に不可欠です.
- 5'カウントルールと5'ポケットは,ある種では保存されているが,他の種では保存されていない.
- 発見は,小型のヘアピンRNAを治療用途のために設計するための洞察を提供します.
関連する概念動画
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...
Transfer 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...
RNA Structure
The basic structure of RNA consists of a string of ribonucleotides attached by phosphodiester bonds. Although most RNA is single-stranded, it can form complex secondary and tertiary structures. Such structures play essential roles in the regulation of transcription and translation.
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA) involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three...
Different Types of RNA Have the Same Basic Structure
There are three main types of ribonucleic acid (RNA) involved in protein synthesis: messenger RNA (mRNA), transfer RNA (tRNA), and ribosomal RNA (rRNA). All three...
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...
Transfer 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...


