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Elsadek LA, Matthews JH, Nishimura S, Nakatani T, Ito A, Gu T, Luo D, Salvador-Reyes LA, Paul VJ, Kakeya H, Luesch H. Genomic and Targeted Approaches Unveil the Cell Membrane as a Major Target of the Antifungal Cytotoxin Amantelide A. Chembiochem 2021; 22:1790-1799. [PMID: 33527693 DOI: 10.1002/cbic.202000685] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2020] [Revised: 01/31/2021] [Indexed: 12/13/2022]
Abstract
Amantelide A, a polyhydroxylated macrolide isolated from a marine cyanobacterium, displays broad-spectrum activity against mammalian cells, bacterial pathogens, and marine fungi. We conducted comprehensive mechanistic studies to identify the molecular targets and pathways affected by amantelide A. Our investigations relied on chemical structure similarities with compounds of known mechanisms, yeast knockout mutants, yeast chemogenomic profiling, and direct biochemical and biophysical methods. We established that amantelide A exerts its antifungal action by binding to ergosterol-containing membranes followed by pore formation and cell death, a mechanism partially shared with polyene antifungals. Binding assays demonstrated that amantelide A also binds to membranes containing epicholesterol or mammalian cholesterol, thus suggesting that the cytotoxicity to mammalian cells might be due to its affinity to cholesterol-containing membranes. However, membrane interactions were not completely dependent on sterols. Yeast chemogenomic profiling suggested additional direct or indirect effects on actin. Accordingly, we performed actin polymerization assays, which suggested that amantelide A also promotes actin polymerization in cell-free systems. However, the C-33 acetoxy derivative amantelide B showed a similar effect on actin dynamics in vitro but no significant activity against yeast. Overall, these studies suggest that the membrane effects are the most functionally relevant for amantelide A mechanism of action.
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Affiliation(s)
- Lobna A Elsadek
- Department of Medicinal Chemistry, University of Florida, 1345 Center Drive, Gainesville, FL 32610, USA.,Center for Natural Products,Drug Discovery and Development (CNPD3), University of Florida, 1345 Center Drive, Gainesville, FL 32610, USA
| | - James H Matthews
- Department of Medicinal Chemistry, University of Florida, 1345 Center Drive, Gainesville, FL 32610, USA.,Center for Natural Products,Drug Discovery and Development (CNPD3), University of Florida, 1345 Center Drive, Gainesville, FL 32610, USA
| | - Shinichi Nishimura
- Department of System Chemotherapy and Molecular Sciences, Division of Bioinformatics and Chemical Genomics, Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan.,Department of Biotechnology, Graduate School of Agricultural and Life Sciences, University of Tokyo, Bunkyo-ku, Tokyo, 113-8657, Japan.,Collaborative Research Institute for Innovative Microbiology, University of Tokyo, 1-1-1 Yayoi, Bunkyo-ku, Tokyo, 113-8657, Japan
| | - Takahiro Nakatani
- Department of System Chemotherapy and Molecular Sciences, Division of Bioinformatics and Chemical Genomics, Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| | - Airi Ito
- Department of System Chemotherapy and Molecular Sciences, Division of Bioinformatics and Chemical Genomics, Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| | - Tongjun Gu
- Interdisciplinary Center for Biotechnology Research, University of Florida, 2033 Mowry Road, Gainesville, FL 32610, USA
| | - Danmeng Luo
- Department of Medicinal Chemistry, University of Florida, 1345 Center Drive, Gainesville, FL 32610, USA.,Center for Natural Products,Drug Discovery and Development (CNPD3), University of Florida, 1345 Center Drive, Gainesville, FL 32610, USA
| | - Lilibeth A Salvador-Reyes
- Department of Medicinal Chemistry, University of Florida, 1345 Center Drive, Gainesville, FL 32610, USA.,Marine Science Institute, College of Science, University of the Philippines Diliman, Quezon City, 1100, Philippines
| | - Valerie J Paul
- Smithsonian Marine Station, 701 Seaway Drive, Ft., Pierce, FL 34949, USA
| | - Hideaki Kakeya
- Department of System Chemotherapy and Molecular Sciences, Division of Bioinformatics and Chemical Genomics, Graduate School of Pharmaceutical Sciences, Kyoto University Sakyo-ku, Kyoto, 606-8501, Japan
| | - Hendrik Luesch
- Department of Medicinal Chemistry, University of Florida, 1345 Center Drive, Gainesville, FL 32610, USA.,Center for Natural Products,Drug Discovery and Development (CNPD3), University of Florida, 1345 Center Drive, Gainesville, FL 32610, USA
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