Division site selection in Bacillus subtilis: Structure and function of the novel component MinJ

在杆状细菌中，分隔的位置通常被精确地发现。在大肠杆菌和枯草芽孢杆菌中，有两个抑制系统与分裂位点选择有关，即类核封闭系统和Min系统。在B。在枯草芽孢杆菌中，Min系统应该由三种蛋白质DivIVA、MinD和MinC组成。MinCD是胞质分裂的实际抑制复合物，而DivIVA对MinCD施加拓扑控制。我们和其他人最近发现了一个B的新成员。subtilis Min系统，MinJ.令人惊讶的是，MinJ是一个连接DivIVA和MinD的实际适配器。我们发现MinCDJ系统不仅在FtsZ抑制水平上控制胞质分裂，而且在膜整合分裂蛋白水平上控制胞质分裂。在这一建议中，我想谈五个要点，这将有助于理解B的职能。subtilis Min系统的详细信息。i）我们将绘制MinJ与DivIVA、MinD以及与膜整合分裂蛋白的相互作用位点。（2）我们想获得MinJ的结构信息。iii）我们将研究MinCD对分裂体膜蛋白的确切影响iv）我们将采用新开发的筛选技术来回答这个过程中是否存在迄今未鉴定的伴侣的问题。v）我们希望发现在B的孢子形成期间如何克服MinCD的抑制功能。枯草芽孢杆菌，虽然Min系统在这些条件下仍然活跃。

In rod-shaped bacteria the site of septation is usually found with exquisite precision. In Escherichia coli and Bacillus subtilis two inhibitory systems have been connected with division site selection, the nucleoid occlusion system and the Min system. In B. subtilis the Min system was supposed to consist out of three proteins, DivIVA, MinD, and MinC. MinCD is the actual inhibitory complex of cytokinesis, while DivIVA imposes topological control on MinCD. We and others recently identified a new member of the B. subtilis Min system, MinJ. It came as a surprise to learn that MinJ is an actual adapter that bridges DivIVA and MinD. We have found that the role of the MinCDJ system controls cytokinesis not only at the level of FtsZ inhibition, but also at the level of membrane integral division proteins. In this proposal I wish to address five major points that will help to understand the function of the B. subtilis Min system in more detail. i) We will map the interactions sites that MinJ has with DivIVA, MinD, and with the membrane integral division proteins. ii) We want to obtain structural information of MinJ. iii) We will investigate what the exact effect of MinCD on the membrane proteins of the divisome is iv) We will employ newly developed screening techniques to answer the question whether there are hitherto unidentified partners in this process. v) We wish to find out how the inhibitory function of MinCD is overcome during sporulation of B. subtilis, although the Min system is still active under these conditions.