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Single-Cell Biophysics: Measurement, Modulation, and Modeling
Poster Abstracts
85
81-POS
Board 41
Imaging Membrane Potential of the Endoplasmic Reticulum with a Genetically-Encoded
Voltage Indicator
Masoud Sepehri rad
1
, Lawrence B. Cohen
1,2
.Bradley J. Baker
1
,
1
Korea Institute of Science and Technology, seoul, South Korea,
2
Yale University School of
Medicine,, New Haven, CT, USA.
In eukaryotic cells, the endoplasmic reticulum (ER) is the largest continuous membrane-enclosed
network which surrounds a single lumen. Using a newly designed genetically encoded voltage
indicator (GEVI), we applied the patch clamp technique to HEK293 cells and found that there is
an electrical interaction between plasma membrane and ER membrane. We have optically
monitored the voltage changes in both of these membranes simultaneously. The optical signal of
the GEVI in the plasma membrane is consistent from trial to trial. However, the ER signal
decreases in size with repeated trials while the plasma membrane resistance remains constant.
This dynamic behavior of the internal signal suggests that voltage may stress the ER causing it to
remodel and change its resistance. Our findings further suggest that the ER may transfer
electrical signals from the plasma membrane to the nuclear envelope.