AKAP150, a switch to convert mechano-, pH- and arachidonic acid-sensitive TREK K(+) channels into open leak channels

EMBO J. 2006 Dec 13;25(24):5864-72. doi: 10.1038/sj.emboj.7601437. Epub 2006 Nov 16.

Abstract

TREK channels are unique among two-pore-domain K(+) channels. They are activated by polyunsaturated fatty acids (PUFAs) including arachidonic acid (AA), phospholipids, mechanical stretch and intracellular acidification. They are inhibited by neurotransmitters and hormones. TREK-1 knockout mice have impaired PUFA-mediated neuroprotection to ischemia, reduced sensitivity to volatile anesthetics and altered perception of pain. Here, we show that the A-kinase-anchoring protein AKAP150 is a constituent of native TREK-1 channels. Its binding to a key regulatory domain of TREK-1 transforms low-activity outwardly rectifying currents into robust leak conductances insensitive to AA, stretch and acidification. Inhibition of the TREK-1/AKAP150 complex by Gs-coupled receptors such as serotonin 5HT4sR and noradrenaline beta2AR is as extensive as for TREK-1 alone, but is faster. Inhibition of TREK-1/AKAP150 by Gq-coupled receptors such as serotonin 5HT2bR and glutamate mGluR5 is much reduced when compared to TREK-1 alone. The association of AKAP150 with TREK channels integrates them into a postsynaptic scaffold where both G-protein-coupled membrane receptors (as demonstrated here for beta2AR) and TREK-1 dock simultaneously.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adaptor Proteins, Signal Transducing / analysis
  • Adaptor Proteins, Signal Transducing / metabolism*
  • Amino Acid Sequence
  • Animals
  • Arachidonic Acid / metabolism*
  • COS Cells
  • Chlorocebus aethiops
  • Dogs
  • GTP-Binding Protein alpha Subunits, Gq-G11 / metabolism
  • Hydrogen-Ion Concentration
  • Mice
  • Mice, Inbred C57BL
  • Molecular Sequence Data
  • Oocytes
  • Potassium Channels, Tandem Pore Domain / chemistry
  • Potassium Channels, Tandem Pore Domain / metabolism*
  • Protein Binding
  • Protein Structure, Tertiary
  • Proteomics
  • Receptors, Adrenergic, beta-2 / metabolism
  • Receptors, Cell Surface / metabolism
  • Up-Regulation / genetics
  • Xenopus

Substances

  • Adaptor Proteins, Signal Transducing
  • Potassium Channels, Tandem Pore Domain
  • Receptors, Adrenergic, beta-2
  • Receptors, Cell Surface
  • potassium channel protein TREK-1
  • Arachidonic Acid
  • GTP-Binding Protein alpha Subunits, Gq-G11