Regulation of Intrinsic Caspofungin Resistance in C. neoformans

新型隐球菌内在卡泊芬净耐药性的调节

• 批准号: 9761969
• 负责人: John C Panepinto
• 金额: $ 22.56万
• 依托单位: STATE UNIVERSITY OF NEW YORK AT BUFFALO
• 依托单位国家: 美国
• 财政年份: 2018
• 资助国家: 美国
• 起止时间: 2018-08-08 至 2021-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9761969
• 关键词: 5' Untranslated Regions; Acquired Immunodeficiency Syndrome; Amino Acid Sequence; Amphotericin B; Antifungal Agents; Antifungal Therapy; Arginine; Binding; C-terminal; Caspofungin; Cell Wall; Cells; Cellular Immunity; Cessation of life; Consensus; Cryptococcosis; Cryptococcus; Cryptococcus neoformans; Cryptococcus neoformans infection; Data; Defect; Drug Targeting; Elements; Exhibits; Fluconazole; Flucytosine; Foundations; Fungal Proteins; Future; Genetic; Genetic Transcription; Hypersensitivity; Immunocompromised Host; In Vitro; Industrial fungicide; Lead; Link; Meningitis; Messenger RNA; Methylation; Modeling; Mutagenesis; Mutation; Pathogenicity; Patients; Pharmaceutical Preparations; Polyadenylation; Post-Transcriptional Regulation; Predisposition; Protein-Arginine N-Methyltransferase; Proteins; RNA Binding; RNA Recognition Motif; RNA-Binding Proteins; Regulation; Resistance; Resources; Ribosomes; Role; Site; Testing; Translating; Translations; Transplant Recipients; Work; echinocandin resistance; glucan synthase; in vivo; inhibitor/antagonist; mRNA Stability; mortality; mutant; protein B; resistance mechanism; stressor

Abstract: Cryptococcosis causes hundreds of thousands of deaths per year, mostly in resource-poor settings. C. neoformans exhibits intrinsic resistance to echinocandin antifungals, eliminating this safe and effective class of antifungal drug from the anti-cryptococcal arsenal. The mechanism of resistance is unknown, but it is independent of drug target inhibition, as the target protein, the β-1,3-glucan synthase Fks1, is sensitive to the drug. We have identified a regulator of caspofungin sensitivity in C. neoformans, Puf4, that controls the FKS1 mRNA at the level of stability, and a puf4 mutant is caspofungin resistant. Deletion putative post-translational regulator of Puf4, the protein arginine methyltransferase (PRMT) Rmt5, confers hypersensitivity to caspofungin, suggesting a role for arginine methylation in the regulation of Puf4 function and caspofungin sensitivity. Our scientific premise is that Puf4 controls caspofungin sensitivity through post-transcriptional regulation of the FKS1 mRNA, and that the ability of Puf4 to regulate FKS1 is dependent on its methylation status. We will investigate the mechanism of Puf4 regulation including its binding to the FKS1 mRNA 5’ UTR and the effect of that interaction on translation and mRNA stability (Aim 1). We will then investigate the role of Puf4 methylation on its ability to regulate the FKS1 mRNA including the effect of rmt5 deletion on FKS1 post- transcriptional regulation, the identification of methylation sites on Puf4 and the use of mutagenesis to determine the consequence of methylation on effector function (Aim 2). PRMTs are known drug targets. Determining the mechanism by which Rmt5 and its putative target Puf4 control caspofungin sensitivity may lead to adjunctive therapies to potentiate the anti-cryptococcal activity of echinocandins.

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