バクテリアの遺伝子発現に対する成長率に依存する全体的な効果
Stefan Klumpp1, Zhongge Zhang, Terence Hwa
1Center for Theoretical Biological Physics, University of California, San Diego, La Jolla, CA 92093-0374, USA. klumpp@ctbp.ucsd.edu
Cell
|January 13, 2010
まとめ
細菌の成長率は,RNAポリメラーゼやリボソームなどの細胞成分の変化により,遺伝子発現に大きく影響します. この研究はこれらの効果をモデル化し,抗生物質耐性や細胞成長に影響を与えるフィードバックメカニズムを明らかにしています.
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
- 合成生物学 合成生物学とは
背景:
- 細菌の遺伝子発現は,特定の規制ネットワークとグローバルな細胞パラメータの両方によって影響を受けます.
- RNAポリメラーゼとリボソームを含む重要な細胞成分は,成長率に依存する豊富さを示し,全体的な遺伝子発現に影響します.
- これらのグローバル効果の定量的な理解は,遺伝子調節の研究と合成回路設計において極めて重要です.
研究 の 目的:
- 細菌の成長率が遺伝子発現に与える影響をモデル化し,実験的に検証する.
- 規制要素を持つ合成遺伝回路における複雑な成長依存性を分析する.
- タンパク質発現,細胞成長,および生理学的機能を結びつける潜在的なフィードバックメカニズムを調査する.
主な方法:
- 測定された成長率に依存する細胞パラメータを組み込む定量モデルの開発.
- 活性化器,抑制器,フィードバックループを備えた合成遺伝子回路を用いた実験的検証.
- 一般的な成長効果によって媒介される新しいフィードバックメカニズムの分析.
主要な成果:
- 単純なモデルは,構成遺伝子発現の成長率依存を正確に説明します.
- 合成回路における複雑な成長依存性は,実験的に分析され,検証されました.
- 明らかな遺伝子調節とは独立した成長フィードバックメカニズムが,細胞の行動に影響を与える可能性があるという証拠がある.
結論:
- 細菌の成長率は遺伝子発現の根本的な決定因子であり,細胞パラメータモデリングで予測できます.
- 合成回路は,複雑で成長に依存する行動を示し,それを設計し理解することができます.
- 一般的な成長フィードバックメカニズムは,抗生物質耐性や持続性などの重要な生理学的適応の基礎となる可能性があります.
関連する概念動画
02:05Gene Evolution - Fast or Slow?
6.2K
The genomes of eukaryotes are punctuated by long stretches of sequence which do not code for proteins or RNAs. Although some of these regions do contain crucial regulatory sequences, the vast majority of this DNA serves no known function. Typically, these regions of the genome are the ones in which the fastest change, in evolutionary terms, is observed, because there is typically little to no selection pressure acting on these regions to preserve their sequences.
In contrast, regions which code...
In contrast, regions which code...
6.2K
01:29Coordination of Gene Expression Processes in Bacteria
1.1K
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...
1.1K
01:27Constitutive and Regulated Gene Expression
1.9K
Gene expression in prokaryotes is governed by constitutive and regulated systems, allowing cells to balance the production of essential proteins with adaptive responses to environmental changes.Constitutive Gene ExpressionConstitutive, or housekeeping, genes are continuously expressed as they encode proteins vital for fundamental cellular processes. These include enzymes for glycolysis, ribosomal components for protein synthesis, and proteins involved in DNA replication. Their constant...
1.9K
01:28Global Regulatory Systems
965
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...
965
01:23Stringent Response in E. coli
533
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...
533
01:29Exponential Growth
287
Bacterial populations exhibit exponential growth when conditions such as nutrient availability and temperature are favorable. In this phase, cells reproduce through binary fission, where each cell divides into two identical daughter cells. This process causes the population to double at regular intervals, resulting in a growth rate that is directly proportional to the current number of cells. As the population increases, the number of new cells formed during each generation also grows, creating...
287