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Updated: Aug 10, 2026
Imaging Protein-protein Interactions in vivo
Published on: October 11, 2010
Using live FRET imaging to reveal early protein-protein interactions during T cell activation
Tomasz Zal1, Nicholas R J Gascoigne
1Department of Immunology, The Scripps Research Institute, La Jolla, California 92037, USA. tzal@scripps.edu
Insights
Understanding protein interactions in living cells is crucial for lymphocyte biology. Fluorescence Resonance Energy Transfer (FRET) imaging offers dynamic, real-time insights into molecular proximity within immune synapses.
Area of Science:
- Proteomics
- Immunology
- Cell Biology
Background:
- Understanding dynamic protein-protein interactions within living cells is a key challenge.
- The T cell receptor-CD3 complex and other immunoreceptors in immune synapses are of particular interest.
- Existing fluorescence microscopy methods primarily show co-localization, not dynamic proximity.
Purpose of the Study:
- To highlight the capabilities of Fluorescence (or Förster) Resonance Energy Transfer (FRET) for studying molecular dynamics.
- To emphasize FRET's advantage in providing nanometer-range proximity information.
- To discuss advancements in real-time FRET imaging and in vivo applications.
Main Methods:
- Utilizing spectral changes in fluorescence intensity for FRET analysis.
- Measuring the modulation of donor lifetime as a FRET indicator.
- Employing two-photon excitation for advanced FRET imaging.
Main Results:
- FRET provides dynamic information on molecular proximity at the nanometer scale.
- Real-time FRET imaging is rapidly developing.
- Two-photon excitation enables in vivo FRET imaging.
Conclusions:
- FRET is a powerful technique for dissecting molecular dynamics in cellular contexts.
- Advancements in FRET imaging allow for real-time and in vivo studies of protein interactions.
- This approach is vital for understanding lymphocyte biology and immune responses.
Abstract:
The emerging challenge for proteomics in general and lymphocyte biology in particular is to understand protein-protein interactions in the dynamic context of the living cell. Particularly interesting are the molecular dynamics of the T cell receptor-CD3 complex and other immunoreceptors in immune synapses. Fluorescence (or Förster) resonance energy transfer (FRET) is one of the few techniques that are capable of giving dynamic information about the nanometer-range proximity between molecules, as opposed to simply the subcellular co-localization that is provided by fluorescence microscopy. Spectral changes in fluorescence intensity and down modulation of donor lifetime are the basis for rapidly developing approaches to real-time FRET imaging. With two-photon excitation, FRET can now be extended to in vivo imaging.
