Cellular stress response to the oxidizing effects of bleach

描述（由申请人提供）：次氯酸（HOCl）是家用漂白剂的活性成分，在先天免疫反应期间起着强效抗菌剂的作用。尽管它被广泛使用，但令人惊讶的是，人们对细菌如何感知和响应漂白剂知之甚少。据我们所知，没有HOCl敏感的转录调控已确定在任何生物体的日期。我们实验室的初步结果表明，保守的NemR蛋白在大肠杆菌中是HOCl特异性转录抑制因子。杆菌我们有证据表明，HOCl氧化导致NemR中形成特定的分子间二硫键，从而调节转录活性并诱导漂白耐受性所需的基因表达。我将使用体外生物化学方法和体内遗传技术来研究NemR在细菌耐漂白剂中的作用。我将通过分析保守的半胱氨酸残基在NemR中的作用以及HOCl处理后NemR中发生的结构和功能变化来研究HOCl传感的机制。这项研究的结果将对我们理解细胞如何感知HOCl和修复细胞损伤产生潜在的广泛影响。过量的HOCl产生涉及许多人类疾病的进展，包括慢性炎症、动脉粥样硬化和癌症，以及细菌与人类免疫系统的相互作用。 公共卫生相关性：本申请中提出的项目将深入了解细菌如何感知和响应次氯酸的氧化应激效应，次氯酸是漂白剂的活性抗菌成分。这项工作与人类健康有关，不仅因为漂白剂是常用的消毒剂，而且因为次氯酸是免疫系统的白色血细胞产生的重要抗菌化合物。

DESCRIPTION (provided by applicant): Hypochlorous acid (HOCl), the active component of household bleach, functions as a powerful antimicrobial during the innate immune response. Despite its widespread use, surprisingly little is known about how bacteria sense and respond to bleach. To our knowledge, no HOCl-sensitive transcriptional regulator has been identified in any organism to date. Preliminary results from our lab implicate the conserved NemR protein as an HOCl-specific transcriptional repressor in E. coli. We have evidence that oxidation by HOCl causes the formation of specific intermolecular disulfide bonds in NemR, which modulate transcriptional activity and induce the expression of genes required for bleach tolerance. I will use both in vitro biochemical approaches and in vivo genetic techniques to examine the role that NemR plays in bacterial bleach resistance. I will investigate the mechanism of HOCl sensing by analyzing the role of conserved cysteine residues in NemR and the structural and functional changes in NemR that occur upon HOCl-treatment. The results of this study will have potentially broad implications on our understanding of how cells sense HOCl and repair cellular damage. Excessive HOCl-production is implicated in the progression of many human diseases, including chronic inflammation, atherosclerosis and cancer and in bacterial interactions with the human immune system. PUBLIC HEALTH RELEVANCE: The project proposed in this application will provide insights into how bacteria sense and respond to the oxidative stress effects of hypochlorous acid, the active antimicrobial component of bleach. This work is relevant to human health not only because bleach is a commonly used disinfectant, but also because hypochlorous acid is an important antimicrobial compound produced by the white blood cells of the immune system.