Improving membrane voltage measurements using FRET with new fluorescent proteins

Area of Science:

• Biophysics
• Molecular Biology
• Neuroscience

Background:

• Voltage sensors are crucial for studying cellular electrical activity.
• Existing voltage sensors have limitations in speed and sensitivity.
• Coral fluorescent proteins offer unique photophysical properties for sensor development.

Purpose of the Study:

• To develop a novel, sensitive voltage sensor using coral fluorescent proteins.
• To enable direct visualization of electrical activity in excitable cells.
• To characterize the performance of the new sensor, named Mermaid.

Main Methods:

• Utilized two new coral fluorescent proteins as Förster Resonance Energy Transfer (FRET) donor and acceptor pairs.
• Engineered the Mermaid voltage sensor by combining these proteins.
• Validated the sensor's performance in cultured excitable cells at physiological temperatures.

Main Results:

• The Mermaid sensor demonstrated approximately 40% change in emission ratio per 100 mV.
• Mermaid exhibited fast on-off kinetics at warm temperatures (approx. 33°C).
• The sensor successfully reported voltage spikes comparable to action potentials.

Conclusions:

• Mermaid is a highly effective voltage sensor for visualizing cellular electrical activity.
• Its fast kinetics and sensitivity make it suitable for real-time monitoring of action potentials.
• This development offers a valuable tool for neuroscience and cell biology research.