循環化とリボソームリサイクル:ポリソームトポロジーから翻訳制御へ
Zhanna A Afonina1, Konstantin S Vassilenko1
1Institute of Protein Research, Russian Academy of Sciences, 142290 Pushchino, Russia.
International journal of molecular sciences
|February 13, 2026
まとめ
ユカリオットのメッセンジャーRNAは,円形のポリソームを形成し,クローズド・ループ・アシスト・リイニシエーション (CLAR) によるタンパク質合成を強化する. このダイナミックな構造は,細胞の条件に応じて線形的な配置で変換効率をバランスさせます.
科学分野:
- 分子生物学は分子生物学である.
- 細胞生物学 細胞生物学
- バイオケミストリー バイオケミストリー
背景:
- ユカリオットメッセンジャーRNA (mRNA) は複数のリボソームによって翻訳され,ポリソームを形成する.
- ポリソームは,閉ループモデルで提案されているように,円形の配列を含む多様なトポロジーを表しています.
- 閉ループモデルは,mRNA端末の空間的近接がリボソームのリサイクルを促進することを示唆しています.
研究 の 目的:
- ポリソームの構造的構成を調査する.
- mRNAの循環とリボソームのリサイクルに関するメカニズム的な洞察を提供するために.
- 翻訳制御におけるmRNAトポロジーの役割を理解する.
主な方法:
- バイオケミカルアッセイ
- 構造生物学技術 (電子顕微鏡,原子力顕微鏡,冷凍電子断層撮影)
- シングル分子光成像技術
- リボソームターンオーバー実験
- 運動分析とコンピューティングモデリング.
主要な成果:
- ポリソームは,コンパクトで異質な形状を採用します.
- 円形のポリソーム集合は,観測された構造の有意な部分を占めています.
- 有効なリボソームリサイクルのための閉ループアシストリイニシエーション (CLAR) を支持する証拠があります.
- mRNAの循環化は,特定の条件下でタンパク質合成を強化する動的,制御された状態です.
結論:
- mRNAの循環は,タンパク質合成の効率に影響を与える重要な規制メカニズムです.
- 円形と線形を含むポリソームアーキテクチャは,トランスレーション制御を動的にバランスさせます.
- mRNAトポロジー,リボソーム動態,および翻訳の相互作用を理解するためにさらなる研究が必要です.
関連する概念動画
01:27Ribosomes
77.7K
Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that synthesize large quantities of protein—such as secretory cells in the human pancreas—can contain millions of ribosomes.
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome...
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome...
77.7K
01:27Ribosomes
11.1K
Ribosomes translate genetic information encoded by messenger RNA (mRNA) into proteins. Both prokaryotic and eukaryotic cells have ribosomes. Cells that synthesize large quantities of protein—such as secretory cells in the human pancreas—can contain millions of ribosomes.
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome...
Ribosome Structure and Assembly
Ribosomes are composed of ribosomal RNA (rRNA) and proteins. In eukaryotes, rRNA is transcribed from genes in the nucleolus—a part of the nucleus that specializes in ribosome...
11.1K
01:31Translation
157.3K
Lesson: Translation
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of...
Translation is the process of synthesizing proteins from the genetic information carried by messenger RNA (mRNA). Following transcription, it constitutes the final step in the expression of genes. This process is carried out by ribosomes, complexes of protein and specialized RNA molecules. Ribosomes, transfer RNA (tRNA), and other proteins produce a chain of amino acids—the polypeptide—as the end product of translation.
Translation Produces the Building Blocks of...
157.3K
02:33Initiation of Translation
39.2K
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...
39.2K
01:44Termination of Translation
27.9K
The large ribosomal subunit has several important structures essential to translation. These include the peptidyl transferase center (PTC) - which is the site where the peptide bond is formed - and a large, internal, water-filled tube through which the nascent polypeptide moves. This latter structure is called the Peptide Exit Tunnel, and it begins at the PTC and spans the body of the large ribosomal subunit. During translation, as the nascent polypeptide chain is synthesized, it passes through...
27.9K
02:53Ribosomal RNA Synthesis
14.9K
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,...
14.9K