ヒスティジンキナーゼの同類反応調節体によるアロステリック調節は,細胞の運命を決定する
Ralf Paul1, Tina Jaeger, Sören Abel
1Biozentrum, University of Basel, Klingelbergstrasse 70, 4056 Basel, Switzerland.
Cell
|May 6, 2008
まとめ
カオロバクター・クレサセントスのDivKタンパク質は,細菌の細胞運命を調節する. アロステル調節剤として作用し,2つの構成要素からなるシステム内のフィードバックループを通じて,リン酸化と局所化を制御します.
科学分野:
- 微生物学 微生物学とは
- バクテリアの生理学
- 細胞生物学 細胞生物学
背景:
- 2つのコンポーネントのシステムは,細菌の成長と生理学にとって不可欠です.
- 信号伝達経路が細菌細胞の運命を決定する.
- Caulobacter crescentusは,細胞の分化のために空間的組織を利用しています.
研究 の 目的:
- コロバクター・クレサセントスにおける信号伝達経路の可塑性と相互接続を調査する.
- 細菌の細胞運命を調節するDivKタンパク質の役割を明らかにする.
- 2つのコンポーネントのリン酸化ネットワーク内のフィードバックメカニズムを理解する.
主な方法:
- PleCフォスファタゼとDivJキナーゼの間の敵対的な活動に関する分析.
- DivKによるPleCとDivJにおけるアロステリック調節を調査する.
- 周期的なdi-GMP依存型形態遺伝プログラムの研究.
主要な成果:
- DivKはアロステル調節剤として作用し,PleCをフォスファターゼからオートキナーゼ状態に切り替えます.
- DivKは,周期的なdi-GMP依存の形態遺伝プログラムを媒介する.
- DivKは,DivJのアロステリック活性化を通じて,自身のリン酸化と極性局所化を刺激する.
結論:
- DivKは,バクテリアの非対称性と細胞運命を制御する統合回路の中心的な効果因子です.
- 空間的に組織されたフィードバックループは,C. crescentus.の細胞運命を決定するために不可欠です.
- 単一ドメインのレスポンスレギュレータは,2つのコンポーネントのネットワークでクロストークとフィードバックを容易にします.
関連する概念動画
Allosteric Regulation
Allosteric regulation of enzymes occurs when the binding of an effector molecule to a site that is different from the active site causes a change in the enzymatic activity. This alternate site is called an allosteric site, and an enzyme can contain more than one of these sites. Allosteric regulation can either be positive or negative, resulting in an increase or decrease in enzyme activity. Most enzymes that display allosteric regulation are metabolic enzymes involved in the degradation or...
Cooperative Allosteric Transitions
Cooperative allosteric transitions can occur in multimeric proteins, where each subunit of the protein has its own ligand-binding site. When a ligand binds to any of these subunits, it triggers a conformational change that affects the binding sites in the other subunits; this can change the affinity of the other sites for their respective ligands. The ability of the protein to change the shape of its binding site is attributed to the presence of a mix of flexible and stable segments in the...
Amplifying Signals via Enzymatic Cascade
When a ligand binds to a cell-surface receptor, the receptor's intracellular domain changes shape, which may either activate its enzyme function or allow its binding to other molecules. The initial signal is amplified by most signal transduction pathways. This means that a single ligand molecule can activate multiple molecules of a downstream target. Proteins that relay a signal are most commonly phosphorylated at one or more sites, activating or inactivating the protein. Kinases catalyze the...
Global 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...
Stringent 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...
Other 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...


