Post-translational N-glycosylation of type I transmembrane KCNE1 peptides: implications for membrane protein biogenesis and disease.

ABSTRACT: N-Glycosylation of membrane proteins is critical for their proper folding, co-assembly and subsequent matriculation through the secretory pathway. Here, we examine the kinetics of N-glycan addition to type I transmembrane KCNE1 K(+) channel β-subunits, where point mutations that prevent N-glycosylation at one consensus site give rise to disorders of the cardiac rhythm and congenital deafness. We show that KCNE1 has two distinct N-glycosylation sites: a typical co-translational site and a consensus site ∼20 residues away that unexpectedly acquires N-glycans after protein synthesis (post-translational). Mutations that ablate the co-translational site concomitantly reduce glycosylation at the post-translational site, resulting in unglycosylated KCNE1 subunits that cannot reach the cell surfac

SUBMITTER: Bas T 

PROVIDER: S-EPMC3151060 | biostudies-literature | 2011 Aug

REPOSITORIES: biostudies-literature