RUI: Characterization of the gene regulatory network promoting hormogonium development in the filamentous cyanobacterium Nostoc punctiforme

RUI：丝状蓝藻发菜中促进激素发育的基因调控网络的表征

• 批准号: 1753690
• 负责人: Doug Risser
• 金额: $ 29.88万
• 依托单位: University of the Pacific
• 依托单位国家: 美国
• 项目类别: Standard Grant
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-03-01 至 2022-02-28
• 项目状态: 已结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=1753690&HistoricalAwards=false
• 关键词: RUI; Characterization; gene; regulatory; network

The filamentous cyanobacteria are a group of photosynthetic microorganisms that first evolved about 2.5 billion years ago, making them one of the first multicellular organisms on earth. These relatively simple multicellular organisms provide an excellent, cost-effective model system for studying fundamental aspects of developmental biology. Additionally, because these bacteria are relatively easy to modify genetically, and are capable of both converting sunlight into energy and providing a source of nitrogen-based fertilizer to certain plants, they are of considerable interest for development in biofuel production and agriculture. This project is focused on characterizing the genetic mechanism controlling the development of specialized filaments that are capable of movement, using the model strain Nostoc punctiforme. As part of the broader impacts, this project will also provide training for both undergraduate and graduate students in state-of-the art genetic and molecular techniques, as well as an outreach program to local area schools which serve a diverse student body, many of whom are economically disadvantaged. Aspects of this project will be incorporated into teaching labs and several undergraduate and graduate students will participate in the research, including students recruited from the Community Involvement Program (C.I.P.) at University of the Pacific, which serves first generation college students from ethnically underrepresented and economically disadvantaged backgrounds. Students recruited from C.I.P. will be provided support for summer research assistantships and also participate in an outreach program for 5th-8th grade classrooms at local schools where they will disseminate a learning module using a portable fluorescence microscope to explore cell biology.Filamentous cyanobacteria are among the most developmentally complex prokaryotes and the study of these organisms has provided valuable insight into developmental biology. Many species develop an array of specialized cell types including motile filaments termed hormogonia that facilitate dispersal. Hormogonia are also essential for the formation of supracellular structures and the establishment of nitrogen-fixing plant- and fungal-cyanobacterial symbioses that contribute significantly to global nitrogen fixation. Currently, the underlying molecular interactions controlling hormogonium development and ecologically important hormogonium-dependent processes are largely undefined. Based on recent studies and preliminary data, the working hypothesis is that hormogonium development is governed by a conserved gene regulatory network that includes sigma factors, partner-switching regulatory systems, the hmp chemotaxis system, and several additional uncharacterized components. This project has two specific aims: 1) Identify and characterize components of the gene regulatory network promoting hormogonium development, and 2) Define the role of sigma factors and partner-switching regulatory systems in hormogonium development. The project uses forward and reverse genetic approaches combined with a range of phenotypic analyses of mutant strains including morphological analyses and immunological assays of hormogonium-specific protein and polysaccharide expression, as well as transcriptomic studies to define the gene regulatory network promoting hormogonium development in the model filamentous cyanobacterium Nostoc punctiforme. Completion of this project will lay the foundation for a model of the gene regulatory network promoting hormogonium development that can then be used to rationally design genetically modified strains of filamentous cyanobacteria for various applications including biofuel production and novel plant-cyanobacterial symbioses.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.

丝状蓝细菌是一组光合微生物，首次进化于大约 25 亿年前，使它们成为地球上最早的多细胞生物之一。这些相对简单的多细胞生物为研究发育生物学的基本方面提供了一个优秀的、具有成本效益的模型系统。此外，由于这些细菌相对容易进行基因改造，并且能够将阳光转化为能量并为某些植物提供氮基肥料来源，因此它们对于生物燃料生产和农业的发展具有很大的兴趣。该项目的重点是利用模式菌株发菜来表征控制能够运动的特殊细丝发育的遗传机制。作为更广泛影响的一部分，该项目还将为本科生和研究生提供最先进的遗传和分子技术方面的培训，并为当地学校提供外展计划，为多元化的学生群体提供服务，其中许多学生在经济上处于不利地位。该项目的各个方面将纳入教学实验室，一些本科生和研究生将参与研究，包括从太平洋大学社区参与计划（C.I.P.）招募的学生，该计划为来自种族代表性不足和经济弱势背景的第一代大学生提供服务。从 C.I.P. 招募的学生将获得暑期研究助学金的支持，并参加当地学校 5 至 8 年级教室的外展计划，在那里他们将传播使用便携式荧光显微镜探索细胞生物学的学习模块。丝状蓝藻是发育最复杂的原核生物之一，对这些生物体的研究为发育生物学提供了宝贵的见解。许多物种发展出一系列特殊的细胞类型，包括被称为激素原细胞的活动丝，促进分散。激素对于细胞上结构的形成以及固氮植物和真菌-蓝藻共生体的建立也至关重要，这些共生体对全球固氮有显着贡献。目前，控制激素发育的潜在分子相互作用和生态上重要的激素依赖性过程在很大程度上尚不清楚。根据最近的研究和初步数据，工作假设是激素的发育是由保守的基因调控网络控制的，该网络包括 sigma 因子、伙伴转换调控系统、hmp 趋化系统和几个其他未表征的组件。该项目有两个具体目标：1）识别和表征促进激素发育的基因调控网络的组成部分，2）定义西格玛因子和伴侣转换调控系统在激素发育中的作用。该项目采用正向和反向遗传方法，结合一系列突变菌株的表型分析，包括形态学分析和激素特异性蛋白和多糖表达的免疫测定，以及转录组研究，以确定丝状蓝藻模型丝状发菜中促进激素发育的基因调控网络。该项目的完成将为促进激素发育的基因调控网络模型奠定基础，该模型随后可用于合理设计丝状蓝藻转基因菌株，用于各种应用，包括生物燃料生产和新型植物-蓝藻共生体。该奖项反映了 NSF 的法定使命，并通过利用基金会的智力价值和更广泛的影响进行评估，认为值得支持。 审查标准。

项目成果

A partner-switching regulatory system controls hormogonium development in the filamentous cyanobacterium Nostoc punctiforme

• DOI: 10.1111/mmi.14061
• 发表时间: 2018-08-01
• 期刊: MOLECULAR MICROBIOLOGY
• 影响因子: 3.6
• 作者: Riley, Kelsey W.;Gonzalez, Alfonso;Risser, Douglas D.
• 通讯作者: Risser, Douglas D.

The Hybrid Histidine Kinase HrmK Is an Early-Acting Factor in the Hormogonium Gene Regulatory Network

混合组氨酸激酶 HrmK 是激素基因调控网络中的早期作用因子

• DOI: 10.1128/jb.00675-19
• 发表时间: 2020
• 期刊: Journal of Bacteriology
• 影响因子: 3.2
• 作者: Zuniga, Esthefani G.;Figueroa, Natalie M.;Gonzalez, Alfonso;Pantoja, Adriana P.;Risser, Douglas D.
• 通讯作者: Risser, Douglas D.

A Tripartite, Hierarchical Sigma Factor Cascade Promotes Hormogonium Development in the Filamentous Cyanobacterium Nostoc punctiforme

• DOI: 10.1128/msphere.00231-19
• 发表时间: 2019-05-01
• 期刊: MSPHERE
• 影响因子: 4.8
• 作者: Gonzalez, Alfonso;Riley, Kelsey W.;Risser, Douglas D.
• 通讯作者: Risser, Douglas D.

The cyanobacterial taxis protein HmpF regulates type IV pilus activity in response to light

• DOI: 10.1073/pnas.2023988118
• 发表时间: 2021-03-23
• 期刊: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA
• 影响因子: 11.1
• 作者: Harwood, Thomas, V;Zuniga, Esthefani G.;Risser, Douglas D.
• 通讯作者: Risser, Douglas D.

Identification of a hormogonium polysaccharide‐specific gene set conserved in filamentous cyanobacteria

• DOI: 10.1111/mmi.14566
• 发表时间: 2020-07
• 期刊: Molecular Microbiology
• 影响因子: 3.6
• 作者: Esthefani G Zuniga;Kelvin K A Boateng;Nhi U Bui;Shadi Kurnfuli;Sawsan M. Muthana;Douglas D. Risser