KCNE1 subunits require co-assembly with K+ channels for efficient trafficking and cell surface expression
Biochemistry & Molecular Pharmacology
Graduate School of Biomedical Sciences; Department of Biochemistry and Molecular Pharmacology
Life Sciences | Medicine and Health Sciences
KCNE peptides are a class of type I transmembrane beta subunits that assemble with and modulate the gating and ion conducting properties of a variety of voltage-gated K(+) channels. Accordingly, mutations that disrupt the assembly and trafficking of KCNE-K(+) channel complexes give rise to disease. The cellular mechanisms responsible for ensuring that KCNE peptides assemble with voltage-gated K(+) channels have yet to be elucidated. Using enzymatic deglycosylation, immunofluorescence, and quantitative cell surface labeling experiments, we show that KCNE1 peptides are retained in the early stages of the secretory pathway until they co-assemble with specific K(+) channel subunits; co-assembly mediates KCNE1 progression through the secretory pathway and results in cell surface expression. We also address an apparent discrepancy between our results and a previous study in human embryonic kidney cells, which showed wild type KCNE1 peptides can reach the plasma membrane without exogenously expressed K(+) channel subunits. By comparing KCNE1 trafficking in three cell lines, our data suggest that the errant KCNE1 trafficking observed in human embryonic kidney cells may be due, in part, to the presence of endogenous voltage-gated K(+) channels in these cells.
DOI of Published Version
J Biol Chem. 2006 Dec 29;281(52):40015-23. Epub 2006 Oct 24. Link to article on publisher's site
The Journal of biological chemistry
Chandrasekhar, Kshama D.; Bas, Tuba; and Kobertz, William R., "KCNE1 subunits require co-assembly with K+ channels for efficient trafficking and cell surface expression" (2006). GSBS Student Publications. 195.