Department of Microbiology, Ludwig-Maximilians-Universität München, Munich, Germany.
Center for Microbial Ecology and Technology, Ghent Universitygrid.5342.0, Ghent, Belgium.
J Bacteriol. 2021 Sep 23;203(20):e0029621. doi: 10.1128/JB.00296-21. Epub 2021 Aug 2.
Pyruvate is a key metabolite in living cells and has been shown to play a crucial role in the virulence of several bacterial pathogens. The bioluminescent Vibrio campbellii, a severe infectious burden for marine aquaculture, excretes extraordinarily large amounts of pyruvate during growth and rapidly retrieves it by an as-yet-unknown mechanism. We have now identified the responsible pyruvate transporter, here named BtsU, and our results show that it is the only pyruvate transporter in . Expression of is tightly regulated by the membrane-integrated LytS-type histidine kinase BtsS, a sensor for extracellular pyruvate, and the LytTR-type response regulator BtsR. Cells lacking either the pyruvate transporter or sensing system show no chemotactic response toward pyruvate, indicating that intracellular pyruvate is required to activate the chemotaxis system. Moreover, pyruvate sensing and uptake were found to be important for the resuscitation of from the viable but nonculturable state and the bacterium's virulence against brine shrimp larvae. Bacterial infections are a serious threat to marine aquaculture, one of the fastest growing food sectors on earth. Therefore, it is extremely important to learn more about the pathogens responsible, one of which is Vibrio campbellii. This study sheds light on the importance of pyruvate sensing and uptake for , and reveals that the bacterium possesses only one pyruvate transporter, which is activated by a pyruvate-responsive histidine kinase/response regulator system. Without the ability to sense or take up pyruvate, the virulence of toward gnotobiotic brine shrimp larvae is strongly reduced.
丙酮酸是活细胞中的一种关键代谢物，已被证明在几种细菌病原体的毒力中起着至关重要的作用。发光弧菌，一种对海水养殖造成严重感染负担的病原体，在生长过程中会排泄出异常大量的丙酮酸，并通过一种未知的机制迅速回收。我们现在已经确定了负责丙酮酸转运的蛋白，将其命名为 BtsU，我们的结果表明它是 中唯一的丙酮酸转运蛋白。的表达受到膜整合型 LytS 型组氨酸激酶 BtsS 的严格调控，BtsS 是细胞外丙酮酸的传感器，以及 LytTR 型响应调节蛋白 BtsR。缺乏丙酮酸转运蛋白或传感系统的细胞对丙酮酸没有趋化反应，表明细胞内丙酮酸是激活趋化系统所必需的。此外，丙酮酸的感应和摄取对于从可存活但非可培养状态复苏以及该细菌对卤虫幼虫的毒力至关重要。细菌感染对海水养殖业是一个严重的威胁，海水养殖业是地球上发展最快的食品行业之一。因此，了解负责的病原体非常重要，其中一种病原体是弧菌。本研究揭示了丙酮酸感应和摄取对 的重要性，并表明该细菌仅拥有一种丙酮酸转运蛋白，该蛋白被一种依赖于丙酮酸的组氨酸激酶/响应调节蛋白系统激活。如果没有感应或摄取丙酮酸的能力， 对无菌卤虫幼虫的毒力会大大降低。
