Regulation of in vivo cardiac contractility by phospholemman: role of Na /Ca exchange
نویسندگان
چکیده
JuFang Wang,* Erhe Gao,* Joseph Rabinowitz, Jianliang Song, Xue-Qian Zhang, Walter J. Koch, Amy L. Tucker, Tung O. Chan, Arthur M. Feldman, Joseph Y. Cheung Division of Nephrology and Center of Translational Medicine, Department of Medicine, Jefferson Medical College, Thomas Jefferson University, Philadelphia, Pennsylvania; and Cardiovascular Division, Department of Internal Medicine, University of Virginia Health Sciences Center, Charlottesville, Virginia
منابع مشابه
Regulation of in vivo cardiac contractility by phospholemman: role of Na+/Ca2+ exchange.
Phospholemman (PLM), when phosphorylated at serine 68, relieves its inhibition on Na(+)-K(+)-ATPase but inhibits Na(+)/Ca(2+) exchanger 1 (NCX1) in cardiac myocytes. Under stress when catecholamine levels are high, enhanced Na(+)-K(+)-ATPase activity by phosphorylated PLM attenuates intracellular Na(+) concentration ([Na(+)](i)) overload. To evaluate the effects of PLM on NCX1 on in vivo cardia...
متن کاملRegulation of cardiac myocyte contractility by phospholemman: Na+/Ca2+ exchange versus Na+ -K+ -ATPase.
Phospholemman (PLM) regulates cardiac Na(+)/Ca(2+) exchanger (NCX1) and Na(+)-K(+)-ATPase in cardiac myocytes. PLM, when phosphorylated at Ser(68), disinhibits Na(+)-K(+)-ATPase but inhibits NCX1. PLM regulates cardiac contractility by modulating Na(+)-K(+)-ATPase and/or NCX1. In this study, we first demonstrated that adult mouse cardiac myocytes cultured for 48 h had normal surface membrane ar...
متن کاملAltered contractility and [Ca2+]i homeostasis in phospholemman-deficient murine myocytes: role of Na+/Ca2+ exchange.
Phospholemman (PLM) regulates contractility and Ca(2+) homeostasis in cardiac myocytes. We characterized excitation-contraction coupling in myocytes isolated from PLM-deficient mice backbred to a pure congenic C57BL/6 background. Cell length, cell width, and whole cell capacitance were not different between wild-type and PLM-null myocytes. Compared with wild-type myocytes, Western blots indicat...
متن کاملNovel regulation of cardiac Na pump via phospholemman.
As the only quantitatively significant Na efflux pathway from cardiac cells, the Na/K ATPase (Na pump) is the primary regulator of intracellular Na. The transmembrane Na gradient it establishes is essential for normal electrical excitability, numerous coupled-transport processes and, as the driving force for Na/Ca exchange, thus setting cardiac Ca load and contractility. As Na influx varies wit...
متن کاملPhospholemman: a novel cardiac stress protein.
Phospholemman (PLM), a member of the FXYD family of regulators of ion transport, is a major sarcolemmal substrate for protein kinases A and C in cardiac and skeletal muscle. In the heart, PLM co-localizes and co-immunoprecipitates with Na(+)-K(+)-ATPase, Na(+)/Ca(2+) exchanger, and L-type Ca(2+) channel. Functionally, when phosphorylated at serine(68), PLM stimulates Na(+)-K(+)-ATPase but inhib...
متن کاملPhospholemman and the cardiac sodium pump: protein kinase C, take a bow.
In excitable tissues, the activity of the plasmalemmal sodium/potassium ATPase (Na/K pump) is vital for the maintenance of normal electrical activity and ion gradients. In cardiac muscle, the transsarcolemmal sodium (Na) gradient established by the Na/K activity is essential not only for generating the rapid upstroke of the action potential but also for driving a number of ion exchange and tran...
متن کامل