Matrix Proteins of the plant ER-Golgi interface

高尔基体是细胞内的关键组成部分，参与蛋白质、碳水化合物和膜的加工和制造，这些蛋白质、碳水化合物和膜是细胞分泌到外部环境的其他区室的目标。我们以前已经表明，在植物细胞中，高尔基体是独特的，它由分布在细胞内的许多被称为池的膜包围的圆盘组成。在许多细胞类型中，这些高尔基堆积也与另一个膜网络密切相关，内质网将生物合成的货物传递给高尔基体进行加工。植物高尔基体与动物和真菌细胞不同的一个显著特征是，高尔基体具有高度的运动性，在包括叶子在内的许多组织中，高尔基体在内质网表面移动。在这个研究项目中我们要解决的关键问题是高尔基体是如何附着在内质网上的以及当它们在细胞质中移动时，单个池池是如何保持完整的？近年来，已经发现了一些蛋白质，它们可能作为锚点或系索，帮助将高尔基体固定在一起，也可能作为内质网产生的运输囊泡的连接物。我们最近发现了一些很好的候选蛋白质，包括一种新的蛋白质。利用融合这些荧光标记蛋白的技术，我们已经显示这些定位到最接近内质网的高尔基体部分。在这项资助中提出的工作将包括研究这些蛋白质之间的相互作用以及这些蛋白质的调节。它们在组织高尔基体中的作用将通过在叶片中表达蛋白质的突变形式以及寻找对高尔基体和蛋白质分泌的形态和生化影响来评估。我们还将研究这些蛋白质在内质网新高尔基体的生物发生中的作用。

The Golgi apparatus is a key component within cells which is involved in the processing and manufacture of proteins, carbohydrates and membranes which are targeted to other compartments of the cells of secreted to the external environment. We have previously shown that in plant cells the Golgi apparatus is unique consisting of numerous stacks of membrane-bounded discs called cisternae distributed within the cell. In many cell types these Golgi stacks are also very closely associated with another membrane network, the endoplasmic reticulum that passes biosynthetic cargo to the Golgi for processing. One remarkable feature of the plant Golgi, which distinguishes it from that in animal and fungal cells, is that the stacks are highly motile and in many tissues including leaves, move over the surface of the endoplasmic reticulum. The key questions that we are going to address in this research programme are how does the Golgi stay attached to the ER and how do the individual stacks of cisternae remain intact when they are moving through the cytoplasm? Over recent years a number of proteins have been discovered that may potentially act as anchors or tethers that help hold the Golgi together and which may also act as linkers for transport vesicles produced by the endoplasmic reticulum. We have recently identified a number of proteins that are good candidates for the plant tethering proteins including one novel protein. Using the technology of fusing these to fluorescent marker proteins we have shown these to locate to the part of the Golgi nearest to the endoplasmic reticulum. The work proposed in this grant will involve investigating the interaction of these proteins with each other and the regulation of these proteins. Their role in organising the Golgi stack will be assessed by expressing in leaves mutant forms of the proteins and looking for both morphological and biochemical effects on the Golgi apparatus and the secretion of proteins. We will also investigate the role these proteins may have in the biogenesis of new Golgi stacks from the endoplasmic reticulum.