Department of Biology, University of Pennsylvania, Philadelphia, PA 19104, USA.
Trends Cell Biol. 2011 Jul;21(7):383-6. doi: 10.1016/j.tcb.2011.03.006. Epub 2011 May 6.
The exocyst, an octameric protein complex mediating vesicle tethering at the plasma membrane for exocytosis, is a downstream effector of the Rab proteins Rab8 and Rab11, which are key regulators of membrane trafficking from the trans-Golgi network and recycling endosome to the plasma membrane. Rab11 and Rab8 coordinate their actions via Rabin8, the guanine nucleotide exchange factor of Rab8. A cascade of protein-protein interactions involving the Rabs and the exocyst complex couples the generation of secretory vesicles at donor compartments to their docking and fusion at the plasma membrane. Here, we discuss recent work implicating Rab proteins and the exocyst in primary ciliogenesis and epithelial lumenogenesis. In addition, we discuss early work in the budding yeast Saccharomyces cerevisiae, which provided the initial insight into the molecular mechanisms of polarized exocytosis.
外被体是一种八聚体蛋白复合物，介导质膜上囊泡的锚定，从而促进胞吐作用。它是 Rab 蛋白 Rab8 和 Rab11 的下游效应物，Rab8 和 Rab11 是从高尔基复合体到质膜的膜运输以及再循环内体的关键调节剂。Rab11 和 Rab8 通过 Rabin8（Rab8 的鸟嘌呤核苷酸交换因子）协调它们的作用。涉及 Rab 蛋白和外被体复合物的蛋白-蛋白相互作用级联反应将分泌囊泡在供体隔室中的产生与它们在质膜上的对接和融合偶联起来。在这里，我们讨论了最近的工作，这些工作表明 Rab 蛋白和外被体参与了初级纤毛发生和上皮腔形成。此外，我们还讨论了芽殖酵母酿酒酵母的早期工作，这些工作为极性胞吐作用的分子机制提供了最初的见解。
