Salmonella sRNAs drive the decision between active stress resistance and persister cell dormancy

沙门氏菌 sRNA 驱动主动应激抵抗和持久细胞休眠之间的决定

• 批准号: 2219900
• 负责人: Glen Borchert
• 金额: $ 99.87万
• 依托单位: University of South Alabama
• 依托单位国家: 美国
• 项目类别: Continuing Grant
• 财政年份: 2022
• 资助国家: 美国
• 起止时间: 2022-08-15 至 2025-07-31
• 项目状态: 未结题
• 来源: https://www.nsf.gov/awardsearch/showAward?AWD_ID=2219900&HistoricalAwards=false
• 关键词: Salmonella; sRNAs; drive; decision; between

Bacterial persister cells are relatively inactive metabolically, able to cope with long-term environmental stress and are relatively tolerant of antibiotics. This project aims to study the processes that lead to persister cell formation, as a better understanding of these processes could significantly improve our ability to address societal challenges such as antibiotic resistance, foodborne illness outbreaks, and agricultural diseases. In addition, this project provides interdisciplinary student training opportunities in microbiology, molecular biology, and computational genetics/bioinformatics. Local high school students will directly benefit from this project through two separate initiatives. Notably, these efforts are intended to increase underrepresented minority student interest and enrollment in biology and other STEM fields. The sRNA profile of Salmonella subjected to short term carbon starvation is highly distinct from that seen during prolonged starvation. Similarly, highly distinct sRNA profiles are associated with initial and prolonged cellular desiccation. In contrast, significant overlaps between the sRNAs expressed in cells subjected to short durations of carbon starvation and desiccation, as well as significant overlaps between the sRNAs expressed during prolonged desiccation and long-term carbon starvation have been observed. Furthermore, several of the sRNAs commonly induced during short duration stress exposures are expressed from promoters transcribed via the RNA polymerase (RNAP) sigma subunit RpoS. Conversely, many of the sRNAs commonly induced during long term exposures are expressed from promoters targeted by the alternative sigma subunit RpoE. Together, these findings suggest the following: alternative RNAP sigma subunit selection and consequent expression of distinct sets of sRNAs drive the decision between active stress resistance and persister formation in Salmonella. Against this background, the work outlined for this project is significant, as it will employ an array of genetic manipulations and transcriptomic assays to characterize new, essential roles for alternative sigma subunits and specific sRNAs in driving the decision between active stress resistance and persister formation. Beyond characterizing the molecular switch driving the decision between active stress resistance and persister formation, the central model tested by this work-alternative sigma factors compete with one another through directing the transcription of distinct sets of sRNAs that inhibit opposing sigma factors-may well constitute a general mechanism of prokaryotic sigma molecular switch regulation with implications for an array of additional processes. As such, the work performed in this study will explore a novel, systems-level regulatory mechanism for global prokaryotic transcriptome reprogramming, which might advance our basic knowledge of the molecular mechanisms driving microbial stress responses.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.

细菌的持留细胞在代谢上相对不活跃，能够科普长期的环境压力，并且对抗生素相对耐受。该项目旨在研究导致持久性细胞形成的过程，因为更好地了解这些过程可以显着提高我们应对抗生素耐药性，食源性疾病爆发和农业疾病等社会挑战的能力。此外，该项目还提供了微生物学，分子生物学和计算遗传学/生物信息学的跨学科学生培训机会。当地高中学生将通过两项单独的举措直接受益于该项目。值得注意的是，这些努力旨在提高少数民族学生对生物学和其他STEM领域的兴趣和入学率。沙门氏菌受到短期碳饥饿的sRNA谱与长期饥饿期间所见的sRNA谱高度不同。类似地，高度不同的sRNA谱与初始和延长的细胞干燥有关。相比之下，已经观察到在经历短时间的碳饥饿和干燥的细胞中表达的sRNA之间的显著重叠，以及在长时间的干燥和长期的碳饥饿期间表达的sRNA之间的显著重叠。此外，在短时间应激暴露期间通常诱导的几种sRNA由经由RNA聚合酶（RNAP）σ亚基RpoS转录的启动子表达。相反，在长期暴露期间通常诱导的许多sRNA由替代性σ亚基RpoE靶向的启动子表达。总之，这些研究结果表明：替代RNAP σ亚基选择和随后的不同sRNA集的表达驱动沙门氏菌中主动应激抗性和持久性形成之间的决定。在此背景下，该项目概述的工作是重要的，因为它将采用一系列遗传操作和转录组学测定来表征替代σ亚基和特定sRNA在驱动主动胁迫抗性和持续形成之间的决定中的新的重要作用。除了表征分子开关驱动之间的决定积极的压力抗性和persister形成，由这项工作测试的中央模型-替代西格玛因素相互竞争，通过指导转录的不同套的sRNA，抑制相反的西格玛因素-很可能构成一个一般的机制，原核西格玛分子开关调节的影响，一系列额外的过程。因此，这项研究将探索一种新的、系统水平的全球原核转录组重编程调控机制，这可能会推进我们对驱动微生物应激反应的分子机制的基本知识。该奖项反映了NSF的法定使命，并通过使用基金会的智力价值和更广泛的影响审查标准进行评估，被认为值得支持。

项目成果

Characterization of a novel sRNA contributing to biofilm formation in Salmonella enterica serovar Typhimurium.

• DOI: 10.17912/micropub.biology.000796
• 发表时间: 2023
• 期刊: microPublication biology
• 作者: Naaz, Sayema;Sakib, Najmuj;Houserova, Dominika;Badve, Rani;Crucello, Aline;Borchert, Glen M
• 通讯作者: Borchert, Glen M