title: Plasma membrane calcium pump (PMCA4)-neuronal nitric-oxide synthase complex regulates cardiac contractility through modulation of a compartmentalized cyclic nucleotide microdomain.
abstract: 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 nitric-oxide 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.
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom; Biochemistry Department, Faculty of Pharmacy, Zagazig University, 44519 Zagazig, Egypt.
authors.forename: Tamer M A
authors.initials: TMA
authors.lastname: Mohamed
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Delvac
authors.initials: D
authors.lastname: Oceandy
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Min
authors.initials: M
authors.lastname: Zi
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Sukhpal
authors.initials: S
authors.lastname: Prehar
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Nasser
authors.initials: N
authors.lastname: Alatwi
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Yanwen
authors.initials: Y
authors.lastname: Wang
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Mohamed A
authors.initials: MA
authors.lastname: Shaheen
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Riham
authors.initials: R
authors.lastname: Abou-Leisa
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Celine
authors.initials: C
authors.lastname: Schelcher
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Zeinab
authors.initials: Z
authors.lastname: Hegab
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Florence
authors.initials: F
authors.lastname: Baudoin
authors.affiliation: Platelet Biology Group, National Heart and Lung Institute, Imperial College London, London SW7 2AZ, United Kingdom.
authors.forename: Michael
authors.initials: M
authors.lastname: Emerson
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Mamas
authors.initials: M
authors.lastname: Mamas
authors.affiliation: Venetian Institute of Molecular Medicine, Via Orus 2, 35100 Padova, Italy.
authors.forename: Giulietta
authors.initials: G
authors.lastname: Di Benedetto
authors.affiliation: Institute of Neuroscience and Psychology, University of Glasgow, Glasgow G12 8QQ, Scotland, United Kingdom.
authors.forename: Manuela
authors.initials: M
authors.lastname: Zaccolo
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Ming
authors.initials: M
authors.lastname: Lei
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom.
authors.forename: Elizabeth J
authors.initials: EJ
authors.lastname: Cartwright
authors.affiliation: Cardiovascular Medicine Research Group, Manchester Academic Health Sciences Centre, University of Manchester, Manchester M13 9PT, United Kingdom. Electronic address: Ludwig.Neyses@cmft.nhs.uk.
authors.forename: Ludwig
authors.initials: L
authors.lastname: Neyses
mesh_terms: D000818:Animals; D002118:Calcium / Q000378:metabolism; D000242:Cyclic AMP / Q000378:metabolism*; D006152:Cyclic GMP / Q000235:genetics / Q000378:metabolism*; D054678:Cyclic Nucleotide Phosphodiesterases, Type 2 / Q000235:genetics / Q000378:metabolism; D017136:Ion Transport / Q000502:physiology; D021962:Membrane Microdomains / Q000201:enzymology* / Q000235:genetics; D051379:Mice; D018345:Mice, Knockout; D009097:Multienzyme Complexes / Q000235:genetics / Q000378:metabolism*; D009124:Muscle Proteins / Q000235:genetics / Q000378:metabolism*; D009200:Myocardial Contraction / Q000502:physiology*; D032383:Myocytes, Cardiac / Q000201:enzymology*; D052248:Nitric Oxide Synthase Type I / Q000235:genetics / Q000378:metabolism*; D053499:Plasma Membrane Calcium-Transporting ATPases / Q000235:genetics / Q000378:metabolism*; D015398:Signal Transduction / Q000502:physiology
chemical_list: D009097:Multienzyme Complexes; D009124:Muscle Proteins; D000242:Cyclic AMP; D052248:Nitric Oxide Synthase Type I; C496321:Nos1 protein, mouse; D054678:Cyclic Nucleotide Phosphodiesterases, Type 2; D053499:Plasma Membrane Calcium-Transporting ATPases; D006152:Cyclic GMP; D002118:Calcium