Department of Life Sciences, School of Natural Sciences, Shiv Nadar University, Delhi NCR, India; Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany; Special Centre for Molecular Medicine, Jawaharlal Nehru University, New Delhi, India.
Division of Cellular and Applied Infection Biology, Institute of Zoology, RWTH Aachen University, Aachen, Germany.
Biochem Pharmacol. 2023 Jun;212:115567. doi: 10.1016/j.bcp.2023.115567. Epub 2023 Apr 22.
Prohibitins (PHBs) are highly conserved pleiotropic proteins as they have been shown to mediate key cellular functions. Here, we characterize PHBs encoding putative genes ofPlasmodium falciparum by exploiting different orthologous models. We demonstrated that PfPHB1 (PF3D7_0829200) and PfPHB2 (PF3D7_1014700) are expressed in asexual and sexual blood stages of the parasite. Immunostaining indicated hese proteins as mitochondrial residents as they were found to be localized as branched structures. We further validated PfPHBs as organellar proteins residing in Plasmodium mitochondria, where they interact with each other. Functional characterization was done in Saccharomyces cerevisiae orthologous model by expressing PfPHB1 and PfPHB2 in cells harboring respective mutants. The PfPHBs functionally complemented the yeast PHB1 and PHB2 mutants, where the proteins were found to be involved in stabilizing the mitochondrial DNA, retaining mitochondrial integrity and rescuing yeast cell growth. Further, Rocaglamide (Roc-A), a known inhibitor of PHBs and anti-cancerous agent, was tested against PfPHBs and as an antimalarial. Roc-A treatment retarded the growth of PHB1, PHB2, and ethidium bromide petite yeast mutants. Moreover, Roc-A inhibited growth of yeast PHBs mutants that were functionally complemented with PfPHBs, validating P. falciparum PHBs as one of the molecular targets for Roc-A. Roc-A treatment led to growth inhibition of artemisinin-sensitive (3D7), artemisinin-resistant (R539T) and chloroquine-resistant (RKL-9) parasites in nanomolar ranges. The compound was able to retard gametocyte and oocyst growth with significant morphological aberrations. Based on our findings, we propose the presence of functional mitochondrial PfPHB1 and PfPHB2 in P. falciparum and their druggability to block parasite growth.
抑制素（PHBs）是高度保守的多功能蛋白，因为它们已被证明可以介导关键的细胞功能。在这里，我们通过利用不同的直系同源模型来描述恶性疟原虫（Plasmodium falciparum）的 PHB 编码假定基因。我们证明 PfPHB1（PF3D7_0829200）和 PfPHB2（PF3D7_1014700）在寄生虫的无性和有性血阶段表达。免疫染色表明这些蛋白质是线粒体居民，因为它们被发现定位于分支结构中。我们进一步验证 PfPHBs 是定位于疟原虫线粒体的细胞器蛋白，它们相互作用。在酿酒酵母直系同源模型中通过在携带相应突变体的细胞中表达 PfPHB1 和 PfPHB2 进行功能表征。PfPHBs 功能上互补了酵母 PHB1 和 PHB2 突变体，其中这些蛋白被发现参与稳定线粒体 DNA、保持线粒体完整性和挽救酵母细胞生长。此外，Rocaglamide（Roc-A），一种已知的 PHB 抑制剂和抗癌剂，被测试针对 PfPHBs 和抗疟药物。Roc-A 处理延迟了 PHB1、PHB2 和溴化乙锭 petite 酵母突变体的生长。此外，Roc-A 抑制了用 PfPHBs 功能互补的酵母 PHBs 突变体的生长，验证了恶性疟原虫 PHBs 是 Roc-A 的一个分子靶标之一。Roc-A 处理以纳摩尔范围抑制青蒿素敏感（3D7）、青蒿素耐药（R539T）和氯喹耐药（RKL-9）寄生虫的生长。该化合物能够以显著的形态异常抑制配子体和卵囊的生长。基于我们的发现，我们提出在恶性疟原虫中存在功能性线粒体 PfPHB1 和 PfPHB2，并且它们具有阻止寄生虫生长的可药性。
