Detecting molecular interactions in live-cell single-molecule imaging with proximity-assisted photoactivation (PAPA).

ABSTRACT: Single-molecule imaging provides a powerful way to study biochemical processes in live cells, yet it remains challenging to track single molecules while simultaneously detecting their interactions. Here, we describe a novel property of rhodamine dyes, proximity-assisted photoactivation (PAPA), in which one fluorophore (the 'sender') can reactivate a second fluorophore (the 'receiver') from a dark state. PAPA requires proximity between the two fluorophores, yet it operates at a longer average intermolecular distance than Förster resonance energy transfer (FRET). We show that PAPA can be used in live cells both to detect protein-protein interactions and to highlight a subpopulation of labeled protein complexes in which two different labels are in proximity. In proof-of-concept experiments, P

SUBMITTER: Graham TGW 

PROVIDER: S-EPMC9531946 | biostudies-literature | 2022 Aug

REPOSITORIES: biostudies-literature