HVEM TOMOGRAPHY OF THE TRANS-GOLGI NETWORK - STRUCTURAL INSIGHTS AND IDENTIFICATION OF A LACE-LIKE VESICLE COAT
HVEM TOMOGRAPHY OF THE TRANS-GOLGI NETWORK - STRUCTURAL INSIGHTS AND IDENTIFICATION OF A LACE-LIKE VESICLE COAT
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DOI：
10.1083/jcb.127.1.29
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发表时间：
1994-10-01
影响因子：
7.8
通讯作者：
HOWELL, KE
中科院分区：
文献类型：
--
作者：
LADINSKY, MS;KREMER, JR;HOWELL, KE
用高压电子显微镜和计算机轴位断层扫描技术研究了NRK细胞中跨高尔基体池和跨高尔基体网的三维结构。使用Pagano等人的技术改进，通过对神经酰胺的荧光类似物进行光转化来特异性地标记这两种结构。(J.Cell Biol.1991年。113：1267-1279)。在固定的染色细胞中的高尔基带区域被切割成250 nm的切片，并在随后的断层重建中通过倾斜系列显微镜酸进行分析。重建的分辨率范围为6~10 nm。TGN的大小和结构在整个高尔基带上有很大的差异；所有的重建都是从TGN明显的区域进行的。大多数被分析的区域含有多个(2-4)高尔基池，神经酰胺染色。这些小管从紧密堆积的脑池中“剥离”下来，在它们的末端与构成TGN的小管相连。TGN内可见的大多数泡状轮廓与TGN小管相连。囊泡的萌发似乎沿着TGN小管的长度同步发生。在萌发的囊泡上可以看到两种不同的涂层：笼状笼子和新颖的花边状结构。单个TGN小管只产生一种被膜类型的囊泡。这些观察结果导致了以下预测：(A)分子的分选必须在TGN小管形成之前进行；(B)小泡的形成几乎是沿着给定的TGN小管同步进行的；以及(C)在胞外小泡上形成花边状的外套。
High voltage electron microscopy and computer axial tomography have been used to study the 3-D structure of trans-Golgi cisternae and trans-Golgi networks (TGNs) in NRK cells. Both structures were specifically labeled by photoconversion of a fluorescent analogue of ceramide using a modification of the technique of Pagano et al. (J. Cell Biol. 1991. 113: 1267-1279). Regions of the Golgi ribbon in fixed, stained cells were cut in 250-nm sections and analyzed by tilt series microscopy acid subsequent tomographic reconstruction. Resolution of the reconstructions ranged from 6 to 10 nm. The size and structure of the TGN varied considerably throughout the Golgi ribbon; all reconstructions were made from regions with pronounced TGN. Most regions analyzed contained multiple (2-4) Golgi cisternae that stain with ceramide. These ''peel off'' from the closely stacked cisternae and are continuous at their ends with tubules that contribute to the TGN. Most vesicular profiles visualized in the TGN are connected to TGN tubules. The budding of vesicles appears to occur synchronously along the length of a TGN tubule. Two distinct coats were visualized on budding vesicles: clathrin cages and a novel, lace-like structure. Individual TGN tubules produce vesicles of only one coat type. These observations lead to the following predictions: (a) sorting of molecules must occur prior to the formation of TGN tubules; (b) vesicle formation takes place almost synchronously along a given TGN tubule; and (c) lace-like coats form on exocytic vesicles.