The pacemaker current If of the sinoatrial node (SAN) is a major determinant of cardiac diastolic depolarization and plays a key role in controlling heart rate and its modulation by neurotransmitters. Substantial expression of two different mRNAs (HCN4, HCN1) of the family of pacemaker channels (HCN) is found in rabbit SAN, suggesting that the native channels may be formed by different isoforms. Here we report the cloning and heterologous expression of HCN1 from rabbit SAN and its specific localization in pacemaker myocytes. rbHCN1 is an 822-amino acid protein that, in human embryonic kidney 293 cells, displayed electrophysiological properties similar to those of If, suggesting that HCN1 can form a pacemaker channel. The presence of HCN1 in the SAN myocytes but not in nearby heart regions, and the electrophysiological properties of the channels formed by it, suggest that HCN1 plays a central and specific role in the formation of SAN pacemaker currents.
|Titolo:||Hyperpolarization-activated cyclic nucleotide-gated channel 1 is a molecular determinant of the cardiac pacemaker current I-f|
|Autori interni:||DI FRANCESCO, DARIO (Ultimo)|
MORONI, ANNA (Primo)
BELTRAME, MONICA DANIELA
|Settore Scientifico Disciplinare:||Settore BIO/04 - Fisiologia Vegetale|
Settore BIO/09 - Fisiologia
Settore BIO/18 - Genetica
|Data di pubblicazione:||2001|
|Digital Object Identifier (DOI):||10.1074/jbc.M100830200|
|Appare nelle tipologie:||01 - Articolo su periodico|
File in questo prodotto:
- PubMed Central loading...