权益分类	功能权益	普通用户	{{item.name}}会员
{{category.name}}	{{benefitItem.name}}

Regulation of the Salmonella Pathogenicity Island 1 Type III Secretion System via the hilD 3' untranslated region

通过 hilD 3 非翻译区调节沙门氏菌致病性岛 1 III 型分泌系统

基本信息

批准号：
10625450
负责人：
JAMES M. SLAUCH
金额：
$ 18.68万
依托单位：
UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-05-20 至 2024-04-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/10625450
关键词：
3&apos Untranslated Regions Affect Bacteria Bacterial Infections Base Pairing Binding Sites Bioinformatics Biological Assay Cells Complex Data Development Diarrhea Disease Epithelial Cells Genetic Genetic Transcription Goals Half-Life Human In Vitro Inflammatory Injections Intestines Invaded Knowledge Laboratories Maps Mediating Messenger RNA Methods Microbiology Modeling Molecular Monitor Mutagenesis Mutate Mutation Nucleotides Pathogenesis Pathogenicity Island Phenotype Post-Transcriptional Regulation Prevention Process Proteins Regulation Role SP1 gene Salmonella Sequence Analysis Signal Transduction Site Small RNA Spottings Structural Genes System Systems Analysis Techniques Time Transcript Translations Type III Secretion System Pathway Untranslated Regions Variant Virulence Virulence Factors Work deletion analysis experimental study foodborne pathogen improved in vivo mRNA Stability mRNA Transcript Degradation mRNA Translation model organism mutant novel pathogen posttranscriptional response rho ribonuclease E tool trait transcription termination

项目摘要

PROJECT SUMMARY The foodborne pathogen Salmonella is an important model organism for understanding genetic regulation and bacterial pathogenesis. A requisite for Salmonella to cause disease is the direct injection of effector proteins into host cells via a Type Three Secretion System (T3SS) encoded on Salmonella Pathogenicity Island 1 (SPI1). This critical virulence factor is controlled in response to a plethora of environmental and regulatory signals that dictate expression of the system at the proper time and place in the host. Our long- term goal is to understand overall signal integration that allows this precise regulation. The SPI1 regulatory circuit is controlled by three AraC-like regulators, HilD, HilC, and RtsA, which act in a complex feed-forward regulatory loop to control expression of hilA, encoding the direct regulator of the SPI1 structural genes. Much of the regulatory input is integrated at the level of HilD, including at hilD mRNA translation or stability. The hilD mRNA has an unusual 300 nucleotide 3’ untranslated region (UTR) that acts as an independent module to confer instability to the mRNA. A primary hypothesis is that the hilD 3’ UTR serves as a critical node for integration of regulatory signals. Preliminary data show that mRNA stability is regulated by a novel mechanism involving interaction between Rho-mediated transcriptional termination at the 3’ UTR and RNase E-dependent degradation. Moreover, these activities are independently controlled by sRNAs. The first aim of this proposal is to identify sRNAs and cis-acting sites that regulate via the hilD 3’ UTR. Interacting sRNAs will be identified using an unbiased molecular technique, with base pairing confirmed by mutagenesis. Deletion analysis will identify the site of Rho action in the 3’ UTR. The resulting hilD mRNAs with mutations in sRNA binding sites or Rho-utilization site provide tools for further mechanistic analyses. The second aim is to characterize the mechanism of post-transcriptional regulation via the hilD 3' UTR. The roles of Rho, RNase E, and the small RNAs in the creation and/or processing of the 3’ ends in the hilD 3’ UTR will be monitored using tagging and deep sequence analysis. In vitro transcription will more precisely define the action of Rho in creating terminated hilD transcripts. The interactions of these factors will reveal the mechanistic details of this novel regulation. The SP1 T3SS regulatory circuit serves as a paradigm for understanding the integration of host environmental signals to control a complex virulence phenotype. Analysis of this system is critical to our understanding of this important pathogen.

项目总结