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Updated: Feb 23, 2026
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Isolation and Kv Channel Recordings in Murine Atrial and Ventricular Cardiomyocytes
Published on: March 12, 2013
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SUMO co-expression modifies KV 11.1 channel activity
A B Steffensen1, M N Andersen1, N Mutsaers1
1Department of Biomedical Sciences, Faculty of Health and Medical Sciences, Danish National Research Foundation Centre for Cardiac Arrhythmia, University of Copenhagen, Copenhagen, Denmark.
Acta Physiologica (Oxford, England)
|September 10, 2017
Summary
Sumoylation modifies the cardiac potassium channel KV 11.1 (also known as IKr), impacting its electrical activity. This study identifies specific sites on the channel affected by sumoylation.
Area of Science:
- Molecular biology
- Cardiovascular physiology
- Ion channel function
Background:
- The KV 11.1 channel (IKr) is crucial for heart rhythm.
- Channel dysfunction causes cardiac arrhythmias.
- Discrepancies between native and experimental currents suggest unknown regulatory factors.
Purpose of the Study:
- To investigate the role of sumoylation in regulating KV 11.1 channel activity.
- To identify specific sumoylation sites on the KV 11.1 channel.
Main Methods:
- Electrophysiological recordings using two-electrode voltage-clamp (TEVC) in Xenopus oocytes.
- Site-directed mutagenesis to pinpoint SUMO-target amino acids.
- Confocal imaging for protein localization studies.
Main Results:
- Sumoylation of KV 11.1 alters electrophysiological properties, decreasing current amplitude.
- Observed effects are attributed to faster inactivation and modified deactivation kinetics.
- Lysines at positions 21, 93, and 116 within the PAS domain were identified as potential SUMOylation targets.
Conclusions:
- KV 11.1 is a target for sumoylation.
- Specific residues (K21, K93, K116) are implicated in this modification.
- Sumoylation of the PAS domain influences channel kinetics.
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