Visualizing dynamics of kinase activity in living animals is essential for mechanistic understanding of cell and developmental biology. We describe GFP-based kinase reporters that phase-separate upon kinase activation via multivalent protein-protein interactions, forming intensively fluorescent droplets. Called SPARK (separation of phases-based activity reporter of kinase), these reporters have large dynamic range (fluorescence change), high brightness, fast kinetics, and are reversible. The SPARK-based protein kinase A (PKA) reporter reveals oscillatory dynamics of PKA activities upon G protein-coupled receptor activation. The SPARK-based extracellular signal-regulated kinase (ERK) reporter unveils transient dynamics of ERK activity during tracheal metamorphosis in live Drosophila. Because of intensive brightness and simple signal pattern, SPARKs allow easy examination of kinase signaling in living animals in a qualitative way. The modular design of SPARK will facilitate development of reporters of other kinases.

可视化活体中激酶活性的动力学对于机械理解细胞和发育生物学至关重要。我们描述了基于GFP的激酶报告基因，该激酶通过多价蛋白质-蛋白质相互作用在激酶激活后发生相分离，形成密集的荧光液滴。所谓火花（小号的eparation p hases基于一个ctivity ř的eporter ķ因此，这些报道分子具有大的动态范围（荧光变化），高亮度，快速的动力学，并且是可逆的。基于SPARK的蛋白激酶A（PKA）报告基因揭示了G蛋白偶联受体激活后PKA活性的振荡动力学。基于SPARK的细胞外信号调节激酶（ERK）报告基因揭示了果蝇活体气管变态过程中ERK活性的瞬时动态。由于密集的亮度和简单的信号模式，SPARKs可以以定性的方式轻松检查活体动物中的激酶信号传导。SPARK的模块化设计将促进其他激酶报道基因的开发。