Characterization of sodium channel alpha- and beta-subunits in rat and mouse cardiac myocytes.

Details

Serval ID
serval:BIB_BA892BD6C15B
Type
Article: article from journal or magazin.
Collection
Publications
Institution
Title
Characterization of sodium channel alpha- and beta-subunits in rat and mouse cardiac myocytes.
Journal
Circulation
Author(s)
Dhar Malhotra J., Chen C., Rivolta I., Abriel H., Malhotra R., Mattei L.N., Brosius F.C., Kass R.S., Isom L.L.
ISSN
1524-4539[electronic]
Publication state
Published
Issued date
03/2001
Volume
103
Number
9
Pages
1303-1310
Language
english
Notes
Journal Article Research Support, U.S. Gov't, Non-P.H.S. Research Support, U.S. Gov't, P.H.S. --- Old month value: Mar 6
Abstract
BACKGROUND: Sodium channels isolated from mammalian brain are composed of alpha-, beta(1)-, and beta(2)-subunits. The composition of sodium channels in cardiac muscle, however, has not been defined, and disagreement exists over which beta-subunits are expressed in the myocytes. Some investigators have demonstrated beta(1) expression in heart. Others have not detected any auxiliary subunits. On the basis of Northern blot analysis of total RNA, beta(2) expression has been thought to be exclusive to neurons and absent from cardiac muscle. METHODS AND RESULTS: The goal of this study was to define the subunit composition of cardiac sodium channels in myocytes. We show that cardiac sodium channels are composed of alpha-, beta(1)-, and beta(2)-subunits. Nav1.5 and Nav1.1 are expressed in myocytes and are associated with beta(1)- and beta(2)-subunits. Immunocytochemical localization of Nav1.1, beta(1), and beta(2) in adult heart sections showed that these subunits are expressed at the Z lines, as shown previously for Nav1.5. Coexpression of Nav1.5 with beta(2) in transfected cells resulted in no detectable changes in sodium current. CONCLUSIONS: Cardiac sodium channels are composed of alpha- (Nav1.1 or Nav1.5), beta(1)-, and beta(2)-subunits. Although beta(1)-subunits modulate cardiac sodium channel current, beta(2)-subunit function in heart may be limited to cell adhesion.
Keywords
Animals, Animals, Newborn, Antibody Specificity, Brain, Cell Line, Electrophysiology, Fluorescent Antibody Technique, Humans, Mice, Myocardium, Protein Subunits, RNA, Messenger, Rats, Reverse Transcriptase Polymerase Chain Reaction, Sodium Channels
Pubmed
Web of science
Create date
24/01/2008 10:56
Last modification date
20/08/2019 15:28
Usage data