Yamasaki Ryota, Song Sooyeon, Benedik Michael J, Wood Thomas K
Department of Chemical Engineering, Pennsylvania State University, University Park, PA 16802-4400, USA.
Department of Biology, Texas A & M University, College Station, TX 77843-3122, USA.
iScience. 2020 Jan 24;23(1):100792. doi: 10.1016/j.isci.2019.100792. Epub 2019 Dec 21.
Persistence, the stress-tolerant state, is arguably the most vital phenotype since nearly all cells experience nutrient stress, which causes a sub-population to become dormant. However, how persister cells wake to reconstitute infections is not understood well. Here, using single-cell observations, we determined that Escherichia coli persister cells resuscitate primarily when presented with specific carbon sources, rather than spontaneously. In addition, we found that the mechanism of persister cell waking is through sensing nutrients by chemotaxis and phosphotransferase membrane proteins. Furthermore, nutrient transport reduces the level of secondary messenger cAMP through enzyme IIA; this reduction in cAMP levels leads to ribosome resuscitation and rescue. Resuscitating cells also immediately commence chemotaxis toward nutrients, although flagellar motion is not required for waking. Hence, persister cells wake by perceiving nutrients via membrane receptors that relay the signal to ribosomes via the secondary messenger cAMP, and persisters wake and utilize chemotaxis to acquire nutrients.
持久性,即应激耐受状态,可以说是最重要的表型,因为几乎所有细胞都会经历营养应激,这会导致一部分亚群进入休眠状态。然而,关于持留菌细胞如何苏醒以重新引发感染,目前还了解得不够透彻。在这里,通过单细胞观察,我们确定大肠杆菌持留菌细胞主要是在遇到特定碳源时复苏,而不是自发复苏。此外,我们发现持留菌细胞苏醒的机制是通过趋化作用和磷酸转移酶膜蛋白感知营养物质。此外,营养物质的转运通过酶IIA降低了第二信使cAMP的水平;cAMP水平的这种降低导致核糖体复苏和挽救。复苏的细胞也会立即开始向营养物质进行趋化运动,尽管鞭毛运动对于苏醒并非必需。因此,持留菌细胞通过膜受体感知营养物质来苏醒,这些受体通过第二信使cAMP将信号传递给核糖体,并且持留菌苏醒并利用趋化作用获取营养物质。