A novel protein export chaperone of Mycobacterium tuberculosis

结核分枝杆菌的新型蛋白质输出伴侣

• 批准号: 10079468
• 负责人: Miriam S. Braunstein
• 金额: $ 57.38万
• 依托单位: UNIV OF NORTH CAROLINA CHAPEL HILL
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-01-03 至 2024-12-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10079468
• 关键词: Antigens; Antitubercular Agents; Attenuated Vaccines; Bacterial Physiology; Bacterial Proteins; Binding Sites; Biochemical; Biochemical Genetics; Biology; Categories; Cessation of life; Complex; Crystallization; Cytoplasm; Data; Development; Engineering; Environment; Epidemic; Exhibits; Future; Genetic Structures; Genus Mycobacterium; Goals; Growth; Health; Hydrophobicity; Immune response; Infection; Interdisciplinary Study; Knowledge; Label; Laboratories; Lead; Length; Lipids; Measures; Molecular; Molecular Biology; Molecular Chaperones; Mycobacterium tuberculosis; Pathogenesis; Pathway interactions; Peptides; Phagosomes; Phosphoric Monoester Hydrolases; Play; Protein Export Pathway; Proteins; Proteomics; Research Personnel; Roentgen Rays; Role; Structure; Substrate Specificity; Testing; Tuberculosis; Virulence; World Health; biological systems; biophysical analysis; cell envelope; drug development; extracellular; improved; macrophage; mycobacterial; novel; novel strategies; novel therapeutics; pathogenic bacteria; prevent; stoichiometry; tool; tuberculosis treatment; vaccine development

Mycobacterium tuberculosis (Mtb), the causative agent of tuberculosis (TB), represents a severe world health crisis (4,000 TB deaths daily). A better understanding of Mtb biology and pathogenesis will drive development of novel strategies to control the TB epidemic. In bacterial pathogens, like Mtb, many proteins are exported to the bacterial cell envelope or the extracellular environment in order to carry out critical functions in bacterial physiology, virulence or immune responses. Thus, Mtb pathways that export proteins could be targeted or exploited for the development of novel anti-TB control measures. However, significant gaps exist in our understanding of Mtb protein export. This proposal is to determine the mechanism of SatS, a novel protein export chaperone we discovered in Mtb. SatS is a chaperone for a subset of proteins that are exported by the specialized SecA2 protein export pathway, and SatS is required for intracellular growth of Mtb in macrophages. However, SatS shares no sequence or structural similarity with any previously characterized proteins and the mechanism of SatS is completely unknown. Substrate specificity and the scope of SatS substrates are also unknown. Aim 1 of this proposal is to determine the mechanistic details of SatS function in protein export. Aim 2 is to determine the structures of SatS and that of SatS in complex with peptides of substrates. Aim 3 is to identify SatS-binding sites in substrates and to identify additional SatS substrates. By completing these Aims, we will determine the mechanism and contribution of SatS to Mtb protein export and biology. More broadly, these studies will improve our understanding of bacterial strategies for exporting proteins and of the diversity of molecular chaperones across biological systems. Long-term, the results could lead to strategies for inhibiting protein export as a novel anti-TB therapy. Alternatively, the knowledge gained could be harnessed to engineer mycobacterial strains with improved capacity to export proteins for use as experimental tools or as live, attenuated vaccines with enhanced antigen export.

结核分枝杆菌 (Mtb) 是结核病 (TB) 的病原体，代表着严重的世界健康问题 危机（每天有 4,000 名结核病患者死亡）。更好地了解结核分枝杆菌生物学和发病机制将推动发展 控制结核病流行的新策略。在细菌病原体（如结核分枝杆菌）中，许多蛋白质被输出到 细菌细胞包膜或细胞外环境，以在细菌中执行关键功能 生理学、毒力或免疫反应。因此，输出蛋白质的 Mtb 途径可以被靶向或 用于开发新型抗结核控制措施。然而，我们在这方面还存在重大差距 了解 Mtb 蛋白输出。 该提案旨在确定 SatS 的机制，SatS 是我们发现的一种新型蛋白质输出伴侣 在山地。 SatS 是由专门的 SecA2 蛋白质导出器导出的蛋白质子集的伴侣 途径，并且 SatS 是巨噬细胞中 Mtb 细胞内生长所必需的。然而，SatS 没有分享 与任何先前表征的蛋白质的序列或结构相似性，SatS 的机制是 完全未知。 SatS 底物的底物特异性和范围也是未知的。这个目标1 提议是确定 SatS 在蛋白质输出中的功能机制细节。目标 2 是确定 SatS 的结构以及 SatS 与底物肽复合物的结构。目标 3 是识别 SatS 结合 底物中的位点并识别其他 SatS 底物。通过完成这些目标，我们将确定 SatS 对 Mtb 蛋白输出和生物学的机制和贡献。更广泛地说，这些研究将 提高我们对细菌输出蛋白质策略和分子多样性的理解 跨生物系统的伴侣。从长远来看，这些结果可能会导致抑制蛋白质的策略 作为一种新型抗结核疗法出口。或者，可以利用所获得的知识来设计 具有改进的输出蛋白质用作实验工具或活体的能力的分枝杆菌菌株， 具有增强抗原输出的减毒疫苗。