TY - JOUR
T1 - Plasma membrane calcium pump (PMCA4)-neuronal nitric-oxide synthase complex regulates cardiac contractility through modulation of a compartmentalized cyclic nucleotide microdomain
AU - Mohamed, Tamer M A
AU - Oceandy, Delvac
AU - Zi, Min
AU - Prehar, Sukhpal
AU - Alatwi, Nasser
AU - Wang, Yanwen
AU - Shaheen, Mohamed A.
AU - Abou-Leisa, Riham
AU - Schelcher, Celine
AU - Hegab, Zeinab
AU - Baudoin, Florence
AU - Emerson, Michael
AU - Mamas, Mamas
AU - Di Benedetto, Giulietta
AU - Zaccolo, Manuela
AU - Lei, Ming
AU - Cartwright, Elizabeth J.
AU - Neyses, Ludwig
N1 - FS/09/046, British Heart Foundation, United KingdomG0200020, Medical Research Council, United KingdomG0500025, Medical Research Council, United KingdomG0802004, Medical Research Council, United KingdomPG/05/082, British Heart Foundation, United Kingdom
PY - 2011/12/2
Y1 - 2011/12/2
N2 - Identification of the signaling pathways that regulate cyclic nucleotide microdomains is essential to our understanding of cardiac physiology and pathophysiology. Although there is growing evidence that the plasma membrane Ca 2+/calmodulin-dependent ATPase 4 (PMCA4) is a regulator of neuronal nitricoxide synthase, the physiological consequence of this regulation is unclear. We therefore tested the hypothesis that PMCA4 has a key structural role in tethering neuronal nitric-oxide synthase to a highly compartmentalized domain in the cardiac cell membrane. This structural role has functional consequences on cAMP and cGMP signaling in a PMCA4-governed microdomain, which ultimately regulates cardiac contractility. In vivo contractility and calcium amplitude were increased in PMCA4 knock-out animals (PMCA4 -/-) with no change in diastolic relaxation or the rate of calcium decay, showing that PMCA4 has a function distinct from beat-to-beat calcium transport. Surprisingly, in PMCA4 -/-, over 36% of membrane-associated neuronal nitric-oxide synthase (nNOS) protein and activity was delocalized to the cytosol with no change in total nNOS protein, resulting in a significant decrease in microdomain cGMP, which in turn led to a significant elevation in local cAMP levels through a decrease in PDE2 activity (measured by FRET-based sensors). This resulted in increased L-type calcium channel activity and ryanodine receptor phosphorylation and hence increased contractility. In the heart, in addition to subsarcolemmal calcium transport, PMCA4 acts as a structural molecule that maintains the spatial and functional integrity of the nNOS signaling complex in a defined microdomain. This has profound consequences for the regulation of local cyclic nucleotide and hence cardiac β-adrenergic signaling. © 2011 by The American Society for Biochemistry and Molecular Biology, Inc.
AB - Identification of the signaling pathways that regulate cyclic nucleotide microdomains is essential to our understanding of cardiac physiology and pathophysiology. Although there is growing evidence that the plasma membrane Ca 2+/calmodulin-dependent ATPase 4 (PMCA4) is a regulator of neuronal nitricoxide synthase, the physiological consequence of this regulation is unclear. We therefore tested the hypothesis that PMCA4 has a key structural role in tethering neuronal nitric-oxide synthase to a highly compartmentalized domain in the cardiac cell membrane. This structural role has functional consequences on cAMP and cGMP signaling in a PMCA4-governed microdomain, which ultimately regulates cardiac contractility. In vivo contractility and calcium amplitude were increased in PMCA4 knock-out animals (PMCA4 -/-) with no change in diastolic relaxation or the rate of calcium decay, showing that PMCA4 has a function distinct from beat-to-beat calcium transport. Surprisingly, in PMCA4 -/-, over 36% of membrane-associated neuronal nitric-oxide synthase (nNOS) protein and activity was delocalized to the cytosol with no change in total nNOS protein, resulting in a significant decrease in microdomain cGMP, which in turn led to a significant elevation in local cAMP levels through a decrease in PDE2 activity (measured by FRET-based sensors). This resulted in increased L-type calcium channel activity and ryanodine receptor phosphorylation and hence increased contractility. In the heart, in addition to subsarcolemmal calcium transport, PMCA4 acts as a structural molecule that maintains the spatial and functional integrity of the nNOS signaling complex in a defined microdomain. This has profound consequences for the regulation of local cyclic nucleotide and hence cardiac β-adrenergic signaling. © 2011 by The American Society for Biochemistry and Molecular Biology, Inc.
U2 - 10.1074/jbc.M111.290411
DO - 10.1074/jbc.M111.290411
M3 - Article
C2 - 21965681
SN - 1083-351X
VL - 286
SP - 41520
EP - 41529
JO - Journal of Biological Chemistry
JF - Journal of Biological Chemistry
IS - 48
ER -