単細胞レベルでの代謝と成長のストキャスティシティ
Daniel J Kiviet1, Philippe Nghe2, Noreen Walker3
11] FOM institute AMOLF, Science Park 104, 1098 XG Amsterdam, the Netherlands [2] Department of Environmental Systems Science, ETH Zurich, Universitaetsstrasse 16, 8092 Zurich, Switzerland [3] Department of Environmental Microbiology, Eawag, Ueberlandstrasse 133, 8600 Duebendorf, Switzerland [4].
Nature
|September 5, 2014
まとめ
代謝酵素における分子騒音は,細胞成長の変動を誘発し,常時代謝の仮定に異議を唱える. このストキャスティシティは,細胞間多様性の主要な源である.
科学分野:
- 細胞生物学 細胞生物学
- システム生物学 システム生物学
- バイオフィジックス 生物物理学
背景:
- 細胞の成長と増殖は,分子ストキャスティシティによって影響を受けます.
- 代謝反応のイベントは,典型的には成長への影響を最小限に抑え,平均すると仮定されます.
- 安定調節メカニズムと細胞バッファリングシステムは,分子変動を抑制すると考えられている.
研究 の 目的:
- 細胞成長における代謝酵素発現における分子ストキャスティシティの役割を調査する.
- 酵素発現の変動,代謝活動,細胞成長の相互作用を定量化するために.
- 携帯電話システムにおける騒音の拡散と消去のメカニズムを理解する.
主な方法:
- タイムラップス顕微鏡を用いて,Escherichia coliの個々の細胞をモニターする.
- 単細胞における瞬時の成長率の変動を測定する.
- 遺伝子/酵素発現と成長率の間の時間解決のクロス相関を定量化する.
主要な成果:
- 代謝活性酵素発現の変動は,直接伝播し,成長率の変動を引き起こします.
- 成長への酵素発現ノイズ伝達は,酵素の制限に依存しています.
- 細胞成長率の変動はフィードバックを与え,酵素発現に影響を与える.
- 酵素は,細胞の成長経由で他の遺伝子へのノイズ伝達のための経路として機能します.
- 細胞容量の膨張によってタンパク質の希釈を伴うノイズキャンセリングメカニズムが特定されました.
結論:
- 分子騒音は,単なる調節タンパク質ではなく,代謝反応によって伝播される.
- 細胞代謝は本質的にストキャスティックであり,現象型異質性に大きく貢献します.
- 騒音伝播の理解は,細胞の安定性と現象型の変化を理解するために重要です.
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