Cryptococcus neoformans cryoultramicrotomy and vesicle fractionation reveals an intimate association between membrane lipids and glucuronoxylomannan.
Cryptococcus neoformans cryoultramicrotomy and vesicle fractionation reveals an intimate association between membrane lipids and glucuronoxylomannan.
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DOI：
10.1016/j.fgb.2009.09.001
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发表时间：
2009-12
影响因子：
3
通讯作者：
Rodrigues, Marcio L.
中科院分区：
文献类型：
--
作者：
Oliveira, Debora L.;Nimrichter, Leonardo;Miranda, Kildare;Frases, Susana;Faull, Kym F.;Casadevall, Arturo;Rodrigues, Marcio L.
新型隐球菌是一种有荚膜的致病真菌。隐球菌荚膜由多糖组成，是毒力所必需的。此前已有报道，主要荚膜成分葡萄糖醛酸木甘露聚糖（GXM）在细胞质区室中合成，并在囊泡中转运至细胞外空间，但对参与多糖合成和运输的细胞器的了解极为有限。在本文中，我们报告了通过冷冻超薄切片法切片并通过透射电子显微镜（TEM）和多糖免疫金染色可视化的新生隐球菌细胞中的GXM分布。真菌细胞的冷冻切片显示细胞内细胞器和细胞壁结构的高度保存。将冷冻切片与 GXM 抗体一起孵育表明，与囊泡区室和网状膜相关的细胞质结构与多糖非常接近。 GXM 通常与细胞内区室膜和细胞壁不同层内相关。通过透射电子显微镜结合血清学、色谱法和光谱方法对隐球菌上清液的细胞外级分进行分析，揭示了含有 GXM 和脂质的级分。这些结果表明 GXM 与细胞内和细胞外空间中的脂质密切相关，这与膜相关结构中的多糖合成和运输一致。
Cryptococcus neoformans is an encapsulated pathogenic fungus. The cryptococcal capsule is composed of polysaccharides and is necessary for virulence. It has been previously reported that glucuronoxylomannan (GXM), the major capsular component, is synthesized in cytoplasmic compartments and transported to the extracellular space in vesicles, but knowledge on the organelles involved in polysaccharide synthesis and traffic is extremely limited. In this paper we report the GXM distribution in C. neoformans cells sectioned by cryoultramicrotomy and visualized by transmission electron microscopy (TEM) and polysaccharide immunogold staining. Cryosections of fungal cells showed high preservation of intracellular organelles and cell wall structure. Incubation of cryosections with an antibody to GXM revealed that cytoplasmic structures associated to vesicular compartments and reticular membranes are in close proximity to the polysaccharide. GXM was generally found in association with the membrane of intracellular compartments and within different layers of the cell wall. Analysis of extracellular fractions from cryptococcal supernatants by transmission electron microscopy in combination with serologic, chromatographic and spectroscopic methods revealed fractions containing GXM and lipids. These results indicate an intimate association of GXM and lipids in both intracellular and extracellular spaces consistent with polysaccharide synthesis and transport in membrane-associated structures.
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影响因子：
14.8
作者：
Slot, Jan W.;Geuze, Hans J.
通讯作者：
Geuze, Hans J.
影响因子：
2.8
作者：
Sebolai, Olihile M.;Pohl, Carolina H.;Kock, Johan L. F.
通讯作者：
Kock, Johan L. F.
影响因子：
3.2
作者：
TAKEO, K;UESAKA, I;NISHIURA, M
通讯作者：
NISHIURA, M
影响因子：
15.9
作者：
Casadevall A;Nosanchuk JD;Williamson P;Rodrigues ML
通讯作者：
Rodrigues ML
DOI：
10.1073/pnas.261418798
发表时间：
2001-12-18
影响因子：
11.1
作者：
Steenbergen, JN;Shuman, HA;Casadevall, A
通讯作者：
Casadevall, A