PMID: 20006580

 

    Legend: Sugar

Title : N-linked glycosylation determines cell surface expression of two-pore-domain K+ channel TRESK

Abstract :

1. Within the first external loop of mouse and human TRESK subunits one or two N-glycosylation consensus sites were identified, respectively
2. Using site directed mutagenesis and Western immunoblotting a single residue of both orthologues was found to be glycosylated upon heterologous expression
3. Two-electrode voltage-clamp recordings from Xenopus oocytes revealed that current amplitudes of N-glycosylation mutants were reduced by 80% as compared to wildtype TRESK
4. To investigate membrane targeting, GFP-tagged TRESK subunits were expressed in Xenopus oocytes and fluorescence intensity at the cell surface was measured by confocal microscopy
5. Signals of the N-glycosylation mutants were reduced by >50%, indicating that their lower current amplitudes substantially result from inadequate surface expression of the channel