Mechanisms and regulation of horizontal gene transfer by natural transformation in Vibrio cholerae

霍乱弧菌自然转化水平基因转移的机制和调控

• 批准号: 10603610
• 负责人: Ankur Dalia
• 金额: $ 46.82万
• 依托单位: TRUSTEES OF INDIANA UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-09-01 至 2028-06-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10603610
• 关键词: ATP phosphohydrolase; Antibiotic Resistance; Area; Bacteria; Basic Science; Binding; Biological; Biological Models; Biology; Cells; Chitin; Cholera; Crustacea; Cues; DNA; DNA Binding; Environment; Fimbriae Proteins; Genes; Genetic; Horizontal Gene Transfer; Infection; Label; Membrane; Microbial Biofilms; Minor; Motor; Nutritional; Pathogenesis; Physiological; Pilum; Play; Predatory Behavior; Process; Regulation; Regulon; Role; Signal Transduction; Surface; Testing; Traction; Vibrio; Vibrio cholerae; Virulence; Virulence Factors; Work; Zooplankton; appendage; clinically relevant; combat; diarrheal disease; genetic approach; membrane activity; microbial; novel strategies; pathogen; pathogenic bacteria; resistance factors; spatiotemporal; stem; tool; transcription factor; transmission process; uptake; waterborne

Project Summary The Dalia lab studies the regulation and mechanisms of horizontal gene transfer by natural transformation (NT) using Vibrio cholerae as a model system. While this bacterium is the causative agent of the diarrheal disease cholera, we do not seek to study bacterial pathogenesis. Instead, we leverage this well- established model system and the genetic tools we have developed to characterize NT in a physiologically relevant context. NT contributes to the rapid spread of antibiotic resistance determinants and virulence factors in bacterial pathogens. Thus, characterizing the regulation and mechanisms of NT may uncover novel approaches to combat diverse clinically relevant infections. The genes required for NT are tightly regulated, and only induced when V. cholerae forms biofilms on the chitinous shells of crustacean zooplankton in the aquatic environment. The formation of chitin biofilms is also important for the survival of this facultative pathogen in its environmental reservoir, and promotes the waterborne transmission of cholera. Vibrio-chitin interactions can be easily studied in a lab setting, which provides a physiologically relevant and highly tractable model system for studying NT. In the next five years, we will focus on three major areas. First, V. cholerae uses dynamic surface appendages called type IV pili to bind to chitinous surfaces and to take up DNA for NT. The mechanisms that regulate the dynamic extension and retraction of these appendages, however, remains poorly characterized. Using tools we helped develop to label type IV pili in live cells, we will address how motor ATPases, minor pilins, and other environmental cues regulate pilus dynamic activity. Second, we will study how two membrane-embedded DNA-binding transcription factors, ChiS and TfoS, coordinate to activate the chitin regulon in V. cholerae. Membrane- embedded regulators are understudied, and this work will help elucidate the dynamics and constraints for the DNA-binding activity of membrane-embedded vs soluble transcription factors. Third, we will use a combination of cell biological and genetic approaches to study horizontal gene transfer by natural transformation. Namely, we will address the spatiotemporal dynamics of natural transformation within chitin biofilms; and the impact of neighbor predation on these dynamics. Also, we will formally test the long-standing, yet untested, hypothesis that DNA uptake during natural transformation plays an important nutritional role. Together, our basic research extends a fundamental understanding of a number of critical and conserved processes (e.g. pili, signal transduction, horizontal gene transfer) that are shared by diverse microbial species, including many pathogens.

项目摘要 Dalia实验室研究了水平基因转移的调节和机制， 使用霍乱弧菌作为模型系统进行转化（NT）。虽然这种细菌是病原体， 对于霍乱这种传染病，我们不寻求研究细菌的致病机理。相反，我们充分利用这一点- 建立的模型系统和遗传工具，我们已经开发出表征NT在生理 相关背景。NT有助于抗生素耐药决定因子和毒力因子的快速传播 细菌病原体中。因此，表征NT的调节和机制可能揭示新的 治疗各种临床相关感染的方法。 NT所需的基因受到严格的调控，并且只有当霍乱弧菌在细胞表面形成生物膜时才被诱导。 水生环境中甲壳类浮游动物的几丁质壳。甲壳素生物膜的形成是 也是重要的生存这种兼性病原体在其环境水库，并促进 霍乱的水传播弧菌-几丁质相互作用可以很容易地在实验室环境中进行研究， 为研究NT提供了一个生理相关的和高度易处理的模型系统。在接下来的五年里， 我们会集中在三个主要范畴。首先，霍乱弧菌使用称为IV型皮利的动态表面附属物， 与几丁质表面结合并吸收NT的DNA。调节动态扩展的机制 然而，这些附属物的收缩仍然没有得到很好的表征。使用我们帮助开发的工具， 标记活细胞中IV型皮利，我们将讨论运动ATP酶、次要菌毛蛋白和其他环境线索 调节菌毛动态活动。第二，我们将研究两个膜嵌入的DNA结合 转录因子ChiS和TfoS协同激活霍乱弧菌中的几丁质调节子。膜- 嵌入式监管机构是欠研究，这项工作将有助于阐明的动态和约束， 膜包埋与可溶性转录因子的DNA结合活性。第三，我们将使用组合 利用细胞生物学和遗传学方法研究自然转化的水平基因转移。也就是说， 我们将讨论甲壳素生物膜内自然转化的时空动力学;以及 邻居捕食这些动态。此外，我们将正式测试长期存在的，但未经检验的假设， DNA在自然转化过程中的吸收起着重要的营养作用。我们的基础研究 扩展了对许多关键和保守过程的基本理解（例如，皮利，信号 转导、水平基因转移），这些基因由包括许多病原体在内的多种微生物物种共享。

项目成果

Retraction ATPase Motors from Three Orthologous Type IVa Pilus Systems Support Promiscuous Retraction of the Vibrio cholerae Competence Pilus.

来自三个直系同源 IVa 型菌毛系统的回缩 ATP 酶马达支持霍乱弧菌能力菌毛的混杂回缩。

• DOI: 10.1128/jb.00126-22
• 发表时间: 2022
• 期刊: Journal of bacteriology
• 影响因子: 3.2
• 作者: Couser,Evan;Chlebek,JenniferL;Dalia,AnkurB
• 通讯作者: Dalia,AnkurB

ComM is a hexameric helicase that promotes branch migration during natural transformation in diverse Gram-negative species.

• DOI: 10.1093/nar/gky343
• 发表时间: 2018-07-06
• 期刊: Nucleic acids research
• 影响因子: 14.9
• 作者: Nero TM;Dalia TN;Wang JC;Kysela DT;Bochman ML;Dalia AB
• 通讯作者: Dalia AB

Membrane-localized expression, production and assembly of Vibrio parahaemolyticus T3SS2 provides evidence for transertion.

• DOI: 10.1038/s41467-023-36762-z
• 发表时间: 2023-03-02
• 期刊: NATURE COMMUNICATIONS
• 影响因子: 16.6
• 作者: Kaval, Karan Gautam;Chimalapati, Suneeta;Siegel, Sara D.;Garcia, Nalleli;Jaishankar, Jananee;Dalia, Ankur B.;Orth, Kim
• 通讯作者: Orth, Kim

The ChiS-Family DNA-Binding Domain Contains a Cryptic Helix-Turn-Helix Variant.

• DOI: 10.1128/mbio.03287-20
• 发表时间: 2021-03-16
• 期刊: mBio
• 影响因子: 6.4
• 作者: Klancher CA;Minasov G;Podicheti R;Rusch DB;Dalia TN;Satchell KJF;Neiditch MB;Dalia AB
• 通讯作者: Dalia AB

Retraction of DNA-bound type IV competence pili initiates DNA uptake during natural transformation in Vibrio cholerae.

• DOI: 10.1038/s41564-018-0174-y
• 发表时间: 2018-07
• 期刊: Nature microbiology
• 影响因子: 28.3
• 作者: Ellison CK;Dalia TN;Vidal Ceballos A;Wang JC;Biais N;Brun YV;Dalia AB
• 通讯作者: Dalia AB