A Quality-Control Mechanism Removes Unfit Cells from a Population of Sporulating Bacteria.
A Quality-Control Mechanism Removes Unfit Cells from a Population of Sporulating Bacteria.
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DOI：
10.1016/j.devcel.2015.08.009
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发表时间：
2015-09-28
影响因子：
11.8
通讯作者：
Ramamurthi KS
中科院分区：
文献类型：
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作者：
Tan IS;Weiss CA;Popham DL;Ramamurthi KS
最近在细菌中发现了受调控的细胞死亡，这引发了人们的猜测，即类似凋亡的途径可能会赋予单细胞生物体以好处。然而，确定这些途径如何提供更好的生态适宜性仍然很难确定。在这里，我们报道了枯草芽孢杆菌的一条途径，在该途径中，受调控的细胞死亡通过选择性地移除错误组装孢子膜的细胞来维持产孢量的保真度。保护休眠孢子基因组免受环境侮辱的孢子囊，使用蛋白质SpoIVA作为组装的支架。我们发现，破坏被膜组装激活了一条细胞死亡途径，其中小蛋白CMPA作为AAA+ClpXP蛋白酶的适配器来降解SpoIVA，从而停止产孢子，导致有缺陷的产孢细胞的裂解。我们认为，从终末分化细胞群体中移除不适合的细胞可以防止孢子形成程序的进化恶化，并最终丧失。
Recent discoveries of regulated cell death in bacteria have led to speculation about possible benefits that apoptosis-like pathways may confer to single-celled organisms. However, establishing how these pathways provide increased ecological fitness has remained difficult to determine. Here, we report a pathway in Bacillus subtilis in which regulated cell death maintains the fidelity of sporulation through selective removal of cells that misassemble the spore envelope. The spore envelope, which protects the dormant spore’s genome from environmental insults, uses the protein SpoIVA as a scaffold for assembly. We found that disrupting envelope assembly activates a cell death pathway wherein the small protein CmpA acts as an adaptor to the AAA+ ClpXP protease to degrade SpoIVA, thereby halting sporulation and resulting in lysis of defective sporulating cells. We propose that removal of unfit cells from a population of terminally differentiating cells protects against evolutionary deterioration, and ultimately loss, of the sporulation program.