Cost-Benefit Tradeoffs in Engineered lac Operons
Cost-Benefit Tradeoffs in Engineered lac Operons
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DOI：
10.1126/science.1219083
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发表时间：
2012-05-18
期刊：
影响因子：
56.9
通讯作者：
Kortemme, Tanja
中科院分区：
文献类型：
--
作者：
Eames, Matt;Kortemme, Tanja
细胞必须平衡蛋白质表达的成本和收益，以优化组织健康。大肠杆菌的乳胶操纵子一直是量化昂贵蛋白质生产的生理影响和阐明由此产生的调控机制的模型。我们报告了27个重新设计的操纵子的定量健身测量，这表明蛋白质生产不是健身成本的主要来源。相反，我们发现，与成本线性相关的紫胶渗透酶活性是细胞的主要生理负担。这些发现解释了乳胶操纵子中的控制点，这些控制点可以最大限度地降低乳胶渗透酶活性的成本，而不是蛋白质表达的成本。确定其他系统中类似关系的特征对于绘制成本/收益权衡对细胞生理和调节的影响将是重要的。
Cells must balance the cost and benefit of protein expression to optimize organismal fitness. The lac operon of the bacterium Escherichia coli has been a model for quantifying the physiological impact of costly protein production and for elucidating the resulting regulatory mechanisms. We report quantitative fitness measurements in 27 redesigned operons that suggested that protein production is not the primary origin of fitness costs. Instead, we discovered that the lac permease activity, which relates linearly to cost, is the major physiological burden to the cell. These findings explain control points in the lac operon that minimize the cost of lac permease activity, not protein expression. Characterizing similar relationships in other systems will be important to map the impact of cost/benefit tradeoffs on cell physiology and regulation.