Characterization of gene cluster for glycophosphoinositides of mycobacteria

分枝杆菌糖磷酸肌醇基因簇的表征

• 批准号: 7660942
• 负责人: Devinder Kaur
• 金额: $ 7.35万
• 依托单位: COLORADO STATE UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2009
• 资助国家: 美国
• 起止时间: 2009-05-08 至 2011-04-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/7660942
• 关键词: Actinobacteria class; Actinomyces; Acyltransferase; Address; Anabolism; Antimycobacterial Agents; Antitubercular Agents; Bacillus (bacterium); Bacterial Physiology; Biochemical; Biochemistry; Biogenesis; Bioinformatics; Biological Assay; Biological Process; Cell Wall; Cell membrane; Cells; Chromatography; Complex; Computer Simulation; Corynebacterium; Development; Dissection; Enzymes; Escherichia coli; Event; Gene Cluster; Gene Components; Genes; Genetic; Genome; Genus Mycobacterium; Goals; Immune response; Integral Membrane Protein; Knowledge; Laboratories; Lead; Lipopolysaccharides; Locales; Mannose; Mannosyltransferases; Membrane; Multi-Drug Resistance; Multienzyme Complexes; Mycobacterium Infections; Mycobacterium tuberculosis; Nature; Nocardia; Open Reading Frames; Paratuberculosis; Pathogenesis; Pathogenicity; Pathway interactions; Phosphatidylinositols; Physiology; Play; Proteins; Recombinants; Role; Side; Structure; Techniques; Therapeutic Agents; Therapeutic Intervention; Tuberculosis; Validation; Work; analytical tool; base; enzyme pathway; genetic analysis; glycosyltransferase; homologous recombination; lipoarabinomannan; lipomannan; mutant; mycobacterial; novel; novel therapeutics; overexpression; periplasm; phosphatidylinositol mannoside; public health relevance; resistant strain; sugar; tuberculosis drugs

DESCRIPTION (provided by applicant): The emergence of multi-drug resistant (MDR) strains of Mycobacterium tuberculosis has led to a critical need for new therapeutic agents against tuberculosis. M. tuberculosis is endowed with a diverse range of glycosylphosphatidylinositides such as phosphatidylinositol mannosides (PIMs), lipomannan (LM) and lipoarabinomannan (LAM), which play an important role in the physiology as well as the immunopathogenesis of mycobacterial infection. Enormous progress has been made in delineating the structure and biosynthesis of PIMs, but until recently the enzymes and steps leading to LM/LAM biosynthesis were not known. The elucidation of the catalytic steps involved in the synthesis of these molecules will help define one of the most complex biosynthetic pathways of mycobacteria in addition to providing new targets for the identification of novel anti-mycobacterial agents. Mutants defective in their synthesis should also enable a precise contribution of these molecules to the immunopathogenesis of tuberculosis. We have recently identified two genes encoding mannosyltransferases responsible for the terminal steps of LM/LAM biosynthesis. In silico analysis of the genetic locale of these genes revealed a possible PIM/LM/LAM biosynthetic gene cluster in the genome of M. tuberculosis. In order to define the PIM/LM/LAM biosynthetic pathways of mycobacteria, we have begun the characterization of genes from this cluster. Thus, the specific aims of this proposal are: 1. Characterization of an acyltransferase by genetic and biochemical approaches; 2. Functional characterization of a protein potentially involved in the transport of PIMs across the plasma membrane. PUBLIC HEALTH RELEVANCE: Identification and characterization of a gene cluster for glycosylphosphatidylinositides of mycobacteria. Dissection of the glycosylphosphatidylinositide (GPI) pathway in mycobacteria will lead to the discovery of a novel class of essential enzymes of M. tuberculosis that may represent new targets for therapeutic intervention. In addition, the mutants defective in some aspects of GPI synthesis will help define the precise role of these molecules in immunopathogenesis.

描述（由申请人提供）：结核分枝杆菌多药抗药性（MDR）菌株的出现导致对结核病的新治疗剂的急需需求。结核分枝杆菌具有多种范围的糖基磷脂酰肌醇，例如磷脂酰肌醇人类糖苷（PIMS），Lipomannan（LM）和脂肪氨基氨基氨基选择素（LAM），在物理学以及免疫原化的Mycobceratial of Mycobacterisearsecial中起着重要作用。在描述PIM的结构和生物合成方面，已经取得了巨大的进步，但是直到最近，尚不清楚导致LM/LAM生物合成的酶和步骤。除了为鉴定新型抗菌群剂的新靶标外，阐明涉及这些分子合成的催化步骤将有助于定义分枝杆菌最复杂的生物合成途径之一。突变体在其合成中有缺陷也应使这些分子对结核病的免疫发病发生有精确的贡献。我们最近确定了两个编码负责LM/LAM生物合成末端步骤的甘露糖基转移酶的基因。在对这些基因的遗传位置的计算机分析中，发现结核分枝杆菌基因组中可能存在PIM/LM/LAM生物合成基因簇。为了定义分枝杆菌的PIM/LM/LAM生物合成途径，我们已经开始从该簇中的基因表征。因此，该提案的具体目的是：1。通过遗传和生化方法对酰基转移酶进行表征； 2。蛋白质的功能表征可能与PIM跨质膜转运有关。公共卫生相关性：分枝杆菌糖基磷脂酰肌醇的基因簇的鉴定和表征。分枝杆菌中糖基磷脂酰肌酸（GPI）途径的解剖会导致发现一类新型结核分枝杆菌的必需酶，这可能代表了治疗性干预的新靶标。此外，在GPI合成的某些方面有缺陷的突变体将有助于定义这些分子在免疫发病发生中的确切作用。