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Bai M, Gallen E, Memarzadeh S, Howie J, Gao X, Kuo CWS, Brown E, Swingler S, Wilson SJ, Shattock MJ, France DJ, Fuller W. Targeted degradation of zDHHC-PATs decreases substrate S-palmitoylation. PLoS One 2024; 19:e0299665. [PMID: 38512906 PMCID: PMC10956751 DOI: 10.1371/journal.pone.0299665] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2023] [Accepted: 02/14/2024] [Indexed: 03/23/2024] Open
Abstract
Reversible S-palmitoylation of protein cysteines, catalysed by a family of integral membrane zDHHC-motif containing palmitoyl acyl transferases (zDHHC-PATs), controls the localisation, activity, and interactions of numerous integral and peripheral membrane proteins. There are compelling reasons to want to inhibit the activity of individual zDHHC-PATs in both the laboratory and the clinic, but the specificity of existing tools is poor. Given the extensive conservation of the zDHHC-PAT active site, development of isoform-specific competitive inhibitors is highly challenging. We therefore hypothesised that proteolysis-targeting chimaeras (PROTACs) may offer greater specificity to target this class of enzymes. In proof-of-principle experiments we engineered cell lines expressing tetracycline-inducible Halo-tagged zDHHC5 or zDHHC20, and evaluated the impact of Halo-PROTACs on zDHHC-PAT expression and substrate palmitoylation. In HEK-derived FT-293 cells, Halo-zDHHC5 degradation significantly decreased palmitoylation of its substrate phospholemman, and Halo-zDHHC20 degradation significantly diminished palmitoylation of its substrate IFITM3, but not of the SARS-CoV-2 spike protein. In contrast, in a second kidney derived cell line, Vero E6, Halo-zDHHC20 degradation did not alter palmitoylation of either IFITM3 or SARS-CoV-2 spike. We conclude from these experiments that PROTAC-mediated targeting of zDHHC-PATs to decrease substrate palmitoylation is feasible. However, given the well-established degeneracy in the zDHHC-PAT family, in some settings the activity of non-targeted zDHHC-PATs may substitute and preserve substrate palmitoylation.
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Affiliation(s)
- Mingjie Bai
- School of Cardiovascular & Metabolic Health, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Emily Gallen
- School of Cardiovascular & Metabolic Health, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Sarah Memarzadeh
- School of Chemistry, University of Glasgow, Glasgow, United Kingdom
| | - Jacqueline Howie
- School of Cardiovascular & Metabolic Health, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Xing Gao
- School of Cardiovascular & Metabolic Health, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Chien-Wen S. Kuo
- School of Cardiovascular & Metabolic Health, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Elaine Brown
- School of Cardiovascular & Metabolic Health, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Simon Swingler
- Medical Research Council–University of Glasgow Centre for Virus Research, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Sam J. Wilson
- Medical Research Council–University of Glasgow Centre for Virus Research, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
| | - Michael J. Shattock
- School of Cardiovascular and Metabolic Medicine & Sciences, King’s College London, London, United Kingdom
| | - David J. France
- School of Chemistry, University of Glasgow, Glasgow, United Kingdom
| | - William Fuller
- School of Cardiovascular & Metabolic Health, College of Medical Veterinary and Life Sciences, University of Glasgow, Glasgow, United Kingdom
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Ashford F, Kuo CW, Dunning E, Brown E, Calagan S, Jayasinghe I, Henderson C, Fuller W, Wypijewski K. Cysteine post-translational modifications regulate protein interactions of caveolin-3. FASEB J 2024; 38:e23535. [PMID: 38466300 DOI: 10.1096/fj.202201497rr] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2022] [Revised: 02/12/2024] [Accepted: 02/20/2024] [Indexed: 03/12/2024]
Abstract
Caveolae are small flask-shaped invaginations of the surface membrane which are proposed to recruit and co-localize signaling molecules. The distinctive caveolar shape is achieved by the oligomeric structural protein caveolin, of which three isoforms exist. Aside from the finding that caveolin-3 is specifically expressed in muscle, functional differences between the caveolin isoforms have not been rigorously investigated. Caveolin-3 is relatively cysteine-rich compared to caveolins 1 and 2, so we investigated its cysteine post-translational modifications. We find that caveolin-3 is palmitoylated at 6 cysteines and becomes glutathiolated following redox stress. We map the caveolin-3 palmitoylation sites to a cluster of cysteines in its C terminal membrane domain, and the glutathiolation site to an N terminal cysteine close to the region of caveolin-3 proposed to engage in protein interactions. Glutathiolation abolishes caveolin-3 interaction with heterotrimeric G protein alpha subunits. Our results indicate that a caveolin-3 oligomer contains up to 66 palmitates, compared to up to 33 for caveolin-1. The additional palmitoylation sites in caveolin-3 therefore provide a mechanistic basis by which caveolae in smooth and striated muscle can possess unique phospholipid and protein cargoes. These unique adaptations of the muscle-specific caveolin isoform have important implications for caveolar assembly and signaling.
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Affiliation(s)
- Fiona Ashford
- School of Medicine, University of Dundee, Dundee, UK
| | - Chien-Wen Kuo
- School of Cardiovascular & Metabolic Health, University of Glasgow, Glasgow, UK
| | - Emma Dunning
- School of Cardiovascular & Metabolic Health, University of Glasgow, Glasgow, UK
| | - Elaine Brown
- School of Cardiovascular & Metabolic Health, University of Glasgow, Glasgow, UK
| | - Sarah Calagan
- School of Biomedical Sciences, University of Leeds, Leeds, UK
| | - Izzy Jayasinghe
- School of Biomedical Sciences, University of New South Wales, Sydney, New South Wales, Australia
| | | | - William Fuller
- School of Cardiovascular & Metabolic Health, University of Glasgow, Glasgow, UK
| | - Krzysztof Wypijewski
- School of Cardiovascular & Metabolic Health, University of Glasgow, Glasgow, UK
- School of Life Sciences, University of Dundee, Dundee, UK
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3
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Howie J, Tulloch LB, Brown E, Reilly L, Ashford FB, Kennedy J, Wypijewski KJ, Aughton KL, Mak JKC, Shattock MJ, Fraser NJ, Fuller W. Glutathione-dependent depalmitoylation of phospholemman by peroxiredoxin 6. Cell Rep 2024; 43:113679. [PMID: 38236777 DOI: 10.1016/j.celrep.2024.113679] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 11/02/2023] [Accepted: 01/01/2024] [Indexed: 03/02/2024] Open
Abstract
Phospholemman (PLM) regulates the cardiac sodium pump: PLM phosphorylation activates the pump whereas PLM palmitoylation inhibits its activity. Here, we show that the anti-oxidant protein peroxiredoxin 6 (Prdx6) interacts with and depalmitoylates PLM in a glutathione-dependent manner. Glutathione loading cells acutely reduce PLM palmitoylation; glutathione depletion significantly increases PLM palmitoylation. Prdx6 silencing abolishes these effects, suggesting that PLM can be depalmitoylated by reduced Prdx6. In vitro, only recombinant Prdx6, among several peroxiredoxin isoforms tested, removes palmitic acid from recombinant palmitoylated PLM. The broad-spectrum depalmitoylase inhibitor palmostatin B prevents Prdx6-dependent PLM depalmitoylation in cells and in vitro. Our data suggest that Prdx6 is a thioesterase that can depalmitoylate proteins by nucleophilic attack via its reactive thiol, linking PLM palmitoylation and hence sodium pump activity to cellular glutathione status. We show that protein depalmitoylation can occur via a catalytic cysteine in which substrate specificity is determined by a protein-protein interaction.
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Affiliation(s)
- Jacqueline Howie
- School of Cardiovascular and Metabolic Health, University of Glasgow, Glasgow, UK; Division of Cellular and Systems Medicine, School of Medicine, University of Dundee, Dundee, UK
| | - Lindsay B Tulloch
- Division of Cellular and Systems Medicine, School of Medicine, University of Dundee, Dundee, UK
| | - Elaine Brown
- School of Cardiovascular and Metabolic Health, University of Glasgow, Glasgow, UK
| | - Louise Reilly
- Division of Cellular and Systems Medicine, School of Medicine, University of Dundee, Dundee, UK
| | - Fiona B Ashford
- Division of Cellular and Systems Medicine, School of Medicine, University of Dundee, Dundee, UK
| | - Jennifer Kennedy
- School of Cardiovascular and Metabolic Health, University of Glasgow, Glasgow, UK; Division of Cellular and Systems Medicine, School of Medicine, University of Dundee, Dundee, UK
| | - Krzysztof J Wypijewski
- School of Cardiovascular and Metabolic Health, University of Glasgow, Glasgow, UK; Division of Cellular and Systems Medicine, School of Medicine, University of Dundee, Dundee, UK
| | - Karen L Aughton
- School of Cardiovascular and Metabolic Medicine and Sciences, King's College London, London, UK
| | - Jason K C Mak
- School of Cardiovascular and Metabolic Medicine and Sciences, King's College London, London, UK
| | - Michael J Shattock
- School of Cardiovascular and Metabolic Medicine and Sciences, King's College London, London, UK
| | - Niall J Fraser
- Division of Cellular and Systems Medicine, School of Medicine, University of Dundee, Dundee, UK.
| | - William Fuller
- School of Cardiovascular and Metabolic Health, University of Glasgow, Glasgow, UK.
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Kuo CWS, Dobi S, Gök C, Da Silva Costa A, Main A, Robertson-Gray O, Baptista-Hon D, Wypijewski KJ, Costello H, Hales TG, MacQuaide N, Smith GL, Fuller W. Palmitoylation of the pore-forming subunit of Ca(v)1.2 controls channel voltage sensitivity and calcium transients in cardiac myocytes. Proc Natl Acad Sci U S A 2023; 120:e2207887120. [PMID: 36745790 PMCID: PMC9963536 DOI: 10.1073/pnas.2207887120] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2022] [Accepted: 12/07/2022] [Indexed: 02/08/2023] Open
Abstract
Mammalian voltage-activated L-type Ca2+ channels, such as Ca(v)1.2, control transmembrane Ca2+ fluxes in numerous excitable tissues. Here, we report that the pore-forming α1C subunit of Ca(v)1.2 is reversibly palmitoylated in rat, rabbit, and human ventricular myocytes. We map the palmitoylation sites to two regions of the channel: The N terminus and the linker between domains I and II. Whole-cell voltage clamping revealed a rightward shift of the Ca(v)1.2 current-voltage relationship when α1C was not palmitoylated. To examine function, we expressed dihydropyridine-resistant α1C in human induced pluripotent stem cell-derived cardiomyocytes and measured Ca2+ transients in the presence of nifedipine to block the endogenous channels. The transients generated by unpalmitoylatable channels displayed a similar activation time course but significantly reduced amplitude compared to those generated by wild-type channels. We thus conclude that palmitoylation controls the voltage sensitivity of Ca(v)1.2. Given that the identified Ca(v)1.2 palmitoylation sites are also conserved in most Ca(v)1 isoforms, we propose that palmitoylation of the pore-forming α1C subunit provides a means to regulate the voltage sensitivity of voltage-activated Ca2+ channels in excitable cells.
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Affiliation(s)
- Chien-Wen S. Kuo
- School of Cardiovascular and Metabolic Health, University of Glasgow, GlasgowG12 8QQ, UK
| | - Sara Dobi
- School of Cardiovascular and Metabolic Health, University of Glasgow, GlasgowG12 8QQ, UK
| | - Caglar Gök
- School of Cardiovascular and Metabolic Health, University of Glasgow, GlasgowG12 8QQ, UK
| | - Ana Da Silva Costa
- School of Cardiovascular and Metabolic Health, University of Glasgow, GlasgowG12 8QQ, UK
| | - Alice Main
- School of Cardiovascular and Metabolic Health, University of Glasgow, GlasgowG12 8QQ, UK
| | - Olivia Robertson-Gray
- School of Cardiovascular and Metabolic Health, University of Glasgow, GlasgowG12 8QQ, UK
| | - Daniel Baptista-Hon
- Division of Systems Medicine, Institute of Academic Anaesthesia, School of Medicine, University of Dundee, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK
- Center for Biomedicine and Innovations, Faculty of Medicine, Macau University of Science and Technology, Macau SAR, 999078China
| | | | - Hannah Costello
- Division of Systems Medicine, Institute of Academic Anaesthesia, School of Medicine, University of Dundee, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK
| | - Tim G. Hales
- Division of Systems Medicine, Institute of Academic Anaesthesia, School of Medicine, University of Dundee, Ninewells Hospital and Medical School, Dundee DD1 9SY, UK
| | - Niall MacQuaide
- School of Cardiovascular and Metabolic Health, University of Glasgow, GlasgowG12 8QQ, UK
| | - Godfrey L. Smith
- School of Cardiovascular and Metabolic Health, University of Glasgow, GlasgowG12 8QQ, UK
| | - William Fuller
- School of Cardiovascular and Metabolic Health, University of Glasgow, GlasgowG12 8QQ, UK
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Gao X, Kuo CW, Main A, Brown E, Rios FJ, Camargo LDL, Mary S, Wypijewski K, Gök C, Touyz RM, Fuller W. Palmitoylation regulates cellular distribution of and transmembrane Ca flux through TrpM7. Cell Calcium 2022; 106:102639. [PMID: 36027648 DOI: 10.1016/j.ceca.2022.102639] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2022] [Revised: 08/03/2022] [Accepted: 08/14/2022] [Indexed: 11/19/2022]
Abstract
The bifunctional cation channel/kinase TrpM7 is ubiquitously expressed and regulates embryonic development and pathogenesis of several common diseases. The TrpM7 integral membrane ion channel domain regulates transmembrane movement of divalent cations, and its kinase domain controls gene expression via histone phosphorylation. Mechanisms regulating TrpM7 are elusive. It exists in two populations in the cell: at the cell surface where it controls divalent cation fluxes, and in intracellular vesicles where it controls zinc uptake and release. Here we report that TrpM7 is palmitoylated at a cluster of cysteines at the C terminal end of its Trp domain. Palmitoylation controls the exit of TrpM7 from the endoplasmic reticulum and the distribution of TrpM7 between cell surface and intracellular pools. Using the Retention Using Selective Hooks (RUSH) system, we demonstrate that palmitoylated TrpM7 traffics from the Golgi to the surface membrane whereas non-palmitoylated TrpM7 is sequestered in intracellular vesicles. We identify the Golgi-resident enzyme zDHHC17 and surface membrane-resident enzyme zDHHC5 as responsible for palmitoylating TrpM7 and find that TrpM7-mediated transmembrane calcium uptake is significantly reduced when TrpM7 is not palmitoylated. The closely related channel/kinase TrpM6 is also palmitoylated on the C terminal side of its Trp domain. Our findings demonstrate that palmitoylation controls ion channel activity of TrpM7 and that TrpM7 trafficking is dependant on its palmitoylation. We define a new mechanism for post translational modification and regulation of TrpM7 and other Trps.
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Affiliation(s)
- Xing Gao
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Chien-Wen Kuo
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Alice Main
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Elaine Brown
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Francisco J Rios
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Livia De Lucca Camargo
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Sheon Mary
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Krzysztof Wypijewski
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Caglar Gök
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom
| | - Rhian M Touyz
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom; Research Institute of the McGill University Health Centre, McGill University, Montreal, Canada
| | - William Fuller
- Institute of Cardiovascular & Medical Sciences, University of Glasgow, Glasgow G12 8QQ, United Kingdom.
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6
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Meyer DJ, Bijlani S, de Sautu M, Spontarelli K, Young VC, Gatto C, Artigas P. FXYD protein isoforms differentially modulate human Na/K pump function. J Gen Physiol 2021; 152:211559. [PMID: 33231612 PMCID: PMC7690937 DOI: 10.1085/jgp.202012660] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2020] [Accepted: 10/29/2020] [Indexed: 12/28/2022] Open
Abstract
Tight regulation of the Na/K pump is essential for cellular function because this heteromeric protein builds and maintains the electrochemical gradients for Na+ and K+ that energize electrical signaling and secondary active transport. We studied the regulation of the ubiquitous human α1β1 pump isoform by five human FXYD proteins normally located in muscle, kidney, and neurons. The function of Na/K pump α1β1 expressed in Xenopus oocytes with or without FXYD isoforms was evaluated using two-electrode voltage clamp and patch clamp. Through evaluation of the partial reactions in the absence of K+ but presence of Na+ in the external milieu, we demonstrate that each FXYD subunit alters the equilibrium between E1P(3Na) and E2P, the phosphorylated conformations with Na+ occluded and free from Na+, respectively, thereby altering the apparent affinity for Na+. This modification of Na+ interaction shapes the small effects of FXYD proteins on the apparent affinity for external K+ at physiological Na+. FXYD6 distinctively accelerated both the Na+-deocclusion and the pump-turnover rates. All FXYD isoforms altered the apparent affinity for intracellular Na+ in patches, an effect that was observed only in the presence of intracellular K+. Therefore, FXYD proteins alter the selectivity of the pump for intracellular ions, an effect that could be due to the altered equilibrium between E1 and E2, the two major pump conformations, and/or to small changes in ion affinities that are exacerbated when both ions are present. Lastly, we observed a drastic reduction of Na/K pump surface expression when it was coexpressed with FXYD1 or FXYD6, with the former being relieved by injection of PKA's catalytic subunit into the oocyte. Our results indicate that a prominent effect of FXYD1 and FXYD6, and plausibly other FXYDs, is the regulation of Na/K pump trafficking.
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Affiliation(s)
- Dylan J Meyer
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock TX
| | - Sharan Bijlani
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock TX
| | - Marilina de Sautu
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock TX
| | - Kerri Spontarelli
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock TX
| | - Victoria C Young
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock TX
| | - Craig Gatto
- School of Biological Sciences, Illinois State University. Normal, IL
| | - Pablo Artigas
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock TX
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7
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Boguslavskyi A, Tokar S, Prysyazhna O, Rudyk O, Sanchez-Tatay D, Lemmey HA, Dora KA, Garland CJ, Warren HR, Doney A, Palmer CN, Caulfield MJ, Vlachaki Walker J, Howie J, Fuller W, Shattock MJ. Phospholemman Phosphorylation Regulates Vascular Tone, Blood Pressure, and Hypertension in Mice and Humans. Circulation 2021; 143:1123-1138. [PMID: 33334125 PMCID: PMC7969167 DOI: 10.1161/circulationaha.119.040557] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/02/2019] [Accepted: 12/09/2020] [Indexed: 11/24/2022]
Abstract
BACKGROUND Although it has long been recognized that smooth muscle Na/K ATPase modulates vascular tone and blood pressure (BP), the role of its accessory protein phospholemman has not been characterized. The aim of this study was to test the hypothesis that phospholemman phosphorylation regulates vascular tone in vitro and that this mechanism plays an important role in modulation of vascular function and BP in experimental models in vivo and in humans. METHODS In mouse studies, phospholemman knock-in mice (PLM3SA; phospholemman [FXYD1] in which the 3 phosphorylation sites on serines 63, 68, and 69 are mutated to alanines), in which phospholemman is rendered unphosphorylatable, were used to assess the role of phospholemman phosphorylation in vitro in aortic and mesenteric vessels using wire myography and membrane potential measurements. In vivo BP and regional blood flow were assessed using Doppler flow and telemetry in young (14-16 weeks) and old (57-60 weeks) wild-type and transgenic mice. In human studies, we searched human genomic databases for mutations in phospholemman in the region of the phosphorylation sites and performed analyses within 2 human data cohorts (UK Biobank and GoDARTS [Genetics of Diabetes Audit and Research in Tayside]) to assess the impact of an identified single nucleotide polymorphism on BP. This single nucleotide polymorphism was expressed in human embryonic kidney cells, and its effect on phospholemman phosphorylation was determined using Western blotting. RESULTS Phospholemman phosphorylation at Ser63 and Ser68 limited vascular constriction in response to phenylephrine. This effect was blocked by ouabain. Prevention of phospholemman phosphorylation in the PLM3SA mouse profoundly enhanced vascular responses to phenylephrine both in vitro and in vivo. In aging wild-type mice, phospholemman was hypophosphorylated, and this correlated with the development of aging-induced essential hypertension. In humans, we identified a nonsynonymous coding variant, single nucleotide polymorphism rs61753924, which causes the substitution R70C in phospholemman. In human embryonic kidney cells, the R70C mutation prevented phospholemman phosphorylation at Ser68. This variant's rare allele is significantly associated with increased BP in middle-aged men. CONCLUSIONS These studies demonstrate the importance of phospholemman phosphorylation in the regulation of vascular tone and BP and suggest a novel mechanism, and therapeutic target, for aging-induced essential hypertension in humans.
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Affiliation(s)
- Andrii Boguslavskyi
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Sergiy Tokar
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Oleksandra Prysyazhna
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Olena Rudyk
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - David Sanchez-Tatay
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Hamish A.L. Lemmey
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Kim A. Dora
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Christopher J. Garland
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Helen R. Warren
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Alexander Doney
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Colin N.A. Palmer
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Mark J. Caulfield
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Julia Vlachaki Walker
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Jacqueline Howie
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - William Fuller
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
| | - Michael J. Shattock
- British Heart Foundation Centre of Research Excellence, King’s College London, United Kingdom (A.B., S.T., O.P., O.R., D.S.-T., M.J.S.). Clinical Pharmacology, The William Harvey Research Institute (O.P., H.R.W., M.J.C.), National Institute for Health Research, Biomedical Research Centre (H.R.W., M.J.C.), Barts and The London School of Medicine and Dentistry, Queen Mary University of London, United Kingdom. Department of Pharmacology, University of Oxford, United Kingdom (H.A.L.L., K.A.D., C.J.G.). Medicines Monitoring Unit, School of Medicine (A.D.), Division of Cardiovascular and Diabetes Medicine (C.N.A.), University of Dundee, United Kingdom. Institute of Cardiovascular and Medical Sciences, University of Glasgow, United Kingdom (J.V.W., J.H., W.F.)
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8
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Yap JQ, Seflova J, Sweazey R, Artigas P, Robia SL. FXYD proteins and sodium pump regulatory mechanisms. J Gen Physiol 2021; 153:211866. [PMID: 33688925 PMCID: PMC7953255 DOI: 10.1085/jgp.202012633] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2020] [Accepted: 02/03/2021] [Indexed: 12/12/2022] Open
Abstract
The sodium/potassium-ATPase (NKA) is the enzyme that establishes gradients of sodium and potassium across the plasma membrane. NKA activity is tightly regulated for different physiological contexts through interactions with single-span transmembrane peptides, the FXYD proteins. This diverse family of regulators has in common a domain containing a Phe-X-Tyr-Asp (FXYD) motif, two conserved glycines, and one serine residue. In humans, there are seven tissue-specific FXYD proteins that differentially modulate NKA kinetics as appropriate for each system, providing dynamic responsiveness to changing physiological conditions. Our understanding of how FXYD proteins contribute to homeostasis has benefitted from recent advances described in this review: biochemical and biophysical studies have provided insight into regulatory mechanisms, genetic models have uncovered remarkable complexity of FXYD function in integrated physiological systems, new posttranslational modifications have been identified, high-resolution structural studies have revealed new details of the regulatory interaction with NKA, and new clinical correlations have been uncovered. In this review, we address the structural determinants of diverse FXYD functions and the special roles of FXYDs in various physiological systems. We also discuss the possible roles of FXYDs in protein trafficking and regulation of non-NKA targets.
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Affiliation(s)
- John Q Yap
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL
| | - Jaroslava Seflova
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL
| | - Ryan Sweazey
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX
| | - Pablo Artigas
- Department of Cell Physiology and Molecular Biophysics, Center for Membrane Protein Research, Texas Tech University Health Sciences Center, Lubbock, TX
| | - Seth L Robia
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL
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9
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Montigny C, Huang DL, Beswick V, Barbot T, Jaxel C, le Maire M, Zheng JS, Jamin N. Sarcolipin alters SERCA1a interdomain communication by impairing binding of both calcium and ATP. Sci Rep 2021; 11:1641. [PMID: 33452371 PMCID: PMC7810697 DOI: 10.1038/s41598-021-81061-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 12/31/2020] [Indexed: 01/08/2023] Open
Abstract
Sarcolipin (SLN), a single-spanning membrane protein, is a regulator of the sarco-endoplasmic reticulum Ca2+-ATPase (SERCA1a). Chemically synthesized SLN, palmitoylated or not (pSLN or SLN), and recombinant wild-type rabbit SERCA1a expressed in S. cerevisiae design experimental conditions that provide a deeper understanding of the functional role of SLN on the regulation of SERCA1a. Our data show that chemically synthesized SLN interacts with recombinant SERCA1a, with calcium-deprived E2 state as well as with calcium-bound E1 state. This interaction hampers the binding of calcium in agreement with published data. Unexpectedly, SLN has also an allosteric effect on SERCA1a transport activity by impairing the binding of ATP. Our results reveal that SLN significantly slows down the E2 to Ca2.E1 transition of SERCA1a while it affects neither phosphorylation nor dephosphorylation. Comparison with chemically synthesized SLN deprived of acylation demonstrates that palmitoylation is not necessary for either inhibition or association with SERCA1a. However, it has a small but statistically significant effect on SERCA1a phosphorylation when various ratios of SLN-SERCA1a or pSLN-SERCA1a are tested.
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Affiliation(s)
- Cédric Montigny
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, 91198, Gif-sur-Yvette, France.
| | - Dong Liang Huang
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China
| | - Veronica Beswick
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, 91198, Gif-sur-Yvette, France
- Department of Physics, Evry-Val-d'Essonne University, 91025, Evry, France
| | - Thomas Barbot
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, 91198, Gif-sur-Yvette, France
| | - Christine Jaxel
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, 91198, Gif-sur-Yvette, France
| | - Marc le Maire
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, 91198, Gif-sur-Yvette, France
| | - Ji-Shen Zheng
- Hefei National Laboratory for Physical Sciences at the Microscale, School of Life Sciences, University of Science and Technology of China, Hefei, 230027, China.
| | - Nadège Jamin
- CEA, CNRS, Institute for Integrative Biology of the Cell (I2BC), Université Paris-Saclay, 91198, Gif-sur-Yvette, France
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10
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Plain F, Howie J, Kennedy J, Brown E, Shattock MJ, Fraser NJ, Fuller W. Control of protein palmitoylation by regulating substrate recruitment to a zDHHC-protein acyltransferase. Commun Biol 2020; 3:411. [PMID: 32737405 PMCID: PMC7395175 DOI: 10.1038/s42003-020-01145-3] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 07/15/2020] [Indexed: 12/18/2022] Open
Abstract
Although palmitoylation regulates numerous cellular processes, as yet efforts to manipulate this post-translational modification for therapeutic gain have proved unsuccessful. The Na-pump accessory sub-unit phospholemman (PLM) is palmitoylated by zDHHC5. Here, we show that PLM palmitoylation is facilitated by recruitment of the Na-pump α sub-unit to a specific site on zDHHC5 that contains a juxtamembrane amphipathic helix. Site-specific palmitoylation and GlcNAcylation of this helix increased binding between the Na-pump and zDHHC5, promoting PLM palmitoylation. In contrast, disruption of the zDHHC5-Na-pump interaction with a cell penetrating peptide reduced PLM palmitoylation. Our results suggest that by manipulating the recruitment of specific substrates to particular zDHHC-palmitoyl acyl transferases, the palmitoylation status of individual proteins can be selectively altered, thus opening the door to the development of molecular modulators of protein palmitoylation for the treatment of disease.
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Affiliation(s)
- Fiona Plain
- School of Medicine, University of Dundee, Dundee, UK
| | - Jacqueline Howie
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Jennifer Kennedy
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Elaine Brown
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK
| | - Michael J Shattock
- Cardiovascular Division, The Rayne Institute, King's College London, London, UK
| | | | - William Fuller
- Institute of Cardiovascular and Medical Sciences, College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow, UK.
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11
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Bastug-Özel Z, Wright PT, Kraft AE, Pavlovic D, Howie J, Froese A, Fuller W, Gorelik J, Shattock MJ, Nikolaev VO. Heart failure leads to altered β2-adrenoceptor/cyclic adenosine monophosphate dynamics in the sarcolemmal phospholemman/Na,K ATPase microdomain. Cardiovasc Res 2020; 115:546-555. [PMID: 30165515 DOI: 10.1093/cvr/cvy221] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/25/2017] [Revised: 11/22/2017] [Accepted: 08/23/2018] [Indexed: 01/09/2023] Open
Abstract
AIMS Cyclic adenosine monophosphate (cAMP) regulates cardiac excitation-contraction coupling by acting in microdomains associated with sarcolemmal ion channels. However, local real time cAMP dynamics in such microdomains has not been visualized before. We sought to directly monitor cAMP in a microdomain formed around sodium-potassium ATPase (NKA) in healthy and failing cardiomyocytes and to better understand alterations of cAMP compartmentation in heart failure. METHODS AND RESULTS A novel Förster resonance energy transfer (FRET)-based biosensor termed phospholemman (PLM)-Epac1 was developed by fusing a highly sensitive cAMP sensor Epac1-camps to the C-terminus of PLM. Live cell imaging in PLM-Epac1 and Epac1-camps expressing adult rat ventricular myocytes revealed extensive regulation of NKA/PLM microdomain-associated cAMP levels by β2-adrenoceptors (β2-ARs). Local cAMP pools stimulated by these receptors were tightly controlled by phosphodiesterase (PDE) type 3. In chronic heart failure following myocardial infarction, dramatic reduction of the microdomain-specific β2-AR/cAMP signals and β2-AR dependent PLM phosphorylation was accompanied by a pronounced loss of local PDE3 and an increase in PDE2 effects. CONCLUSIONS NKA/PLM complex forms a distinct cAMP microdomain which is directly regulated by β2-ARs and is under predominant control by PDE3. In heart failure, local changes in PDE repertoire result in blunted β2-AR signalling to cAMP in the vicinity of PLM.
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Affiliation(s)
- Zeynep Bastug-Özel
- Clinic of Cardiology and Heart Research Center, University Medical Center Göttingen, Göttingen, Germany.,Cardiovascular Division, King's College London, London, UK
| | - Peter T Wright
- National Heart and Lung Institute, Imperial College London, London, UK
| | - Axel E Kraft
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Martinistr. 52, D-20246 Hamburg, Germany.,German Center for Cardiovascular Research (DZHK), Partner site Hamburg/Kiel/Lübeck, Martinistr. 52, D-20246 Hamburg, Germany
| | - Davor Pavlovic
- Institute of Cardiovascular Sciences, University of Birmingham, Birmingham, UK
| | - Jacqueline Howie
- Division of Cardiovascular and Diabetes Medicine, University of Dundee, Dundee, UK
| | - Alexander Froese
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Martinistr. 52, D-20246 Hamburg, Germany.,German Center for Cardiovascular Research (DZHK), Partner site Hamburg/Kiel/Lübeck, Martinistr. 52, D-20246 Hamburg, Germany
| | - William Fuller
- Division of Cardiovascular and Diabetes Medicine, University of Dundee, Dundee, UK
| | - Julia Gorelik
- National Heart and Lung Institute, Imperial College London, London, UK
| | | | - Viacheslav O Nikolaev
- Institute of Experimental Cardiovascular Research, University Medical Center Hamburg-Eppendorf, Martinistr. 52, D-20246 Hamburg, Germany.,German Center for Cardiovascular Research (DZHK), Partner site Hamburg/Kiel/Lübeck, Martinistr. 52, D-20246 Hamburg, Germany
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12
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Howie J, Wypijewski KJ, Plain F, Tulloch LB, Fraser NJ, Fuller W. Greasing the wheels or a spanner in the works? Regulation of the cardiac sodium pump by palmitoylation. Crit Rev Biochem Mol Biol 2018; 53:175-191. [PMID: 29424237 DOI: 10.1080/10409238.2018.1432560] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
The ubiquitous sodium/potassium ATPase (Na pump) is the most abundant primary active transporter at the cell surface of multiple cell types, including ventricular myocytes in the heart. The activity of the Na pump establishes transmembrane ion gradients that control numerous events at the cell surface, positioning it as a key regulator of the contractile and metabolic state of the myocardium. Defects in Na pump activity and regulation elevate intracellular Na in cardiac muscle, playing a causal role in the development of cardiac hypertrophy, diastolic dysfunction, arrhythmias and heart failure. Palmitoylation is the reversible conjugation of the fatty acid palmitate to specific protein cysteine residues; all subunits of the cardiac Na pump are palmitoylated. Palmitoylation of the pump's accessory subunit phospholemman (PLM) by the cell surface palmitoyl acyl transferase DHHC5 leads to pump inhibition, possibly by altering the relationship between the pump catalytic α subunit and specifically bound membrane lipids. In this review, we discuss the functional impact of PLM palmitoylation on the cardiac Na pump and the molecular basis of recognition of PLM by its palmitoylating enzyme DHHC5, as well as effects of palmitoylation on Na pump cell surface abundance in the cardiac muscle. We also highlight the numerous unanswered questions regarding the cellular control of this fundamentally important regulatory process.
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Affiliation(s)
- Jacqueline Howie
- a Institute of Cardiovascular and Medical Sciences , University of Glasgow , Glasgow , UK
| | | | - Fiona Plain
- b Molecular and Clinical Medicine , University of Dundee , Dundee , UK
| | - Lindsay B Tulloch
- b Molecular and Clinical Medicine , University of Dundee , Dundee , UK
| | - Niall J Fraser
- b Molecular and Clinical Medicine , University of Dundee , Dundee , UK
| | - William Fuller
- a Institute of Cardiovascular and Medical Sciences , University of Glasgow , Glasgow , UK
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13
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Arystarkhova E, Bouley R, Liu YB, Sweadner KJ. Impaired AQP2 trafficking in Fxyd1 knockout mice: A role for FXYD1 in regulated vesicular transport. PLoS One 2017; 12:e0188006. [PMID: 29155857 PMCID: PMC5695786 DOI: 10.1371/journal.pone.0188006] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2017] [Accepted: 10/30/2017] [Indexed: 01/08/2023] Open
Abstract
The final adjustment of urine volume occurs in the inner medullary collecting duct (IMCD), chiefly mediated by the water channel aquaporin 2 (AQP2). With vasopressin stimulation, AQP2 accumulation in the apical plasma membrane of principal cells allows water reabsorption from the lumen. We report that FXYD1 (phospholemman), better known as a regulator of Na,K-ATPase, has a role in AQP2 trafficking. Daytime urine of Fxyd1 knockout mice was more dilute than WT despite similar serum vasopressin, but both genotypes could concentrate urine during water deprivation. FXYD1 was found in IMCD. In WT mice, phosphorylated FXYD1 was detected intracellularly, and vasopressin induced its dephosphorylation. We tested the hypothesis that the dilute urine in knockouts was caused by alteration of AQP2 trafficking. In WT mice at baseline, FXYD1 and AQP2 were not strongly co-localized, but elevation of vasopressin produced translocation of both FXYD1 and AQP2 to the apical plasma membrane. In kidney slices, baseline AQP2 distribution was more scattered in the Fxyd1 knockout than in WT. Apical recruitment of AQP2 occurred in vasopressin-treated Fxyd1 knockout slices, but upon vasopressin washout, there was more rapid reversal of apical AQP2 localization and more heterogeneous cytoplasmic distribution of AQP2. Notably, in sucrose gradients, AQP2 was present in a detergent-resistant membrane domain that had lower sedimentation density in the knockout than in WT, and vasopressin treatment normalized its density. We propose that FXYD1 plays a role in regulating AQP2 retention in apical membrane, and that this involves transfers between raft-like membrane domains in endosomes and plasma membranes.
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Affiliation(s)
- Elena Arystarkhova
- Laboratory of Membrane Biology, Dept. of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, Unites States of America
- * E-mail: (EA); (KJS)
| | - Richard Bouley
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, United States of America
| | - Yi Bessie Liu
- Laboratory of Membrane Biology, Dept. of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, Unites States of America
| | - Kathleen J. Sweadner
- Laboratory of Membrane Biology, Dept. of Neurosurgery, Massachusetts General Hospital and Harvard Medical School, Boston, Massachusetts, Unites States of America
- * E-mail: (EA); (KJS)
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14
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Hurst CH, Turnbull D, Plain F, Fuller W, Hemsley PA. Maleimide scavenging enhances determination of protein S-palmitoylation state in acyl-exchange methods. Biotechniques 2017; 62:69-75. [PMID: 28193150 PMCID: PMC5400063 DOI: 10.2144/000114516] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2016] [Accepted: 12/09/2016] [Indexed: 11/23/2022] Open
Abstract
S-palmitoylation (S-acylation) is emerging as an important dynamic post-translational modification of cysteine residues within proteins. Current assays for protein S-palmitoylation involve either in vivo labeling or chemical cleavage of S-palmitoyl groups to reveal a free cysteine sulfhydryl that can be subsequently labeled with an affinity handle (acyl-exchange). Assays for protein S-palmitoylation using acyl-exchange chemistry therefore require blocking of non-S-palmitoylated cysteines, typically using N-ethylmaleimide (NEM), to prevent non-specific detection. This in turn necessitates multiple precipitation-based clean-up steps to remove reagents between stages, often leading to variable sample loss, reduced signal, or protein aggregation. These combine to reduce the sensitivity, reliability, and accuracy of these assays, which also require a substantial amount of time to perform. By substituting these precipitation steps with chemical scavenging of NEM by 2,3-dimethyl-1,3-butadiene in an aqueous Diels-Alder 4+2 cyclo-addition reaction, it is possible to greatly improve sensitivity and accuracy while reducing the hands-on time and overall time required for the assay.
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Affiliation(s)
- Charlotte H. Hurst
- Division of Plant Sciences, School of Life Sciences, University of Dundee, Dundee, UK
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, UK
| | - Dionne Turnbull
- Division of Plant Sciences, School of Life Sciences, University of Dundee, Dundee, UK
| | - Fiona Plain
- Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, School of Medicine, Dentistry, and Nursing, University of Dundee, Dundee, UK
| | - William Fuller
- Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, School of Medicine, Dentistry, and Nursing, University of Dundee, Dundee, UK
| | - Piers A. Hemsley
- Division of Plant Sciences, School of Life Sciences, University of Dundee, Dundee, UK
- Cell and Molecular Sciences, The James Hutton Institute, Invergowrie, UK
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15
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Himes RD, Smolin N, Kukol A, Bossuyt J, Bers DM, Robia SL. L30A Mutation of Phospholemman Mimics Effects of Cardiac Glycosides in Isolated Cardiomyocytes. Biochemistry 2016; 55:6196-6204. [PMID: 27718550 DOI: 10.1021/acs.biochem.6b00633] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
To determine if mutations introduced into phospholemman (PLM) could increase the level of PLM-Na,K-ATPase (NKA) binding, we performed scanning mutagenesis of the transmembrane domain of PLM and measured Förster resonance energy transfer (FRET) between each mutant and NKA. We observed an increased level of binding to NKA for several PLM mutants compared to that of the wild type (WT), including L27A, L30A, and I32A. In isolated cardiomyocytes, overexpression of WT PLM increased the amplitude of the Ca2+ transient compared to the GFP control. The Ca2+ transient amplitude was further increased by L30A PLM overexpression. The L30A mutation also delayed Ca2+ extrusion and increased the duration of cardiomyocyte contraction. This mimics aspects of the effect of cardiac glycosides, which are known to increase contractility through inhibition of NKA. No significant differences between WT and L30A PLM-expressing myocytes were observed after treatment with isoproterenol, suggesting that the superinhibitory effects of L30A are reversible with β-adrenergic stimulation. We also observed a decrease in the extent of PLM tetramerization with L30A compared to WT using FRET, suggesting that L30 is an important residue for mediating PLM-PLM binding. Molecular dynamics simulations revealed that the potential energy of the L30A tetramer is greater than that of the WT, and that the transmembrane α helix is distorted by the mutation. The results identify PLM residue L30 as an important determinant of PLM tetramerization and of functional inhibition of NKA by PLM.
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Affiliation(s)
- Ryan D Himes
- Department of Cell and Molecular Physiology, Loyola University Chicago , Maywood, Illinois 60153, United States
| | - Nikolai Smolin
- Department of Cell and Molecular Physiology, Loyola University Chicago , Maywood, Illinois 60153, United States
| | - Andreas Kukol
- School of Life and Medical Sciences, University of Hertfordshire , Hatfield, U.K
| | - Julie Bossuyt
- Department of Pharmacology, The University of California , Davis, California 95616, United States
| | - Donald M Bers
- Department of Pharmacology, The University of California , Davis, California 95616, United States
| | - Seth L Robia
- Department of Cell and Molecular Physiology, Loyola University Chicago , Maywood, Illinois 60153, United States
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16
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Lubarski Gotliv I. FXYD5: Na(+)/K(+)-ATPase Regulator in Health and Disease. Front Cell Dev Biol 2016; 4:26. [PMID: 27066483 PMCID: PMC4812908 DOI: 10.3389/fcell.2016.00026] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2016] [Accepted: 03/14/2016] [Indexed: 01/13/2023] Open
Abstract
FXYD5 (Dysadherin, RIC) is a single span type I membrane protein that plays multiple roles in regulation of cellular functions. It is expressed in a variety of epithelial tissues and acts as an auxiliary subunit of the Na+/K+-ATPase. During the past decade, a correlation between enhanced expression of FXYD5 and tumor progression has been established for various tumor types. In this review, current knowledge on FXYD5 is discussed, including experimental data on the functional effects of FXYD5 on the Na+/K+-ATPase. FXYD5 modulates cellular junctions, influences chemokine production, and affects cell adhesion. The accumulated data may provide a basis for understanding the molecular mechanisms underlying FXYD5 mediated phenotypes.
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17
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Feldman AM, Gordon J, Wang J, Song J, Zhang XQ, Myers VD, Tilley DG, Gao E, Hoffman NE, Tomar D, Madesh M, Rabinowitz J, Koch WJ, Su F, Khalili K, Cheung JY. BAG3 regulates contractility and Ca(2+) homeostasis in adult mouse ventricular myocytes. J Mol Cell Cardiol 2016; 92:10-20. [PMID: 26796036 PMCID: PMC4789075 DOI: 10.1016/j.yjmcc.2016.01.015] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/23/2015] [Revised: 01/14/2016] [Accepted: 01/17/2016] [Indexed: 12/22/2022]
Abstract
Bcl2-associated athanogene 3 (BAG3) is a 575 amino acid anti-apoptotic protein that is constitutively expressed in the heart. BAG3 mutations, including mutations leading to loss of protein, are associated with familial cardiomyopathy. Furthermore, BAG3 levels have been found to be reduced in end-stage non-familial failing myocardium. In contrast to neonatal myocytes in which BAG3 is found in the cytoplasm and involved in protein quality control and apoptosis, in adult mouse left ventricular (LV) myocytes BAG3 co-localized with Na(+)-K(+)-ATPase and L-type Ca(2+) channels in the sarcolemma and t-tubules. BAG3 co-immunoprecipitated with β1-adrenergic receptor, L-type Ca(2+) channels and phospholemman. To simulate decreased BAG3 protein levels observed in human heart failure, we targeted BAG3 by shRNA (shBAG3) in adult LV myocytes. Reducing BAG3 by 55% resulted in reduced contraction and [Ca(2+)]i transient amplitudes in LV myocytes stimulated with isoproterenol. L-type Ca(2+) current (ICa) and sarcoplasmic reticulum (SR) Ca(2+) content but not Na(+)/Ca(2+) exchange current (INaCa) or SR Ca(2+) uptake were reduced in isoproterenol-treated shBAG3 myocytes. Forskolin or dibutyryl cAMP restored ICa amplitude in shBAG3 myocytes to that observed in WT myocytes, consistent with BAG3 having effects upstream and at the level of the receptor. Resting membrane potential and action potential amplitude were unaffected but APD50 and APD90 were prolonged in shBAG3 myocytes. Protein levels of Ca(2+) entry molecules and other important excitation-contraction proteins were unchanged in myocytes with lower BAG3. Our findings that BAG3 is localized at the sarcolemma and t-tubules while modulating myocyte contraction and action potential duration through specific interaction with the β1-adrenergic receptor and L-type Ca(2+) channel provide novel insight into the role of BAG3 in cardiomyopathies and increased arrhythmia risks in heart failure.
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MESH Headings
- Action Potentials/drug effects
- Adaptor Proteins, Signal Transducing/biosynthesis
- Adaptor Proteins, Signal Transducing/genetics
- Animals
- Apoptosis Regulatory Proteins/biosynthesis
- Apoptosis Regulatory Proteins/genetics
- Arrhythmias, Cardiac/genetics
- Arrhythmias, Cardiac/metabolism
- Arrhythmias, Cardiac/pathology
- Calcium/metabolism
- Calcium Channels, L-Type/metabolism
- Cardiomyopathy, Dilated/genetics
- Cardiomyopathy, Dilated/metabolism
- Cardiomyopathy, Dilated/pathology
- Excitation Contraction Coupling
- Heart Failure/genetics
- Heart Failure/metabolism
- Heart Failure/pathology
- Heart Ventricles/metabolism
- Heart Ventricles/pathology
- Homeostasis
- Humans
- Isoproterenol/administration & dosage
- Membrane Proteins/metabolism
- Mice
- Myocytes, Cardiac/metabolism
- Myocytes, Cardiac/pathology
- Phosphoproteins/metabolism
- RNA, Small Interfering/genetics
- Receptors, Adrenergic, beta-1/metabolism
- Sarcolemma/metabolism
- Sodium-Potassium-Exchanging ATPase/metabolism
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Affiliation(s)
- Arthur M Feldman
- Department of Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA; Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Jennifer Gordon
- Comprehensive NeuroAIDS Center, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - JuFang Wang
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Jianliang Song
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Xue-Qian Zhang
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Valerie D Myers
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Douglas G Tilley
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Erhe Gao
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Nicholas E Hoffman
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Dhanendra Tomar
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Muniswamy Madesh
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Joseph Rabinowitz
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Walter J Koch
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Feifei Su
- Cardiovascular Research Center, Temple University School of Medicine, Philadelphia, PA 19140, USA; Department of Cardiology, Tangdu Hospital, the Fourth Military Medical University, Xi'an, China
| | - Kamel Khalili
- Comprehensive NeuroAIDS Center, Temple University School of Medicine, Philadelphia, PA 19140, USA
| | - Joseph Y Cheung
- Center of Translational Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA; Department of Medicine, Temple University School of Medicine, Philadelphia, PA 19140, USA.
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18
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Shattock MJ, Ottolia M, Bers DM, Blaustein MP, Boguslavskyi A, Bossuyt J, Bridge JHB, Chen-Izu Y, Clancy CE, Edwards A, Goldhaber J, Kaplan J, Lingrel JB, Pavlovic D, Philipson K, Sipido KR, Xie ZJ. Na+/Ca2+ exchange and Na+/K+-ATPase in the heart. J Physiol 2015; 593:1361-82. [PMID: 25772291 PMCID: PMC4376416 DOI: 10.1113/jphysiol.2014.282319] [Citation(s) in RCA: 145] [Impact Index Per Article: 16.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2014] [Accepted: 10/30/2014] [Indexed: 12/17/2022] Open
Abstract
This paper is the third in a series of reviews published in this issue resulting from the University of California Davis Cardiovascular Symposium 2014: Systems approach to understanding cardiac excitation–contraction coupling and arrhythmias: Na+ channel and Na+ transport. The goal of the symposium was to bring together experts in the field to discuss points of consensus and controversy on the topic of sodium in the heart. The present review focuses on cardiac Na+/Ca2+ exchange (NCX) and Na+/K+-ATPase (NKA). While the relevance of Ca2+ homeostasis in cardiac function has been extensively investigated, the role of Na+ regulation in shaping heart function is often overlooked. Small changes in the cytoplasmic Na+ content have multiple effects on the heart by influencing intracellular Ca2+ and pH levels thereby modulating heart contractility. Therefore it is essential for heart cells to maintain Na+ homeostasis. Among the proteins that accomplish this task are the Na+/Ca2+ exchanger (NCX) and the Na+/K+ pump (NKA). By transporting three Na+ ions into the cytoplasm in exchange for one Ca2+ moved out, NCX is one of the main Na+ influx mechanisms in cardiomyocytes. Acting in the opposite direction, NKA moves Na+ ions from the cytoplasm to the extracellular space against their gradient by utilizing the energy released from ATP hydrolysis. A fine balance between these two processes controls the net amount of intracellular Na+ and aberrations in either of these two systems can have a large impact on cardiac contractility. Due to the relevant role of these two proteins in Na+ homeostasis, the emphasis of this review is on recent developments regarding the cardiac Na+/Ca2+ exchanger (NCX1) and Na+/K+ pump and the controversies that still persist in the field.
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Affiliation(s)
- Michael J Shattock
- King's College London BHF Centre of Excellence, The Rayne Institute, St Thomas' Hospital, London, SE1 7EH, UK
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19
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Hafver TL, Hodne K, Wanichawan P, Aronsen JM, Dalhus B, Lunde PK, Lunde M, Martinsen M, Enger UH, Fuller W, Sjaastad I, Louch WE, Sejersted OM, Carlson CR. Protein Phosphatase 1c Associated with the Cardiac Sodium Calcium Exchanger 1 Regulates Its Activity by Dephosphorylating Serine 68-phosphorylated Phospholemman. J Biol Chem 2015; 291:4561-79. [PMID: 26668322 DOI: 10.1074/jbc.m115.677898] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2015] [Indexed: 11/06/2022] Open
Abstract
The sodium (Na(+))-calcium (Ca(2+)) exchanger 1 (NCX1) is an important regulator of intracellular Ca(2+) homeostasis. Serine 68-phosphorylated phospholemman (pSer-68-PLM) inhibits NCX1 activity. In the context of Na(+)/K(+)-ATPase (NKA) regulation, pSer-68-PLM is dephosphorylated by protein phosphatase 1 (PP1). PP1 also associates with NCX1; however, the molecular basis of this association is unknown. In this study, we aimed to analyze the mechanisms of PP1 targeting to the NCX1-pSer-68-PLM complex and hypothesized that a direct and functional NCX1-PP1 interaction is a prerequisite for pSer-68-PLM dephosphorylation. Using a variety of molecular techniques, we show that PP1 catalytic subunit (PP1c) co-localized, co-fractionated, and co-immunoprecipitated with NCX1 in rat cardiomyocytes, left ventricle lysates, and HEK293 cells. Bioinformatic analysis, immunoprecipitations, mutagenesis, pulldown experiments, and peptide arrays constrained PP1c anchoring to the K(I/V)FF motif in the first Ca(2+) binding domain (CBD) 1 in NCX1. This binding site is also partially in agreement with the extended PP1-binding motif K(V/I)FF-X5-8Φ1Φ2-X8-9-R. The cytosolic loop of NCX1, containing the K(I/V)FF motif, had no effect on PP1 activity in an in vitro assay. Dephosphorylation of pSer-68-PLM in HEK293 cells was not observed when NCX1 was absent, when the K(I/V)FF motif was mutated, or when the PLM- and PP1c-binding sites were separated (mimicking calpain cleavage of NCX1). Co-expression of PLM and NCX1 inhibited NCX1 current (both modes). Moreover, co-expression of PLM with NCX1(F407P) (mutated K(I/V)FF motif) resulted in the current being completely abolished. In conclusion, NCX1 is a substrate-specifying PP1c regulator protein, indirectly regulating NCX1 activity through pSer-68-PLM dephosphorylation.
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Affiliation(s)
- Tandekile Lubelwana Hafver
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Kjetil Hodne
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway, the Department of Basic Sciences and Aquatic Medicine, Norwegian University of Life Sciences (NMBU), 0454 Oslo, Norway
| | - Pimthanya Wanichawan
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Jan Magnus Aronsen
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the Bjørknes College, Oslo, Norway
| | - Bjørn Dalhus
- the Department of Microbiology, Oslo University Hospital, Rikshospitalet, 0424 Oslo, Norway, the Department of Medical Biochemistry, Institute for Clinical Medicine, University of Oslo, 0424 Oslo, Norway and
| | - Per Kristian Lunde
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Marianne Lunde
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Marita Martinsen
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Ulla Helene Enger
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - William Fuller
- the Cardiovascular and Diabetes Medicine, School of Medicine, University of Dundee, Dundee, Scotland, United Kingdom DD1 9SY
| | - Ivar Sjaastad
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - William Edward Louch
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Ole Mathias Sejersted
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway
| | - Cathrine Rein Carlson
- From the Institute for Experimental Medical Research, Oslo University Hospital and University of Oslo, 0450 Oslo, Norway, the KG Jebsen Cardiac Research Center and Center for Heart Failure Research, University of Oslo, 0316 Oslo, Norway,
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20
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Manoharan P, Radzyukevich TL, Hakim Javadi H, Stiner CA, Landero Figueroa JA, Lingrel JB, Heiny JA. Phospholemman is not required for the acute stimulation of Na⁺-K⁺-ATPase α₂-activity during skeletal muscle fatigue. Am J Physiol Cell Physiol 2015; 309:C813-22. [PMID: 26468207 DOI: 10.1152/ajpcell.00205.2015] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2015] [Accepted: 09/08/2015] [Indexed: 11/22/2022]
Abstract
The Na(+)-K(+)-ATPase α2-isoform in skeletal muscle is rapidly stimulated during muscle use and plays a critical role in fatigue resistance. The acute mechanisms that stimulate α2-activity are not completely known. This study examines whether phosphorylation of phospholemman (PLM/FXYD1), a regulatory subunit of Na(+)-K(+)-ATPase, plays a role in the acute stimulation of α2 in working muscles. Mice lacking PLM (PLM KO) have a normal content of the α2-subunit and show normal exercise capacity, in contrast to the greatly reduced exercise capacity of mice that lack α2 in the skeletal muscles. Nerve-evoked contractions in vivo did not induce a change in total PLM or PLM phosphorylated at Ser63 or Ser68, in either WT or PLM KO. Isolated muscles of PLM KO mice maintain contraction and resist fatigue as well as wild type (WT). Rb(+) transport by the α2-Na(+)-K(+)-ATPase is stimulated to the same extent in contracting WT and contracting PLM KO muscles. Phosphorylation of sarcolemmal membranes prepared from WT but not PLM KO skeletal muscles stimulates the activity of both α1 and α2 in a PLM-dependent manner. The stimulation occurs by an increase in Na(+) affinity without significant change in Vmax and is more effective for α1 than α2. These results demonstrate that phosphorylation of PLM is capable of stimulating the activity of both isozymes in skeletal muscle; however, contractile activity alone is not sufficient to induce PLM phosphorylation. Importantly, acute stimulation of α2, sufficient to support exercise and oppose fatigue, does not require PLM or its phosphorylation.
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Affiliation(s)
- Palanikumar Manoharan
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio
| | - Tatiana L Radzyukevich
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio; and
| | - Hesamedin Hakim Javadi
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio; and
| | - Cory A Stiner
- Department of Chemistry, University of Cincinnati, Cincinnati, Ohio
| | | | - Jerry B Lingrel
- Department of Molecular Genetics, Biochemistry and Microbiology, University of Cincinnati, Cincinnati, Ohio
| | - Judith A Heiny
- Department of Molecular and Cellular Physiology, University of Cincinnati, Cincinnati, Ohio; and
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21
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Reilly L, Howie J, Wypijewski K, Ashford MLJ, Hilgemann DW, Fuller W. Palmitoylation of the Na/Ca exchanger cytoplasmic loop controls its inactivation and internalization during stress signaling. FASEB J 2015; 29:4532-43. [PMID: 26174834 PMCID: PMC4608915 DOI: 10.1096/fj.15-276493] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2015] [Accepted: 06/30/2015] [Indexed: 01/02/2023]
Abstract
The electrogenic Na/Ca exchanger (NCX) mediates bidirectional Ca movements that are highly sensitive to changes of Na gradients in many cells. NCX1 is implicated in the pathogenesis of heart failure and a number of cardiac arrhythmias. We measured NCX1 palmitoylation using resin-assisted capture, the subcellular location of yellow fluorescent protein–NCX1 fusion proteins, and NCX1 currents using whole-cell voltage clamping. Rat NCX1 is substantially palmitoylated in all tissues examined. Cysteine 739 in the NCX1 large intracellular loop is necessary and sufficient for NCX1 palmitoylation. Palmitoylation of NCX1 occurs in the Golgi and anchors the NCX1 large regulatory intracellular loop to membranes. Surprisingly, palmitoylation does not influence trafficking or localization of NCX1 to surface membranes, nor does it strongly affect the normal forward or reverse transport modes of NCX1. However, exchangers that cannot be palmitoylated do not inactivate normally (leading to substantial activity in conditions when wild-type exchangers are inactive) and do not promote cargo-dependent endocytosis that internalizes 50% of the cell surface following strong G-protein activation or large Ca transients. The palmitoylated cysteine in NCX1 is found in all vertebrate and some invertebrate NCX homologs. Thus, NCX palmitoylation ubiquitously modulates Ca homeostasis and membrane domain function in cells that express NCX proteins.—Reilly, L., Howie, J., Wypijewski, K., Ashford, M. L. J., Hilgemann, D. W., Fuller, W. Palmitoylation of the Na/Ca exchanger cytoplasmic loop controls its inactivation and internalization during stress signaling.
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Affiliation(s)
- Louise Reilly
- *Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, College of Medicine, Dentistry, and Nursing, University of Dundee, Dundee, United Kingdom; and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Jacqueline Howie
- *Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, College of Medicine, Dentistry, and Nursing, University of Dundee, Dundee, United Kingdom; and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Krzysztof Wypijewski
- *Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, College of Medicine, Dentistry, and Nursing, University of Dundee, Dundee, United Kingdom; and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Michael L J Ashford
- *Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, College of Medicine, Dentistry, and Nursing, University of Dundee, Dundee, United Kingdom; and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - Donald W Hilgemann
- *Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, College of Medicine, Dentistry, and Nursing, University of Dundee, Dundee, United Kingdom; and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
| | - William Fuller
- *Division of Cardiovascular and Diabetes Medicine, Medical Research Institute, College of Medicine, Dentistry, and Nursing, University of Dundee, Dundee, United Kingdom; and Department of Physiology, University of Texas Southwestern Medical Center, Dallas, Texas, USA
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22
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Wypijewski KJ, Tinti M, Chen W, Lamont D, Ashford MLJ, Calaghan SC, Fuller W. Identification of caveolar resident proteins in ventricular myocytes using a quantitative proteomic approach: dynamic changes in caveolar composition following adrenoceptor activation. Mol Cell Proteomics 2015; 14:596-608. [PMID: 25561500 PMCID: PMC4349980 DOI: 10.1074/mcp.m114.038570] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022] Open
Abstract
The lipid raft concept proposes that membrane environments enriched in cholesterol and sphingolipids cluster certain proteins and form platforms to integrate cell signaling. In cardiac muscle, caveolae concentrate signaling molecules and ion transporters, and play a vital role in adrenergic regulation of excitation–contraction coupling, and consequently cardiac contractility. Proteomic analysis of cardiac caveolae is hampered by the presence of contaminants that have sometimes, erroneously, been proposed to be resident in these domains. Here we present the first unbiased analysis of the proteome of cardiac caveolae, and investigate dynamic changes in their protein constituents following adrenoreceptor (AR) stimulation. Rat ventricular myocytes were treated with methyl-β-cyclodextrin (MβCD) to deplete cholesterol and disrupt caveolae. Buoyant caveolin-enriched microdomains (BCEMs) were prepared from MβCD-treated and control cell lysates using a standard discontinuous sucrose gradient. BCEMs were harvested, pelleted, and resolubilized, then alkylated, digested, and labeled with iTRAQ reagents, and proteins identified by LC-MS/MS on a LTQ Orbitrap Velos Pro. Proteins were defined as BCEM resident if they were consistently depleted from the BCEM fraction following MβCD treatment. Selective activation of α-, β1-, and β2-AR prior to preparation of BCEMs was achieved by application of agonist/antagonist pairs for 10 min in populations of field-stimulated myocytes. We typically identified 600–850 proteins per experiment, of which, 249 were defined as high-confidence BCEM residents. Functional annotation clustering indicates cardiac BCEMs are enriched in integrin signaling, guanine nucleotide binding, ion transport, and insulin signaling clusters. Proteins possessing a caveolin binding motif were poorly enriched in BCEMs, suggesting this is not the only mechanism that targets proteins to caveolae. With the notable exception of the cavin family, very few proteins show altered abundance in BCEMs following AR activation, suggesting signaling complexes are preformed in BCEMs to ensure a rapid and high fidelity response to adrenergic stimulation in cardiac muscle.
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Affiliation(s)
- Krzysztof J Wypijewski
- From the ‡Division of Cardiovascular and Diabetes Medicine, College of Medicine, Dentistry and Nursing, University of Dundee, Dundee, United Kingdom
| | - Michele Tinti
- §College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Wenzhang Chen
- §College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Douglas Lamont
- §College of Life Sciences, University of Dundee, Dundee, United Kingdom
| | - Michael L J Ashford
- From the ‡Division of Cardiovascular and Diabetes Medicine, College of Medicine, Dentistry and Nursing, University of Dundee, Dundee, United Kingdom
| | - Sarah C Calaghan
- ¶School of Biomedical Sciences, University of Leeds, Leeds, United Kingdom
| | - William Fuller
- From the ‡Division of Cardiovascular and Diabetes Medicine, College of Medicine, Dentistry and Nursing, University of Dundee, Dundee, United Kingdom;
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23
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Abstract
The cardiac phosphoprotein phospholemman (PLM) regulates the cardiac sodium pump, activating the pump when phosphorylated and inhibiting it when palmitoylated. Protein palmitoylation, the reversible attachment of a 16 carbon fatty acid to a cysteine thiol, is catalyzed by the Asp-His-His-Cys (DHHC) motif-containing palmitoyl acyltransferases. The cell surface palmitoyl acyltransferase DHHC5 regulates a growing number of cellular processes, but relatively few DHHC5 substrates have been identified to date. We examined the expression of DHHC isoforms in ventricular muscle and report that DHHC5 is among the most abundantly expressed DHHCs in the heart and localizes to caveolin-enriched cell surface microdomains. DHHC5 coimmunoprecipitates with PLM in ventricular myocytes and transiently transfected cells. Overexpression and silencing experiments indicate that DHHC5 palmitoylates PLM at two juxtamembrane cysteines, C40 and C42, although C40 is the principal palmitoylation site. PLM interaction with and palmitoylation by DHHC5 is independent of the DHHC5 PSD-95/Discs-large/ZO-1 homology (PDZ) binding motif, but requires a ∼ 120 amino acid region of the DHHC5 intracellular C-tail immediately after the fourth transmembrane domain. PLM C42A but not PLM C40A inhibits the Na pump, indicating PLM palmitoylation at C40 but not C42 is required for PLM-mediated inhibition of pump activity. In conclusion, we demonstrate an enzyme-substrate relationship for DHHC5 and PLM and describe a means of substrate recruitment not hitherto described for this acyltransferase. We propose that PLM palmitoylation by DHHC5 promotes phospholipid interactions that inhibit the Na pump.
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24
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Gong XM, Ding Y, Yu J, Yao Y, Marassi FM. Structure of the Na,K-ATPase regulatory protein FXYD2b in micelles: implications for membrane-water interfacial arginines. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2014; 1848:299-306. [PMID: 24794573 DOI: 10.1016/j.bbamem.2014.04.021] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Revised: 04/19/2014] [Accepted: 04/23/2014] [Indexed: 01/06/2023]
Abstract
FXYD2 is a membrane protein responsible for regulating the function of the Na,K-ATPase in mammalian kidney epithelial cells. Here we report the structure of FXYD2b, one of two splice variants of the protein, determined by NMR spectroscopy in detergent micelles. Solid-state NMR characterization of the protein embedded in phospholipid bilayers indicates that several arginine side chains may be involved in hydrogen bond interactions with the phospholipid polar head groups. The structure and the NMR data suggest that FXYD2b could regulate the Na,K-ATPase by modulating the effective membrane surface electrostatics near the ion binding sites of the pump.
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Affiliation(s)
- Xiao-Min Gong
- Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Yi Ding
- Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Jinghua Yu
- Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Yong Yao
- Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Francesca M Marassi
- Sanford-Burnham Medical Research Institute, 10901 North Torrey Pines Road, La Jolla, CA 92037, USA.
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25
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Pavlovic D, Fuller W, Shattock MJ. Novel regulation of cardiac Na pump via phospholemman. J Mol Cell Cardiol 2013; 61:83-93. [PMID: 23672825 DOI: 10.1016/j.yjmcc.2013.05.002] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/03/2013] [Revised: 04/30/2013] [Accepted: 05/03/2013] [Indexed: 12/19/2022]
Abstract
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 with electrical excitation, heart rate and pathology, the dynamic regulation of Na efflux is essential. It is now widely recognized that phospholemman, a 72 amino acid accessory protein which forms part of the Na pump complex, is the key nexus linking cellular signaling to pump regulation. Phospholemman is the target of a variety of post-translational modifications (including phosphorylation, palmitoylation and glutathionation) and these can dynamically alter the activity of the Na pump. This review summarizes our current understanding of the multiple regulatory mechanisms that converge on phospholemman and govern NA pump activity in the heart. The corrected Fig. 4 is reproduced below. The publisher would like to apologize for any inconvenience caused. [corrected].
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Affiliation(s)
- Davor Pavlovic
- Cardiovascular Division, King's College London, The Rayne Institute, St Thomas' Hospital, London, UK.
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