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

基本信息

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
项目类别：
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

项目摘要

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.

项目概要 Dalia实验室研究自然水平基因转移的调控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腹泻病霍乱，我们并不寻求研究细菌发病机制。相反，我们充分利用了这一点建立了模型系统和我们开发的遗传工具来表征 NT 的生理学特征相关背景。 NT 导致抗生素耐药性决定因素和毒力因子的快速传播在细菌病原体中。因此，表征 NT 的调控和机制可能会揭示新的对抗各种临床相关感染的方法。 NT 所需的基因受到严格调控，并且仅当霍乱弧菌在其上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对于这种兼性病原体在其环境储存库中的生存也很重要，并促进霍乱的水传播。弧菌-几丁质相互作用可以在实验室环境中轻松研究，这为研究 NT 提供了一个生理相关且高度易于处理的模型系统。未来五年，我们将重点关注三个主要领域。首先，霍乱弧菌使用称为 IV 型菌毛的动态表面附属物来与几丁质表面结合并吸收 DNA 以进行 NT。调节动态延伸的机制然而，这些附属物的缩回仍不清楚。使用我们帮助开发的工具标记活细胞中的 IV 型菌毛，我们将讨论运动 ATP 酶、次要菌毛蛋白和其他环境线索如何调节菌毛动态活动。其次，我们将研究两个膜嵌入的DNA如何结合转录因子 ChiS 和 TfoS 协调激活霍乱弧菌中的几丁质调节子。膜- 嵌入式监管机构尚未得到充分研究，这项工作将有助于阐明嵌入式监管机构的动态和限制膜嵌入转录因子与可溶性转录因子的 DNA 结合活性。第三，我们将使用组合通过自然转化研究水平基因转移的细胞生物学和遗传学方法。即，我们将解决甲壳素生物膜内自然转化的时空动态；以及影响邻居掠夺这些动态。此外，我们将正式检验长期存在但未经检验的假设自然转化过程中 DNA 的摄取起着重要的营养作用。我们共同开展基础研究扩展了对许多关键和保守过程（例如 pili、信号转导、水平基因转移）是不同微生物物种（包括许多病原体）共有的。

项目成果

期刊论文数量（20）

专著数量（0）

科研奖励数量（0）

会议论文数量（0）

专利数量（0）

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.