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Dithiolopyrrolone Antibiotics: Biosynthesis, Mode of Action and Cellular Function

二硫代吡咯酮抗生素：生物合成、作用方式和细胞功能

基本信息

批准号：
8720018
负责人：
Bo Li
金额：
$ 24.81万
依托单位：
UNIV OF NORTH CAROLINA CHAPEL HILL
依托单位国家：
美国
项目类别：
财政年份：
2012
资助国家：
美国
起止时间：
2012-03-01 至 2016-06-30
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8720018
关键词：
Accounting Affect Affinity Affinity Labels Anabolism Animal Model Antibiotics Antineoplastic Agents Bacteria Biochemical Pathway Biochemistry Bioinformatics Biological Factors Biological Process Cancer cell line Cell physiology Chemicals Chemistry Communicable Diseases Coupled DNA DNA-Directed RNA Polymerase Data Development Disulfides Engineering Environment Enzymatic Biochemistry Enzymes Escherichia coli Exhibits Family Flavins Foundations Future Gene Cluster Gene Expression Genes Genetic Genome Homologous Gene Human In Vitro Individual Investigation Label Learning Light Logic Malignant Neoplasms Mentors Methods Microbial Genetics Microbiology Mining Modeling Molecular Target Nature Organism Oxidation-Reduction Oxidative Stress Pathway interactions Pharmaceutical Preparations Pharmacologic Substance Phase Physiological Post-Translational Protein Processing Production Proteomics RNA chemical synthesis Radio Regulation Regulator Genes Research Role Signal Transduction Signaling Molecule Streptomyces Structure Structure-Activity Relationship Systems Biology Testing Therapeutic Thinking Training Work affinity labeling analog antimicrobial base biological adaptation to stress design enzyme mechanism experience follow-up fungus genetic manipulation improved in vivo insight medical schools member microorganism novel novel therapeutics oxidation promoter research study scaffold skills synthetic enzyme tool

项目摘要

Project Summary Dithiolopyrrolone antibiotics share a unique disulfide-bridged heterobicyclic core and exhibit potent activities against bacteria, fungi, and mammalian cancer cell lines. Although the dithiolopyrrolones have been known for over sixty years, their therapeutic mode of action, biosynthesis, and physiological functions are not well understood. A genome-mining approach was used to identify the biosynthetic gene cluster of a particular dithiolopyrrolone compound, holomycin, in its producing strain, Streptomyces clavuligerus. This preliminary work established the foundation for more intensive investigations of the dithiolopyrrolone scaffold, described herein. This proposal includes three specific aims: 1) Elucidating the modes of action of dithiolopyrrolones including holomycin. Holomycin is hypothesized to exert its activity through redox cycling and/or protein modification. A systems biology approach will be undertaken to group holomycin with antibiotics with known mechanisms of action. In conjunction, transcriptional profiling studies of holomycin-treated bacteria will be carried out to further provide clues regarding the mode of action. Pull down experiments will also be performed in bacterial culture to identify the molecular target(s) and chemical reactivity of holomycin; 2) Investigating the biosynthetic pathway of dithiolopyrrolones. In-depth characterization of the order and mechanisms of individual enzymatic transformations will be carried out regarding the holomycin biosynthetic pathway, in particular the redox chemistry involved in the oxidation steps and bicyclic ring formation. Further, a genome-mining approach will be utilized to uncover unknown dithiolopyrrolone gene clusters and novel dithiolopyrrolone compounds; 3) Scrutinizing the functions and regulatory mechanisms of holomycin in Streptomyces. Though identified as antibiotics and anticancer molecules, dithiolopyrrolones are hypothesized to serve as signaling molecules for their producing organisms. Transcriptional profiling studies will be undertaken to examine the effects of holomycin in S. clavuligerus and model Streptomyces strain, S. coelicolor. The regulatory mechanism of holomycin production will be explored through transcriptional analysis and genetic manipulation of the regulatory genes present in the cluster. The studies described in this proposal will significantly advance our understanding of Nature's logic to assemble dithiolopyrrolones and their mechanisms of action, provide new ways to convert them into viable therapeutics for cancer and infectious diseases, and shed light on the intricate regulatory network of secondary metabolites in Streptomyces, the industrial workhorses accounting for a large number of drugs in current use.

项目总结