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Updated: May 11, 2026
FLIM-FRET Measurements of Protein-Protein Interactions in Live Bacteria.
Published on: August 25, 2020
FtsW protein-protein interactions visualized in live Staphylococcus aureus cells by FLIM-FRET
Nils Y Meiresonne1, Sara F Costa2,3, Simon Schäper2
1Bacterial Cell Biology, Instituto de Tecnologia Química e Biológica António Xavier, Universidade NOVA de Lisboa, Oeiras, Portugal. nmeiresonne@itqb.unl.pt.
This study visualizes bacterial protein interactions in vivo using fluorescence-lifetime imaging microscopy combined with Förster resonance energy transfer (FLIM-FRET). We mapped interactions within the Staphylococcus aureus peptidoglycan synthesis complex, revealing FtsW self-interaction and altered FtsW-PBP1 interactions upon antibiotic treatment.
Area of Science:
- Microbiology
- Cell Biology
- Biophysics
Background:
- Bacterial cell cycle progression depends on dynamic protein interactions.
- Visualizing these interactions in vivo is crucial but challenging.
Purpose of the Study:
- To establish and validate fluorescence-lifetime imaging microscopy combined with Förster resonance energy transfer (FLIM-FRET) for in vivo visualization of protein interactions.
- To map protein interactions within the peptidoglycan synthesis complex in Staphylococcus aureus.
Main Methods:
- Established and validated FLIM-FRET for in vivo protein interaction studies in Staphylococcus aureus.
- Utilized control proteins to achieve FRET efficiencies up to 40%.
Main Results:
- Mapped interactions of the glycosyltransferase FtsW within the septal peptidoglycan-synthesizing complex.
- Confirmed FtsW interactions with PBP1 and DivIB.
- Discovered FtsW self-interaction, suggesting multimeric complex formation.
- Observed weakened FtsW-PBP1 interaction upon imipenem treatment, indicating conformational changes or uncoupling of activities.
Conclusions:
- FLIM-FRET is a robust technique for visualizing bacterial protein interactions in vivo.
- Septal peptidoglycan synthesis involves multimeric complexes.
- Antibiotic-induced changes in FtsW interactions are linked to conformational alterations or activity uncoupling, not just loss of synthesis.
