A sequence motif responsible for ER export and surface expression of Kir2.0 inward rectifier K+ channels

Integral membrane proteins are sorted va the secretory pathway. It was prop osed that this pathway is nonselective provided that the cargo protein is p roperly assembled and lacks an endoplasmic reticulum (ER) retention signal, However, recent experimental evidence suggests that efficient export of pr oteins from the ER to the Golgi complex is not simply a default pathway. He re we demonstrate a novel sequence motif (FsYENEV) in the cytoplasmic C-ter minus of mammalian inward rectifier potassium (Kir) channels which determin es ER export, This motif is found to be both necessary and sufficient for e fficient export from the ER that eventually leads to efficient surface expr ession of Kir2.1 channels. (C) 2001 Federation of European Biochemical Soci eties. Published by Elsevier Science B.V, All rights reserved,