Patino Ramiro, Kühn Marco J, Macmillan Henriette, Inclan Yuki F, Chavez Ivan, Persat Alexandre, Engel Joanne N
Department of Medicine, University of California, San Francisco, San Francisco, CA 94158, USA.
Institute of Bioengineering and Global Health Institute, School of Life Sciences, EPFL, 1015 Lausanne, Switzerland.
Cell Rep. 2025 Apr 22;44(4):115536. doi: 10.1016/j.celrep.2025.115536. Epub 2025 Apr 8.
Most bacterial chemosensory systems encode enzymes that are predicted to methylate and demethylate their chemoreceptors to control signaling activity. Here, we show that a predicted methyltransferase (PilK) and methylesterase (ChpB) methylate and demethylate, respectively, the chemoreceptor PilJ in the Pseudomonas aeruginosa (P. aeruginosa) Pil-Chp surface sensing system. PilJ methylation modulates the amplitude of cAMP production and the frequency of twitching motility reversals, outputs of Pil-Chp signaling. Dynamic imaging of fluorescent fusion proteins in individual twitching cells reveals that PilK and ChpB localize to opposite poles, with PilK at the lagging pole and ChpB at the leading pole. These enzymes switch poles upon bacterial reversals, a process dependent on the Pil-Chp response regulators PilG and PilH. Our results suggest that the PilJ population at each pole exists in dynamic and opposite methylation states that may reset the PilJ signaling activity at each pole during P. aeruginosa surface sensing, a key feature of adaptation.
大多数细菌化学传感系统编码的酶预计可使化学感受器甲基化和去甲基化，以控制信号传导活性。在此，我们表明，在铜绿假单胞菌（P. aeruginosa）的Pil-Chp表面传感系统中，一种预测的甲基转移酶（PilK）和甲基酯酶（ChpB）分别使化学感受器PilJ甲基化和去甲基化。PilJ甲基化调节cAMP产生的幅度和颤动运动逆转的频率，这是Pil-Chp信号传导的输出。对单个颤动细胞中荧光融合蛋白的动态成像显示，PilK和ChpB定位于相反的极，PilK位于滞后极，ChpB位于前端极。这些酶在细菌逆转时会切换极，这一过程依赖于Pil-Chp反应调节因子PilG和PilH。我们的结果表明，每个极处的PilJ群体处于动态且相反的甲基化状态，这可能在铜绿假单胞菌表面传感过程中重置每个极处的PilJ信号传导活性，这是适应性的一个关键特征。
