N-glycosylation of TREK-1/hK2P2.1: two-pore-domain potassium (K2P) channels
Mechanosensitive hTREK-1 two-pore-domain potassium (hK2P2.1) channels give rise to background currents that control cellular excitability. Recently, TREK-1 currents have been linked to the regulation of cardiac rhythm as well as to hypertrophy and fibrosis. Even though the pharmacological and biophy...
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| Main Authors: | , , , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
20 October 2019
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| In: |
International journal of molecular sciences
Year: 2019, Volume: 20, Issue: 20, Pages: 5193 |
| ISSN: | 1422-0067 |
| DOI: | 10.3390/ijms20205193 |
| Online Access: | Verlag, Volltext: https://doi.org/10.3390/ijms20205193 Verlag: https://www.mdpi.com/1422-0067/20/20/5193 
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| Author Notes: | Felix Wiedmann, Daniel Schlund, Francisco Faustino, Manuel Kraft, Antonius Ratte, Dierk Thomas, Hugo A. Katus and Constanze Schmidt |
| Summary: | Mechanosensitive hTREK-1 two-pore-domain potassium (hK2P2.1) channels give rise to background currents that control cellular excitability. Recently, TREK-1 currents have been linked to the regulation of cardiac rhythm as well as to hypertrophy and fibrosis. Even though the pharmacological and biophysical characteristics of hTREK-1 channels have been widely studied, relatively little is known about their posttranslational modifications. This study aimed to evaluate whether hTREK-1 channels are N-glycosylated and whether glycosylation may affect channel functionality. Following pharmacological inhibition of N-glycosylation, enzymatic digestion or mutagenesis, immunoblots of Xenopus laevis oocytes and HEK-293T cell lysates were used to assess electrophoretic mobility. Two-electrode voltage clamp measurements were employed to study channel function. TREK-1 channel subunits undergo N-glycosylation at asparagine residues 110 and 134. The presence of sugar moieties at these two sites increases channel function. Detection of glycosylation-deficient mutant channels in surface fractions and recordings of macroscopic potassium currents mediated by these subunits demonstrated that nonglycosylated hTREK-1 channel subunits are able to reach the cell surface in general but with seemingly reduced efficiency compared to glycosylated subunits. These findings extend our understanding of the regulation of hTREK-1 currents by posttranslational modifications and provide novel insights into how altered ion channel glycosylation may promote arrhythmogenesis. |
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| Item Description: | Im Titel ist 2P tiefgestellt Gesehen am 31.01.2020 |
| Physical Description: | Online Resource |
| ISSN: | 1422-0067 |
| DOI: | 10.3390/ijms20205193 |