Plasmonic Imaging of Dynamic Interactions between Membrane Receptor Clusters beyond the Diffraction Limit in Live...

Area of Science:

• Cellular Biology
• Biophysics
• Nanotechnology

Background:

• Ligand-induced receptor clustering is crucial for cell signaling.
• Studying dynamic receptor cluster interactions in live cells is challenging due to labeling and monitoring limitations.

Purpose of the Study:

• To develop and apply a novel microscopy technique for real-time monitoring of dynamic cluster-cluster interactions.
• To investigate the fusion process of protease-activated receptor 1 (PAR1) clusters and the effect of allosteric inhibitors.

Main Methods:

• Plasmon coupling microscopy integrated with data-mining techniques.
• Activation and labeling of receptor clusters with multivalent plasmonic nanoprobes.
• Utilizing K-means-based hidden Markov model for analyzing dynamic state transitions.

Main Results:

• Real-time monitoring of individual receptor clusters and their interactions beyond the diffraction limit.
• Observed PAR1 cluster dynamics: initial contact, weak complex formation, and subsequent fusion into signaling complexes.
• Demonstrated that allosteric inhibitors suppress cluster fusion and downregulate intracellular calcium signaling.

Conclusions:

• The developed plasmon coupling microscopy is effective for studying dynamic receptor clustering and protein phase separation.
• Understanding cluster-cluster interactions provides insights into allosteric inhibitor mechanisms.
• This strategy holds promise for various biological and physiological process monitoring.