Sivars Ulf, Aivazian Dikran, Pfeffer Suzanne
Methods Enzymol. 2005;403:348-56. doi: 10.1016/S0076-6879(05)03030-2.
Prenylated Rab proteins exist in the cytosol bound to guanine dissociation inhibitor (GDI). These dimeric complexes contain all of the information needed for accurate membrane delivery. We have shown that membranes contain a proteinaceous activity that is required for Rab delivery, and we named that activity GDI displacement factor (GDF). Biochemical analysis revealed that GDF activity was membrane associated and had a mass of approximately 25 kDa. We therefore used a candidate gene approach and were able to show that pure Yip3/PRA1 protein displays GDF activity. In this chapter, we review key aspects of GDF analysis: our assay and the method by which we purify Yip3/PRA1 in active form.
异戊二烯化的Rab蛋白存在于与鸟嘌呤解离抑制剂（GDI）结合的胞质溶胶中。这些二聚体复合物包含准确膜递送所需的所有信息。我们已经表明，膜含有Rab递送所需的一种蛋白质活性，我们将该活性命名为GDI置换因子（GDF）。生化分析表明，GDF活性与膜相关，质量约为25 kDa。因此，我们采用候选基因方法，能够证明纯Yip3/PRA1蛋白具有GDF活性。在本章中，我们回顾了GDF分析的关键方面：我们的检测方法以及纯化活性形式的Yip3/PRA1的方法。
