"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: 10401858
• 负责人: Elizabeth Hesper Rego
• 金额: $ 41.78万
• 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/10401858
• 关键词: Antibiotic Resistance; Antibiotic Therapy; Antibiotic susceptibility; Antibiotics; Bacteria; Bacterial Infections; Behavior; Biochemical; Cause of Death; Cell division; Cells; Characteristics; Communication; Complex; Coupled; Cytokinesis; Data; Daughter; Disease; Drug Design; Drug Tolerance; Escherichia coli; Event; Foundations; Frequencies; Future; Gene Deletion; Genes; Genetic; 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; 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）是由结核分枝杆菌引起的细菌感染（MTB），现在是主要原因 单一传染毒剂的死亡。原因之一是MTB细胞的亚群甚至可以生存 冗长的化学疗法，防止治愈疾病。这些幸存的细胞在表型上具有耐受性，但不是 具有抗生素治疗的遗传性抗性。因此，遗传上相同细菌表现出不同的能力 表型是治疗结核病的重要障碍。更好地理解分子 这种现象的基础机制可能会导致结核病和其他分枝杆菌的治疗进步 感染。许多异质性始于分枝杆菌细胞分裂。每次分枝杆菌 分割它会产生具有不同特征的女儿。我们最近发现这个过程是 遗传编码。删除我们命名为喇嘛的单个基因会导致细胞生长和分裂 更对称地，更容易受到某些抗生素的影响。喇嘛的功能及其如何 介导的不对称生长和分裂尚不清楚。在这里，我们建议研究分子 喇嘛的功能。我们发布的初步数据表明，喇嘛本地化到了部门的地点 抑制新生长极的成熟。此外，我们已经将喇嘛连接到磷酸化 必不可少的肽聚糖合酶的状态，并发现其自身的本地化受到监管 磷酸化。这导致了我们的假设，即喇嘛动态地打断了未知的交流 在磷酸化中完成分裂和伸长的多蛋白复合物之间的继电器 - 依赖方式。要测试该模型，我们提出以下目的：（1）定义通信继电器 在分裂和伸长综合体之间； （2）动态绘制导致的调节事件 不对称。我们的创新是研究一种分枝杆菌特异性蛋白，在 遗传上相同的人群。我们将利用我们在高级成像技术方面的专业知识来做到这一点 结合更传统的方法。这些目标的成功完成将导致关于 可以用分子和生化方法测试喇嘛的功能。此外，我们的结果将 促进我们对细胞分区介导的异质性的分子基础的理解，这具有远大的 对结核病的治疗产生后果。例如，确定分子机制 导致细菌的亚群可以更好地生存抗生素疗法，这将使我们能够设计药物 针对异质性的策略。这种干预措施可以更快地治疗结核 极大地有助于减轻结核病疾病的全球负担。