Kir2 inward rectification–controlled precise and dynamic balances between Kir2 and HCN currents initiate pacemaking activity

What is it about?

Spontaneous rhythmic action potential or pacemaking activity is a distinct electrical excitability that occurs in pacemaker cells of the heart and other tissues. Pacemaking activity controls rhythmic signalling or behaviours such as heartbeat. The ionic mechanisms underlying pacemaking activity are not well understood. In this study, we engineered "blank" HEK293 cells into the cells that show pacemaking activity by heterologous expression of three types of ion channels that exist in pacemaker cells, to systematically investigate roles of ionic currents through these channels in pacemaking activity. Analyses of engineered pacmaking HEK293 cells elucidate a common mechanism for generation of spontaneous rhythmic action potential and reveal an origin of pacemaking activity. This study improves current understanding of both the mechanisms underlying pacemaking activity and functional roles of ion channels, and may help develop biological pacemaker.

Featured Image