Bayramova Firuza, Jacquier Nicolas, Greub Gilbert
Center for Research on Intracellular Bacteria, Institute of Microbiology, University Hospital Center and University of Lausanne, Bugnon 48, CH-1011 Lausanne, Switzerland.
Microorganisms. 2019 Nov 26;7(12):617. doi: 10.3390/microorganisms7120617.
order members are obligate intracellular bacteria, dividing by binary fission. However, lack the otherwise conserved homologue of the bacterial division organizer FtsZ and certain division protein homologues. FtsZ might be functionally replaced in by the actin homologue MreB. RodZ, the membrane anchor of MreB, localizes early at the division septum. In order to better characterize the organization of the chlamydial divisome, we performed co-immunoprecipitations and yeast-two hybrid assays to study the interactome of RodZ, using , a potentially pathogenic -related bacterium, as a model organism. Three potential interactors were further investigated: SecA, FtsH, and SufD. The gene and protein expression profiles of these three genes were measured and are comparable with recently described division proteins. Moreover, SecA, FtsH, and SufD all showed a peripheral localization, consistent with putative inner membrane localization and interaction with RodZ. Notably, heterologous overexpression of the abovementioned proteins could not complement mutants, indicating that these proteins might play different functions in these two bacteria or that important regulators are not conserved. Altogether, this study brings new insights to the composition of the chlamydial divisome and points to links between protein secretion, degradation, iron homeostasis, and chlamydial division.
衣原体成员是专性胞内细菌，通过二分裂进行繁殖。然而，它们缺乏细菌分裂组织者FtsZ的其他保守同源物以及某些分裂蛋白同源物。在衣原体中，肌动蛋白同源物MreB可能在功能上替代了FtsZ。MreB的膜锚定蛋白RodZ早期定位于分裂隔膜处。为了更好地表征衣原体分裂体的组织，我们进行了免疫共沉淀和酵母双杂交试验，以研究RodZ的相互作用组，使用一种潜在致病性的与衣原体相关的细菌作为模式生物。进一步研究了三个潜在的相互作用蛋白：SecA、FtsH和SufD。测量了这三个基因的基因和蛋白质表达谱，它们与最近描述的分裂蛋白相当。此外，SecA、FtsH和SufD均显示外周定位，这与假定的内膜定位以及与RodZ的相互作用一致。值得注意的是，上述蛋白质的异源过表达不能互补衣原体突变体，这表明这些蛋白质可能在这两种细菌中发挥不同的功能，或者重要的调节因子不保守。总之，这项研究为衣原体分裂体的组成带来了新的见解，并指出了蛋白质分泌、降解、铁稳态与衣原体分裂之间的联系。
