Institute for General Microbiology, Christian-Albrechts-University Kiel, Kiel, Germany.
Arnold-Sommerfeld-Center for Theoretical Physics and Center for NanoScience, Ludwig-Maximilians-Universität München, Munich, Germany.
mBio. 2021 Apr 13;12(2):e00296-21. doi: 10.1128/mBio.00296-21.
Division site selection is a vital process to ensure generation of viable offspring. In many rod-shaped bacteria, a dynamic protein system, termed the Min system, acts as a central regulator of division site placement. The Min system is best studied in where it shows a remarkable oscillation from pole to pole with a time-averaged density minimum at midcell. Several components of the Min system are conserved in the Gram-positive model organism However, in it is commonly believed that the system forms a stationary bipolar gradient from the cell poles to midcell. Here, we show that the Min system of localizes dynamically to active sites of division, often organized in clusters. We provide physical modeling using measured diffusion constants that describe the observed enrichment of the Min system at the septum. Mathematical modeling suggests that the observed localization pattern of Min proteins corresponds to a dynamic equilibrium state. Our data provide evidence for the importance of ongoing septation for the Min dynamics, consistent with a major role of the Min system in controlling active division sites but not cell pole areas. The molecular mechanisms that help to place the division septum in bacteria is of fundamental importance to ensure cell proliferation and maintenance of cell shape and size. The Min protein system, found in many rod-shaped bacteria, is thought to play a major role in division site selection. It was assumed that there are strong differences in the functioning and in the dynamics of the Min system in and Most previous attempts to address Min protein dynamics in have been hampered by the use of overexpression constructs. Here, functional fusions to Min proteins have been constructed by allelic exchange and state-of-the-art imaging techniques allowed to unravel an unexpected fast dynamic behavior of the Min system. Our data show that the molecular mechanisms leading to Min protein dynamics are not fundamentally different in and .
分裂位点选择对于确保产生可行的后代至关重要。在许多杆状细菌中，一个动态的蛋白质系统，称为 Min 系统，作为分裂位点放置的中央调节剂。Min 系统在 中得到了最好的研究，它在极到极之间表现出显著的振荡，在细胞中部有一个平均时间密度最小的区域。Min 系统的几个组成部分在革兰氏阳性模式生物 中得到了保守。然而，在 中，通常认为该系统从细胞极到细胞中部形成一个固定的双极梯度。在这里，我们展示了 Min 系统在分裂的活跃位点动态定位，通常组织成簇。我们使用测量的扩散常数进行物理建模，这些常数描述了 Min 系统在隔膜处的富集情况。数学模型表明，观察到的 Min 蛋白定位模式对应于一个动态平衡状态。我们的数据为 Min 动力学与正在进行的隔膜分离之间的重要性提供了证据，这与 Min 系统在控制活跃分裂位点而不是细胞极区方面的主要作用一致。有助于将细菌的分裂隔膜定位的分子机制对于确保细胞增殖和维持细胞形状和大小至关重要。Min 蛋白系统存在于许多杆状细菌中，被认为在分裂位点选择中发挥主要作用。在 和 中，Min 系统的功能和动态被认为存在很大差异。以前大多数试图在 中解决 Min 蛋白动力学的尝试都受到过度表达构建体的使用的阻碍。在这里，通过等位基因交换构建了 Min 蛋白的功能融合，并使用最先进的成像技术揭示了 Min 系统出人意料的快速动态行为。我们的数据表明，导致 Min 蛋白动力学的分子机制在 和 中并没有根本的不同。
