関連する実験動画
Updated: Aug 9, 2026

10:59
Analysis of Translation Initiation During Stress Conditions by Polysome Profiling
Published on: May 19, 2014
細胞mRNAの5'リーダーによって媒介される翻訳の内部開始
1Department of Biochemistry, Biophysics and Genetics, University of Colorado Health Sciences Center, Denver 80262.
Nature
|September 5, 1991
まとめ
ユカリオットのメッセンジャーRNAは,5'キャップ構造だけでなく,内部リボソーム結合を使用して翻訳を開始することができます. このメカニズムは,キャップ依存経路が遮断されたときに,ウイルス感染中に細胞のmRNA翻訳を可能にします.
科学分野:
- 分子生物学は分子生物学である.
- ウイルス学 ウイルス学 ウイルス学
- 遺伝学 遺伝学とは
背景:
- ユカリオットmRNAの翻訳は,通常,キャップ依存スキャニングで開始されます.
- ピコルナウイルスのmRNAには5'キャップ構造がなく,内部リボソーム結合を利用する.
- セルラーmRNA翻訳は,キャップ依存抑制にもかかわらず,ポリオウイルス感染中に持続することができます.
研究 の 目的:
- eukaryotic mRNAsにおける代替翻訳開始メカニズムを調査する.
- 細胞のmRNAが内部リボソーム結合を利用できるかどうかを判断する.
主な方法:
- ポリオウイルスに感染した細胞における免疫グロブリン重鎖結合タンパク質mRNA翻訳の分析.
- 結合タンパク質mRNAの5'リーダー配列の機能的特徴.
主要な成果:
- 結合タンパク質mRNAは,ポリオウイルスに感染した細胞に翻訳されます.
- 結合タンパク質mRNAの5'リーダーは,内部リボソーム結合能力を授与する.
- これは,キャップ独立の翻訳開始経路を示しています.
結論:
- ユカリオットのmRNAは,内部リボソーム結合を利用して翻訳を開始することができます.
- このメカニズムは,ウイルス感染症中に細胞のmRNA翻訳のための手段を提供します.
- 内部リボソーム結合は,キャップ依存の翻訳開始の代替手段である.
関連する概念動画
Initiation of Translation
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
Regulated mRNA Transport
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing specific...
Leaky Scanning
During most eukaryotic translation processes, the small 40S ribosome subunit scans an mRNA from its 5' end until it encounters the first start AUG codon. The large 60S ribosomal subunit then joins the smaller one to initiate protein synthesis. The location of the translation initiation is largely determined by the nucleotides near the start codon as there may be multiple translation initiation sites present on the mRNA. Marilyn Kozak discovered that the sequence RCCAUGG (where R stands for...
Initiation of Translation
Initiating translation is complex because it involves multiple molecules. Initiator tRNA, ribosomal subunits, and eukaryotic initiation factors (eIFs) are all required to assemble on the initiation codon of mRNA. This process consists of several steps that are mediated by different eIFs.
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
First, the initiator tRNA must be selected from the pool of elongator tRNAs by eukaryotic initiation factor 2 (eIF2). The initiator tRNA (Met-tRNAi) has conserved sequence elements including modified bases at...
Regulated mRNA Transport
In eukaryotes, transcription and translation are compartmentalized; an mRNA is first synthesized in the nucleus and then selectively transported to the cytoplasm for protein synthesis. Before transport, a pre-mRNA undergoes several steps of post-transcriptional modifications including splicing, 5' capping, and the addition of a poly-adenine tail. Various proteins bind to the pre-mRNA during these modifications. The mRNA transport takes place with the help of multiple proteins playing specific...
Translation in Prokaryotes
Prokaryote translation is a complex, highly coordinated process that converts genetic information from mRNA into functional proteins. It involves three stages: initiation, elongation, and termination, each facilitated by specific molecular components.Initiation of TranslationThe process begins with the assembly of the ribosomal subunits and initiation factors on the mRNA. In bacteria, the 30S ribosomal subunit recognizes the Shine-Dalgarno sequence in the mRNA, a conserved region upstream of...

