TREK-2, a new member of the mechanosensitive tandem-pore K+ channel family

J Biol Chem. 2000 Jun 9;275(23):17412-9. doi: 10.1074/jbc.M000445200.


Recently, several mammalian K(+) channel subunits (TWIK, TREK-1, TRAAK, and TASK) possessing four transmembrane segments and two pore-forming domains have been identified. We report the cloning of a new member of this tandem-pore K(+) channel from a rat cerebellum cDNA library. It is a 538-amino acid protein and shares 65% amino acid sequence identity with TREK-1. Therefore, the new clone was named TREK-2. Unlike TREK-1, whose mRNA has been reported to be expressed in many different tissues, TREK-2 mRNA is expressed mainly in the cerebellum, spleen, and testis as judged by reverse transcriptase-polymerase chain reaction and Northern blot analysis. Expression of TREK-2 in COS-7 cells induced a time-independent and non-inactivating K(+)-selective current. TREK-2 was partially blocked (36%) by 2 mm Ba(2+). In symmetrical 150 mm KCl, the single-channel conductances were 110 picosiemens at -40 mV and 68 picosiemens at +40 mV, and the mean open time was 0.9 ms at -40 mV. TREK-2 was activated by membrane stretch or acidic pH. At -40 mm Hg pressure, channel activity increased 10-fold above the basal level. TREK-2 was also activated by arachidonic acid and other naturally occurring unsaturated free fatty acids. These results show that TREK-2 is a new member of the tandem-pore K(+) channel family and belongs to the class of mechanosensitive and fatty acid-stimulated K(+) channels.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • COS Cells
  • Cerebellum / metabolism*
  • Cloning, Molecular
  • Gene Library
  • Glycosylation
  • Membrane Potentials / physiology
  • Models, Molecular
  • Molecular Sequence Data
  • Nerve Tissue Proteins / chemistry
  • Potassium Channels / chemistry
  • Potassium Channels / genetics*
  • Potassium Channels / physiology*
  • Potassium Channels, Tandem Pore Domain*
  • Potassium Chloride / pharmacology
  • Protein Structure, Secondary
  • RNA, Messenger / genetics
  • Rats
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Transfection


  • Kcnk10 protein, rat
  • Kcnk4 protein, rat
  • Nerve Tissue Proteins
  • Potassium Channels
  • Potassium Channels, Tandem Pore Domain
  • RNA, Messenger
  • Recombinant Proteins
  • potassium channel protein TREK-1
  • Potassium Chloride

Associated data

  • GENBANK/AF196965