細菌のストレス反応におけるストキャスティックパルス調節
James C W Locke1, Jonathan W Young, Michelle Fontes
1Howard Hughes Medical Institute, Division of Biology and Bioengineering, Broad Center, California Institute of Technology, 1200 East California Boulevard, Pasadena, CA 91125, USA.
Science (New York, N.Y.)
|October 8, 2011
まとめ
バシルス・サブティリスは,ストキャスティックパルスを使って,エネルギーストレスをシグナルします. この遺伝子調節メカニズムは,超敏感なスイッチ,細胞のノイズ,精密なストレス反応のためのフィードバックループに依存しています.
科学分野:
- 微生物学 微生物学とは
- システム生物学 システム生物学
- 分子生物学は分子生物学である.
背景:
- 遺伝子調節回路は,環境適応のためのダイナミックでストキャスティックな戦略を採用しています.
- プロカリオットの一般的なストレス反応は,不利な条件下での生存に不可欠です.
研究 の 目的:
- 単一のバチルス・サブティリス細胞におけるシグマB (σ(B)) によって媒介される一般的なストレス反応の活性化ダイナミクスを調査する.
- ストキャスティックストレス応答シグナリングの基礎となる分子メカニズムを解明する.
主な方法:
- エネルギーストレスの下でのバチルス・サブティリスの単細胞分析.
- 内部 σ (B) 調節回路の混乱と再配線.
- サーキットダイナミクスを理解するための数学的モデリング.
主要な成果:
- エネルギーストレスは,離散的でストキャスティックなパルスで σ (((B) の活性化を誘発します.
- ストレスレベルの増加は,より高いパルス周波数と相関しています.
- σ(B) 回路は,超敏感なリン酸化スイッチ,ストキャスティックノイズ,および混合転写フィードバックを備えています.
結論:
- プロカリオットは,信号エンコーディングのためにストカスティックパルス周波数調節を使用します.
- コンパクトな規制アーキテクチャにより,バチルス・サブティリスのダイナミックなストレス反応が可能になります.
- 超敏感性,ノイズ,フィードバックの相互作用がパルス発生と終了を駆動する.
関連する概念動画
01:30Other Stress Responses in Bacteria
Bacteria have global regulatory systems that control several types of stress mechanisms. These include Pho regulon and the heat shock response, which are essential systems for environmental adaptation, such as nutrient limitation and proteotoxic stress. The Pho regulon and the heat shock response exemplify bacterial resilience, enabling rapid adaptation to fluctuating environmental conditions.Pho RegulonBacteria require phosphorus for essential cellular processes, including nucleic acid...
01:23Stringent Response in E. coli
Bacterial growth is closely tied to nutrient availability, with cells proliferating exponentially under favorable conditions and entering a stationary phase when resources become scarce. This transition is mediated by a regulatory mechanism known as the stringent response, which allows bacteria to adapt to nutrient deprivation by modulating gene expression and metabolic activity.During nutrient scarcity, intracellular amino acid levels decline. It results in the accumulation of uncharged tRNAs...
01:28Global Regulatory Systems
Global regulatory systems in bacteria enable rapid and coordinated responses to environmental changes by integrating sensory inputs with gene expression, ensuring efficient adaptation to fluctuating conditions. Key global regulatory mechanisms include regulons, two-component systems, sigma factors, and secondary messengers.Regulons and Global RegulatorsA regulon is a collection of genes and operons controlled by a common global regulator. These regulators enable bacteria to prioritize resource...
01:28Regulation of Bacterial Virulence
Pathogenic bacteria employ a range of regulatory mechanisms to modulate the expression of virulence genes in response to environmental and host-derived signals. These mechanisms ensure that virulence factors are expressed only under favorable conditions, thereby optimizing infection and survival strategies.Mechanisms of Virulence RegulationKey regulatory strategies include:Two-Component Systems: These consist of a membrane-bound sensor kinase and a cytoplasmic response regulator. Environmental...
01:29Translational Regulation
Translational regulation in prokaryotes ensures efficient protein synthesis by controlling ribosome access to mRNA. This regulation is mediated by secondary RNA structures, including translational riboswitches, RNA thermometers, and small RNAs (sRNAs), which respond to intracellular and environmental signals to modulate gene expression.Translational RiboswitchesRiboswitches in the leader region of mRNAs can regulate translation by altering the accessibility of the Shine-Dalgarno (SD) sequence,...
01:29Coordination of Gene Expression Processes in Bacteria
The DNA replication, transcription, and translation processes are intricately coupled in bacteria, allowing efficient gene expression and rapid protein synthesis. While this physical and functional coordination is advantageous, it introduces challenges that bacteria overcome through specific regulatory mechanisms.Coupling of Replication, Transcription, and TranslationThe coupling of replication, transcription, and translation is a hallmark of bacterial gene expression. As the replisome unwinds...