A Polar Flagellar Transcriptional Program Mediated by Diverse Two-Component Signal Transduction Systems and Basal Flagellar Proteins Is Broadly Conserved in Polar Flagellates
A Polar Flagellar Transcriptional Program Mediated by Diverse Two-Component Signal Transduction Systems and Basal Flagellar Proteins Is Broadly Conserved in Polar Flagellates
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DOI：
10.1128/mbio.03107-19
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发表时间：
2020-03-01
期刊：
影响因子：
6.4
通讯作者：
Hendrixson, David R.
中科院分区：
文献类型：
--
作者：
Burnham, Peter M.;Kolar, William P.;Hendrixson, David R.
细菌鞭毛是运动所需的旋转纳米机器。鞭毛基因表达和蛋白质分泌是协调的有效鞭毛生物发生。极性鞭毛虫，不像围毛细菌，通常顺序鞭毛杆和钩基因转录作为一个单独的步骤后，生产的MS环，C环，和鞭毛III型分泌系统（fT 3SS）的核心蛋白，形成一个主管fT 3SS。保守的调节机制，在不同的极性鞭毛，以创造这种极性鞭毛转录程序还没有被彻底同化。使用在硅片和遗传分析和我们以前的研究结果在空肠弯曲菌作为基础，我们观察到一个大的革兰氏阴性菌的FIhF/FIhG调控系统的极性鞭毛拥有鞭毛相关的双组分信号转导系统（TCS）。我们目前的数据支持一个一般的主题，在极地鞭毛虫，MS环，转子，和fT 3SS蛋白有助于在极地鞭毛虫生物发生的监管检查点。我们证明，霍乱弧菌和铜绿假单胞菌需要形成这个监管检查点的TCS直接激活随后的杆和钩基因转录，这是标志性的极鞭毛转录程序。通过重编程霍乱弧菌中的转录以更紧密地遵循围毛鞭毛转录程序，我们发现了极性鞭毛转录程序与FIhF/FIhG鞭毛生物发生调节剂的活性之间的联系，其中转录程序允许极性鞭毛在FIhF或FIhG活性可能改变时继续产生用于运动的鞭毛。我们的研究结果整合了鞭毛转录和生物发生的监管过程中涉及的极性flagellationinmany species.IMPORTANCE相对于peritrichous细菌，极性鞭毛虫具有调控系统，以不同的鞭毛基因转录和产生鞭毛在特定的数量只在两极。转录和鞭毛生物发生调控系统如何相互联系，以促进不同物种中极性鞭毛的正确合成，在很大程度上尚未探索。我们发现了许多革兰氏阴性极性鞭毛虫编码双组分信号转导系统的证据，该系统具有与鞭毛III型分泌系统的形成相关的活性，从而能够在鞭毛组装期间的离散后续阶段产生鞭毛杆和钩蛋白。这种极性鞭毛转录程序以某种方式协助FIhF/FIhG鞭毛生物发生调节系统，当FIhF或FIhG的活性可能改变时，该系统在极性鞭毛中形成特定的鞭毛形成模式以维持鞭毛形成和运动。我们的工作提供了深入了解极地鞭毛虫所需的多个监管过程。
Bacterial flagella are rotating nanomachines required for motility. Flagellar gene expression and protein secretion are coordinated for efficient flagellar biogenesis. Polar flagellates, unlike peritrichous bacteria, commonly order flagellar rod and hook gene transcription as a separate step after production of the MS ring, C ring, and flagellar type Ill secretion system (fT3SS) core proteins that form a competent fT3SS. Conserved regulatory mechanisms in diverse polar flagellates to create this polar flagellar transcriptional program have not been thoroughly assimilated. Using in silico and genetic analyses and our previous findings in Campylobacter jejuni as a foundation, we observed a large subset of Gram-negative bacteria with the FIhF/FIhG regulatory system for polar flagellation to possess flagellum-associated two-component signal transduction systems (TCSs). We present data supporting a general theme in polar flagellates whereby MS ring, rotor, and fT3SS proteins contribute to a regulatory checkpoint during polar flagellar biogenesis. We demonstrate that Vibrio cholerae and Pseudomonas aeruginosa require the formation of this regulatory checkpoint for the TCSs to directly activate subsequent rod and hook gene transcription, which are hallmarks of the polar flagellar transcriptional program. By reprogramming transcription in V. cholerae to more closely follow the peritrichous flagellar transcriptional program, we discovered a link between the polar flagellar transcription program and the activity of FIhF/FIhG flagellar biogenesis regulators in which the transcriptional program allows polar flagellates to continue to produce flagella for motility when FIhF or FIhG activity may be altered. Our findings integrate flagellar transcriptional and biogenesis regulatory processes involved in polar flagellation in many species.IMPORTANCE Relative to peritrichous bacteria, polar flagellates possess regulatory systems that order flagellar gene transcription differently and produce flagella in specific numbers only at poles. How transcriptional and flagellar biogenesis regulatory systems are interlinked to promote the correct synthesis of polar flagella in diverse species has largely been unexplored. We found evidence for many Gram-negative polar flagellates encoding two-component signal transduction systems with activity linked to the formation of flagellar type Ill secretion systems to enable production of flagellar rod and hook proteins at a discrete, subsequent stage during flagellar assembly. This polar flagellar transcriptional program assists, in some manner, the FIhF/FIhG flagellar biogenesis regulatory system, which forms specific flagellation patterns in polar flagellates in maintaining flagellation and motility when activity of FIhF or FIhG might be altered. Our work provides insight into the multiple regulatory processes required for polar flagellation.