ネイブリンパ球におけるプロモーター溶解のグローバル規制
Fedor Kouzine1, Damian Wojtowicz, Arito Yamane
1Laboratory of Pathology, Center for Cancer Research, NCI, National Institutes of Health, Bethesda, MD 20892, USA.
Cell
|May 28, 2013
まとめ
ネイブリンパ球は,迅速な免疫反応を起こすために準備されています. 新たに特定された規制ステップであるプロモーター溶解は,メッセンジャーRNAの合成を制御し,病原体に迅速な反応を保証します.
科学分野:
- 分子生物学は分子生物学である.
- 免疫学 免疫学とは
- 遺伝学 遺伝学とは
背景:
- リンパ球の活性化には,伝達 RNA の合成が著しく増加し,免疫反応の形成に不可欠です.
- 免疫活性化中にトランスクリプトームを増幅する正確なメカニズムは,ほとんど解明されていないままです.
- 現存する知識は,プレイニシテーション・コンプレックス・アセンブリとポリメラーゼ・パウジングを重要なエウカリオット遺伝子発現の調節因子として特定している.
研究 の 目的:
- ネイヴリンパ球におけるトランスクリプトーム増幅を駆動するメカニズムを調査する.
- 免疫活性化の初期段階において,グローバルな遺伝子発現を制御する新たな規制ステップを特定する.
- 休息しているリンパ球が,病原菌と接触すると,迅速に活性化する準備ができていることを理解する.
主な方法:
- ネイブリンパ球における単一鎖DNAの全ゲノム監視.
- G0相におけるプロモーター結合RNAポリメラーゼの状態 (負荷が加えられたが溶けていない) の分析.
- 流産性の転写延長から生産性の転写延長への移行の運動学的評価.
- XPBおよびXPDヘリケーズを含む転写因子IIH複合体の発現の評価.
主要な成果:
- ネイブリンパ球のゲノムは急速な活性化に備わっており,循環リンパ球遺伝子のプロモーターの約90%がポリメラーゼに負荷されているが,溶かっていない.
- 流産性の延長から生産性の延長への移行は,運動的に制限されるステップであり,転写開始部位の近くのポリメラーゼの蓄積につながる.
- 休息しているリンパ球は,転写因子IIHの成分の制限された発現を示し,プロモーターの溶解とオープンコンプレックス形成に影響を与えます.
結論:
- プロモーターの溶解は,ユカリオットのグローバル遺伝子発現を制御する第3の重要な規制ステップとして特定されています.
- この調節メカニズムは,リンパ球が侵入した病原体に迅速かつ効果的に反応する準備ができていることを保証します.
- この発見は,免疫細胞の準備と応答の開始の分子基礎に関する新しい洞察を提供します.
関連する概念動画
The Eukaryotic Promoter Region
The eukaryotic promoter region is a segment of DNA located upstream of a gene. It contains an RNA polymerase binding site, a transcription start site, and several cis-regulatory sequences. The proximal promoter region is located in the vicinity of the gene and has cis-regulatory sequences and the core promoter. The core promoter is the binding site for RNA polymerase and is usually located between -35 and +35 nucleotides from the transcription start site. The distal promoter regions are...
The Eukaryotic Promoter Region
The eukaryotic promoter region is a segment of DNA located upstream of a gene. It contains an RNA polymerase binding site, a transcription start site, and several cis-regulatory sequences. The proximal promoter region is located in the vicinity of the gene and has cis-regulatory sequences and the core promoter. The core promoter is the binding site for RNA polymerase and is usually located between -35 and +35 nucleotides from the transcription start site. The distal promoter regions are...
Master Transcription Regulators
Master transcription regulators are regulatory proteins that are predominantly responsible for regulating the expression of multiple genes. Often these genes work in concert to drive a complex process. Activation of a master transcription regulator can lead to a cascade of transcriptional activation necessary for that outcome. These regulators can directly bind to the regulatory sequences of the various genes involved, or they can indirectly regulate transcription by binding to regulatory...
RNA Polymerase II Accessory Proteins
Proteins that regulate transcription can do so either via direct contact with RNA Polymerase or through indirect interactions facilitated by adaptors, mediators, histone-modifying proteins, and nucleosome remodelers. Direct interactions to activate transcription is seen in bacteria as well as in some eukaryotic genes. In these cases, upstream activation sequences are adjacent to the promoters, and the activator proteins interact directly with the transcriptional machinery. For example, in...
Cooperative Binding of Transcription Regulators
Transcriptional regulators bind to specific cis-regulatory sequences in the DNA to regulate gene transcription. These cis-regulatory sequences are very short, usually less than ten nucleotide pairs in length. The short length means that there is a high probability of the exact same sequence randomly occurring throughout the genome. Since regulators can also bind to groups of similar sequences, this further increases the chances of random binding. Transcriptional regulators form dimers that...
Regulation of Expression at Multiple Steps
The gene expression in cells is regulated at different stages: (i) transcription, (ii) RNA processing, (iii) RNA localization, and (iv) translation. Transcriptional regulation is mediated by regulatory proteins such as transcription factors, activators, or repressors—these control gene expression by initiating or inhibiting the transcription of genes. Once a precursor or pre-mRNA is produced, it undergoes post-transcriptional modification, including 5' capping, splicing, and the addition of a...


