Molecular heterogeneity of large-conductance calcium-activated potassium channels in canine intracardiac ganglia

• DOI: 10.4161/chan.25485
• Publication Date: 2013-06-27T10:59:58Z
• Authors: Elisabet Selga; Alexandra Pérez-S...; Alba Moreno-Asso; Seth Anderson; Kristen Thomas; Mayurika Desai; Ramon Brugada; Guillermo J Pérez; Fabiana S Scornik
• Keywords: 0299 Other Physical Sciences; Molecular Sequence Data; Cardiology; β subunits; College of Sports and Exercise Science; 630; Cardiologia; alternative splicing; 03 medical and health sciences; Dogs; Cor -- Malalties; Animals; Amino Acid Sequence; Large-Conductance Calcium-Activated Potassium Channels; Exercise and Active Living (ISEAL); Neurons; 0303 health sciences; autonomic; intracardiac neurons; Myocardium; 600; Heart -- Diseases; Institute of Sport; Article Addendum; Protein Subunits; Calcium; Ganglia; BK channels

Large conductance calcium-activated potassium (BK) channels are widely expressed in the nervous system. We have recently shown that principal neurons from canine intracardiac ganglia (ICG) express a paxilline- and TEA-sensitive BK current, which increases neuronal excitability. In the present work, we further explore the molecular constituents of the BK current in canine ICG. We found that the β1 and β4 regulatory subunits are expressed in ICG. Single channel voltage-dependence at different calcium concentrations suggested that association of the BKα with a particular β subunit was not enough to explain the channel activity in this tissue. Indeed, we detected the presence of several splice variants of the BKα subunit. In conclusion, BK channels in canine ICG may result from the arrangement of different BKα splice variants, plus accessory β subunits. The particular combinations expressed in canine IC neurons likely rule the excitatory role of BK current in this tissue.