Cyclic di-GMP Regulation of PilB in Motility and Biofilm

去还是留，这是细菌在它遇到的任何环境中必须做出的决定。要想离开，它必须组装一个运动装置，并使附着在表面的结构失效。为了生存，它需要通过生产自己的建筑材料在固体表面形成细菌生物膜来建立一个受保护的定居点。细菌的这一决定及其执行对我们的生活和社会产生了深远的影响，因为生物膜可以在许多关键的环境表面上形成。 该研究项目在分子水平上探索细菌如何做出和执行这一决定，以形成生物膜或通过使其运动而移动。除了推进基础微生物学，该项目将允许综合教学和学习的机会，以及研究生和本科生的跨学科培训。此外，我们还将开展各种外展活动，以帮助我们的STEM员工多样化。该项目重点关注通用细菌第二信使cyclic-di-GMP（cdG）对PilB的调控。PilB是一种ATP酶，其为细菌IV型菌毛（T4 P）的组装提供动力，作为在固体表面上运动的运动装置。另外，黄色粘球菌T4 P已被证明刺激胞外多糖（EPS）的产生，胞外多糖是细菌生物膜的主要构建材料。M.因此，似乎xanthusPilB（MxPilB）促进运动性和生物膜形成，这是细菌的两种交替且相互排斥的生活方式。有证据表明，MxPilB及其嗜热氯酸杆菌直系同源物（CtPilB）都使用保守的cdG结合结构域结合cdG。研究人员提出了一个模型，其中cdG反向调节PilB的两个看似不相容和相反的功能。这个项目的一部分使用M。结合体外cdG结合试验，在体内对该模型进行测试。该项目的其余部分采用CtPilB作为模型蛋白，通过体外定量和结构分析以及先进的成像平台（包括单粒子冷冻EM和高速原子力显微镜）来分析PilB与cdG的相互作用。该项目的成功完成将为深入了解存在于众多生态系统和系统发育树的许多分支中的T4 P运动细菌的生活方式决策提供帮助。该奖项反映了NSF的法定使命，并通过使用基金会的知识价值和更广泛的影响审查标准进行评估，被认为值得支持。

To go, or to stay, that is the decision a bacterium must make in any environment it encounters. To go, it must assemble a motility apparatus and disable structures for attachment to surfaces. To stay, it needs to establish a protected settlement by producing building materials of its own to form a bacterial biofilm on a solid surface. This decision and its execution by bacteria profoundly impact our lives and society because biofilms can form on so many critical environmental surfaces. This research project probes at the molecular level how a bacterium makes and executes this decision to either form biofilms or move by enabling its motility. Besides advancing basic microbiology, this project will allow integrated teaching and learning opportunities as well as interdisciplinary training of both graduate and undergraduate students. In addition, a variety of outreach activities will be performed to help diversify our STEM workforce.This project focuses on the regulation of PilB by the universal bacterial second messenger cyclic-di-GMP (cdG). PilB is an ATPase that powers the assembly of bacterial type IV pilus (T4P) as a motility apparatus for movement on solid surfaces. Additionally, Myxococcus xanthus T4P has been demonstrated to stimulate the production of exopolysaccharide (EPS) which is the major building materia of bacterial biofilms. M. xanthus PilB (MxPilB) would thus appear to promote both motility and biofilm formation, which are two alternate and mutually exclusive lifestyles of bacteria. Evidence indicates that MxPilB and its Chloracidobacterium thermophilum orthologue (CtPilB) both bind cdG using a conserved cdG-binding domain. The investigators propose a model wherein cdG inversely regulates the two seemingly incompatible and opposing functions of PilB. One part of this project uses M. xanthus to test this model in vivo combined with cdG binding assays in vitro. The rest of the project employs CtPilB as the model protein to analyze the interactions of PilB with cdG by quantitative and structural analysis in vitro as well as advanced imagining platforms including single-particle cryo-EM and high-speed atomic force microscopy. The successful completion of this project will provide insight into the lifestyle decision-making by T4P-motile bacteria that are present in numerous ecosystems and on many branches of the phylogenetic tree.This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.