N-glycosylation of TREK-1/hK2P2.1

• Verfasst von: Wiedmann, Felix Tobias [VerfasserIn]
• Verfasst von: Kraft, Manuel [VerfasserIn]
• Verfasst von: Ratte, Antonius [VerfasserIn]
• Verfasst von: Thomas, Dierk [VerfasserIn]
• Verfasst von: Katus, Hugo [VerfasserIn]
• Verfasst von: Schmidt, Constanze [VerfasserIn]
• Titel: N-glycosylation of TREK-1/hK2P2.1
• Titelzusatz: two-pore-domain potassium (K2P) channels
• Verf.angabe: Felix Wiedmann, Daniel Schlund, Francisco Faustino, Manuel Kraft, Antonius Ratte, Dierk Thomas, Hugo A. Katus and Constanze Schmidt
• E-Jahr: 2019
• Jahr: 20 October 2019
• Umfang: 18 S.
• Fussnoten: Im Titel ist 2P tiefgestellt ; Gesehen am 31.01.2020
• Titel Quelle: Enthalten in: International journal of molecular sciences
• Ort Quelle: Basel : Molecular Diversity Preservation International, 2000
• Jahr Quelle: 2019
• Band/Heft Quelle: 20(2019,20) Artikel-Nummer 5193, 18 Seiten
• ISSN Quelle: 1422-0067
• ISSN Quelle: 1661-6596
• DOI: doi:10.3390/ijms20205193
• Datenträger: Online-Ressource
• Sprache: eng
• Sach-SW: <i>N</i>-glycosylation
• Sach-SW: ion channel
• Sach-SW: K_2P2.1
• Sach-SW: KCNK2
• Sach-SW: membrane trafficking
• Sach-SW: TREK-1
• Sach-SW: two-pore-domain potassium channels
• K10plus-PPN: 1688991670

Abstract

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.