Tripathi Siddharth K, Xu Tao, Feng Qin, Avula Bharathi, Shi Xiaomin, Pan Xuewen, Mask Melanie M, Baerson Scott R, Jacob Melissa R, Ravu Ranga Rao, Khan Shabana I, Li Xing-Cong, Khan Ikhlas A, Clark Alice M, Agarwal Ameeta K
From the National Center for Natural Products Research.
the Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, Texas 77030, and.
J Biol Chem. 2017 Oct 6;292(40):16578-16593. doi: 10.1074/jbc.M117.781773. Epub 2017 Aug 18.
Eupolauridine and liriodenine are plant-derived aporphinoid alkaloids that exhibit potent inhibitory activity against the opportunistic fungal pathogens and However, the molecular mechanism of this antifungal activity is unknown. In this study, we show that eupolauridine 9591 (E9591), a synthetic analog of eupolauridine, and liriodenine methiodide (LMT), a methiodide salt of liriodenine, mediate their antifungal activities by disrupting mitochondrial iron-sulfur (Fe-S) cluster synthesis. Several lines of evidence supported this conclusion. First, both E9591 and LMT elicited a transcriptional response indicative of iron imbalance, causing the induction of genes that are required for iron uptake and for the maintenance of cellular iron homeostasis. Second, a genome-wide fitness profile analysis showed that yeast mutants with deletions in iron homeostasis-related genes were hypersensitive to E9591 and LMT. Third, treatment of wild-type yeast cells with E9591 or LMT generated cellular defects that mimicked deficiencies in mitochondrial Fe-S cluster synthesis including an increase in mitochondrial iron levels, a decrease in the activities of Fe-S cluster enzymes, a decrease in respiratory function, and an increase in oxidative stress. Collectively, our results demonstrate that E9591 and LMT perturb mitochondrial Fe-S cluster biosynthesis; thus, these two compounds target a cellular pathway that is distinct from the pathways commonly targeted by clinically used antifungal drugs. Therefore, the identification of this pathway as a target for antifungal compounds has potential applications in the development of new antifungal therapies.
欧波劳里定和鹅掌楸碱是植物来源的阿朴啡类生物碱，对机会性真菌病原体具有强大的抑制活性。然而，这种抗真菌活性的分子机制尚不清楚。在本研究中，我们表明，欧波劳里定的合成类似物欧波劳里定9591（E9591）和鹅掌楸碱的甲碘化物（LMT）通过破坏线粒体铁硫（Fe-S）簇的合成来介导它们的抗真菌活性。多条证据支持这一结论。首先，E9591和LMT都引发了表明铁失衡的转录反应，导致铁摄取和维持细胞铁稳态所需基因的诱导。其次，全基因组适应性分析表明，铁稳态相关基因缺失的酵母突变体对E9591和LMT高度敏感。第三，用E9591或LMT处理野生型酵母细胞会产生类似于线粒体Fe-S簇合成缺陷的细胞缺陷，包括线粒体铁水平增加、Fe-S簇酶活性降低、呼吸功能降低和氧化应激增加。总的来说，我们的结果表明E9591和LMT扰乱了线粒体Fe-S簇的生物合成；因此，这两种化合物靶向的细胞途径不同于临床使用的抗真菌药物通常靶向的途径。因此，将该途径鉴定为抗真菌化合物的靶点在开发新的抗真菌疗法方面具有潜在应用。
