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

• Published in: FEBS letters 2001-03, Vol.493 (2), p.129-133
• Main Authors: Stockklausner, C, Ludwig, J, Ruppersberg, J.P, Klöcker, N
• Format: Article
• Language: English
• Subjects: Amino Acid Motifs; Amino Acid Sequence; Animals; Biological Transport, Active; Cell Membrane - metabolism; Cells, Cultured; Endoplasmic reticulum; Endoplasmic Reticulum - metabolism; Golgi; Green Fluorescent Proteins; Luminescent Proteins - genetics; Luminescent Proteins - metabolism; Microscopy, Confocal; Molecular Sequence Data; Potassium channel; Potassium Channels - chemistry; Potassium Channels - genetics; Potassium Channels - metabolism; Potassium Channels, Inwardly Rectifying; PSD-95; Recombinant Fusion Proteins - chemistry; Recombinant Fusion Proteins - genetics; Recombinant Fusion Proteins - metabolism
• ISSN: 0014-5793; 1873-3468
• DOI: 10.1016/S0014-5793(01)02286-4

Integral membrane proteins are sorted via the secretory pathway. It was proposed that this pathway is non-selective provided that the cargo protein is properly assembled and lacks an endoplasmic reticulum (ER) retention signal. However, recent experimental evidence suggests that efficient export of proteins from the ER to the Golgi complex is not simply a default pathway. Here we demonstrate a novel sequence motif (FxYENEV) in the cytoplasmic C-terminus of mammalian inward rectifier potassium (Kir) channels which determines ER export. This motif is found to be both necessary and sufficient for efficient export from the ER that eventually leads to efficient surface expression of Kir2.1 channels.