Stop-and-go movements of plant Golgi stacks are mediated by the acto-myosin system
Stop-and-go movements of plant Golgi stacks are mediated by the acto-myosin system
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DOI：
10.1104/pp.121.4.1127
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发表时间：
1999-12-01
期刊：
影响因子：
7.4
通讯作者：
Staehelin, LA
中科院分区：
文献类型：
--
作者：
Nebenführ, A;Gallagher, LA;Staehelin, LA
植物细胞中的高尔基体由大量独立的高尔基体堆叠/反式高尔基体网络/高尔基体基质单元组成，它们似乎随机分布在整个细胞质中。为了研究这些高尔基体单位在活植物细胞中的动态行为，我们从大豆（Glycine max）中克隆了一个cDNA，Gm-Man 1，编码高尔基体蛋白α-1，2甘露糖苷酶1。预测的约65 kD的蛋白质显示出与I类动物和真菌α-1，2甘露糖苷酶的一般结构和序列的相似性（45%同一性）。GmMan 1：：绿色荧光蛋白融合构建体在烟草（Nicotiana tabacum）Bright Yellow 2悬浮培养细胞中的表达揭示了数百至数千个荧光点的存在。免疫电子显微镜表明，这些斑点对应于个别高尔基体堆栈和融合蛋白主要局限于顺式侧堆栈。在活细胞中，细胞堆进行走走停停的运动，在定向运动和随机“摆动”之间快速摆动。定向运动（最大速度4.2 μ m/s）与细胞质流动有关，发生在沿着直线轨迹上，并依赖于完整的肌动蛋白微丝和肌球蛋白马达，因为用细胞松弛素D或丁二酮单肟处理阻断了流动运动。相比之下，微管破坏药物似乎有一个小的，但可重复的刺激作用的流动行为。我们提出了一个模型，假设高尔基体反高尔基体网络单位的停止和去的运动是由内质网出口网站和局部扩大细胞壁结构域，以优化内质网高尔基体和高尔基体细胞壁贩运产生的“停止信号”调节。
The Golgi apparatus in plant cells consists of a large number of independent Golgi stack/trans-Golgi network/Golgi matrix units that appear to be randomly distributed throughout the cytoplasm. To study the dynamic behavior of these Golgi units in living plant cells, we have cloned a cDNA from soybean (Glycine max), Gm-Man1, encoding the resident Golgi protein alpha-1,2 mannosidase 1. The predicted protein of approximately 65 kD shows similarity of general structure and sequence (45% identity) to class I animal and fungal alpha-1,2 mannosidases. Expression of a GmMan1::green fluorescent protein fusion construct in tobacco (Nicotiana tabacum) Bright Yellow 2 suspension-cultured cells revealed the presence of several hundred to thousands of fluorescent spots. Immunoelectron microscopy demonstrates that these spots correspond to individual Golgi stacks and that the fusion protein is largely confined to the cis-side of the stacks. In living cells, the stacks carry out stop-and-go movements, oscillating rapidly between directed movement and random "wiggling." Directed movement (maximal velocity 4.2 mu m/s) is related to cytoplasmic streaming, occurs along straight trajectories, and is dependent upon intact actin microfilaments and myosin motors, since treatment with cytochalasin D or butanedione monoxime blocks the streaming motion. In contrast, microtubule-disrupting drugs appear to have a small but reproducible stimulatory effect on streaming behavior. We present a model that postulates that the stop-and-go motion of Golgi-trans-Golgi network units is regulated by "stop signals" produced by endoplasmic reticulum export sites and locally expanding cell wall domains to optimize endoplasmic reticulum to Golgi and Golgi to cell wall trafficking.