Asymmetric division triggers cell-specific gene expression through coupled capture and stabilization of a phosphatase
Asymmetric division triggers cell-specific gene expression through coupled capture and stabilization of a phosphatase
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DOI：
10.7554/elife.08145
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发表时间：
2015-10-14
期刊：
影响因子：
7.7
通讯作者：
Losick, Richard
中科院分区：
文献类型：
--
作者：
Bradshaw, Niels;Losick, Richard
在枯草芽孢杆菌的孢子形成过程中，在随机选择的极附近形成分裂隔膜，从而产生具有不同基因表达程序的大小不等的子细胞。一个悬而未决的问题是极性分隔如何选择性地激活小细胞中的转录因子 (sigma(F))。我们提供的证据表明，sigma(F) 的上游调节剂磷酸酶 SpoIIE 通过从极隔膜转移到相邻的细胞极而在小细胞中区室化，其中 SpoIIE 受到保护免于蛋白水解并被激活。极性识别、防止蛋白水解和刺激磷酸酶活性与 SpoIIE 寡聚化有关。这种启动细胞特异性基因表达的机制不依赖于额外的孢子形成蛋白。营养细胞被设计为在极隔离 SpoIIE 附近分裂并激活小细胞中的 sigma(F)。因此，一个简单的模型解释了 SpoIIE 如何响应随机生成的提示，以在正确的时间和正确的位置激活 sigma(F)。
Formation of a division septum near a randomly chosen pole during sporulation in Bacillus subtilis creates unequal sized daughter cells with dissimilar programs of gene expression. An unanswered question is how polar septation activates a transcription factor (sigma(F)) selectively in the small cell. We present evidence that the upstream regulator of sigma(F), the phosphatase SpoIIE, is compartmentalized in the small cell by transfer from the polar septum to the adjacent cell pole where SpoIIE is protected from proteolysis and activated. Polar recognition, protection from proteolysis, and stimulation of phosphatase activity are linked to oligomerization of SpoIIE. This mechanism for initiating cell-specific gene expression is independent of additional sporulation proteins; vegetative cells engineered to divide near a pole sequester SpoIIE and activate sigma(F) in small cells. Thus, a simple model explains how SpoIIE responds to a stochastically-generated cue to activate sigma(F) at the right time and in the right place.