Kcnq1 contributes to an adrenergic-sensitive steady-state K+ current in mouse heart

Authors

    Authors

    B. C. Knollmann; S. Sirenko; Q. Rong; A. N. Katchman; M. Casimiro; K. Pfeifer;S. N. Ebert

    Comments

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    Abbreviated Journal Title

    Biochem. Biophys. Res. Commun.

    Keywords

    potassium channel; transgenic mouse; electrophysiology; adrenergic; heart; LANGE-NIELSEN-SYNDROME; POTASSIUM CHANNEL; VENTRICULAR MYOCYTES; TARGETED DISRUPTION; RAT-HEART; EXPRESSION; MICE; PROTEINS; SUBUNIT; KVLQT1; Biochemistry & Molecular Biology; Biophysics

    Abstract

    It has been suggested that Kcnel subunits are required for adrenergic regulation of Kcnq1 potassium channels. However, in adult mouse hearts, which do not express Kcne1, loss of Kcnq1 causes a Long QT phenotype during adrenergic challenge, raising the possibility that native Kcnq1 currents exist and are adrenergically regulated even in absence of Kcnel. Here, we used immunoblotting and immunohistochemical staining to show that Kcnq1 protein is present in adult mouse hearts. Voltage-clamp experiments demonstrated that Kcnq1 contributes to a steady-state outward current (I-SS) in wild-type (Kcnq1+/+) ventricular myocytes during isoproterenol stimulation, resulting in a significant 7.1% increase in Iss density (0.43 +/- 0.16 pA/pF, p < 0.05, n = 15), an effect that was absent in Kcnq1-deficient (Kcnq1(-/-)) myocytes (-0.14 +/- 0.13 pA/pF, n = 17). These results demonstrate for the first time that Kcnq1 protein is expressed in adult mouse hearts where it contributes to a beta-adrenergic-induced component of Iss that does not require co-assembly with Kcnel. (c) 2007 Elsevier Inc. All rights reserved.

    Journal Title

    Biochemical and Biophysical Research Communications

    Volume

    360

    Issue/Number

    1

    Publication Date

    1-1-2007

    Document Type

    Article

    Language

    English

    First Page

    212

    Last Page

    218

    WOS Identifier

    WOS:000248137400034

    ISSN

    0006-291X

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