High time resolution FRET analysis of the activation of G protein

G蛋白偶联受体（gpcr）是重要的信号分子，与特定配体结合后被激活，通过激活G蛋白触发下游信号。利用荧光共振能量转移（FRET）技术分析了GPCR信号传导的初始过程、受体的激活和随后的G蛋白结合。通过高时间分辨率的FRET分析，我们发现G蛋白的结合稳定了gpcr的活性构象，并减缓了活化受体的失活。进一步的FRET研究表明，G蛋白结合的影响取决于偶联受体的类型。

G protein coupled receptors (GPCRs) are the important signaling molecules which are activated upon the binding with the specific ligand and trigger the downstream signaling through activating G protein. These initial processes of GPCR signaling, the activation of receptor and the following G protein binding, were analyzed by using a fluorescence resonance energy transfer (FRET) technique. With the high time resolution FRET analysis, we found that binding of G protein stabilizes the active conformations of GPCRs and slows the deactivation of the activated receptor. Further FRET studies revealed that the effects of G protein binding differ depending on the type of the coupled receptors.