Expanded repertoire of polaris, a versatile fluorescent probe for molecular orientation

Abstract

Fluorescence polarization microscopy (FPM) can visualize the dipole orientation of fluorescent molecules and has been used for analyzing architectural dynamics of biomolecules including cytoskeletal proteins. To monitor the orientation of target molecules by FPM, target molecules need to be labeled with fluorophores in a sterically constrained manner, so that the fluorophores do not freely rotate. Recently, we reported a versatile probe for such labeling using fluorescent proteins, POLArIS (Probe for Orientation and Localization Assessment, recognizing specific Intracellular Structures of interest) (PNAS 2021).