"The molecular mechanisms of asymmetric cell division in mycobacteria."

“分枝杆菌不对称细胞分裂的分子机制。”

• 批准号: 10612036
• 负责人: Elizabeth Hesper Rego
• 金额: $ 40.64万
• 依托单位: YALE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-05-12 至 2025-04-30
• 项目状态: 未结题
• 来源: https://reporter.nih.gov/project-details/10612036
• 关键词: Antibiotic Therapy; Antibiotic susceptibility; Antibiotics; Bacteria; Bacterial Infections; Behavior; Biochemical; Cause of Death; Cell Survival; Cell division; Cells; Characteristics; Communication; Complex; Coupled; Cytokinesis; Data; Daughter; Disease; Drug Design; Drug Tolerance; Escherichia coli; Event; Experimental Genetics; Frequencies; Future; Gene Deletion; Genes; Genus Mycobacterium; Goals; Growth; Heterogeneity; Imaging Techniques; Infection; Infectious Agent; Interruption; Intervention; Lead; Maps; Mediating; Methods; Modeling; Molecular; Multiprotein Complexes; Mycobacterium Infections; Mycobacterium tuberculosis; Names; Organism; Peptidoglycan; Phenotype; Phosphorylation; Phosphotransferases; Population; Predisposition; Process; Proteins; Publishing; Regulatory Pathway; Resistance; Route; Series; Site; Source; Testing; Therapeutic; Time; Tuberculosis; Tyrosine; Work; cell growth; chemotherapy; design; experimental study; gene function; human pathogen; innovation; mutant; mycobacterial; new growth; pathogenic bacteria; prevent; protein protein interaction; tuberculosis treatment

Abstract Tuberculosis (TB), a bacterial infection caused by Mycobacterium tuberculosis (Mtb), is now the leading cause of death by a single infectious agent. One reason for this is that subpopulations of Mtb cells can survive even lengthy chemotherapy, preventing cure of disease. These surviving cells are phenotypically tolerant, but not genetically resistant, to antibiotic therapy. Thus, the ability of genetically identical bacteria to display different phenotypes is a significant obstacle for the treatment of TB. A better understanding of the molecular mechanisms underlying this phenomenon could lead to therapeutic advances for TB and other mycobacterial infections. Much of the heterogeneity begins at mycobacterial cell division. Every time a mycobacterium divides it produces daughters with different characteristics. We have recently discovered that this process is genetically encoded. Deleting a single gene, which we have named lamA, leads to cells that grow and divide more symmetrically and are more uniformly susceptible to certain antibiotics. The function of LamA and how it mediates asymmetric growth and division are unknown. Here, we propose to investigate the molecular function of LamA. Our published and preliminary data show that LamA localizes to the site of division, where it inhibits the maturation of the new growth poles. In addition, we have connected LamA to the phosphorylation state of an essential peptidoglycan synthase, and have discovered that its own localization is regulated by phosphorylation. This leads to our hypothesis that LamA dynamically interrupts an unknown communication relay between the multi-protein complexes that accomplish division and elongation, in a phosphorylation- dependent manner. To test this model, we propose the following aims: (1) define the communication relay between the division and elongation complexes; and, (2) dynamically map the regulatory events that lead to asymmetry. Our innovation is to study a mycobacterial-specific protein that creates heterogeneity in a genetically identical population. We will do so by leveraging our expertise in advanced imaging techniques in combination with more traditional methods. Successful completion of these aims will lead to hypotheses about the function of LamA that can be tested with molecular and biochemical approaches. Further, our results will advance our understanding of the molecular basis of cell-division mediated heterogeneity, which has far- reaching consequences for the treatment of TB. For example, identifying the molecular mechanism(s) that leads to subpopulations of bacteria better able to survive antibiotic therapy will allow us to design drug strategies that target heterogeneity. Such interventions could treat TB more quickly, something that would greatly help reduce the global burden of TB disease.

抽象的 结核病 (TB) 是一种由结核分枝杆菌 (Mtb) 引起的细菌感染，现已成为主要原因 单一传染源导致的死亡。原因之一是 Mtb 细胞亚群甚至可以存活 漫长的化疗，阻碍了疾病的治愈。这些存活的细胞具有表型耐受性，但不耐受 对抗生素治疗有遗传耐药性。因此，基因相同的细菌表现出不同的能力 表型是结核病治疗的重大障碍。更好地了解分子 这种现象背后的机制可能会导致结核病和其他分枝杆菌的治疗进展 感染。大部分异质性始于分枝杆菌细胞分裂。每次出现分枝杆菌 分裂产生了具有不同特征的女儿。我们最近发现这个过程是 基因编码的。删除单个基因（我们将其命名为 lamA）会导致细胞生长和分裂 更加对称，并且对某些抗生素更加敏感。 LamA 的功能及其作用 介导不对称生长和分裂尚不清楚。在这里，我们建议研究分子 拉玛的功能。我们公布的初步数据表明 LamA 定位于分裂部位，在那里它 抑制新生长极的成熟。此外，我们已将 LamA 连接到磷酸化 一种必需的肽聚糖合酶的状态，并发现其自身的定位受 磷酸化。这导致我们假设 LamA 动态中断未知通信 在完成分裂和伸长的多蛋白复合物之间进行中继，以磷酸化- 依赖方式。为了测试这个模型，我们提出以下目标：（1）定义通信中继 分裂复合体和伸长复合体之间； (2) 动态映射导致的监管事件 不对称。我们的创新是研究一种分枝杆菌特异性蛋白质，该蛋白质在 基因相同的群体。我们将利用我们在先进成像技术方面的专业知识来做到这一点 与更传统的方法相结合。成功完成这些目标将导致以下假设 LamA 的功能可以通过分子和生化方法进行测试。此外，我们的结果将 增进了我们对细胞分裂介导的异质性的分子基础的理解，这已经远 达到结核病治疗的效果。例如，确定分子机制 导致细菌亚群能够更好地在抗生素治疗中生存，这将使我们能够设计药物 针对异质性的策略。此类干预措施可以更快地治疗结核病， 极大地有助于减轻全球结核病负担。