QuasAr Odyssey: the origin of fluorescence and its voltage sensitivity in microbial rhodopsins.

Rhodopsins had long been considered non-fluorescent until a peculiar voltage-sensitive fluorescence was reported for archaerhodopsin-3 (Arch3) derivatives. These proteins named QuasArs have been used for imaging membrane voltage changes in cell cultures and small animals, but they could not be applied in living rodents. To develop the next generation of sensors, it is indispensable to first understand the molecular basis of the fluorescence and its modulation by the membrane voltage.

Split-HaloTag imaging assay for sophisticated microscopy of protein-protein interactions .

An ever-increasing number of intracellular multi-protein networks have been identified in plant cells. Split-GFP-based protein-protein interaction assays combine the advantages of interaction studies in a native environment with additional visualization of protein complex localization. Because of their simple protocols, they have become some of the most frequently used methods.