Howard Hughes Medical Institute and Department of Molecular Biology and Microbiology, Tufts University School of Medicine, Boston, MA 02111, USA.
Mol Microbiol. 2010 Sep;77(6):1595-605. doi: 10.1111/j.1365-2958.2010.07310.x. Epub 2010 Aug 16.
Vibrio cholerae is a facultative pathogen that thrives in two nutritionally disparate environments, aquatic and human small intestine. Phosphate (P(i) ) is an essential nutrient that is limited in aquatic ecosystems and of unknown availability in the small intestine. Here, we show that the P(i) (Pho) regulon, which is controlled by the P(i)-specific transporter (Pst) and two-component system PhoBR, is required for V. cholerae survival in both environments, though for differing reasons. While induction of P(i) acquisition systems including Pst is critical for survival in the aquatic environment, regulation of virulence genes by PhoB and not P(i) transport per se is required for colonization of the small intestine. We show that PhoB regulates virulence genes by directly controlling expression of a key upstream transcriptional regulator, tcpPH. Thus, the Pho regulon includes virulence genes and represents a diverse gene set essential to pathogenic V. cholerae throughout its life cycle.
霍乱弧菌是一种兼性病原体，能够在两种营养环境中茁壮成长，即水生环境和人类小肠。磷酸盐（Pi）是一种必需的营养物质，在水生生态系统中受到限制，而在小肠中的可用性未知。在这里，我们表明，Pi（Pho）调控基因簇受 Pi 特异性转运蛋白（Pst）和双组分系统 PhoBR 控制，对于霍乱弧菌在两种环境中的生存都是必需的，尽管原因不同。虽然诱导 Pi 摄取系统，包括 Pst，对于在水生环境中的生存至关重要，但 PhoB 对毒力基因的调节，而不是 Pi 转运本身，是在小肠中定植所必需的。我们表明，PhoB 通过直接控制关键上游转录调节剂 tcpPH 的表达来调节毒力基因。因此，Pho 调控基因簇包含毒力基因，代表了整个生命周期中致病性霍乱弧菌必需的多样化基因集。
