Choudhury Swarup Roy, Westfall Corey S, Hackenberg Dieter, Pandey Sona
Donald Danforth Plant Science Center, St. Louis, MO, USA.
Methods Mol Biol. 2013;1043:13-20. doi: 10.1007/978-1-62703-532-3_2.
Heterotrimeric G-proteins are important signaling intermediates in all eukaryotes. These proteins link signal perception by a cell surface localized receptor to the downstream effectors of a given signaling pathways. The minimal core of the heterotrimeric G-protein complex consists of Gα, Gβ, and Gγ subunits, the G protein coupled receptor (GPCR) and the regulator of G-protein signaling (RGS) proteins. Signal transduction by heterotrimeric G-proteins is controlled by the distinct biochemical activities of Gα protein, which binds and hydrolyses GTP. Evaluation of the rate of GTP binding, the rate of GTP hydrolysis, and the rate of GTP/GDP exchange on Gα protein are required to better understand the mechanistic aspects of heterotrimeric G-protein signaling, which remains significantly limited for the plant G-proteins. Here we describe the optimized methods for measurement of the distinct biochemical activities of the Arabidopsis Gα protein.
异源三聚体G蛋白是所有真核生物中重要的信号转导中间体。这些蛋白质将细胞表面定位受体的信号感知与给定信号通路的下游效应器联系起来。异源三聚体G蛋白复合物的最小核心由Gα、Gβ和Gγ亚基、G蛋白偶联受体（GPCR）和G蛋白信号调节剂（RGS）蛋白组成。异源三聚体G蛋白的信号转导由结合并水解GTP的Gα蛋白的独特生化活性控制。评估Gα蛋白上的GTP结合速率、GTP水解速率和GTP/GDP交换速率，对于更好地理解异源三聚体G蛋白信号转导的机制方面是必要的，而这对于植物G蛋白来说仍然受到很大限制。在这里，我们描述了用于测量拟南芥Gα蛋白独特生化活性的优化方法。
