Molecular cloning and functional expression of a novel amiloride-sensitive Na+ channel.
We have isolated a cDNA for a novel human amiloride-sensitive Na+ channel isoform (called delta) which is expressed mainly in brain, pancreas, testis, and ovary. When expressed in Xenopus oocytes, it generates an amiloride-sensitive Na+ channel with biophysical and pharmacological properties distinct from those of the epithelial Na+ channel, a multimeric assembly of alpha, beta, and gamma subunits. The Na+ current produced by the new delta isoform is increased by two orders of magnitude after coexpression of the beta and gamma subunit of the epithelial Na+ channel showing that delta can associate with other subunits and is part of a novel multisubunit ion channel.
D000584:Amiloride / Q000494:pharmacology*; D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D003001:Cloning, Molecular / Q000379:methods; D017931:DNA Primers; D004594:Electrophysiology; D005260:Female; D015723:Gene Library; D006801:Humans; D007668:Kidney / Q000378:metabolism; D046911:Macromolecular Substances; D008297:Male; D008564:Membrane Potentials / Q000187:drug effects; D008969:Molecular Sequence Data; D009865:Oocytes / Q000187:drug effects / Q000502:physiology; D009928:Organ Specificity; D016133:Polymerase Chain Reaction; D012333:RNA, Messenger / Q000032:analysis / Q000096:biosynthesis; D011994:Recombinant Proteins / Q000096:biosynthesis / Q000737:chemistry / Q000187:drug effects; D017386:Sequence Homology, Amino Acid; D015222:Sodium Channels / Q000096:biosynthesis* / Q000737:chemistry / Q000187:drug effects; D014981:Xenopus
D017931:DNA Primers; D046911:Macromolecular Substances; D012333:RNA, Messenger; D011994:Recombinant Proteins; D015222:Sodium Channels; D000584:Amiloride