Aberrant Cell Division and Random FtsZ Ring Positioning in Escherichia coli cpxA* Mutants

In Escherichia coli, certain mutations in the cpxA gene (encoding a sensor kinase of a two-component signal transduction system) randomize the location of FtsZ ring assembly and dramatically affect cell division. However, deletion of the cpxRA operon, encoding the sensor kinase and its cognate regulator CpxR, has no effect on division site biogenesis. It appears that certain mutant sensor kinases (CpxA*) either exhibit hyperactivity on CpxR or extend their signalling activity to one or more noncognate response regulators involved in cell division.

在大肠杆菌（Escherichia coli）中，cpxA基因（编码双组分信号转导系统（two-component signal transduction system）的传感激酶（sensor kinase））的特定突变会使FtsZ环组装的位点随机化，并显著影响细胞分裂过程。然而，删除同时编码该传感激酶及其同源调控蛋白CpxR的cpxRA操纵子（cpxRA operon），却对分裂位点的生成无任何影响。现有研究显示，部分突变型传感激酶（CpxA*）要么对CpxR呈现过度激活活性，要么将其信号转导功能拓展至一种或多种参与细胞分裂的非同源反应调控因子（noncognate response regulators）。