Direct ligand-based control of C. albicans zinc cluster transcription factors

基于配体的直接控制白色念珠菌锌簇转录因子

• 批准号: 9807037
• 负责人: Lawrence Christopher Myers
• 金额: $ 24.6万
• 依托单位: DARTMOUTH COLLEGE
• 依托单位国家: 美国
• 财政年份: 2019
• 资助国家: 美国
• 起止时间: 2019-06-01 至 2021-05-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9807037
• 关键词: Address; Affect; Agonist; Antifungal Agents; Azole resistance; Azoles; Binding; Biological Assay; Candida albicans; Centers for Disease Control and Prevention (U.S.); Cessation of life; Clinic; Clinical; Complex; DNA Binding; Development; Disease; Disseminated candidiasis; Drug Efflux; Drug Screening; Drug Targeting; Drug resistance; Family; Fluorescence Polarization; Fungal Drug Resistance; Genes; Genetic Transcription; Goals; Head; Health; Hospitals; Human; Hybrids; Immobilization; In Vitro; Infection; Knowledge; Lead; Ligand Binding; Ligand Binding Domain; Ligands; Malaria; Malignant Neoplasms; Mammals; Mediator of activation protein; Molecular Conformation; Nuclear Receptors; Pharmaceutical Preparations; Physiological; Play; Polyenes; Positioning Attribute; Property; Proteins; Proteolysis; Publishing; Radiolabeled; Regulation; Role; Sepsis; Sequence-Specific DNA Binding Protein; Source; Structure; Testing; Therapeutic; Transcription Coactivator; Transcriptional Activation; Transcriptional Activation Domain; Tuberculosis; United States; Ursidae Family; Virulence; Work; Zinc Cluster; base; drug development; efflux pump; factor A; farnesoid X-activated receptor; gain of function mutation; high throughput screening; human disease; in vivo; luminescence; mortality; multi drug transporter; new therapeutic target; novel therapeutics; pathogen; pathogenic fungus; protein protein interaction; prototype; recruit; resistant strain; small molecule; success; transcription factor

C. albicans is a prevalent human fungal pathogen and a leading cause of hospital-acquired bloodstream infections. There is an approximately 40% mortality rate, and over 10,000 deaths per year in the U.S. associated with systemic candidiasis. Collectively, fungal pathogens account for more deaths worldwide (~1.6 million people annually), than tuberculosis and malaria combined. These mortality rates indicate that existing classes of antifungal drugs are insufficient to meet the need. The development of new drugs has been slow in coming. Two of the three main classes of antifungals (azoles and polyenes) in current use have been in the clinic for close to 40 years, and the discovery of the third class (echinocandins) dates to this same era. Moreover, the limited success achieved by azole drugs is now threatened by azole resistant C. albicans strains, which the CDC considers a ‘serious’ threat to human health in the U.S. The goal of this proposal is to address these needs by characterizing, and contributing to the development of a high-throughput ligand binding assay for, a new class of antifungal targets that play important roles in in both virulence and azole resistance. These proteins are known collectively as the zinc cluster transcription factors (ZCFs). ZCFs represent a fungal specific family of more than 80 sequence-specific DNA-binding transcriptional regulators bearing the Zn(II)2Cys6 motif. Despite their importance, most of the ZCFs currently lack a clearly characterized function; and even for those with an associated function, little is understood about the mechanism of their regulation. The central hypothesis of this proposal is that small-molecule inducers directly bind to ZCFs and trigger a conformational change that enables direct interactions between the ZCF transcriptional activation domain and a specific sub-unit of Mediator, a large multi-protein transcriptional co-activator complex. Our previous work showed that inducers and gain of function mutations in certain ZCFs lead to the recruitment of Mediator and the transcriptional activation of multi-drug efflux pump genes that confer azole resistance. The objective of this exploratory proposal is to characterize the domains that facilitate the inducer dependent interactions between ZCFs and Mediator, and leverage this information to create a ligand binding assay that can be applied to multiple ZCFs in C. albicans in a high-throughput manner to discover physiological ligands, and small-molecule antagonists that counteract ZCF promotion of virulence and drug resistance. Utilizing a platform similar to one successfully used for high-throughput ligand-binding assays screening for drugs that target mammalian nuclear receptors, the functional equivalent of fungal ZCFs, will help maximize the success and impact of this project.

白色念珠菌是一种流行的人类真菌病原体，也是医院获得性血流的主要原因