Single-cell time-lapse analysis of depletion of the universally conserved essential protein YgjD
Single-cell time-lapse analysis of depletion of the universally conserved essential protein YgjD
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DOI：
10.1186/1471-2180-11-118
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发表时间：
2011-05-27
期刊：
影响因子：
4.2
通讯作者：
Ackermann, Martin
中科院分区：
文献类型：
--
作者：
Bergmiller, Tobias;Pena-Miller, Rafael;Ackermann, Martin
背景：大肠杆菌必需基因 ygjD 属于一组普遍保守的基因，其功能一直是最近许多研究的焦点。在这里，我们将 ygjD 置于诱导型启动子的控制下，并使用延时显微镜和单细胞分析来研究生长细胞中 YgjD 蛋白耗尽的表型后果。 结果：我们表明，YgjD 的缺失会导致细胞大小显着减小和细胞分裂终止。向较小尺寸的转变以受控方式发生：细胞伸长和细胞分裂保持耦合，但分裂时的细胞尺寸减小。我们还发现证据表明，YgjD 的消耗会导致细胞内信号分子 (p) ppGpp 的合成，从而诱导类似于严格反应的细胞反应。同时删除 relA 和 spoT 基因 - 导致菌株无法合成 (p) ppGpp，会消除细胞大小的减小，但不会阻止 YgjD 耗尽后细胞分裂的终止。结论：生长细胞中 YgjD 蛋白的耗尽会导致细胞大小减小，这取决于 (p) ppGpp，并导致细胞分裂终止。单细胞延时显微镜和统计分析的结合可以详细了解必需基因丢失的表型后果，因此可以作为研究必需基因功能的新工具。
Background: The essential Escherichia coli gene ygjD belongs to a universally conserved group of genes whose function has been the focus of a number of recent studies. Here, we put ygjD under control of an inducible promoter, and used time-lapse microscopy and single cell analysis to investigate the phenotypic consequences of the depletion of YgjD protein from growing cells.Results: We show that loss of YgjD leads to a marked decrease in cell size and termination of cell division. The transition towards smaller size occurs in a controlled manner: cell elongation and cell division remain coupled, but cell size at division decreases. We also find evidence that depletion of YgjD leads to the synthesis of the intracellular signaling molecule (p) ppGpp, inducing a cellular reaction resembling the stringent response. Concomitant deletion of the relA and spoT genes - leading to a strain that is uncapable of synthesizing (p) ppGpp abrogates the decrease in cell size, but does not prevent termination of cell division upon YgjD depletion.Conclusions: Depletion of YgjD protein from growing cells leads to a decrease in cell size that is contingent on (p) ppGpp, and to a termination of cell division. The combination of single-cell time-lapse microscopy and statistical analysis can give detailed insights into the phenotypic consequences of the loss of essential genes, and can thus serve as a new tool to study the function of essential genes.