Department of Microbiology and Molecular Genetics, UTHealth-Houston, Houston, Texas, USA.
Department of Biology, Canisius College, Buffalo, New York, USA.
Mol Microbiol. 2023 Oct;120(4):525-538. doi: 10.1111/mmi.15067. Epub 2023 Apr 28.
Most bacteria use the tubulin homolog FtsZ to organize their cell division. FtsZ polymers initially assemble into mobile complexes that circle around a ring-like structure at the cell midpoint, followed by the recruitment of other proteins that will constrict the cytoplasmic membrane and synthesize septal peptidoglycan to divide the cell. Despite the need for FtsZ polymers to associate with the membrane, FtsZ lacks intrinsic membrane binding ability. Consequently, FtsZ polymers have evolved to interact with the membrane through adaptor proteins that both bind FtsZ and the membrane. Here, we discuss recent progress in understanding the functions of these FtsZ membrane tethers. Some, such as FtsA and SepF, are widely conserved and assemble into varied oligomeric structures bound to the membrane through an amphipathic helix. Other less-conserved proteins, such as EzrA and ZipA, have transmembrane domains, make extended structures, and seem to bind to FtsZ through two separate interactions. This review emphasizes that most FtsZs use multiple membrane tethers with overlapping functions, which not only attach FtsZ polymers to the membrane but also organize them in specific higher-order structures that can optimize cell division activity. We discuss gaps in our knowledge of these concepts and how future studies can address them.
大多数细菌利用微管蛋白同源物 FtsZ 来组织细胞分裂。FtsZ 聚合物最初组装成可移动的复合物，围绕细胞中部的环状结构旋转，然后招募其他蛋白质，这些蛋白质将收缩细胞质膜并合成隔膜肽聚糖以分裂细胞。尽管 FtsZ 聚合物需要与膜结合，但 FtsZ 缺乏内在的膜结合能力。因此，FtsZ 聚合物通过与膜结合的衔接蛋白进化为与膜相互作用。在这里，我们讨论了理解这些 FtsZ 膜系绳功能的最新进展。有些，如 FtsA 和 SepF，广泛保守，通过一个两亲性螺旋组装成各种寡聚体结构，与膜结合。其他不太保守的蛋白质，如 EzrA 和 ZipA，具有跨膜结构域，形成延伸结构，似乎通过两个单独的相互作用与 FtsZ 结合。这篇综述强调，大多数 FtsZ 使用具有重叠功能的多个膜系绳，不仅将 FtsZ 聚合物附着在膜上，而且将它们组织成特定的高级结构，从而优化细胞分裂活性。我们讨论了我们对这些概念的了解中的差距，以及未来的研究如何解决这些差距。
