Fluorescent protein-based biosensors and their clinical applications.

Green fluorescent protein and its relatives have shed their light on a wide range of biological problems. To date, with a color palette consisting of fluorescent proteins with different spectra, researchers can "paint" living cells as they desire. Moreover, sophisticated biosensors engineered to contain single or multiple fluorescent proteins, including FRET-based biosensors, spatiotemporally unveil molecular mechanisms underlying physiological processes. Although such molecules have contributed considerably to basic research, their abilities to be used in applied life sciences have yet to be fully explored. Here, we review the molecular bases of fluorescent proteins and fluorescent protein-based biosensors and focus on approaches aimed at applying such proteins to the clinic.