PT  - JOURNAL ARTICLE
AU  - Dong I. Lee
AU  - Michael G. Klein
AU  - Weizhong Zhu
AU  - Rui-Ping Xiao
AU  - Volodymyr Gerzanich
AU  - Kai Y. Xu
TI  - Activation of (Na<sup>+</sup>+K<sup>+</sup>)-ATPase Modulates Cardiac L-Type Ca<sup>2+</sup> Channel Function
AID  - 10.1124/mol.108.052597
DP  - 2009 Apr 01
TA  - Molecular Pharmacology
PG  - 774--781
VI  - 75
IP  - 4
4099  - http://molpharm.aspetjournals.org/content/75/4/774.short
4100  - http://molpharm.aspetjournals.org/content/75/4/774.full
SO  - Mol Pharmacol2009 Apr 01; 75
AB  - Cellular Ca2+ signaling underlies diverse vital biological processes, including muscle contractility, memory encoding, fertilization, cell survival, and cell death. Despite extensive studies, the fundamental control mechanisms that regulate intracellular Ca2+ movement remain enigmatic. We have found recently that activation of the (Na++K+)-ATPase markedly potentiates intracellular Ca2+ transients and contractility of rat heart cells. Little is known about the pathway responsible for the activation of the (Na++K+)-ATPase-initiated Ca2+ signaling. Here, we demonstrate a novel mechanism in which activation of the (Na++K+)-ATPase is coupled to increased L-type Ca2+ channel function through a signaling cascade involving Src and ERK1/2 but not well established regulators of the channel, such as adrenergic receptor system or activation of PKA or CaMKII. We have also identified Ser1928, a phosphorylation site for the α1 subunit of the L-type Ca2+ channel that may participate in the activation of the (Na++K+)-ATPase-mediated Ca2+ signaling. The findings reported here uncover a novel molecular cross-talk between activation of the (Na++K+)-ATPase and L-type Ca2+ channel and provide new insights into Ca2+ signaling mechanisms for deeper understanding of the nature of cellular Ca2+ handling in heart. U.S. Government work not protected by U.S. copyright