.... Fig. 2. Genetically encoded fluorescent biosensors for ERK. (A) Miu2 binding to mitogen-activated protein kinase kinase (MEK) shows closed conformation with high Förster (or fluorescence) resonance energy transfer (FRET) level. Upon stimulation, Miu2 is dissociated from MEK, leading to a decrease...

... in individual cells during this transition is unclear. Using a FRET-based biosensor, we monitored ERK signalling dynamics of single mouse ESCs during differentiation. ERK activity was highly heterogeneous, with considerable variability in ERK signalling between single cells within ESC colonies. Different...

... of development. Although individual components are known, the relationships among them remain unresolved. We now use FRET measurements of pathway activity, analysis of protein localization and genetic epistasis to dissect the structure of this network in Drosophila . We find that the adaptor protein Disabled...