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The SUMO-specific protease SENP2 plays an essential role in the regulation of Kv7.2 and Kv7.3 potassium channels.

Authors :
Xu Chen
Yuhong Zhang
Xiang Ren
Qi Su
Yan Liu
Xing Dang
Yuanyuan Qin
Xinyi Yang
Zhengcao Xing
Yajie Shen
Yaya Wang
Zhantao Bai
Yeh, Edward T. H.
Hongmei Wu
Yitao Qi
Source :
Journal of Biological Chemistry. Oct2021, Vol. 297 Issue 4, p1-14. 14p.
Publication Year :
2021

Abstract

Sentrin/small ubiquitin-like modifier (SUMO)-specific pro-tease 2 (SENP2)-deficient mice develop spontaneous seizures in early life because of a marked reduction in M currents, which regulate neuronal membrane excitability. We have previously shown that hyper-SUMOylation of the Kv7.2 and Kv7.3 channels is critically involved in the regulation of the M currents conducted by these potassium voltage-gated channels. Here, we show that hyper-SUMOylation of the Kv7.2 and Kv7.3 proteins reduced binding to the lipid secondary messenger PIP2. CaM1 has been shown to be tethered to the Kv7 subunits via hydrophobic motifs in its C termini and implicated in the channel assembly. Mutation of the SUMOylation sites on Kv7.2 and Kv7.3 specifically resulted in decreased binding to CaM1 and enhanced CaM1-mediated assembly of Kv7.2 and Kv7.3, whereas hyper-SUMOylation of Kv7.2 and Kv7.3 inhibited channel assembly. SENP2-deficient mice exhibited increased acetylcholine levels in the brain and the heart tissue because of increases in the vagal tone induced by recurrent seizures. The SENP2-deficient mice develop seizures followed by a period of sinus pauses or atrioventricular conduction blocks. Chronic administration of the parasympathetic blocker atropine or unilateral vagotomy significantly prolonged the life of the SENP2-deficient mice. Furthermore, we showed that retigabine, an M-current opener, reduced the transcription of SUMO-activating enzyme SAE1 and inhibited SUMOylation of the Kv7.2 and Kv7.3 channels, and also prolonged the life of SENP2-deficient mice. Taken together, the previously demonstrated roles of PIP2, CaM1, and retigabine on the regulation of Kv7.2 and Kv7.3 channel function can be explained by their roles in regulating SUMOylation of this critical potassium channel. [ABSTRACT FROM AUTHOR]

Details

Language :
English
ISSN :
00219258
Volume :
297
Issue :
4
Database :
Academic Search Index
Journal :
Journal of Biological Chemistry
Publication Type :
Academic Journal
Accession number :
154590603
Full Text :
https://doi.org/10.1016/j.jbc.2021.101183