PKC and AMPK regulation of Kv1.5 potassium channels

Channels (Austin). 2015;9(3):121-8. doi: 10.1080/19336950.2015.1036205.

Abstract

The voltage-gated Kv1.5 potassium channel, conducting the ultra-rapid rectifier K(+) current (IKur), is regulated through several pathways. Here we investigate if Kv1.5 surface expression is controlled by the 2 kinases PKC and AMPK, using Xenopus oocytes, MDCK cells and atrial derived HL-1 cells. By confocal microscopy combined with electrophysiology we demonstrate that PKC activation reduces Kv1.5 current, through a decrease in membrane expressed channels. AMPK activation was found to decrease the membrane expression in MDCK cells, but not in HL-1 cells and was furthermore shown to be dependent on co-expression of Nedd4-2 in Xenopus oocytes. These results indicate that Kv1.5 channels are regulated by both kinases, although through different molecular mechanisms in different cell systems.

MeSH terms

  • AMP-Activated Protein Kinases / metabolism*
  • Animals
  • Cell Line, Tumor
  • Dogs
  • Endosomal Sorting Complexes Required for Transport / metabolism
  • Female
  • Kv1.5 Potassium Channel / metabolism*
  • Madin Darby Canine Kidney Cells
  • Nedd4 Ubiquitin Protein Ligases
  • Oocytes / metabolism
  • Protein Kinase C / metabolism*
  • Ubiquitin-Protein Ligases / metabolism
  • Xenopus Proteins
  • Xenopus laevis

Substances

  • Endosomal Sorting Complexes Required for Transport
  • Kv1.5 Potassium Channel
  • Xenopus Proteins
  • Nedd4 Ubiquitin Protein Ligases
  • Nedd4 protein, Xenopus
  • nedd4l protein, Xenopus
  • Ubiquitin-Protein Ligases
  • Protein Kinase C
  • AMP-Activated Protein Kinases