ARF6‐dependent interaction of the TWIK1 K+ channel with EFA6, a GDP/GTP exchange factor for ARF6

• DOI: 10.1038/sj.embor.7400292
• Publication Date: 2004-11-12T10:57:04Z
• Authors: Sonia Decressac; Michel Franco; Said Bendahhou; Richard Warth; Sebastian Knauer; Jacques Barhanin; Michel Lazdunski; Florian Lesage
• Keywords: 0303 health sciences; Potassium Channels; ADP-Ribosylation Factors; Transferrin; Fluorescent Antibody Technique; Nerve Tissue Proteins; Kidney; Peptide Elongation Factors; Guanosine Diphosphate; Endocytosis; Mice; 03 medical and health sciences; ADP-Ribosylation Factor 6; Animals; Guanine Nucleotide Exchange Factors; Humans; Guanosine Triphosphate; HeLa Cells

TWIK1 belongs to a family of K+ channels involved in neuronal excitability and cell volume regulation. Its tissue distribution suggests a role in epithelial potassium transport. Here we show that TWIK1 is expressed in a subapical compartment in renal proximal tubules and in polarized MDCK cells. In nonpolarized cells, this compartment corresponds to pericentriolar recycling endosomes. We identified EFA6, an exchange factor for the small G protein ADP‐ribosylation factor 6 (ARF6), as a protein binding to TWIK1. EFA6 interacts with TWIK1 only when it is bound to ARF6. Because ARF6 modulates endocytosis at the apical surface of epithelial cells, the ARF6/EFA6/TWIK1 association is probably important for channel internalization and recycling.