Genetically encoded optical probes for molecular processes in living cells

The intracellular signaling can be monitored in vivo in living cells by genetically encoded intracellular fluorescent and bioluminescent probes or indicators, which include second messengers, protein phosphorylation, protein conformational changes, protein-protein interactions, and protein localizations. These probes are of general use not only for fundamental biological studies, but also for assay and screening of possible pharmaceutical or toxic chemicals that inhibit or facilitate cellular signaling pathways.