Mutations in two global regulators lower individual mortality in Escherichia coli.
Mutations in two global regulators lower individual mortality in Escherichia coli.
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DOI：
10.1111/j.1365-2958.2007.05988.x
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发表时间：
2008-01
影响因子：
3.6
通讯作者：
Taddei F
中科院分区：
文献类型：
--
作者：
Fontaine F;Stewart EJ;Lindner AB;Taddei F
对细菌细胞在应激条件下的存活情况进行了大量的研究，但对在没有外源性应激的情况下死亡的原因知之甚少。在这样的群体中存在细胞死亡的基础频率可能反映出，要么不可能避免所有致命事件，要么成本太高。在这里，通过在模式生物大肠杆菌的遗传筛选，我们确定了两个突变体的死亡率较低的频率：rssB和fliA。有趣的是，这两个基因都影响细胞内不同sigma因子的水平。rssB突变体显示出对多种外部应激的增强的抗性，这可能表明细胞通过对自发的内源性应激的增强的抗性来获得其增加的活力。fliA的丧失不会导致应激抗性的提高;相反，它的存活显然是由于与鞭毛穿过膜的插入有关的物理应力降低以及通过马达蛋白的丧失节省的能量。这两个突变体的鉴定意味着降低死亡率不是不可能的;相反，由于其成本，它受到与其他有助于生物体竞争成功的性状的权衡。
There has been considerable investigation into the survival of bacterial cells under stress conditions, but little is known about the causes of mortality in the absence of exogenous stress. That there is a basal frequency of cell death in such populations may reflect that it is either impossible to avoid all lethal events, or alternatively, that it is too costly. Here, through a genetic screen in the model organism Escherichia coli, we identify two mutants with lower frequencies of mortality: rssB and fliA. Intriguingly, these two genes both affect the levels of different sigma factors within the cell. The rssB mutant displays enhanced resistance to multiple external stresses, possibly indicating that the cell gains its increased vitality through elevated resistance to spontaneous, endogenous stresses. The loss of fliA does not result in elevated stress resistance; rather, its survival is apparently due to a decreased physical stress linked to the insertion of the flagellum through the membrane and energy saved through the loss of the motor proteins. The identification of these two mutants implies that reducing mortality is not impossible; rather, due to its cost, it is subject to trade-offs with other traits that contribute to the competitive success of the organism.
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影响因子：
10.5
作者：
Jishage, M;Kvint, K;Nyström, T
通讯作者：
Nyström, T
DOI：
10.1073/pnas.120163297
发表时间：
2000-06-06
影响因子：
11.1
作者：
Datsenko, KA;Wanner, BL
通讯作者：
Wanner, BL
影响因子：
3.2
作者：
Jishage, M;Ishihama, A
通讯作者：
Ishihama, A
影响因子：
3.2
作者：
Ericsson, M;Hanstorp, D;Nyström, T
通讯作者：
Nyström, T
DOI：
10.1073/pnas.0334340100
发表时间：
2003-02-04
影响因子：
11.1
作者：
Cooper, TF;Rozen, DE;Lenski, RE
通讯作者：
Lenski, RE