Nucleoid structure and energy metabolism in chlamydial gene expression

衣原体基因表达中的核结构和能量代谢

基本信息

批准号：
8887302
负责人：
SCOTT S GRIESHABER
金额：
$ 18.41万
依托单位：
UNIVERSITY OF IDAHO
依托单位国家：
美国
项目类别：
财政年份：
2014
资助国家：
美国
起止时间：
2014-08-15 至 2017-07-31
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8887302
关键词：
Affect Bacteria Bacterial Sexually Transmitted Diseases Binding Biogenesis Blindness Cell-Free System Cells Chlamydia Chlamydia Infections Chlamydia trachomatis Chromatin Chromatin Structure Chromosomes DNA DNA Footprint DNA Sequence DNA-Directed RNA Polymerase DNase I hypersensitive sites sequencing Deoxyribonuclease I Developing Countries Development Developmental Biology Dissociation Elements Energy Metabolism Forms Controls Funding Mechanisms Gene Expression Gene Expression Profile Gene Expression Regulation Genes Genetic Transcription Germination Glucose Glyceraldehyde Glycolysis Goals Health Hexoses Higher Order Chromatin Structure Histones Human In Vitro Indium Infection Inorganic Phosphate Transporter Knowledge Life Cycle Stages Link Mammalian Cell Maps Measures Medical Metabolic Activation Metabolism Methods Microarray Analysis Pathway interactions Pattern Physical condensation Proteins Protocols documentation Pyruvate RNA Regulation Relaxation Research Role Sexually Transmitted Diseases Site Structure Techniques Time Trachoma Virulence cell type genetic regulatory protein in vivo inorganic phosphate insight isoprenoid novel obligate intracellular parasite pathogen prevent promoter protein expression research study transcriptome sequencing

项目摘要

DESCRIPTION (provided by applicant): Bacteria of the genus Chlamydia are obligate intracellular parasites and include common human pathogens such as Chlamydia trachomatis, a leading cause of sexually transmitted diseases and blinding trachoma. Unlike most bacterial pathogens, C. trachomatis alternates between two physiologically distinct cell forms to establish infection: the infectious Elementary Body (EB) and replicative Reticulate Body (RB). Two histone related proteins, HctA and HctB, regulate compaction and relaxation of chlamydial chromatin during transition between developmental forms and control RNA polymerase access to the DNA. Biogenesis of the chlamydial replication niche depends on the re-initiation of protein expression as the EB germinates into the RB cell type. The factors controlling chlamydial gene expression during differentiation remains a significant knowledge gap. 2-C-methyl-D-erythritol-2,4-cyclodiphosphate (MEC) is an intermediate of the methylerythritol phosphate (MEP) pathway for isoprenoid synthesis that promotes dissociation of chlamydial histones from isolated EB chromatin structures. The MEP pathway starts with condensation of the glycolytic intermediates glyceraldehyde 3-P and pyruvate and is therefore likely to be regulated by glycolytic activity. Expression of the chlamydial hexose phosphate transporter UhpC at the onset of morphological differentiation and recently demonstrated metabolic activation of EBs by glucose 6-P in vitro suggests that activation of glycolysis and pathogen energy metabolism is temporally linked to chromatin decondensation. We hypothesize that the histones, by binding to specific sites or structural elements on the chromosome, allow ordered control of early gene expression by affecting the access of regulatory proteins to promoters and genes involved in the control of differentiation. We further predict that initiation of metabolism is a key element in controlling histone release. The aim of this proposal is to determine the role of chromatin structure in developmental regulation and to establish a link between initiation of EB energy metabolism and regulation of EB chromatin structure immediately upon infection. The relationship between chromatin structure and de novo gene transcription will be determined using high throughput DNA- and RNA-seq techniques to measure changes in DNA accessibility and RNA transcription upon incubation of bacteria in a host cell-free medium containing glucose 6-P, and during early differentiation. Comparing the regulation of the EB chromatin structure early in development in vivo to chromatin structure changes of activated EBs in vitro will provide unprecedented insight into the mechanisms of EB germination. Additionally, as the MEP pathway is not present in mammalian cells, understanding the novel role of metabolism in activating the chlamydial pathogenic cycle will provide potential avenues for preventing or treating chlamydial infections.

描述（由申请人提供）：衣原体属细菌是专性细胞内寄生虫，包括常见的人类病原体，例如沙眼衣原体，它是性传播疾病和致盲沙眼的主要原因。与大多数细菌病原体不同，沙眼衣原体在两种生理上不同的细胞形式之间交替来建立感染：传染性基本体（EB）和复制性网状体（RB）。两种组蛋白相关蛋白 HctA 和 HctB 在发育形式之间的转变过程中调节衣原体染色质的压缩和松弛，并控制 RNA 聚合酶接近 DNA。衣原体复制生态位的生物发生取决于 EB 萌发为 RB 细胞类型时蛋白质表达的重新启动。在分化过程中控制衣原体基因表达的因素仍然是一个重大的知识空白。 2-C-甲基-D-赤藓糖醇-2,4-环二磷酸 (MEC) 是甲基赤藓糖醇磷酸 (MEP) 类异戊二烯合成途径的中间体，可促进衣原体组蛋白从分离的 EB 染色质结构中解离。 MEP 途径始于糖酵解中间体甘油醛 3-P 和丙酮酸的缩合，因此可能受到糖酵解活性的调节。衣原体己糖磷酸转运蛋白 UhpC 在形态分化开始时的表达以及最近在体外通过葡萄糖 6-P 进行的 EB 代谢激活表明，糖酵解和病原体能量代谢的激活在时间上与染色质解缩相关。我们假设组蛋白通过与染色体上的特定位点或结构元件结合，通过影响调节蛋白与启动子和参与分化控制的基因的接触来有序控制早期基因表达。我们进一步预测新陈代谢的启动是控制组蛋白释放的关键因素。该提案的目的是确定染色质结构在发育调节中的作用，并在感染后立即启动 EB 能量代谢和调节 EB 染色质结构之间建立联系。将使用高通量 DNA 和 RNA 测序技术来确定染色质结构和从头基因转录之间的关系，以测量在含有葡萄糖 6-P 的宿主无细胞培养基中孵育细菌时 DNA 可及性和 RNA 转录的变化，以及早期分化期间。将体内发育早期 EB 染色质结构的调节与体外激活的 EB 染色质结构的变化进行比较，将为 EB 萌发机制提供前所未有的见解。此外，由于哺乳动物细胞中不存在 MEP 途径，了解代谢在激活衣原体致病循环中的新作用将为预防或治疗衣原体感染提供潜在途径。