Golgi structure in three dimensions: functional insights from the normal rat kidney cell.
Golgi structure in three dimensions: functional insights from the normal rat kidney cell.
复制标题
DOI：
10.1083/jcb.144.6.1135
复制
发表时间：
1999-03-22
影响因子：
7.8
通讯作者：
Staehelin, L A
中科院分区：
文献类型：
--
作者：
Ladinsky, M S;Mastronarde, D N;McIntosh, J R;Howell, K E;Staehelin, L A
三维重建的部分高尔基复合体从冷冻固定，冷冻替代正常大鼠肾细胞已作出双轴，高电压EM断层扫描在107 nm的分辨率。图中所示的重建图（101 × 1 × 4 μm3）包含两个由7个池组成的堆叠，由一个非紧凑区域隔开，桥穿过该区域连接一些水平相等的池，但不连接水平不相等的池。非致密区的其余部分充满了囊泡和多形膜元件。所有的池都是有孔的，并显示被衣芽。它们的表面积大致相同，但体积差异高达50%。反式最大的池只产生网格蛋白包被的芽，而其他的只显示nonclathrin包被的芽。这一发现挑战了传统的观点，在高尔基复合体中的排序发生。具芽状轮廓的小管从顺式和反式池的边缘延伸。它们穿过邻近的池，表明这些小管有助于交通和/或从高尔基体。囊泡填充的“威尔斯”向叠层的顺侧和侧边开放。池的堆栈位于两种类型的ER，顺式和反式。顺式ER位于相邻的ER-高尔基体中间室，它由离散的多形膜元件层在前面的顺式最高尔基池。广泛的反式ER形式密切接触的两个反式最cisterbranch，这种并置可能允许直接转移之间的ER和高尔基体膜的脂质。在研究的池的0.2 μm内，有394个囊泡（8个网格蛋白包被，190个非网格蛋白包被，196个非包被），表明在高尔基体区域有相当多的囊泡运输。我们的数据将结构上的限制模型的贩运，通过和从高尔基复合体。
Three-dimensional reconstructions of portions of the Golgi complex from cryofixed, freeze-substituted normal rat kidney cells have been made by dual-axis, high-voltage EM tomography at ∼7-nm resolution. The reconstruction shown here (∼1 × 1 × 4 μm3) contains two stacks of seven cisternae separated by a noncompact region across which bridges connect some cisternae at equivalent levels, but none at nonequivalent levels. The rest of the noncompact region is filled with both vesicles and polymorphic membranous elements. All cisternae are fenestrated and display coated buds. They all have about the same surface area, but they differ in volume by as much as 50%. The trans-most cisterna produces exclusively clathrin-coated buds, whereas the others display only nonclathrin coated buds. This finding challenges traditional views of where sorting occurs within the Golgi complex. Tubules with budding profiles extend from the margins of both cis and trans cisternae. They pass beyond neighboring cisternae, suggesting that these tubules contribute to traffic to and/or from the Golgi. Vesicle-filled “wells” open to both the cis and lateral sides of the stacks. The stacks of cisternae are positioned between two types of ER, cis and trans. The cis ER lies adjacent to the ER-Golgi intermediate compartment, which consists of discrete polymorphic membranous elements layered in front of the cis-most Golgi cisterna. The extensive trans ER forms close contacts with the two trans-most cisternae; this apposition may permit direct transfer of lipids between ER and Golgi membranes. Within 0.2 μm of the cisternae studied, there are 394 vesicles (8 clathrin coated, 190 nonclathrin coated, and 196 noncoated), indicating considerable vesicular traffic in this Golgi region. Our data place structural constraints on models of trafficking to, through, and from the Golgi complex.