Temporal dynamics of microbial rhodopsin fluorescence reports absolute membrane voltage

Area of Science:

• Cellular biology
• Biophysics
• Genetics

Background:

• Plasma membrane voltage is critical for cellular functions like transport and communication.
• Existing fluorescent voltage reporters struggle to measure absolute voltage accurately.

Purpose of the Study:

• To develop a novel genetically encoded fluorescent voltage sensor capable of reporting absolute membrane voltage.
• To overcome the limitations of current voltage reporters that primarily indicate relative changes.

Main Methods:

• Developed an Archaerhodopsin-based fluorescent voltage sensor.
• Utilized time-domain response to illumination changes to encode absolute voltage.
• Validated the sensor in human embryonic kidney cells.

Main Results:

• The sensor accurately encodes absolute membrane voltage.
• Measurements demonstrated robustness against variations in imaging parameters and gene expression.
• Achieved an absolute voltage accuracy of 10 mV.

Conclusions:

• The developed sensor enables precise measurement of absolute membrane voltage.
• Time-domain encoding offers a new approach for studying bioelectric phenomena.
• Potential applications in investigating previously intractable cellular processes.