Smooth to Rugose phase variation in Vibrio cholerae

霍乱弧菌导致霍乱，是水生动物的自然居住者 环境。季节性霍乱暴发发生在疾病流行并可传播的地方 全世界。霍乱弧菌引起疫情的能力与其在水生环境中生存的能力有关 栖息地。已经提出霍乱弧菌形成生物膜的能力(即，基质封闭， 表面相关群落)对其在疫情期间在水生生境中的生存至关重要 并且在流行期间有利于宿主间的传播。这样做的目的是 建议是为了提高我们对生物膜基质成分、机理和 生物膜形成的调节，环状二聚鸟苷一磷酸(c-GMP)的作用机制。 DiGMP)信号，以及它们在霍乱弧菌生物学中的重要性。 在目标1中，我们将重点研究生物膜基质成分的表征。我们会 确定弧菌多糖(VPS)的结合能力和基质的定位模式 生物膜中的蛋白质，并检验我们的假设，即这些蛋白质与VPS结合以稳定 矩阵。我们将确定vps基因簇中的哪些基因是生物被膜所必需的。 队形。我们还将研究一种可能的VPS裂解酶的酶性质。最后，我们 将确定已知的生物膜决定因素在霍乱弧菌致病中的作用。在AIM 2、对生物膜形成的规律进行剖析。生物被膜调控网络由两个 正转录调节因子(VpsR和VpsT)，负转录调节因子(HapR)， 以及我们最近发现的传感器组氨酸激酶(VPSS)。我们将确定VPSS是否 磷酸化VpsR并识别控制VPSS的重要信号。我们将描述 VPs和基质蛋白基因的顺式作用特征并阐明其转录是否 调节因子VpsR、VpsT和HapR直接与这些启动子相互作用。在《目标3》中，我们将 阐明c-diGMP信号控制生物膜形成的分子机制。我们 将决定调节生物膜形成的c-diGMP信号蛋白是否依赖于 蛋白质之间的相互作用。为了鉴定c-di-GMP信号系统的靶蛋白， 我们将寻找与c-diGMP信号蛋白相互作用的蛋白质，以及c-diGMP。 皱纹变异体中的受体蛋白。然后我们将评估这些c-diGMP信号是如何 蛋白质影响霍乱弧菌的致病机制。 更好地了解生物被膜的形成机制、c-diGMP信号转导和 这两个过程在霍乱弧菌生物学中的重要性将被证明是有用的 制定未来预测和控制霍乱流行的战略，并将 促进确定新的药物靶点，以在感染期间对抗病原体。

Vibrio cholerae causes the disease cholera and is a natural inhabitant of aquatic environments. Seasonal cholera outbreaks occur where the disease is endemic and can spread worldwide. V. cholerae's ability to cause epidemics is tied to its ability to survive in aquatic habitats. It has been proposed that V. cholerae's ability to form biofilms (i.e., matrix-enclosed, surface-associated communities) is crucial for its survival in aquatic habitats between epidemics and is advantageous for host-to-host transmission during epidemics. The objective of this proposal is to improve our understanding of biofilm matrix components, the mechanisms and regulation of biofilm formation, the mechanism of cyclic dimeric guanosine monophosphate (c- diGMP) signaling, and their importance in the biology of V. cholerae. In Aim 1, we will focus on characterization of biofilm matrix components. We will determine Vibrio polysaccharide (VPS) binding capacities and localization patterns of the matrix proteins in biofilms, and test our hypothesis that these proteins bind to VPS in order to stabilize the matrix. We will determine which genes within the vps gene clusters are required for biofilm formation. We will also investigate the enzymatic properties of a putative VPS lyase. Finally, we will ascertain the contribution of known biofilm determinants in V. cholerae pathogenesis. In Aim 2, we will dissect regulation of biofilm formation. Biofilm regulatory network consists of two positive transcriptional regulators (VpsR and VpsT), a negative transcriptional regulator (HapR), and our recently-identified sensor histidine kinase (VpsS). We will determine whether VpsS phoshorylates VpsR and identify important signals that control VpsS. We will characterize the cis-acting features of the vps and matrix-protein genes and elucidate whether the transcriptional regulators VpsR, VpsT and HapR interact directly with these promoters. In Aim 3, we will elucidate the molecular mechanisms by which c-diGMP signaling controls biofilm formation. We will determine whether c-diGMP signaling proteins that modulate biofilm formation rely on protein-protein interactions. To identify the target proteins of the c-di-GMP signaling systems, we will search for proteins interacting with c-diGMP signaling proteins, as well as for c-diGMP receptor proteins within the rugose variants. We will then assess how these c-diGMP signaling proteins affect V. cholerae pathogenesis. Better understanding of the mechanism of biofilm formation, c-diGMP signaling, and the importance of both of these processes in V. cholerae biology will prove useful for the development of future strategies for predicting and controlling cholera epidemics, and will facilitate identification of novel drug targets for combating the pathogen during infection.