Cardiac pacemaker function of HCN4 channels in mice is confined to embryonic development and requires cyclic AMP
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چکیده
منابع مشابه
Cardiac pacemaker function of HCN4 channels in mice is confined to embryonic development and requires cyclic AMP.
Important targets for cAMP signalling in the heart are hyperpolarization-activated and cyclic nucleotide-gated (HCN) channels that underlie the depolarizing 'pacemaker' current, I(f). We studied the role of I(f) in mice, in which binding of cAMP to HCN4 channels was abolished by a single amino-acid exchange (R669Q). Homozygous HCN4(R669Q/R669Q) mice die during embryonic development. Prior to E1...
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Pacemaker (HCN) channels are hyperpolarization-activated and their activity is enhanced by cyclic AMP (CAMP), but whether CAMP-gating is coupled to voltage-gating remains unresolved. With long hyperpolarizations, HCN channels form a secondary open state after the initial opening; this briefly sustains the activation of open channels after a return to a resting voltage. CAMP effects on the forma...
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Cardiac pacemaking is controlled by a mixed Na(+)/K(+) current named I(f), which is activated by hyperpolarized membrane potentials. Recently, a family of hyperpolarization-activated cyclic nucleotide-gated cation (HCN) channels has been cloned. The members of this family exhibit the general features of I(f) channels. This review describes the molecular diversity of the HCN channel family and t...
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In sino-atrial and atrio-ventricular nodal cells, hyperpolarization-activated cyclic nucleotide-gated (HCN) inward current carrying cationic channels, I(f), are expressed that contribute importantly to the diastolic depolarization critical for cardiac pacemaker activity. Although previous studies have demonstrated myocardial expression of both the HCN2 and HCN4 subunits, the specific roles of t...
متن کاملThe hyperpolarization-activated channel HCN4 is required for the generation of pacemaker action potentials in the embryonic heart.
Hyperpolarization-activated, cyclic nucleotide-gated cation currents, termed If or Ih, are generated by four members of the hyperpolarization-activated, cyclic nucleotide-gated cation (HCN) channel family. These currents have been proposed to contribute to several functions including pacemaker activity in heart and brain, control of resting potential, and neuronal plasticity. Transcripts of the...
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ژورنال
عنوان ژورنال: The EMBO Journal
سال: 2008
ISSN: 0261-4189,1460-2075
DOI: 10.1038/emboj.2008.3