Department of Biology, University of Alabama, Birmingham, AL, USA.
Methods Mol Biol. 2023;2690:9-22. doi: 10.1007/978-1-0716-3327-4_2.
Protein-protein interaction mapping has gained immense importance in understanding protein functions in diverse biological pathways. There are various in vivo and in vitro techniques associated with the protein-protein interaction studies but generally, the focus is confined to understanding the protein interaction in the nucleus of the cell, and thus it limits the availability to explore protein interactions that are happening in the cytoplasm of the cell. Since posttranslational modification is a crucial step in signaling pathways and cellular protein interactions harnessing the cytoplasmic protein and evaluating the interaction in the cytoplasm, this protocol will provide more information about studying these types of protein interactions. Cytotrap is a type of yeast-two-hybrid system that differs in its ability to anchor along the membrane, thus directing the protein of interest to anchor along the membrane through the myristoylation signaling unit. The vector containing the target protein contains the myristoylation unit, called the prey, and the bait unit contains the protein of interest as a fusion with the hSos protein. In an event of interaction between the target and the protein of interest, the hSos protein unit will be localized to the membrane and the GDP/GTP exchange unit will trigger the activation of the Ras pathway that leads to the survival of the temperature-sensitive yeast strain at a higher temperature.
蛋白质-蛋白质相互作用图谱在理解不同生物途径中的蛋白质功能方面具有重要意义。有各种与蛋白质-蛋白质相互作用研究相关的体内和体外技术,但通常,重点仅限于了解细胞核内的蛋白质相互作用,因此限制了探索发生在细胞质中的蛋白质相互作用的可能性。由于翻译后修饰是信号通路和细胞蛋白质相互作用中的关键步骤,利用细胞质蛋白质并评估细胞质中的相互作用,该方案将提供更多关于研究这些类型的蛋白质相互作用的信息。Cytotrap 是一种酵母双杂交系统,其区别在于它能够沿着膜锚定,从而通过肉豆蔻酰化信号单元将感兴趣的蛋白质引导到膜上锚定。含有靶蛋白的载体包含肉豆蔻酰化单元,称为诱饵,诱饵单元包含与 hSos 蛋白融合的感兴趣的蛋白。在靶蛋白和感兴趣的蛋白之间发生相互作用的情况下,hSos 蛋白单元将定位于膜上,GDP/GTP 交换单元将触发 Ras 途径的激活,从而导致对温度敏感的酵母菌株在较高温度下存活。