title: hSK4, a member of a novel subfamily of calcium-activated potassium channels.
abstract: The gene for hSK4, a novel human small conductance calcium-activated potassium channel, or SK channel, has been identified and expressed in Chinese hamster ovary cells. In physiological saline hSK4 generates a conductance of approximately 12 pS, a value in close agreement with that of other cloned SK channels. Like other members of this family, the polypeptide encoded by hSK4 contains a previously unnoted leucine zipper-like domain in its C terminus of unknown function. hSK4 appears unique, however, in its very high affinity for Ca2+ (EC50 of 95 nM) and its predominant expression in nonexcitable tissues of adult animals. Together with the relatively low homology of hSK4 to other SK channel polypeptides (approximately 40% identical), these data suggest that hSK4 belongs to a novel subfamily of SK channels.
authors.affiliation: Department of Cellular and Molecular Physiology, Yale University School of Medicine, 333 Cedar Street, New Haven, CT 06520, USA.
authors.forename: W J
authors.initials: WJ
authors.lastname: Joiner
authors.forename: L Y
authors.initials: LY
authors.lastname: Wang
authors.forename: M D
authors.initials: MD
authors.lastname: Tang
authors.forename: L K
authors.initials: LK
authors.lastname: Kaczmarek
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001464:Barium / Q000378:metabolism; D016466:CHO Cells; D002118:Calcium / Q000378:metabolism*; D003001:Cloning, Molecular; D006224:Cricetinae; D006801:Humans; D051660:Intermediate-Conductance Calcium-Activated Potassium Channels; D008969:Molecular Sequence Data; D015221:Potassium Channels / Q000235:genetics* / Q000378:metabolism; D024681:Potassium Channels, Calcium-Activated; D017386:Sequence Homology, Amino Acid
chemical_list: D051660:Intermediate-Conductance Calcium-Activated Potassium Channels; C496923:KCNN4 protein, human; D015221:Potassium Channels; D024681:Potassium Channels, Calcium-Activated; D001464:Barium; D002118:Calcium