Reorganization of the endosomal system in Salmonella-infected cells: the ultrastructure of Salmonella-induced tubular compartments.
Reorganization of the endosomal system in Salmonella-infected cells: the ultrastructure of Salmonella-induced tubular compartments.
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DOI：
10.1371/journal.ppat.1004374
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发表时间：
2014-09
期刊：
影响因子：
6.7
通讯作者：
Hensel M
中科院分区：
文献类型：
--
作者：
Krieger V;Liebl D;Zhang Y;Rajashekar R;Chlanda P;Giesker K;Chikkaballi D;Hensel M
在肠沙门氏菌的细胞内生活期间，形成了一种独特的膜结合室，称为含沙门氏菌液泡或SCV。通过易位效应蛋白，胞内沙门氏菌还诱导形成广泛的、高度动态的膜小管，称为沙门氏菌诱导细丝或SIF。在这里，我们报告了通过电子显微镜（EM），电子断层扫描和活细胞相关光电子显微镜（CLEM）对SCV和SIF进行的第一次详细的超微结构分析。我们发现SIF的一个子集由双膜组成，该双膜将宿主细胞细胞质和细胞骨架丝的部分包裹在内腔内。尽管在形态学上有一些相似之处，但我们发现SIF双膜的形成不依赖于自噬，需要效应蛋白SseF和SseG的作用。各种类型的内吞物质都可以进入SIF网络的管腔，我们对双膜SIF的CLEM分析表明，液相标记物仅在这些结构的内外膜之间积累，与内体管腔相连。我们的工作揭示了细胞内病原体如何操纵内体膜系统导致宿主细胞独特的管状膜区隔化，从而产生一个允许沙门氏菌细胞内增殖的屏蔽生态位。肠沙门氏菌是一种侵袭性的兼性细胞内细菌病原体。在哺乳动物宿主细胞内，沙门氏菌居住在一个特殊的膜结合腔室，即含沙门氏菌液泡（SCV），重定向宿主细胞囊泡运输并大规模重塑内体系统。这些活性取决于III型分泌系统及其易位效应蛋白的功能。细胞内沙门氏菌诱导了几种被称为沙门氏菌诱导小管（Salmonella-induced tubules， SIT）的管状室，但其生物发生和生物学功能仅部分被了解。我们的工作将活细胞成像与相关的光学和电子显微镜相结合，以提供对SIT的超微结构洞察。我们报道，SIT以单膜小管的形式出现，转化为双膜小管，包裹细胞质和细胞骨架细丝。内体室的标记和细胞化学表明，内外SIT膜之间的空间由内化物质组成，并与SCV内的沙门氏菌相连。胞内沙门氏菌易位的效应蛋白SseF和SseG对单膜SIT转化为双膜SIT至关重要。这些发现挑战了沙门氏菌细胞内生活方式及其细胞内栖息地组成的当前模型。
During the intracellular life of Salmonella enterica, a unique membrane-bound compartment termed Salmonella-containing vacuole, or SCV, is formed. By means of translocated effector proteins, intracellular Salmonella also induce the formation of extensive, highly dynamic membrane tubules termed Salmonella-induced filaments or SIF. Here we report the first detailed ultrastructural analyses of the SCV and SIF by electron microscopy (EM), EM tomography and live cell correlative light and electron microscopy (CLEM). We found that a subset of SIF is composed of double membranes that enclose portions of host cell cytosol and cytoskeletal filaments within its inner lumen. Despite some morphological similarities, we found that the formation of SIF double membranes is independent from autophagy and requires the function of the effector proteins SseF and SseG. The lumen of SIF network is accessible to various types of endocytosed material and our CLEM analysis of double membrane SIF demonstrated that fluid phase markers accumulate only between the inner and outer membrane of these structures, a space continual with endosomal lumen. Our work reveals how manipulation of the endosomal membrane system by an intracellular pathogen results in a unique tubular membrane compartmentalization of the host cell, generating a shielded niche permissive for intracellular proliferation of Salmonella. Salmonella enterica is an invasive, facultative intracellular bacterial pathogen. Within mammalian host cells, Salmonella inhabits a specialized membrane-bound compartment, the Salmonella-containing vacuole (SCV), redirects host cell vesicular transport and massively remodels the endosomal system. These activities depend on the function of a type III secretion system and its translocated effector proteins. Intracellular Salmonella induces several types of tubular compartments termed Salmonella-induced tubules (SIT), but the biogenesis and biological function of SIT is only partially understood. Our work combines live cell imaging with correlative light and electron microscopy to provide ultrastructural insight into SIT. We report that SIT emerge as single membrane tubules that convert into double membrane tubules entrapping cytosol and cytoskeletal filaments. Labeling of the endosomal compartment and cytochemistry demonstrate that the space between inner and outer SIT membrane is composed of internalized material and connected to Salmonella within the SCV. The effector proteins SseF and SseG translocated by intracellular Salmonella are essential for the conversion of single to double membrane SIT. These findings challenge current models for the intracellular lifestyle of Salmonella and the composition of its intracellular habitat.
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将鼠伤寒沙门氏菌靶向含有溶酶体膜糖蛋白的囊泡，绕过带有甘露糖6-磷酸受体的室。
影响因子：
7.8
作者：
GARCIADELPORTILLO, F;FINLAY, BB
通讯作者：
FINLAY, BB
DOI：
10.1083/jcb.201304188
发表时间：
2013-10-14
期刊：
The Journal of cell biology
影响因子：
--
作者：
Fujita N;Morita E;Itoh T;Tanaka A;Nakaoka M;Osada Y;Umemoto T;Saitoh T;Nakatogawa H;Kobayashi S;Haraguchi T;Guan JL;Iwai K;Tokunaga F;Saito K;Ishibashi K;Akira S;Fukuda M;Noda T;Yoshimori T
通讯作者：
Yoshimori T
影响因子：
4.8
作者：
Boucrot, E;Beuzón, CR;Méresse, S
通讯作者：
Méresse, S
影响因子：
3
作者：
Kremer, JR;Mastronarde, DN;McIntosh, JR
通讯作者：
McIntosh, JR
影响因子：
3.4
作者：
Ibarra JA;Steele-Mortimer O
通讯作者：
Steele-Mortimer O