Visualization of lipid-receptor interactions on single cells by time-resolved imaging fluorescence microscopy

Area of Science:

• Cell biology
• Biophysics
• Microscopy

Background:

• Plasma membrane lipids and receptors play crucial roles in cellular signaling.
• Understanding lipid-receptor interactions is key to deciphering cell surface dynamics and function.

Purpose of the Study:

• To investigate the physical interaction between plasma-membrane lipids and the epidermal growth factor (EGF) receptor.
• To demonstrate the utility of time-resolved imaging fluorescence microscopy for studying these interactions at the single-cell level.

Main Methods:

• Utilized single A431 human epidermoid carcinoma cells.
• Employed fluorescence resonance energy transfer (FRET) microscopy with donor-photobleaching.
• Used fluorescein-labeled EGF (donor) and Bodipy-PC lipid (acceptor) to monitor interactions.

Main Results:

• Detected a mean FRET efficiency of 13%, indicating a physical interaction between EGF receptor and plasma-membrane lipids.
• Demonstrated the high sensitivity and potential of time-resolved imaging FRET microscopy.

Conclusions:

• Confirms a direct physical interaction between EGF receptor and specific plasma-membrane lipids.
• Highlights FRET-microscopy as a powerful technique for dissecting molecular interactions on single cell membranes.