Identification of Vital and Dispensable Sulfur Utilization Factors in the Plasmodium Apicoplast
Identification of Vital and Dispensable Sulfur Utilization Factors in the Plasmodium Apicoplast
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DOI：
10.1371/journal.pone.0089718
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发表时间：
2014-02-21
期刊：
影响因子：
3.7
通讯作者：
Kooij, Taco W. A.
中科院分区：
文献类型：
--
作者：
Haussig, Joana M.;Matuschewski, Kai;Kooij, Taco W. A.
铁硫[Fe-S]簇是各种生化过程中普遍存在的关键辅助因子。它们通过不同的[Fe-S]簇生物合成途径组装，通常在内共生起源的细胞器中组装。包括疟疾病原体疟原虫在内的顶复合体寄生虫在其线粒体和顶质体中具有两个独立的[Fe-S]簇生物合成途径。在本研究中，我们通过实验遗传学系统地定位了小鼠疟疾模型寄生虫伯氏疟原虫顶端质体[Fe-S]簇生物合成途径的5个核编码硫利用因子（SUF）。我们发现四种SUFs，即SUFC， D， E和S对靶向基因缺失是难的，验证了它们是抗疟疾药物开发的潜在靶点。我们实现了SUFA的靶向缺失，SUFA编码了一种潜在的[Fe-S]转移蛋白，表明在体内无性血期生长中起着不可或缺的作用。此外，在昆虫和哺乳动物宿主的生命周期进程中没有观察到异常。将一个荧光标记与内源性柏氏假体suf融合，表明所有的基因座都可以进行遗传修饰，并且所有五个标记的suf都定位在顶质体上。总之，我们的实验遗传学分析确定了疟原虫顶体中SUF [Fe-S]簇生物合成途径的关键组分，并表明体内缺乏SUFC， D， E或S与疟原虫血液感染不相容。
Iron-sulfur [Fe-S] clusters are ubiquitous and critical cofactors in diverse biochemical processes. They are assembled by distinct [Fe-S] cluster biosynthesis pathways, typically in organelles of endosymbiotic origin. Apicomplexan parasites, including Plasmodium, the causative agent of malaria, harbor two separate [Fe-S] cluster biosynthesis pathways in the their mitochondrion and apicoplast. In this study, we systematically targeted the five nuclear-encoded sulfur utilization factors (SUF) of the apicoplast [Fe-S] cluster biosynthesis pathway by experimental genetics in the murine malaria model parasite Plasmodium berghei. We show that four SUFs, namely SUFC, D, E, and S are refractory to targeted gene deletion, validating them as potential targets for antimalarial drug development. We achieved targeted deletion of SUFA, which encodes a potential [Fe-S] transfer protein, indicative of a dispensable role during asexual blood stage growth in vivo. Furthermore, no abnormalities were observed during Plasmodium life cycle progression in the insect and mammalian hosts. Fusion of a fluorescent tag to the endogenous P. berghei SUFs demonstrated that all loci were accessible to genetic modification and that all five tagged SUFs localize to the apicoplast. Together, our experimental genetics analysis identifies the key components of the SUF [Fe-S] cluster biosynthesis pathway in the apicoplast of a malarial parasite and shows that absence of SUFC, D, E, or S is incompatible with Plasmodium blood infection in vivo.