School of Life Sciences, Oxford Brookes University, Headington Campus, Gipsy Lane, Oxford, OX3 0BP, UK.
Traffic. 2009 May;10(5):567-71. doi: 10.1111/j.1600-0854.2009.00891.x. Epub 2009 Feb 11.
In many vacuolate plant cells, individual Golgi bodies appear to be attached to tubules of the pleiomorphic cortical endoplasmic reticulum (ER) network. Such observations culminated in the controversial mobile secretory unit hypothesis to explain transport of cargo from the ER to Golgi via Golgi attached export sites. This proposes that individual Golgi bodies and an attached-ER exit machinery move over or with the surface of the ER whilst collecting cargo for secretion. By the application of infrared laser optical traps to individual Golgi bodies within living leaf cells, we show that individual Golgi bodies can be micromanipulated to reveal their association with the ER. Golgi bodies are physically attached to ER tubules and lateral displacement of individual Golgi bodies results in the rapid growth of the attached ER tubule. Remarkably, the ER network can be remodelled in living cells simply by movement of laser trapped Golgi dragging new ER tubules through the cytoplasm and new ER anchor sites can be established. Finally, we show that trapped Golgi ripped off the ER are 'sticky' and can be docked on to and attached to ER tubules, which will again show rapid growth whilst pulled by moving Golgi.
在许多液泡植物细胞中，单个高尔基体似乎附着在多形质皮质内质网（ER）网络的小管上。这些观察结果最终导致了有争议的移动分泌单元假说，以解释通过高尔基体附着的出口部位从 ER 向高尔基体运输货物。该假说提出，单个高尔基体和附着的 ER 出口机制在收集分泌货物的同时在 ER 表面上移动或与 ER 一起移动。通过将红外激光光阱应用于活叶细胞中的单个高尔基体，我们表明可以对单个高尔基体进行微操作以揭示其与 ER 的关联。高尔基体与 ER 小管物理连接，单个高尔基体的横向位移导致附着的 ER 小管迅速生长。值得注意的是，通过激光捕获的高尔基体的运动可以简单地在活细胞中重塑 ER 网络，从而通过细胞质拉动新的 ER 小管，并可以建立新的 ER 锚定位点。最后，我们表明，被捕获的高尔基体从 ER 上“粘性”脱落，并可以停靠在 ER 小管上并附着在其上，而当移动的高尔基体拉动时，ER 小管将再次迅速生长。
