Abstract
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.
Copyright 2001 Academic Press.
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
Substances
-
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