Bradley Michelle, Ramirez Ivan, Cheung Keith, Gholkar Ankur A, Torres Jorge Z
Department of Chemistry and Biochemistry, University of California, Los Angeles.
Department of Chemistry and Biochemistry, University of California, Los Angeles; Molecular Biology Institute, University of California, Los Angeles; Jonsson Comprehensive Cancer Center, University of California, Los Angeles;
J Vis Exp. 2016 Dec 24(118):54870. doi: 10.3791/54870.
Multi-protein complexes, rather than single proteins acting in isolation, often govern molecular pathways regulating cellular homeostasis. Based on this principle, the purification of critical proteins required for the functioning of these pathways along with their native interacting partners has not only allowed the mapping of the protein constituents of these pathways, but has also provided a deeper understanding of how these proteins coordinate to regulate these pathways. Within this context, understanding a protein's spatiotemporal localization and its protein-protein interaction network can aid in defining its role within a pathway, as well as how its misregulation may lead to disease pathogenesis. To address this need, several approaches for protein purification such as tandem affinity purification (TAP) and localization and affinity purification (LAP) have been designed and used successfully. Nevertheless, in order to apply these approaches to pathway-scale proteomic analyses, these strategies must be supplemented with modern technological developments in cloning and mammalian stable cell line generation. Here, we describe a method for generating LAP-tagged human inducible stable cell lines for investigating protein subcellular localization and protein-protein interaction networks. This approach has been successfully applied to the dissection of multiple cellular pathways including cell division and is compatible with high-throughput proteomic analyses.
多蛋白复合物而非孤立作用的单个蛋白,常常调控着调节细胞稳态的分子通路。基于这一原理,纯化这些通路运作所需的关键蛋白及其天然相互作用伴侣,不仅能够绘制这些通路的蛋白质组成图谱,还能更深入地理解这些蛋白如何协同调节这些通路。在此背景下,了解蛋白质的时空定位及其蛋白质-蛋白质相互作用网络,有助于确定其在通路中的作用,以及其失调如何导致疾病发病机制。为满足这一需求,已设计并成功应用了多种蛋白质纯化方法,如串联亲和纯化(TAP)和定位与亲和纯化(LAP)。然而,为了将这些方法应用于通路规模的蛋白质组学分析,这些策略必须辅以克隆和哺乳动物稳定细胞系生成方面的现代技术发展。在此,我们描述了一种生成LAP标签的人诱导型稳定细胞系的方法,用于研究蛋白质亚细胞定位和蛋白质-蛋白质相互作用网络。该方法已成功应用于剖析包括细胞分裂在内的多个细胞通路,并且与高通量蛋白质组学分析兼容。