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The Gβ1 and Gβ3 Subunits Differentially Regulate Rat Vascular Kv7 Channels
Iain A Greenwood1, Jennifer B Stott1
1Vascular Biology Research Centre, Institute of Molecular and Clinical Sciences, St George's University of London, London, United Kingdom.
Frontiers in Physiology
|January 30, 2020
Summary
G-protein beta subunits Gβ1 and Gβ3 differentially regulate Kv7 potassium channels. Gβ1 impacts Kv7.4 protein levels, while Gβ3 controls basal vascular tone via Kv7 channels.
Area of Science:
- Physiology
- Molecular Biology
- Cardiovascular Research
Background:
- Kv7 channels regulate vascular tone and vasorelaxation.
- Kv7.4 channels require G-protein βγ subunits for activity.
- Specific Gβγ subunit combinations may confer effector selectivity.
Purpose of the Study:
- Characterize Gβ subunits regulating Kv7.4 and native vascular Kv7 channels.
- Investigate the roles of different Gβ isoforms in Kv7 channel function.
Main Methods:
- Overexpression of Kv7.4 and Gβx subunits in CHO cells.
- Proximity ligation assay in rat renal artery myocytes.
- Morpholino-directed knockdown of Gβ1 and Gβ3 in rat renal arteries.
Main Results:
- Gβ1, Gβ3, and Gβ5 enhanced Kv7.4 currents in CHO cells.
- Kv7.4 interacted with Gβ1 and Gβ3 in rat renal myocytes.
- Gβ1 knockdown reduced Kv7.4 protein expression.
- Gβ3 knockdown decreased basal K+ currents, insensitive to Kv7 inhibition.
Conclusions:
- Gβ1 subunit is implicated in Kv7.4 protein synthesis or stability.
- Gβ3 subunit regulates basal activity of native vascular Kv7 channels.
- Distinct Gβ subunits play individual roles in ion channel regulation.
Keywords:
G protein signalingG protein βγ subunitsKv7 channelspotassium channelvascular smooth muscleMore Related Videos
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