Plasmodium falciparum exports the Golgi marker sphingomyelin synthase into a tubovesicular network in the cytoplasm of mature erythrocytes.
Plasmodium falciparum exports the Golgi marker sphingomyelin synthase into a tubovesicular network in the cytoplasm of mature erythrocytes.
复制标题
DOI：
10.1083/jcb.124.4.449
复制
发表时间：
1994-02
期刊：
影响因子：
--
通讯作者：
Haldar K
中科院分区：
文献类型：
--
作者：
Elmendorf HG;Haldar K
这项工作描述了真核细胞膜发育的两个不寻常的特征。(a)在成熟红细胞的细胞质中由恶性疟原虫诱导的管泡膜的广泛网络，以及用两种神经酰胺类似物C5-DMB-神经酰胺和C6-NBD-神经酰胺的可视化。使用激光共聚焦显微镜对受感染的红细胞进行“切片”，可以重建这种新型膜网络的详细三维图像。(b)鞘磷脂合成酶的阶段特异性出口，集中在哺乳动物细胞的高尔基体的生物合成活性，这个tubovesicular网络。证据表明，在细胞外裂殖子阶段的寄生虫保留鞘磷脂合酶在其质膜。然而，细胞内的环和滋养体阶段的寄生虫出口的鞘磷脂合酶活性的相当大的一部分（约26%）的膜超出他们的质膜。重要的是，我们在这些细胞内阶段没有观察到新酶的合成。总之，这些结果强烈表明，这种经典的高尔基体酶的出口发育调节疟原虫。我们讨论的意义，这个出口和管泡网络膜的发展和功能在红细胞胞质溶胶。
This work describes two unusual features of membrane development in a eukaryotic cell. (a) The induction of an extensive network of tubovesicular membranes by the malaria parasite Plasmodium falciparum in the cytoplasm of the mature erythrocyte, and its visualization with two ceramide analogues C5-DMB-ceramide and C6-NBD-ceramide. "Sectioning" of the infected erythrocytes using laser confocal microscopy has allowed the reconstruction of detailed three-dimensional images of this novel membrane network. (b) The stage-specific export of sphingomyelin synthase, a biosynthetic activity concentrated in the Golgi of mammalian cells, to this tubovesicular network. Evidence is presented that in the extracellular merozoite stage the parasite retains sphingomyelin synthase within its plasma membrane. However, intracellular ring- and trophozoite-stage parasites export a substantial fraction (approximately 26%) of sphingomyelin synthase activity to membranes beyond their plasma membrane. Importantly we do not observe synthesis of new enzyme during these intracellular stages. Taken together these results strongly suggest that the export of this classic Golgi enzyme is developmentally regulated in Plasmodium. We discuss the significance of this export and the tubovesicular network with respect to membrane development and function in the erythrocyte cytosol.