Defining the morphology and mechanism of the hemoglobin transport pathway in Plasmodium falciparum-infected erythrocytes.
Defining the morphology and mechanism of the hemoglobin transport pathway in Plasmodium falciparum-infected erythrocytes.
复制标题
定义恶性疟原虫感染的红细胞中血红蛋白转运途径的形态和机制。
DOI：
10.1128/ec.00267-14
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发表时间：
2015
期刊：
影响因子：
--
通讯作者：
Taraschi,TheodoreF
中科院分区：
文献类型：
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作者：
Milani,KatharineJ;Schneider,TimothyG;Taraschi,TheodoreF
在恶性疟原虫的无性周期中，血红蛋白降解是疟原虫发育和存活的一个必需过程。已证实血红蛋白从宿主红细胞转运到寄生虫消化泡（DV），但这一生物学过程尚未得到很好的表征。由未处理的、滋养体阶段恶性疟原虫感染的红细胞（IRBC）或用不同药物处理的IRBC的连续薄片电子显微照片制成的三维重建为血红蛋白转运途径的组织和调节提供了新的见解。血红蛋白的内化开始与形成的cytostomes从本地化，电子致密的衣领在界面上的寄生虫血浆和寄生虫空泡膜。细胞口领不起囊泡分裂的作用，而是起稳定成熟的细胞口的作用。我们提供的第一个证据表明，血红蛋白运输到DV使用肌动蛋白肌球蛋白电机系统。短寿命的，充满血红蛋白的囊泡从细胞孔的远端通过肌动蛋白和动力蛋白介导的过程形成。用N-乙基马来酰亚胺（NEM）处理的IRBC获得的结果表明，含血红蛋白的囊泡与DV的融合可能涉及可溶性NEM敏感因子附着蛋白受体依赖性机制。在这份报告中，我们确定了血红蛋白转运途径的新的关键组成部分，并提供了其形态组织和调节的详细表征。
Hemoglobin degradation during the asexual cycle of Plasmodium falciparum is an obligate process for parasite development and survival. It is established that hemoglobin is transported from the host erythrocyte to the parasite digestive vacuole (DV), but this biological process is not well characterized. Three-dimensional reconstructions made from serial thin-section electron micrographs of untreated, trophozoite-stage P. falciparum-infected erythrocytes (IRBC) or IRBC treated with different pharmacological agents provide new insight into the organization and regulation of the hemoglobin transport pathway. Hemoglobin internalization commences with the formation of cytostomes from localized, electron-dense collars at the interface of the parasite plasma and parasitophorous vacuolar membranes. The cytostomal collar does not function as a site of vesicle fission but rather serves to stabilize the maturing cytostome. We provide the first evidence that hemoglobin transport to the DV uses an actin-myosin motor system. Short-lived, hemoglobin-filled vesicles form from the distal end of the cytostomes through actin and dynamin-mediated processes. Results obtained with IRBC treated withN-ethylmaleimide (NEM) suggest that fusion of hemoglobin-containing vesicles with the DV may involve a soluble NEM-sensitive factor attachment protein receptor-dependent mechanism. In this report, we identify new key components of the hemoglobin transport pathway and provide a detailed characterization of its morphological organization and regulation.