1. Academic Validation
  2. FRET-enhanced photostability allows improved single-molecule tracking of proteins and protein complexes in live mammalian cells

FRET-enhanced photostability allows improved single-molecule tracking of proteins and protein complexes in live mammalian cells

  • Nat Commun. 2018 Jun 28;9(1):2520. doi: 10.1038/s41467-018-04486-0.
Srinjan Basu 1 Lisa-Maria Needham 2 David Lando 1 Edward J R Taylor 1 Kai J Wohlfahrt 1 Devina Shah 1 Wayne Boucher 1 Yi Lei Tan 1 Lawrence E Bates 1 Olga Tkachenko 1 Julie Cramard 3 B Christoffer Lagerholm 4 Christian Eggeling 4 Brian Hendrich 1 3 Dave Klenerman 5 Steven F Lee 6 Ernest D Laue 7
Affiliations

Affiliations

  • 1 Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK.
  • 2 Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK.
  • 3 Wellcome Trust - MRC Stem Cell Institute, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QR, UK.
  • 4 Medical Research Council Human Immunology Unit and Wolfson Imaging Centre, Weatherall Institute of Molecular Medicine, University of Oxford, Headley Way, Oxford, OX3 9DS, UK.
  • 5 Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK. dk10012@cam.ac.uk.
  • 6 Department of Chemistry, University of Cambridge, Lensfield Road, Cambridge, CB2 1EW, UK. sl591@cam.ac.uk.
  • 7 Department of Biochemistry, University of Cambridge, 80 Tennis Court Road, Cambridge, CB2 1GA, UK. e.d.laue@bioc.cam.ac.uk.
Abstract

A major challenge in single-molecule imaging is tracking the dynamics of proteins or complexes for long periods of time in the dense environments found in living cells. Here, we introduce the concept of using FRET to enhance the photophysical properties of photo-modulatable (PM) fluorophores commonly used in such studies. By developing novel single-molecule FRET pairs, consisting of a PM donor fluorophore (either mEos3.2 or PA-JF549) next to a photostable acceptor dye JF646, we demonstrate that FRET competes with normal photobleaching kinetic pathways to increase the photostability of both donor fluorophores. This effect was further enhanced using a triplet-state quencher. Our approach allows us to significantly improve single-molecule tracking of chromatin-binding proteins in live mammalian cells. In addition, it provides a novel way to track the localization and dynamics of protein complexes by labeling one protein with the PM donor and its interaction partner with the acceptor dye.

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