We have developed new methods for visualization of modified proteins in living cells. The ubiquitin-mediated fluorescence complementation (UbFC) analysis enables simultaneous imaging of specific ubiqutin and SUMO conjugates in the normal cellular environment (Fang, 2004).
By
visualizing the fluorescence of UbFC ubiquitin conjugates in living
cells, we found that ubiquitinated Jun is translocated into lysosomes (Ikeda, 2008).