The Effect of the Second Messenger c-di-GMP on Bacterial Chemotaxis in Escherichia coli
The Effect of the Second Messenger c-di-GMP on Bacterial Chemotaxis in Escherichia coli
复制标题
第二信使c-di-GMP对大肠杆菌趋化性的影响
DOI：
10.1128/aem.00373-22
复制
发表时间：
2022-04
影响因子：
4.4
通讯作者：
Junhua Yuan
中科院分区：
文献类型：
--
作者：
Xiang Liu;Chi Zhang;Rongjing Zhang;Junhua Yuan
普遍存在的细菌第二信使c-di-GMP可调节多种细菌的趋化性，但其对大肠杆菌趋化性的影响尚不清楚。在这里，我们研究了c-di-GMP水平升高对大肠杆菌趋化性的影响。摘要c-di-GMP是一种普遍存在的细菌第二信使，在多种生物过程中起着重要的调节作用。已知c-di-GMP对多种细菌的趋化性有调节作用，但其对大肠杆菌趋化性的影响尚不清楚。作为大肠杆菌中c-di-GMP的效应子，YcgR与c-di-GMP结合时与鞭毛马达相互作用，降低鞭毛马达的速度和顺时针旋转的可能性(CW偏差)。在这里，我们发现很大一部分c-di-GMP：：YcgR在马达和胞浆之间动态交换。通过荧光测量，我们发现趋化反应调节因子Chey-P和c-di-GMP：：YcgR之间不存在与马达的竞争结合。为了检测c-di-GMP水平升高对趋化途径的影响，我们用FRET方法测定了大肠杆菌细胞的趋化反应，发现c-di-GMP水平升高对趋化途径的上游部分乃至Chey-P浓度水平都没有影响。这提示c-di-GMP水平升高对趋化运动的影响可能是通过调节运动速度和CW偏差来实现的。通过对趋化游泳的随机模拟，我们发现降低运动速度和减少CW偏向对趋化漂移速度的影响是相互补偿的，导致c-di-GMP水平升高对大肠杆菌趋化性的影响很小。因此，升高的c-di-GMP水平通过降低细菌的游动速度和CW偏向，促进细菌从活动形式向静止形式的转变，同时仍保持在大肠杆菌中几乎完整的趋化能力。重要的是，普遍存在的细菌第二信使c-di-GMP在许多细菌物种中调节趋化性，但它对大肠杆菌趋化性的影响尚不清楚。在这里，我们研究了c-di-GMP水平升高对大肠杆菌趋化性的影响。我们发现c-di-GMP：：YcgR(其效应子)和趋化反应调节因子Chey-P与鞭毛运动的结合是非竞争性的，c-di-GMP水平的升高不会影响趋化途径的上游部分，直到Chey-P的浓度水平。升高的c-di-GMP水平通过降低鞭毛运动的速度和连续波偏压对鞭毛运动产生直接影响，但由此产生的对趋化性能的影响是相互补偿的。我们的研究结果表明，c-di-GMP水平的升高在促进细菌在大肠杆菌中从活动形式向静止形式转变时，保持了几乎完整的趋化能力。
The ubiquitous bacterial second messenger c-di-GMP was known to regulate chemotaxis in many bacterial species, but its effect on E. coli chemotaxis was unclear. Here we studied the effect of elevated c-di-GMP levels on chemotaxis in E. coli. ABSTRACT c-di-GMP is a ubiquitous bacterial second messenger that plays a central regulatory role in diverse biological processes. c-di-GMP was known to regulate chemotaxis in multiple bacterial species, but its effect on Escherichia coli chemotaxis remained unclear. As an effector of c-di-GMP in E. coli, YcgR when bound with c-di-GMP interacts with the flagellar motor to reduce its speed and its probability of rotating clockwise (CW bias). Here, we found that a significant fraction of the c-di-GMP::YcgR dynamically exchange between the motor and the cytosol. Through fluorescent measurements, we found that there was no competitive binding between the chemotaxis response regulator CheY-P and c-di-GMP::YcgR to the motor. To test the influence of elevated c-di-GMP levels on the chemotaxis pathway, we measured the chemotactic responses of E. coli cells using a FRET assay, finding that elevated c-di-GMP levels had no effect on the upstream part of chemotaxis pathway down to the level of CheY-P concentration. This suggested that the possible effect of elevated c-di-GMP levels on chemotactic motion was through regulation of motor speed and CW bias. Using stochastic simulations of chemotactic swimming, we showed that the effects of reducing motor speed and decreasing CW bias on chemotactic drift velocity are compensating for each other, resulting in minimal effect of elevated c-di-GMP levels on E. coli chemotaxis. Therefore, elevated c-di-GMP levels promote the transition from motile to sedentary forms of bacterial life by reducing the bacterial swimming speed and CW bias, while still maintaining a nearly intact chemotaxis capability in E. coli. IMPORTANCE The ubiquitous bacterial second messenger c-di-GMP was known to regulate chemotaxis in many bacterial species, but its effect on E. coli chemotaxis was unclear. Here we studied the effect of elevated c-di-GMP levels on chemotaxis in E. coli. We found that the binding of c-di-GMP::YcgR (its effector) and the chemotaxis response regulator CheY-P to the flagellar motor are noncompetitive, and elevated c-di-GMP levels do not affect the upstream part of the chemotaxis pathway down to the level of CheY-P concentration. Elevated c-di-GMP levels exert direct effects on the flagellar motor by reducing its speed and CW bias, but the resulting effects on chemotaxis performance are compensating for each other. Our findings here showed that elevated c-di-GMP levels maintain a nearly intact chemotaxis capability when promoting the transition from motile to sedentary forms of bacterial life in E. coli.
登录
查看更多内容
影响因子：
64.5
作者：
M. Santiveri;A. Roa-Eguiara;Caroline Kühne;N. Wadhwa;H. Berg;M. Erhardt;N. Taylor
通讯作者：
M. Santiveri;A. Roa-Eguiara;Caroline Kühne;N. Wadhwa;H. Berg;M. Erhardt;N. Taylor
影响因子：
16
作者：
Paul K;Nieto V;Carlquist WC;Blair DF;Harshey RM
通讯作者：
Harshey RM
影响因子：
4.5
作者：
Girgis, Hany S.;Liu, Yirchung;Ryu, William S.;Tavazoie, Saeed
通讯作者：
Tavazoie, Saeed
影响因子：
5.6
作者：
Bren, A;Eisenbach, M
通讯作者：
Eisenbach, M
影响因子：
4.3
作者：
Jiang L;Ouyang Q;Tu Y
通讯作者：
Tu Y