title: A voltage-gated calcium-selective channel encoded by a sodium channel-like gene.
abstract: BSC1, which was originally identified by its sequence similarity to voltage-gated Na(+) channels, encodes a functional voltage-gated cation channel whose properties differ significantly from Na(+) channels. BSC1 has slower kinetics of activation and inactivation than Na(+) channels, it is more selective for Ba(2+) than for Na(+), it is blocked by Cd(2+), and Na(+) currents through BSC1 are blocked by low concentrations of Ca(2+). All of these properties are more similar to voltage-gated Ca(2+) channels than to voltage-gated Na(+) channels. The selectivity for Ba(2+) is partially due to the presence of a glutamate in the pore-forming region of domain III, since replacing that residue with lysine (normally present in voltage-gated Na(+) channels) makes the channel more selective for Na(+). BSC1 appears to be the prototype of a novel family of invertebrate voltage-dependent cation channels with a close structural and evolutionary relationship to voltage-gated Na(+) and Ca(2+) channels.
authors.affiliation: Department of Microbiology and Molecular Genetics, University of California, Irvine, Irvine, CA 92697, USA.
authors.forename: Wei
authors.initials: W
authors.lastname: Zhou
authors.forename: Inbum
authors.initials: I
authors.lastname: Chung
authors.forename: Zhiqi
authors.initials: Z
authors.lastname: Liu
authors.forename: Alan L
authors.initials: AL
authors.lastname: Goldin
authors.forename: Ke
authors.initials: K
authors.lastname: Dong
mesh_terms: D000595:Amino Acid Sequence; D000779:Anesthetics, Local / Q000494:pharmacology; D000818:Animals; D001464:Barium / Q000494:pharmacology; D002104:Cadmium / Q000494:pharmacology; D015220:Calcium Channels / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D002412:Cations / Q000494:pharmacology; D003035:Cobalt / Q000494:pharmacology; D016861:Cyclooxygenase Inhibitors / Q000494:pharmacology; D004305:Dose-Response Relationship, Drug; D004347:Drug Interactions; D019143:Evolution, Molecular; D015640:Ion Channel Gating / Q000502:physiology*; D007700:Kinetics; D008564:Membrane Potentials / Q000187:drug effects / Q000502:physiology; D009544:Niflumic Acid / Q000494:pharmacology; D009865:Oocytes; D018408:Patch-Clamp Techniques / Q000379:methods; D010802:Phylogeny; D017354:Point Mutation; D011188:Potassium / Q000494:pharmacology; D012964:Sodium / Q000494:pharmacology; D015222:Sodium Channels / Q000187:drug effects / Q000235:genetics / Q000378:metabolism*; D028021:Sodium-Potassium-Chloride Symporters / Q000235:genetics / Q000378:metabolism*; D064466:Solute Carrier Family 12, Member 1; D013779:Tetrodotoxin / Q000494:pharmacology; D014981:Xenopus
chemical_list: D000779:Anesthetics, Local; D015220:Calcium Channels; D002412:Cations; D016861:Cyclooxygenase Inhibitors; D015222:Sodium Channels; D028021:Sodium-Potassium-Chloride Symporters; D064466:Solute Carrier Family 12, Member 1; D002104:Cadmium; D001464:Barium; D003035:Cobalt; D013779:Tetrodotoxin; D009544:Niflumic Acid; D012964:Sodium; D011188:Potassium