Interaction of bacterial actin-like proteins with the cell membrane

许多原核细胞含有肌动蛋白的同源物，称为MreB，它与肌动蛋白有许多保守的性质，对于许多细菌的细胞形状保持和生存是必不可少的。我们发现它和它的两个同源基因MBL和MreBH一起定位于细胞膜下的动态螺旋丝。MreB和MBL与参与细胞形状维持的两种膜蛋白MreC和RodA相互作用，也与胞浆蛋白相互作用，其中许多蛋白具有酶功能。MreB还沿着螺旋轨道与翻译因子EF-Tu相互作用，EF-Tu对维持细胞形状也很重要，表明EF-Tu在细菌细胞中具有双重作用。EF-Tu显示出与MreB相似的相互作用光谱，表明两种蛋白质都在细菌细胞膜下建立了相互作用网络。在FOR中，我们将为这个网络寻找进一步的证据，并将调查它在细菌生理学中的作用。我们还将详细研究MreB和MBL如何指导膜蛋白的定位，RodA就是这样的情况，我们已经开始研究其在细胞形态中的功能，并希望通过确定其3D结构等来继续阐明。我们还将研究膜蛋白RODZ的功能，它以一种未知的方式影响许多细菌的细胞形状。

Many prokaryotic cells contain a homolog of actin, called MreB, which shares many conserved properties with actin, and is essential for cell shape maintenance and viability in many bacteria. We have found that it localizes as dynamic helical filaments underneath the cell membrane, together with its two paralogs, Mbl and MreBH. MreB and Mbl interact with two membrane proteins, MreC and RodA, involved in cell shape maintenance, as well as with cytosolic proteins, many of which have an enzymatic function. MreB also interacts with translation factor EF-Tu along the helical tracks, and EF-Tu is also important for cell shape maintenance, showing that EF-Tu serves a dual role in a bacterial cell. EF-Tu shows a similar spectrum of interactions as MreB, suggesting that both proteins set up an interaction network underneath the bacterial cell membrane. Within the FOR, we will search for further evidence for this network and will investigate its role in bacterial physiology. We will also study in detail how MreB and Mbl direct the positioning of membrane proteins, which is the case for RodA, whose function in cell morphology we have begun to study and want to continue to elucidate, amongst others by determining its 3D structure. We will also study the function of membrane protein RodZ, which affects cell shape in an unknown manner in many bacteria.