Engulfment during sporulation in Bacillus subtilis is governed by a multi-protein complex containing tandemly acting autolysins
Engulfment during sporulation in Bacillus subtilis is governed by a multi-protein complex containing tandemly acting autolysins
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DOI：
10.1111/j.1365-2958.2007.05652.x
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发表时间：
2007-04-01
影响因子：
3.6
通讯作者：
Losick, Richard
中科院分区：
文献类型：
--
作者：
Chastanet, Arnaud;Losick, Richard
在枯草芽孢杆菌中，生长细胞转化为内生孢子涉及一个吞噬样过程，其中发育中的孢子（前孢子）被相邻的母细胞完全吞噬。吞噬的先决条件是从分隔前孢子和母细胞的隔膜中去除肽聚糖，这一过程依赖于自溶素SpoIID和两种功能未知的蛋白质SpoIIM和SpoIIP。在这里，我们提出的证据表明，SpoIIP也是一种自溶素，它与SpoIID串联作用，并且所有三种蛋白质都相互复合。我们进一步表明，该复合物的成员表现出一种层次关系，其中SpoIIM负责定位到隔膜，SpoIIP通过与SpoIIM相互作用定位到隔膜，而SpoIID反过来又通过与SpoIIP相互作用定位。最后，我们表明SpoIIM的定位依赖于第四种蛋白SpoIIB，提高了复合体包含额外组件的可能性，并创建了形式为SpoIIB-> SpoIIM-> SpoIIP-> SpoIID的总体层次结构。
The conversion of a growing cell into an endospore in Bacillus subtilis involves a phagocytic-like process in which the developing spore (the forespore) is wholly engulfed by the adjacent mother cell. A prerequisite for engulfment is the removal of peptidoglycan from the septum that separates the forespore from the mother cell, a process that depends on the autolysin SpoIID and two proteins of unknown function, SpoIIM and SpoIIP. Here we present evidence that SpoIIP is also an autolysin, that it acts in tandem with SpoIID, and that all three proteins are in a complex with each other. We further show that the members of the complex exhibit a hierarchical relationship in which SpoIIM is responsible for localization to the septal membrane, SpoIIP localizes to the septal membrane by interacting with SpoIIM, and SpoIID, in turn, localizes by interacting with SpoIIP Finally, we show that localization of SpoIIM depends on a fourth protein SpoIIB, raising the possibility that the complex contains an additional component and creating an overall hierarchy of the form: SpoIIB -> SpoIIM -> SpoIIP -> SpoIID.