TASK-5, a new member of the tandem-pore K(+) channel family

Biochem Biophys Res Commun. 2001 Jun 22;284(4):923-30. doi: 10.1006/bbrc.2001.5064.


TASKs are members of the recently identified K(+) channel family (KCNKx). Four TASKs (TASK1-4) identified so far form functional K(+) channels and encode background K(+) channels in various cell types. Recently, another member (TASK-5) was identified in the human genome. We cloned it and studied its tissue expression and functional properties. TASK-5 shares 51% amino acid identity with TASK-1 and TASK-3. Northern blot analysis showed that TASK-4 mRNA was expressed primarily in the adrenal gland and pancreas. Single nucleotide polymorphism (SNP) was found at amino acid position 95 that normally forms part of the K(+) channel selectivity filter. Neither form of TASK-5 showed channel activity when transfected in COS-7 cells. Exchange of C-termini of TASK-3 and TASK-5 failed to generate whole-cell currents. Thus, TASK-5 is a new member of the tandem-pore K(+) channel family but does not produce a functional plasma membrane K(+) current by itself.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • COS Cells
  • Chlorocebus aethiops
  • Chromosome Mapping
  • Chromosomes, Human, Pair 20*
  • Genome, Human
  • Humans
  • Models, Molecular
  • Molecular Sequence Data
  • Multigene Family
  • Nerve Tissue Proteins*
  • Patch-Clamp Techniques
  • Polymorphism, Single Nucleotide
  • Potassium Channels / chemistry
  • Potassium Channels / genetics*
  • Potassium Channels / physiology
  • Potassium Channels, Tandem Pore Domain*
  • Protein Structure, Secondary
  • Recombinant Fusion Proteins / chemistry
  • Recombinant Fusion Proteins / metabolism
  • Recombinant Proteins / chemistry
  • Recombinant Proteins / metabolism
  • Reverse Transcriptase Polymerase Chain Reaction
  • Sequence Alignment
  • Sequence Homology, Amino Acid
  • Transfection


  • KCNK15 protein, human
  • KCNK17 protein, human
  • KCNK9 protein, human
  • Kcnk15 protein, rat
  • Nerve Tissue Proteins
  • Potassium Channels
  • Potassium Channels, Tandem Pore Domain
  • Recombinant Fusion Proteins
  • Recombinant Proteins
  • potassium channel subfamily K member 3