Zinc Homeostasis in Bacillus subtilis

枯草芽孢杆菌中的锌稳态

• 批准号: 9222760
• 负责人: John D Helmann
• 金额: $ 30.7万
• 依托单位: CORNELL UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2000
• 资助国家: 美国
• 起止时间: 2000-02-01 至 2018-02-28
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9222760
• 关键词: Acclimatization; Address; Affect; Affinity; Animal Model; Apoproteins; Bacillus subtilis; Binding; Biochemical; Biological Models; Buffers; Cells; Communicable Diseases; Cytoplasm; DNA Binding; Development; Dimerization; Elements; Enzymes; Factor V; Foundations; Gene Expression; Genes; Genetic; Glutathione; Growth; Homeostasis; Human; In Vitro; Inductively Coupled Plasma Mass Spectrometry; Innate Immune Response; Invaded; Ions; Kinetics; Leukocyte L1 Antigen Complex; Maintenance; Measures; Mediating; Metalloproteins; Metals; Molecular; Molecular Weight; Monitor; Nature; Nutrient; Outcome; Pathogenicity; Pathway interactions; Peroxides; Physiology; Process; Proteins; Regulation; Regulon; Reporter; Repression; Resolution; Reverse Transcriptase Polymerase Chain Reaction; Ribosomal Proteins; Ribosomes; Role; Site; Staphylococcus aureus; Sulfhydryl Compounds; System; Testing; Thermodynamics; Vision; Work; Zinc; Zinc deficiency; analog; antimicrobial drug; cell type; cofactor; deprivation; dimer; improved; in vivo; innovation; insight; metalloenzyme; metalloregulatory protein; paralogous gene; pathogen; prevent; public health relevance; response; sensor; uptake

DESCRIPTION (provided by applicant): Zinc is an essential nutrient for all cells due to its key role as a catalytic and structural cofactor. Competition for zinc and other nutrient metal ions is critical for determining the outcome of host- pathogen interactions. Metalloregulatory proteins sense both zinc deficiency and excess and are required for bacterial acclimation to changes in zinc availability. In Bacillus subtilis, a Gram positive model organism, zinc sufficiency is sensed by Zur (zinc uptake repressor) and zinc excess by CzrA. When zinc levels are limiting for growth, Zur repression is relieved resulting it increased zinc uptake (mediated by the ZnuABC transporter), Zn mobilization by displacement of small, ribosome-associated zinc proteins (L31 and L33), and replacement of a key zinc dependent enzyme (FolE) by a non-zinc requiring alternate enzyme. In the next project period, we will investigate the detailed molecular mechanisms of zinc sensing and define the major components of the labile zinc pool in the cell. Preliminary results have led to five core hypotheses that form the foundation of the Specific Aims. Aim 1a will address the hypothesis that regulation by Zur involves a graded response as the cell transitions from zinc sufficiency to deficiency, and will test the role of negative cooperativity in zinc-binding to Zur in expanding the range of zinc responsiveness. In Aim 1b, we will adapt genetically encoded fluorescent reporters to monitor free zinc levels in vivo and seek to reconcile the exceptionally high (sub-picomolar) zinc affinity of the Zur and CzrA sensors with emerging evidence consistent with free zinc levels in the mid-picomolar range. Aim 2 will address the role of the low molecular weight thiol bacillithiol (BSH) as the major buffer of the labile zinc pool (Aim 2a), the role of small, dispensable ribosome-associated proteins as the major storage form of zinc (Aim 2b), and the roles of these two zinc pools in metallation of FolE, a zinc metalloenzyme sensitive to zinc availability, and other key zinc enzymes. Limitation for zinc by calprotectin, and likely other factors, is a key part of the human innate immune response. Since all of the key zinc homeostasis factors described here are conserved in many important human pathogens, these studies will provide key background information to facilitate the ultimate development of antimicrobial agents that affect metal ion homeostasis.

描述（由申请人提供）：由于锌作为催化和结构辅助因子的关键作用，因此它是所有细胞的必需营养素。锌和其他营养金属离子的竞争对于确定宿主-病原体相互作用的结果至关重要。金属调节蛋白能够感知锌的缺乏和过量，并且是细菌适应锌可用性变化所必需的。在枯草芽孢杆菌（一种革兰氏阳性模式生物）中，检测到锌充足 Zur（锌摄取阻遏物）引起的锌过量和 CzrA 引起的锌过量。当锌水平限制生长时，Zur 抑制会缓解，导致锌摄取增加（由 ZnuABC 转运蛋白介导），通过置换小的核糖体相关锌蛋白（L31 和 L33）来动员锌，以及用不需要锌的替代酶替代关键的锌依赖性酶 (FolE)。在下一个项目期间，我们将研究锌传感的详细分子机制，并定义细胞中不稳定锌池的主要成分。初步结果得出了五个核心假设，构成了具体目标的基础。目标 1a 将解决这样的假设：当细胞从锌充足过渡到缺锌时，Zur 的调节涉及分级反应，并将测试锌与 Zur 结合的负协同性在扩大锌反应范围中的作用。在目标 1b 中，我们将采用基因编码的荧光报告基因来监测体内游离锌水平，并寻求将 Zur 和 CzrA 传感器的极高（亚皮摩尔）锌亲和力与与中皮摩尔范围内的游离锌水平一致的新证据相协调。目标 2 将解决低分子量硫醇杆菌硫醇 (BSH) 作为主要缓冲剂的作用 不稳定的锌池（目标 2a），小的、可有可无的核糖体相关蛋白作为锌的主要储存形式的作用（目标 2b），以及这两个锌池在 FolE（一种对锌可用性敏感的锌金属酶）和其他关键锌酶的金属化中的作用。钙卫蛋白和可能的其他因素对锌的限制是人类先天免疫反应的关键部分。由于本文描述的所有关键锌稳态因子在许多重要的人类病原体中都是保守的，因此这些研究将提供关键的背景信息，以促进影响金属离子稳态的抗菌药物的最终开发。

项目成果

Metal homeostasis and resistance in bacteria.

• DOI: 10.1038/nrmicro.2017.15
• 发表时间: 2017-06
• 期刊: Nature reviews. Microbiology
• 作者: Chandrangsu P;Rensing C;Helmann JD
• 通讯作者: Helmann JD

Intracellular Zn(II) Intoxication Leads to Dysregulation of the PerR Regulon Resulting in Heme Toxicity in Bacillus subtilis.

• DOI: 10.1371/journal.pgen.1006515
• 发表时间: 2016-12
• 期刊: PLoS genetics
• 影响因子: 4.5
• 作者: Chandrangsu P;Helmann JD
• 通讯作者: Helmann JD

Roles of the A and C sites in the manganese-specific activation of MntR.

A和C位点在MNTR的锰特异性激活中的作用。

• DOI: 10.1021/bi301550t
• 发表时间: 2013-01-29
• 期刊: Biochemistry
• 影响因子: 2.9
• 作者: McGuire AM;Cuthbert BJ;Ma Z;Grauer-Gray KD;Brunjes Brophy M;Spear KA;Soonsanga S;Kliegman JI;Griner SL;Helmann JD;Glasfeld A
• 通讯作者: Glasfeld A

Methylglyoxal resistance in Bacillus subtilis: contributions of bacillithiol-dependent and independent pathways.

• DOI: 10.1111/mmi.12489
• 发表时间: 2014-02
• 期刊: Molecular microbiology
• 影响因子: 3.6
• 作者: Chandrangsu P;Dusi R;Hamilton CJ;Helmann JD
• 通讯作者: Helmann JD

Bacillithiol is a major buffer of the labile zinc pool in Bacillus subtilis.

• DOI: 10.1111/mmi.12794
• 发表时间: 2014-11
• 期刊: Molecular microbiology
• 影响因子: 3.6
• 作者: Ma Z;Chandrangsu P;Helmann TC;Romsang A;Gaballa A;Helmann JD
• 通讯作者: Helmann JD