1
|
Goto S, Takahashi T, Sato T, Toyama F, Takayama-Watanabe E, Watanabe A. A CatSper-Uninvolved Mechanism to Induce Forward Sperm Motility in the Internal Fertilization. Zoolog Sci 2024; 41:302-313. [PMID: 38809869 DOI: 10.2108/zs230046] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2023] [Accepted: 01/04/2024] [Indexed: 05/31/2024]
Abstract
Sperm-specific cation channel (CatSper), sperm-specific Na + /H + exchanger (sNHE), and soluble adenylyl cyclase (sAC) are necessary in the signaling pathways to control sperm motility in many animals, whereas some animals have lost some or all of them. In the present study, we examined CatSper-uninvolved signaling for vigorous undulation of the undulating membrane that is attached to the sperm tail and gives thrust for forward motility in the internally fertilizing newt Cynops pyrrhogaster. Reverse-transcription PCR failed to detect sNHE in the newt sperm. However, the pH of sperm cytoplasm was raised under a high extracellular pH equivalent to that of egg jelly, where sperm motility is initiated by sperm motility-initiating substance (SMIS). Carbonic anhydrase XII/ XVI and SLC4A4/8 were suggested to be present in the sperm, and transported bicarbonates raised the intracellular pH. In egg jelly extract that contained SMIS, the anion transporter inhibitor DIDS weakened the undulation of the undulating membrane, while bicarbonates enhanced it. The cyclic AMP concentration was found to increase in sperm cytoplasm in the egg-jelly extract. An inhibitor of sAC (KH7) weakened the undulation of the undulating membrane, and dibutyryl cyclic AMP blocked the inhibitory effect. Inhibitor of transmembrane AC (DDA) limitedly affected the undulation. The undulation was weakened by an inhibitor of protein kinase A (H89), and by an inhibitor of transient receptor potential (TRP) channels (RN1747). Our results support the conclusions that the high pH of the egg jelly triggers a signaling pathway through sAC, PKA, and TRP channels, and coacts with SMIS to induce forward sperm motility.
Collapse
Affiliation(s)
- Sayuri Goto
- Faculty of Science, Biological Division, Yamagata University, Yamagata 990-8560, Japan
| | - Tomoe Takahashi
- Faculty of Science, Biological Division, Yamagata University, Yamagata 990-8560, Japan
| | - Tae Sato
- Faculty of Science, Biological Division, Yamagata University, Yamagata 990-8560, Japan
| | - Fubito Toyama
- Graduate School of Engineering, Utsunomiya University, Utsunomiya, Tochigi 321-8505, Japan
| | | | - Akihiko Watanabe
- Faculty of Science, Biological Division, Yamagata University, Yamagata 990-8560, Japan,
| |
Collapse
|
2
|
Sharma AK, Singh S, Bhat M, Gill K, Zaid M, Kumar S, Shakya A, Tantray J, Jose D, Gupta R, Yangzom T, Sharma RK, Sahu SK, Rathore G, Chandolia P, Singh M, Mishra A, Raj S, Gupta A, Agarwal M, Kifayat S, Gupta A, Gupta P, Vashist A, Vaibhav P, Kathuria N, Yadav V, Singh RP, Garg A. New drug discovery of cardiac anti-arrhythmic drugs: insights in animal models. Sci Rep 2023; 13:16420. [PMID: 37775650 PMCID: PMC10541452 DOI: 10.1038/s41598-023-41942-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Accepted: 09/04/2023] [Indexed: 10/01/2023] Open
Abstract
Cardiac rhythm regulated by micro-macroscopic structures of heart. Pacemaker abnormalities or disruptions in electrical conduction, lead to arrhythmic disorders may be benign, typical, threatening, ultimately fatal, occurs in clinical practice, patients on digitalis, anaesthesia or acute myocardial infarction. Both traditional and genetic animal models are: In-vitro: Isolated ventricular Myocytes, Guinea pig papillary muscles, Patch-Clamp Experiments, Porcine Atrial Myocytes, Guinea pig ventricular myocytes, Guinea pig papillary muscle: action potential and refractory period, Langendorff technique, Arrhythmia by acetylcholine or potassium. Acquired arrhythmia disorders: Transverse Aortic Constriction, Myocardial Ischemia, Complete Heart Block and AV Node Ablation, Chronic Tachypacing, Inflammation, Metabolic and Drug-Induced Arrhythmia. In-Vivo: Chemically induced arrhythmia: Aconitine antagonism, Digoxin-induced arrhythmia, Strophanthin/ouabain-induced arrhythmia, Adrenaline-induced arrhythmia, and Calcium-induced arrhythmia. Electrically induced arrhythmia: Ventricular fibrillation electrical threshold, Arrhythmia through programmed electrical stimulation, sudden coronary death in dogs, Exercise ventricular fibrillation. Genetic Arrhythmia: Channelopathies, Calcium Release Deficiency Syndrome, Long QT Syndrome, Short QT Syndrome, Brugada Syndrome. Genetic with Structural Heart Disease: Arrhythmogenic Right Ventricular Cardiomyopathy/Dysplasia, Dilated Cardiomyopathy, Hypertrophic Cardiomyopathy, Atrial Fibrillation, Sick Sinus Syndrome, Atrioventricular Block, Preexcitation Syndrome. Arrhythmia in Pluripotent Stem Cell Cardiomyocytes. Conclusion: Both traditional and genetic, experimental models of cardiac arrhythmias' characteristics and significance help in development of new antiarrhythmic drugs.
Collapse
Affiliation(s)
- Ashish Kumar Sharma
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India.
| | - Shivam Singh
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Mehvish Bhat
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Kartik Gill
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Mohammad Zaid
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Sachin Kumar
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Anjali Shakya
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Junaid Tantray
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Divyamol Jose
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Rashmi Gupta
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Tsering Yangzom
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Rajesh Kumar Sharma
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | | | - Gulshan Rathore
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Priyanka Chandolia
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Mithilesh Singh
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Anurag Mishra
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Shobhit Raj
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Archita Gupta
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Mohit Agarwal
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Sumaiya Kifayat
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Anamika Gupta
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Prashant Gupta
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Ankit Vashist
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Parth Vaibhav
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Nancy Kathuria
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Vipin Yadav
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Ravindra Pal Singh
- NIMS Institute of Pharmacy, NIMS University Rajasthan, Jaipur, Rajasthan, 303121, India
| | - Arun Garg
- MVN University, Palwal, Haryana, India
| |
Collapse
|
3
|
Collins KB, Scott JD. Phosphorylation, compartmentalization, and cardiac function. IUBMB Life 2023; 75:353-369. [PMID: 36177749 PMCID: PMC10049969 DOI: 10.1002/iub.2677] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2022] [Accepted: 09/15/2022] [Indexed: 11/08/2022]
Abstract
Protein phosphorylation is a fundamental element of cell signaling. First discovered as a biochemical switch in glycogen metabolism, we now know that this posttranslational modification permeates all aspects of cellular behavior. In humans, over 540 protein kinases attach phosphate to acceptor amino acids, whereas around 160 phosphoprotein phosphatases remove phosphate to terminate signaling. Aberrant phosphorylation underlies disease, and kinase inhibitor drugs are increasingly used clinically as targeted therapies. Specificity in protein phosphorylation is achieved in part because kinases and phosphatases are spatially organized inside cells. A prototypic example is compartmentalization of the cyclic adenosine 3',5'-monophosphate (cAMP)-dependent protein kinase A through association with A-kinase anchoring proteins. This configuration creates autonomous signaling islands where the anchored kinase is constrained in proximity to activators, effectors, and selected substates. This article primarily focuses on A kinase anchoring protein (AKAP) signaling in the heart with an emphasis on anchoring proteins that spatiotemporally coordinate excitation-contraction coupling and hypertrophic responses.
Collapse
Affiliation(s)
- Kerrie B. Collins
- Department of Pharmacology, University of Washington, School of Medicine, 1959 NE Pacific Ave, Seattle WA, 98195
| | - John D. Scott
- Department of Pharmacology, University of Washington, School of Medicine, 1959 NE Pacific Ave, Seattle WA, 98195
| |
Collapse
|
4
|
Hovey L, Guo X, Chen Y, Liu Q, Catterall WA. Impairment of β-adrenergic regulation and exacerbation of pressure-induced heart failure in mice with mutations in phosphoregulatory sites in the cardiac Ca V1.2 calcium channel. Front Physiol 2023; 14:1049611. [PMID: 36846334 PMCID: PMC9944942 DOI: 10.3389/fphys.2023.1049611] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2022] [Accepted: 01/10/2023] [Indexed: 02/10/2023] Open
Abstract
The cardiac calcium channel CaV1.2 conducts L-type calcium currents that initiate excitation-contraction coupling and serves as a crucial mediator of β-adrenergic regulation of the heart. We evaluated the inotropic response of mice with mutations in C-terminal phosphoregulatory sites under physiological levels of β-adrenergic stimulation in vivo, and we assessed the impact of combining mutations of C-terminal phosphoregulatory sites with chronic pressure-overload stress. Mice with Ser1700Ala (S1700A), Ser1700Ala/Thr1704Ala (STAA), and Ser1928Ala (S1928A) mutations had impaired baseline regulation of ventricular contractility and exhibited decreased inotropic response to low doses of β-adrenergic agonist. In contrast, treatment with supraphysiogical doses of agonist revealed substantial inotropic reserve that compensated for these deficits. Hypertrophy and heart failure in response to transverse aortic constriction (TAC) were exacerbated in S1700A, STAA, and S1928A mice whose β-adrenergic regulation of CaV1.2 channels was blunted. These findings further elucidate the role of phosphorylation of CaV1.2 at regulatory sites in the C-terminal domain for maintaining normal cardiac homeostasis, responding to physiological levels of β-adrenergic stimulation in the fight-or-flight response, and adapting to pressure-overload stress.
Collapse
Affiliation(s)
- Liam Hovey
- Department of Pharmacology, School of Medicine, University of Washington, Seattle, WA, United States
- Medical Scientist Training Program, School of Medicine, University of Washington, Seattle, WA, United States
| | - Xiaoyun Guo
- Department of Physiology and Biophysics, School of Medicine, University of Washington, Seattle, WA, United States
| | - Yi Chen
- Department of Physiology and Biophysics, School of Medicine, University of Washington, Seattle, WA, United States
| | - Qinghang Liu
- Department of Physiology and Biophysics, School of Medicine, University of Washington, Seattle, WA, United States
| | - William A. Catterall
- Medical Scientist Training Program, School of Medicine, University of Washington, Seattle, WA, United States
| |
Collapse
|
5
|
Martín-Aragón Baudel M, Flores-Tamez VA, Hong J, Reddy GR, Maillard P, Burns AE, Man KNM, Sasse KC, Ward SM, Catterall WA, Bers DM, Hell JW, Nieves-Cintrón M, Navedo MF. Spatiotemporal Control of Vascular Ca V1.2 by α1 C S1928 Phosphorylation. Circ Res 2022; 131:1018-1033. [PMID: 36345826 PMCID: PMC9722584 DOI: 10.1161/circresaha.122.321479] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/05/2022] [Revised: 10/13/2022] [Accepted: 10/27/2022] [Indexed: 11/10/2022]
Abstract
BACKGROUND L-type CaV1.2 channels undergo cooperative gating to regulate cell function, although mechanisms are unclear. This study tests the hypothesis that phosphorylation of the CaV1.2 pore-forming subunit α1C at S1928 mediates vascular CaV1.2 cooperativity during diabetic hyperglycemia. METHODS A multiscale approach including patch-clamp electrophysiology, super-resolution nanoscopy, proximity ligation assay, calcium imaging' pressure myography, and Laser Speckle imaging was implemented to examine CaV1.2 cooperativity, α1C clustering, myogenic tone, and blood flow in human and mouse arterial myocytes/vessels. RESULTS CaV1.2 activity and cooperative gating increase in arterial myocytes from patients with type 2 diabetes and type 1 diabetic mice, and in wild-type mouse arterial myocytes after elevating extracellular glucose. These changes were prevented in wild-type cells pre-exposed to a PKA inhibitor or cells from knock-in S1928A but not S1700A mice. In addition, α1C clustering at the surface membrane of wild-type, but not wild-type cells pre-exposed to PKA or P2Y11 inhibitors and S1928A arterial myocytes, was elevated upon hyperglycemia and diabetes. CaV1.2 spatial and gating remodeling correlated with enhanced arterial myocyte Ca2+ influx and contractility and in vivo reduction in arterial diameter and blood flow upon hyperglycemia and diabetes in wild-type but not S1928A cells/mice. CONCLUSIONS These results suggest that PKA-dependent S1928 phosphorylation promotes the spatial reorganization of vascular α1C into "superclusters" upon hyperglycemia and diabetes. This triggers CaV1.2 activity and cooperativity, directly impacting vascular reactivity. The results may lay the foundation for developing therapeutics to correct CaV1.2 and arterial function during diabetic hyperglycemia.
Collapse
Affiliation(s)
- Miguel Martín-Aragón Baudel
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Victor A. Flores-Tamez
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Junyoung Hong
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Gopyreddy R. Reddy
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Pauline Maillard
- Department of Neurology, University of California Davis, Davis, CA (P.M.)
| | - Abby E. Burns
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Kwun Nok Mimi Man
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | | | - Sean M. Ward
- Department of Physiology and Cell Biology, University of Nevada Reno, Reno, NV (S.M.W.)
| | | | - Donald M. Bers
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Johannes W. Hell
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Madeline Nieves-Cintrón
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| | - Manuel F. Navedo
- Department of Pharmacology, University of California Davis, Davis, CA (M.M.-A.B., V.A.F.-T., J.H., G.R.R., A.E.B., K.N.M.M., D.M.B., J.W.H., M.N.-C., M.F.N.)
| |
Collapse
|
6
|
Hool LC. Elucidating the role of the L-type calcium channel in excitability and energetics in the heart: The ISHR 2020 Research Achievement Award Lecture. J Mol Cell Cardiol 2022; 172:100-108. [PMID: 36041287 DOI: 10.1016/j.yjmcc.2022.08.001] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/13/2022] [Revised: 07/31/2022] [Accepted: 08/08/2022] [Indexed: 12/14/2022]
Abstract
Cardiovascular disease continues to be the leading health burden worldwide and with the rising rates in obesity and type II diabetes and ongoing effects of long COVID, it is anticipated that the burden of cardiovascular morbidity and mortality will increase. Calcium is essential to cardiac excitation and contraction. The main route for Ca2+ influx is the L-type Ca2+ channel (Cav1.2) and embryos that are homozygous null for the Cav1.2 gene are lethal at day 14 postcoitum. Acute changes in Ca2+ influx through the channel contribute to arrhythmia and sudden death, and chronic increases in intracellular Ca2+ contribute to pathological hypertrophy and heart failure. We use a multidisciplinary approach to study the regulation of the channel from the molecular level through to in vivo CRISPR mutant animal models. Here we describe some examples of our work from over 2 decades studying the role of the channel under physiological and pathological conditions. Our single channel analysis of purified human Cav1.2 protein in proteoliposomes has contributed to understanding direct molecular regulation of the channel including identifying the critical serine involved in the "fight or flight" response. Using the same approach we identified the cysteine responsible for altered function during oxidative stress. Chronic activation of the L-type Ca2+ channel during oxidative stress occurs as a result of persistent glutathionylation of the channel that contributes to the development of hypertrophy. We describe for the first time that activation of the channel alters mitochondrial function (and energetics) on a beat-to-beat basis via movement of cytoskeletal proteins. In translational studies we have used this response to "report" mitochondrial function in models of cardiomyopathy and to test efficacy of novel therapies to prevent cardiomyopathy.
Collapse
Affiliation(s)
- Livia C Hool
- School of Human Sciences, University of Western Australia, Crawley, WA, Australia; Victor Chang Cardiac Research Institute, Sydney, NSW, Australia.
| |
Collapse
|
7
|
Convergent regulation of Ca V1.2 channels by direct phosphorylation and by the small GTPase RAD in the cardiac fight-or-flight response. Proc Natl Acad Sci U S A 2022; 119:e2208533119. [PMID: 36215501 PMCID: PMC9586275 DOI: 10.1073/pnas.2208533119] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
The L-type calcium currents conducted by the cardiac CaV1.2 calcium channel initiate excitation-contraction coupling and serve as a key regulator of heart rate, rhythm, and force of contraction. CaV1.2 is regulated by β-adrenergic/protein kinase A (PKA)-mediated protein phosphorylation, proteolytic processing, and autoinhibition by its carboxyl-terminal domain (CT). The small guanosine triphosphatase (GTPase) RAD (Ras associated with diabetes) has emerged as a potent inhibitor of CaV1.2, and accumulating evidence suggests a key role for RAD in mediating β-adrenergic/PKA upregulation of channel activity. However, the relative roles of direct phosphorylation of CaV1.2 channels and phosphorylation of RAD in channel regulation remain uncertain. Here, we investigated the hypothesis that these two mechanisms converge to regulate CaV1.2 channels. Both RAD and the proteolytically processed distal CT (dCT) strongly reduced CaV1.2 activity. PKA phosphorylation of RAD and phosphorylation of Ser-1700 in the proximal CT (pCT) synergistically reversed this inhibition and increased CaV1.2 currents. Our findings reveal that the proteolytically processed form of CaV1.2 undergoes convergent regulation by direct phosphorylation of the CT and by phosphorylation of RAD. These parallel regulatory pathways provide a flexible mechanism for upregulation of the activity of CaV1.2 channels in the fight-or-flight response.
Collapse
|
8
|
Blackwell DJ, Schmeckpeper J, Knollmann BC. Animal Models to Study Cardiac Arrhythmias. Circ Res 2022; 130:1926-1964. [PMID: 35679367 DOI: 10.1161/circresaha.122.320258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Cardiac arrhythmias are a significant cause of morbidity and mortality worldwide, accounting for 10% to 15% of all deaths. Although most arrhythmias are due to acquired heart disease, inherited channelopathies and cardiomyopathies disproportionately affect children and young adults. Arrhythmogenesis is complex, involving anatomic structure, ion channels and regulatory proteins, and the interplay between cells in the conduction system, cardiomyocytes, fibroblasts, and the immune system. Animal models of arrhythmia are powerful tools for studying not only molecular and cellular mechanism of arrhythmogenesis but also more complex mechanisms at the whole heart level, and for testing therapeutic interventions. This review summarizes basic and clinical arrhythmia mechanisms followed by an in-depth review of published animal models of genetic and acquired arrhythmia disorders.
Collapse
Affiliation(s)
- Daniel J Blackwell
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - Jeffrey Schmeckpeper
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| | - Bjorn C Knollmann
- Vanderbilt Center for Arrhythmia Research and Therapeutics, Division of Clinical Pharmacology, Vanderbilt University Medical Center, Nashville, TN
| |
Collapse
|
9
|
Abstract
Each heartbeat is initiated by the action potential, an electrical signal that depolarizes the plasma membrane and activates a cycle of calcium influx via voltage-gated calcium channels, calcium release via ryanodine receptors, and calcium reuptake and efflux via calcium-ATPase pumps and sodium-calcium exchangers. Agonists of the sympathetic nervous system bind to adrenergic receptors in cardiomyocytes, which, via cascading signal transduction pathways and protein kinase A (PKA), increase the heart rate (chronotropy), the strength of myocardial contraction (inotropy), and the rate of myocardial relaxation (lusitropy). These effects correlate with increased intracellular concentration of calcium, which is required for the augmentation of cardiomyocyte contraction. Despite extensive investigations, the molecular mechanisms underlying sympathetic nervous system regulation of calcium influx in cardiomyocytes have remained elusive over the last 40 years. Recent studies have uncovered the mechanisms underlying this fundamental biologic process, namely that PKA phosphorylates a calcium channel inhibitor, Rad, thereby releasing inhibition and increasing calcium influx. Here, we describe an updated model for how signals from adrenergic agonists are transduced to stimulate calcium influx and contractility in the heart.
Collapse
Affiliation(s)
- Arianne Papa
- Department of Physiology and Cellular Biophysics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| | - Jared Kushner
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA;
| | - Steven O Marx
- Division of Cardiology, Department of Medicine, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA;
- Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University, New York, NY, USA
| |
Collapse
|
10
|
Kwon HK, Choi H, Park SG, Park WJ, Kim, DH, Park ZY. Integrated Quantitative Phosphoproteomics and Cell-based Functional Screening Reveals Specific Pathological Cardiac Hypertrophy-related Phosphorylation Sites. Mol Cells 2021; 44:500-516. [PMID: 34158421 PMCID: PMC8334354 DOI: 10.14348/molcells.2021.4002] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2019] [Accepted: 01/07/2019] [Indexed: 12/29/2022] Open
Abstract
Cardiac hypertrophic signaling cascades resulting in heart failure diseases are mediated by protein phosphorylation. Recent developments in mass spectrometry-based phosphoproteomics have led to the identification of thousands of differentially phosphorylated proteins and their phosphorylation sites. However, functional studies of these differentially phosphorylated proteins have not been conducted in a large-scale or high-throughput manner due to a lack of methods capable of revealing the functional relevance of each phosphorylation site. In this study, an integrated approach combining quantitative phosphoproteomics and cell-based functional screening using phosphorylation competition peptides was developed. A pathological cardiac hypertrophy model, junctate-1 transgenic mice and control mice, were analyzed using label-free quantitative phosphoproteomics to identify differentially phosphorylated proteins and sites. A cell-based functional assay system measuring hypertrophic cell growth of neonatal rat ventricle cardiomyocytes (NRVMs) following phenylephrine treatment was applied, and changes in phosphorylation of individual differentially phosphorylated sites were induced by incorporation of phosphorylation competition peptides conjugated with cell-penetrating peptides. Cell-based functional screening against 18 selected phosphorylation sites identified three phosphorylation sites (Ser-98, Ser-179 of Ldb3, and Ser-1146 of palladin) displaying near-complete inhibition of cardiac hypertrophic growth of NRVMs. Changes in phosphorylation levels of Ser-98 and Ser-179 in Ldb3 were further confirmed in NRVMs and other pathological/physiological hypertrophy models, including transverse aortic constriction and swimming models, using site-specific phospho-antibodies. Our integrated approach can be used to identify functionally important phosphorylation sites among differentially phosphorylated sites, and unlike conventional approaches, it is easily applicable for large-scale and/or high-throughput analyses.
Collapse
Affiliation(s)
- Hye Kyeong Kwon
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Hyunwoo Choi
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Sung-Gyoo Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Woo Jin Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Do Han Kim,
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| | - Zee-Yong Park
- School of Life Sciences, Gwangju Institute of Science and Technology (GIST), Gwangju 61005, Korea
| |
Collapse
|
11
|
Kushner J, Papa A, Marx SO. Use of Proximity Labeling in Cardiovascular Research. JACC Basic Transl Sci 2021; 6:598-609. [PMID: 34368510 PMCID: PMC8326230 DOI: 10.1016/j.jacbts.2021.01.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Revised: 12/11/2020] [Accepted: 01/06/2021] [Indexed: 10/31/2022]
Abstract
Protein-protein interactions are of paramount importance in regulating normal cardiac physiology. Methodologies to elucidate these interactions in vivo have been limited. Recently, proximity-dependent biotinylation, with the use of BioID, TurboID, and ascorbate peroxidase, has been developed to uncover cellular neighborhoods and novel protein-protein interactions. These cutting-edge techniques have enabled the identification of subcellular localizations of specific proteins and the neighbors or interacting proteins within these subcellular regions. In contrast to classic methods such as affinity purification and subcellular fractionation, these techniques add covalently bound tags in living cells, such that spatial relationships and interaction networks are not disrupted. Recently, these methodologies have been used to identify novel protein-protein interactions relevant to the cardiovascular system. In this review, we discuss the development and current use of proximity biotin-labeling for cardiovascular research.
Collapse
Affiliation(s)
- Jared Kushner
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, New York, USA
| | - Arianne Papa
- Department of Physiology and Cellular Biophysics, Columbia University, Vagelos College of Physicians and Surgeons, New York, New York, USA
| | - Steven O. Marx
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, New York, USA
- Department of Molecular Pharmacology and Therapeutics, Vagelos College of Physicians and Surgeons, Columbia University, New York, New York, USA
| |
Collapse
|
12
|
Resveratrol Prevents Right Ventricle Dysfunction, Calcium Mishandling, and Energetic Failure via SIRT3 Stimulation in Pulmonary Arterial Hypertension. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2021; 2021:9912434. [PMID: 34239697 PMCID: PMC8238598 DOI: 10.1155/2021/9912434] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2021] [Revised: 05/20/2021] [Accepted: 05/25/2021] [Indexed: 12/17/2022]
Abstract
Pulmonary arterial hypertension (PAH) is characterized by pulmonary vessel remodeling; however, its severity and impact on survival depend on right ventricular (RV) failure. Resveratrol (RES), a polyphenol found in red wine, exhibits cardioprotective effects on RV dysfunction in PAH. However, most literature has focused on RES protective effect on lung vasculature; recent finding indicates that RES has a cardioprotective effect independent of pulmonary arterial pressure on RV dysfunction, although the underlying mechanism in RV has not been determined. Therefore, this study is aimed at evaluating sirtuin-3 (SIRT3) modulation by RES in RV using a monocrotaline- (MC-) induced PAH rat model. Myocyte function was evaluated by confocal microscopy as cell contractility, calcium signaling, and mitochondrial membrane potential (ΔΨm); cell energetics was assessed by high-resolution respirometry, and western blot and immunoprecipitation evaluated posttranslational modifications. PAH significantly affects mitochondrial function in RV; PAH is prone to mitochondrial permeability transition pore (mPTP) opening, thus decreasing the mitochondrial membrane potential. The compromised cellular energetics affects cardiomyocyte function by decreasing sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) activity and delaying myofilament unbinding, disrupting cell relaxation. RES partially protects mitochondrial integrity by deacetylating cyclophilin-D, a critical component of the mPTP, increasing SIRT3 expression and activity and preventing mPTP opening. The preserved energetic capability rescues cell relaxation by maintaining SERCA activity. Avoiding Ca2+ transient and cell contractility mismatch by preserving mitochondrial function describes, for the first time, impairment in excitation-contraction-energetics coupling in RV failure. These results highlight the importance of mitochondrial energetics and mPTP in PAH.
Collapse
|
13
|
Shin SK, Li HY, Cho K, Cho YW, Lee JH, Park KS. Sites and Regulation of L-Type Ca 2+ Channel Ca v1.2 Phosphorylation in Brain. Cell Mol Neurobiol 2021; 42:2427-2431. [PMID: 33909214 DOI: 10.1007/s10571-021-01095-2] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 04/19/2021] [Indexed: 12/01/2022]
Abstract
Cav1.2 channel phosphorylation plays an important role in regulating neuronal plasticity by action potential-dependent Ca2+ entry. Most studies of Cav1.2 regulation by phosphorylation have been reported in heart and muscles. Here, we identified phosphorylation sites of neuronal Cav1.2 channel protein purified from rat brain using mass spectrometry. The functional characterization of these phosphorylation sites showed altered voltage-dependent biophysical properties of the channel, without affecting current density. These results show that neuronal Cav1.2 channel is regulated by phosphorylation in a complex mechanism involving multiple phosphorylation sites.
Collapse
Affiliation(s)
- Seok Kyo Shin
- Department of Physiology, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dondaemun-gu, Seoul, 02447, South Korea
| | - Hai Ying Li
- Department of Life Science, Sogang University, Shinsu-dong, Seoul, 04107, South Korea
| | - Kun Cho
- Biomedical Omics Group, Korea Basic Science Institute, Cheongju-si, Chungcheongbuk-do, 28119, South Korea
| | - Young Wuk Cho
- Department of Physiology, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dondaemun-gu, Seoul, 02447, South Korea
| | - Jung-Ha Lee
- Department of Life Science, Sogang University, Shinsu-dong, Seoul, 04107, South Korea
| | - Kang-Sik Park
- Department of Physiology, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dondaemun-gu, Seoul, 02447, South Korea.
| |
Collapse
|
14
|
Kaidonis X, Niu W, Chan AY, Kesteven S, Wu J, Iismaa SE, Vatner S, Feneley M, Graham RM. Adaptation to exercise-induced stress is not dependent on cardiomyocyte α 1A-adrenergic receptors. J Mol Cell Cardiol 2021; 155:78-87. [PMID: 33647309 DOI: 10.1016/j.yjmcc.2021.02.010] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/17/2020] [Revised: 01/20/2021] [Accepted: 02/21/2021] [Indexed: 12/31/2022]
Abstract
The 'fight or flight' response to physiological stress involves sympathetic nervous system activation, catecholamine release and adrenergic receptor stimulation. In the heart, this induces positive inotropy, previously attributed to the β1-adrenergic receptor subtype. However, the role of the α1A-adrenergic receptor, which has been suggested to be protective in cardiac pathology, has not been investigated in the setting of physiological stress. To explore this, we developed a tamoxifen-inducible, cardiomyocyte-specific α1A-adrenergic receptor knock-down mouse model, challenged mice to four weeks of endurance swim training and assessed cardiac outcomes. With 4-OH tamoxifen treatment, expression of the α1A-adrenergic receptor was knocked down by 80-89%, without any compensatory changes in the expression of other adrenergic receptors, or changes to baseline cardiac structure and function. Swim training caused eccentric hypertrophy, regardless of genotype, demonstrated by an increase in heart weight/tibia length ratio (30% and 22% in vehicle- and tamoxifen-treated animals, respectively) and an increase in left ventricular end diastolic volume (30% and 24% in vehicle- and tamoxifen-treated animals, respectively) without any change in the wall thickness/chamber radius ratio. Consistent with physiological hypertrophy, there was no increase in fetal gene program (Myh7, Nppa, Nppb or Acta1) expression. In response to exercise-induced volume overload, stroke volume (39% and 30% in vehicle- and tamoxifen-treated animals, respectively), cardiac output/tibia length ratio (41% in vehicle-treated animals) and stroke work (61% and 33% in vehicle- and tamoxifen-treated animals, respectively) increased, regardless of genotype. These findings demonstrate that cardiomyocyte α1A-adrenergic receptors are not necessary for cardiac adaptation to endurance exercise stress and their acute ablation is not deleterious.
Collapse
Affiliation(s)
- Xenia Kaidonis
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia
| | - Wenxing Niu
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; School of Medical Sciences, University of NSW, Kensington, NSW 2052, Australia
| | - Andrea Y Chan
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Scott Kesteven
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia
| | - Jianxin Wu
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia
| | - Siiri E Iismaa
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia
| | - Stephen Vatner
- Cardiovascular Research Institute, Dept. of Cell Biology and Molecular Medicine, Rutgers, New Jersey Medical School, Newark, NJ 07103, USA
| | - Michael Feneley
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia
| | - Robert M Graham
- Victor Chang Cardiac Research Institute, Darlinghurst, NSW 2010, Australia; St.Vincent's Clinical School, University of NSW, Kensington, NSW 2052, Australia.
| |
Collapse
|
15
|
Murakami M, Xu F, Ohba T, Kobayashi T, Inoue Y, Murakami AM, Miyoshi I, Ono K, Tohse N. Requirement of the Ca 2+ channel β 2 subunit for sympathetic PKA phosphorylation. J Pharmacol Sci 2021; 145:253-261. [PMID: 33602505 DOI: 10.1016/j.jphs.2020.12.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2020] [Revised: 12/10/2020] [Accepted: 12/28/2020] [Indexed: 11/29/2022] Open
Abstract
Facilitation of cardiac function in response to signals from the sympathetic nervous system is initiated by the phosphorylation of L-type voltage-dependent Ca2+ channels (VDCCs) by protein kinase A (PKA), which in turn is activated by β-adrenoceptors. Among the five subunits (α1, β, α2/δ, and γ) of VDCCs, the α1 subunit and the family of β subunits are substrates for PKA-catalyzed phosphorylation; however, the subunit responsible for β-adrenergic augmentation of Ca2+ channel function has yet to be specifically identified. Here we show that the VDCC β2 subunit is required for PKA phosphorylation upon sympathetic acceleration. In mice with β2 subunit-null mutations, cardiac muscle contraction in response to isoproterenol was reduced and there was no significant increase in Ca2+ channel currents upon PKA-dependent phosphorylation. These findings indicate that within the sympathetic nervous system the β2 subunit of VDCCs is required for physiological PKA-dependent channel phosphorylation.
Collapse
Affiliation(s)
- Manabu Murakami
- Department of Pharmacology, Hirosaki University Graduate School of Medicine, Aomori, 036-8562, Japan.
| | - Feng Xu
- Department of Pharmacology, Akita University, Graduate School of Medicine, Akita, 010-8543, Japan
| | - Takayoshi Ohba
- Department of Cell Physiology, Akita University, Graduate School of Medicine, Akita, 010-8543, Japan
| | - Takeshi Kobayashi
- Department of Cellular Physiology and Signal Transduction, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Japan
| | - Yoshiro Inoue
- Division of Tumor Animals Institute for Experimental Animals, Institute of Development, Aging and Cancer, Tohoku University School of Medicine, Sendai, Japan
| | - Agnieszka M Murakami
- Department of Pharmacology, Hirosaki University Graduate School of Medicine, Aomori, 036-8562, Japan
| | - Ichiro Miyoshi
- Animal Care Center, Tohoku University School of Medicine, Sendai, Japan
| | - Kyoichi Ono
- Department of Cell Physiology, Akita University, Graduate School of Medicine, Akita, 010-8543, Japan
| | - Noritsugu Tohse
- Department of Cellular Physiology and Signal Transduction, Sapporo Medical University School of Medicine, Sapporo, 060-8556, Japan
| |
Collapse
|
16
|
Roybal D, Hennessey JA, Marx SO. The quest to identify the mechanism underlying adrenergic regulation of cardiac Ca 2+ channels. Channels (Austin) 2020; 14:123-131. [PMID: 32195622 PMCID: PMC7153787 DOI: 10.1080/19336950.2020.1740502] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2020] [Accepted: 02/21/2020] [Indexed: 11/25/2022] Open
Abstract
Activation of protein kinase A by cyclic AMP results in a multi-fold upregulation of CaV1.2 currents in the heart, as originally reported in the 1970's and 1980's. Despite considerable interest and much investment, the molecular mechanisms responsible for this signature modulation remained stubbornly elusive for over 40 years. A key manifestation of this lack of understanding is that while this regulation is readily apparent in heart cells, it has not been possible to reconstitute it in heterologous expression systems. In this review, we describe the efforts of many investigators over the past decades to identify the mechanisms responsible for the β-adrenergic mediated activation of voltage-gated Ca2+ channels in the heart and other tissues.
Collapse
Affiliation(s)
- Daniel Roybal
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, USA
- Department of Pharmacology, Columbia University, Vagelos College of Physicians and Surgeons
| | - Jessica A. Hennessey
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, USA
| | - Steven O. Marx
- Division of Cardiology, Department of Medicine, Columbia University, Vagelos College of Physicians and Surgeons, New York, USA
- Department of Pharmacology, Columbia University, Vagelos College of Physicians and Surgeons
| |
Collapse
|
17
|
Montenarh M, Götz C. Protein kinase CK2 and ion channels (Review). Biomed Rep 2020; 13:55. [PMID: 33082952 PMCID: PMC7560519 DOI: 10.3892/br.2020.1362] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2020] [Accepted: 07/28/2020] [Indexed: 12/18/2022] Open
Abstract
Protein kinase CK2 appears as a tetramer or higher molecular weight oligomer composed of catalytic CK2α, CK2α' subunits and non-catalytic regulatory CK2β subunits or as individual subunits. It is implicated in a variety of different regulatory processes, such as Akt signalling, splicing and DNA repair within eukaryotic cells. The present review evaluates the influence of CK2 on ion channels in the plasma membrane. CK2 phosphorylates platform proteins such as calmodulin and ankyrin G, which bind to channel proteins for a physiological transport to and positioning into the membrane. In addition, CK2 directly phosphorylates a variety of channel proteins directly to regulate opening and closing of the channels. Thus, modulation of CK2 activities by specific inhibitors, by siRNA technology or by CRISPR/Cas technology has an influence on intracellular ion concentrations and thereby on cellular signalling. The physiological regulation of the intracellular ion concentration is important for cell survival and correct intracellular signalling. Disturbance of this regulation results in a variety of different diseases including epilepsy, heart failure, cystic fibrosis and diabetes. Therefore, these effects should be considered when using CK2 inhibition as a treatment option for cancer.
Collapse
Affiliation(s)
- Mathias Montenarh
- Medical Biochemistry and Molecular Biology, Saarland University, D-66424 Homburg, Saarland, Germany
| | - Claudia Götz
- Medical Biochemistry and Molecular Biology, Saarland University, D-66424 Homburg, Saarland, Germany
| |
Collapse
|
18
|
Scheuer R, Philipp SE, Becker A, Nalbach L, Ampofo E, Montenarh M, Götz C. Protein Kinase CK2 Controls Ca V2.1-Dependent Calcium Currents and Insulin Release in Pancreatic β-Cells. Int J Mol Sci 2020; 21:ijms21134668. [PMID: 32630015 PMCID: PMC7370021 DOI: 10.3390/ijms21134668] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2020] [Revised: 06/18/2020] [Accepted: 06/26/2020] [Indexed: 12/21/2022] Open
Abstract
The regulation of insulin biosynthesis and secretion in pancreatic β-cells is essential for glucose homeostasis in humans. Previous findings point to the highly conserved, ubiquitously expressed serine/threonine kinase CK2 as having a negative regulatory impact on this regulation. In the cell culture model of rat pancreatic β-cells INS-1, insulin secretion is enhanced after CK2 inhibition. This enhancement is preceded by a rise in the cytosolic Ca2+ concentration. Here, we identified the serine residues S2362 and S2364 of the voltage-dependent calcium channel CaV2.1 as targets of CK2 phosphorylation. Furthermore, co-immunoprecipitation experiments revealed that CaV2.1 binds to CK2 in vitro and in vivo. CaV2.1 knockdown experiments showed that the increase in the intracellular Ca2+ concentration, followed by an enhanced insulin secretion upon CK2 inhibition, is due to a Ca2+ influx through CaV2.1 channels. In summary, our results point to a modulating role of CK2 in the CaV2.1-mediated exocytosis of insulin.
Collapse
Affiliation(s)
- Rebecca Scheuer
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Kirrberger Str., bldg. 44, D-66424 Homburg, Germany; (R.S.); (M.M.)
| | - Stephan Ernst Philipp
- Department of Experimental and Clinical Pharmacology and Toxicology, Saarland University Kirrberger Str., bldg. 45-46, D-66424 Homburg, Germany; (S.E.P.); (A.B.)
| | - Alexander Becker
- Department of Experimental and Clinical Pharmacology and Toxicology, Saarland University Kirrberger Str., bldg. 45-46, D-66424 Homburg, Germany; (S.E.P.); (A.B.)
| | - Lisa Nalbach
- Institute for Clinical & Experimental Surgery, Saarland University Kirrberger Str., bldg. 65, D-66424 Homburg, Germany; (L.N.); (E.A.)
| | - Emmanuel Ampofo
- Institute for Clinical & Experimental Surgery, Saarland University Kirrberger Str., bldg. 65, D-66424 Homburg, Germany; (L.N.); (E.A.)
| | - Mathias Montenarh
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Kirrberger Str., bldg. 44, D-66424 Homburg, Germany; (R.S.); (M.M.)
| | - Claudia Götz
- Department of Medical Biochemistry and Molecular Biology, Saarland University, Kirrberger Str., bldg. 44, D-66424 Homburg, Germany; (R.S.); (M.M.)
- Correspondence:
| |
Collapse
|
19
|
Dolphin AC, Kadurin I. Fight or flight: The culprit is lurking in the neighbourhood. Cell Calcium 2020; 87:102180. [DOI: 10.1016/j.ceca.2020.102180] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2020] [Revised: 02/10/2020] [Accepted: 02/10/2020] [Indexed: 12/30/2022]
|
20
|
New aspects in cardiac L-type Ca2+ channel regulation. Biochem Soc Trans 2020; 48:39-49. [PMID: 32065210 DOI: 10.1042/bst20190229] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2019] [Revised: 01/24/2020] [Accepted: 01/24/2020] [Indexed: 12/23/2022]
Abstract
Cardiac excitation-contraction coupling is initiated with the influx of Ca2+ ions across the plasma membrane through voltage-gated L-type calcium channels. This process is tightly regulated by modulation of the channel open probability and channel localization. Protein kinase A (PKA) is found in close association with the channel and is one of the main regulators of its function. Whether this kinase is modulating the channel open probability by phosphorylation of key residues or via alternative mechanisms is unclear. This review summarizes recent findings regarding the PKA-mediated channel modulation and will highlight recently discovered regulatory mechanisms that are independent of PKA activity and involve protein-protein interactions and channel localization.
Collapse
|
21
|
|
22
|
Abstract
This review will first describe the importance of Ca2+ entry for function of excitable cells, and the subsequent discovery of voltage-activated calcium conductances in these cells. This finding was rapidly followed by the identification of multiple subtypes of calcium conductance in different tissues. These were initially termed low- and high-voltage activated currents, but were then further subdivided into L-, N-, PQ-, R- and T-type calcium currents on the basis of differing pharmacology, voltage-dependent and kinetic properties, and single channel conductance. Purification of skeletal muscle calcium channels allowed the molecular identification of the pore-forming and auxiliary α2δ, β and ϒ subunits present in these calcium channel complexes. These advances then led to the cloning of the different subunits, which permitted molecular characterisation, to match the cloned channels with physiological function. Studies with knockout and other mutant mice then allowed further investigation of physiological and pathophysiological roles of calcium channels. In terms of pharmacology, cardiovascular L-type channels are targets for the widely used antihypertensive 1,4-dihydropyridines and other calcium channel blockers, N-type channels are a drug target in pain, and α2δ-1 is the therapeutic target of the gabapentinoid drugs, used in neuropathic pain. Recent structural advances have allowed a deeper understanding of Ca2+ permeation through the channel pore and the structure of both the pore-forming and auxiliary subunits. Voltage-gated calcium channels are subject to multiple pathways of modulation by G-protein and second messenger regulation. Furthermore, their trafficking pathways, subcellular localisation and functional specificity are the subjects of active investigation.
Collapse
|
23
|
Lei M, Xu J, Gao Q, Minobe E, Kameyama M, Hao L. PKA phosphorylation of Cav1.2 channel modulates the interaction of calmodulin with the C terminal tail of the channel. J Pharmacol Sci 2018; 137:187-194. [PMID: 30042022 DOI: 10.1016/j.jphs.2018.05.010] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2018] [Revised: 05/18/2018] [Accepted: 05/28/2018] [Indexed: 11/16/2022] Open
Abstract
Activity of cardiac Cav1.2 channels is enhanced by cyclic AMP-PKA signaling. In this study, we studied the effects of PKA phosphorylation on the binding of calmodulin to the fragment peptide of the proximal C-terminal tail of α1C subunit (CT1, a.a. 1509-1789 of guinea-pig). In the pull-down assay, in vitro PKA phosphorylation significantly decreased calmodulin binding to CT1 (61%) at high [Ca2+]. The phosphoresistant (CT1SA) and phosphomimetic (CT1SD) CT1 mutants, in which three PKA sites (Ser1574, 1626, 1699) were mutated to Ala and Asp, respectively, bound with calmodulin with 99% and 65% amount, respectively, compared to that of wild-type CT1. In contrast, at low [Ca2+], calmodulin-binding to CT1SD was higher (33-35%) than that to CT1SA. The distal C-terminal region of α1C (CT3, a.a. 1942-2169) is known to interact with CT1 and inhibit channel activity. CT3 bound to CT1SD was also significantly less than that to CT1SA. In inside-out patch, PKA catalytic subunit (PKAc) facilitated Ca2+ channel activity at both high and low Ca2+ condition. Altogether, these results support the hypothesis that PKA phosphorylation may enhance channel activity and attenuate the Ca2+-dependent inactivation, at least partially, by modulating calmodulin-CT1 interaction both directly and indirectly via CT3-CT1 interaction.
Collapse
Affiliation(s)
- Ming Lei
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, 110122, China; Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan
| | - Jianjun Xu
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan.
| | - Qinghua Gao
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, 110122, China; Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan
| | - Etsuko Minobe
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan
| | - Masaki Kameyama
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, 8-35-1 Sakuragaoka, Kagoshima, 890-8544, Japan
| | - Liying Hao
- Department of Pharmaceutical Toxicology, School of Pharmacy, China Medical University, Shenyang, 110122, China.
| |
Collapse
|
24
|
Yu H, Yuan C, Westenbroek RE, Catterall WA. The AKAP Cypher/Zasp contributes to β-adrenergic/PKA stimulation of cardiac Ca V1.2 calcium channels. J Gen Physiol 2018; 150:883-889. [PMID: 29743299 PMCID: PMC5987873 DOI: 10.1085/jgp.201711818] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2017] [Revised: 09/26/2017] [Accepted: 03/07/2018] [Indexed: 11/24/2022] Open
Abstract
A-kinase anchoring proteins are required for β-adrenergic stimulation of L-type Ca2+ channels in cardiac myocytes, but the molecular species that is responsible for this regulation remains unknown. Yu et al. reveal that Cypher/Zasp is a key regulator of β-adrenergic regulation in cardiac myocytes. Stimulation of the L-type Ca2+ current conducted by CaV1.2 channels in cardiac myocytes by the β-adrenergic/protein kinase A (PKA) signaling pathway requires anchoring of PKA to the CaV1.2 channel by an A-kinase anchoring protein (AKAP). However, the AKAP(s) responsible for regulation in vivo remain unknown. Here, we test the role of the AKAP Cypher/Zasp in β-adrenergic regulation of CaV1.2 channels using physiological studies of cardiac ventricular myocytes from young-adult mice lacking the long form of Cypher/Zasp (LCyphKO mice). These myocytes have increased protein levels of CaV1.2, PKA, and calcineurin. In contrast, the cell surface density of CaV1.2 channels and the basal Ca2+ current conducted by CaV1.2 channels are significantly reduced without substantial changes to kinetics or voltage dependence. β-adrenergic regulation of these L-type Ca2+ currents is also significantly reduced in myocytes from LCyphKO mice, whether calculated as a stimulation ratio or as net-stimulated Ca2+ current. At 100 nM isoproterenol, the net β-adrenergic–Ca2+ current conducted by CaV1.2 channels was reduced to 39 ± 12% of wild type. However, concentration–response curves for β-adrenergic stimulation of myocytes from LCyphKO mice have concentrations that give a half-maximal response similar to those for wild-type mice. These results identify Cypher/Zasp as an important AKAP for β-adrenergic regulation of cardiac CaV1.2 channels. Other AKAPs may work cooperatively with Cypher/Zasp to give the full magnitude of β-adrenergic regulation of CaV1.2 channels observed in vivo.
Collapse
Affiliation(s)
- Haijie Yu
- Department of Pharmacology, University of Washington, Seattle, WA.,State Key Laboratory of Quality Research in Chinese Medicine, Macau University of Science and Technology, Taipa, Macau
| | - Can Yuan
- Department of Pharmacology, University of Washington, Seattle, WA
| | | | | |
Collapse
|
25
|
|
26
|
Norman R, Fuller W, Calaghan S. Caveolae and the cardiac myocyte. CURRENT OPINION IN PHYSIOLOGY 2018. [DOI: 10.1016/j.cophys.2017.08.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/18/2022]
|
27
|
Kumari N, Gaur H, Bhargava A. Cardiac voltage gated calcium channels and their regulation by β-adrenergic signaling. Life Sci 2017; 194:139-149. [PMID: 29288765 DOI: 10.1016/j.lfs.2017.12.033] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2017] [Revised: 12/17/2017] [Accepted: 12/24/2017] [Indexed: 01/08/2023]
Abstract
Voltage-gated calcium channels (VGCCs) are the predominant source of calcium influx in the heart leading to calcium-induced calcium release and ultimately excitation-contraction coupling. In the heart, VGCCs are modulated by the β-adrenergic signaling. Signaling through β-adrenergic receptors (βARs) and modulation of VGCCs by β-adrenergic signaling in the heart are critical signaling and changes to these have been significantly implicated in heart failure. However, data related to calcium channel dysfunction in heart failure is divergent and contradictory ranging from reduced function to no change in the calcium current. Many recent studies have highlighted the importance of functional and spatial microdomains in the heart and that may be the key to answer several puzzling questions. In this review, we have briefly discussed the types of VGCCs found in heart tissues, their structure, and significance in the normal and pathological condition of the heart. More importantly, we have reviewed the modulation of VGCCs by βARs in normal and pathological conditions incorporating functional and structural aspects. There are different types of βARs, each having their own significance in the functioning of the heart. Finally, we emphasize the importance of location of proteins as it relates to their function and modulation by co-signaling molecules. Its implication on the studies of heart failure is speculated.
Collapse
Affiliation(s)
- Neema Kumari
- Ion Channel Biology Lab, Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana 502285, India
| | - Himanshu Gaur
- Ion Channel Biology Lab, Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana 502285, India
| | - Anamika Bhargava
- Ion Channel Biology Lab, Department of Biotechnology, Indian Institute of Technology Hyderabad, Telangana 502285, India.
| |
Collapse
|
28
|
Regulation of microdomain voltage-gated L-type calcium channels in cardiac health and disease. CURRENT OPINION IN PHYSIOLOGY 2017; 2:13-18. [PMID: 29963649 DOI: 10.1016/j.cophys.2017.12.005] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Cav1.2 channels in the heart mediate excitation-contraction (E-C) coupling; tune cardiac excitability; and regulate gene expression. In ventricular myocytes, CaV1.2 channels are predominantly located in t-tubules where they are in proximity to ryanodine receptors to trigger cardiac E-C coupling. A subset of ventricular CaV1.2 channels existing on the surface sarcolemma, including in caveolae, have less well-defined functions. Cardiac CaV1.2 channels are famously up-regulated by protein kinase A as a component of the 'fight-or-flight' response. The molecular details of how this kinase regulates cardiac CaV1.2 channels are controversial and under intensive study. Here, we critically review recent work addressing the putative functions of microdomain cardiac CaV1.2 channels, and their regulation by distinct kinases in health and disease.
Collapse
|
29
|
Cserne Szappanos H, Muralidharan P, Ingley E, Petereit J, Millar AH, Hool LC. Identification of a novel cAMP dependent protein kinase A phosphorylation site on the human cardiac calcium channel. Sci Rep 2017; 7:15118. [PMID: 29123182 PMCID: PMC5680263 DOI: 10.1038/s41598-017-15087-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2017] [Accepted: 10/19/2017] [Indexed: 11/09/2022] Open
Abstract
The "Fight or Flight" response is elicited by extrinsic stress and is necessary in many species for survival. The response involves activation of the β-adrenergic signalling pathway. Surprisingly the mechanisms have remained unresolved. Calcium influx through the cardiac L-type Ca2+ channel (Cav1.2) is absolutely required. Here we identify the functionally relevant site for PKA phosphorylation on the human cardiac L-type Ca2+ channel pore forming α1 subunit using a novel approach. We used a cell free system where we could assess direct effects of PKA on human purified channel protein function reconstituted in proteoliposomes. In addition to assessing open probability of channel protein we used semi-quantitative fluorescent phosphoprotein detection and MS/MS mass spectrometry analysis to demonstrate the PKA specificity of the site. Robust increases in frequency of channel openings were recorded after phosphorylation of the long and short N terminal isoforms and the channel protein with C terminus truncated at aa1504. A protein kinase A anchoring protein (AKAP) was not required. We find the novel PKA phosphorylation site at Ser1458 is in close proximity to the Repeat IV S6 region and induces a conformational change in the channel protein that is necessary and sufficient for increased calcium influx through the channel.
Collapse
Affiliation(s)
| | - Padmapriya Muralidharan
- School of Human Sciences, University of Western Australia, Crawley, Western Australia, Australia
| | - Evan Ingley
- Harry Perkins Institute of Medical Research and Centre for Medical Research, University of Western Australia, Nedlands, Western Australia, Australia.,School of Veterinary and Life Sciences, Murdoch University, Murdoch, Western Australia, Australia
| | - Jakob Petereit
- ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia, Australia
| | - A Harvey Millar
- ARC Centre of Excellence in Plant Energy Biology, University of Western Australia, Crawley, Western Australia, Australia
| | - Livia C Hool
- School of Human Sciences, University of Western Australia, Crawley, Western Australia, Australia. .,Victor Chang Cardiac Research Institute, Darlinghurst, New South Wales, Australia.
| |
Collapse
|
30
|
Proteolytic cleavage and PKA phosphorylation of α 1C subunit are not required for adrenergic regulation of Ca V1.2 in the heart. Proc Natl Acad Sci U S A 2017; 114:9194-9199. [PMID: 28784807 DOI: 10.1073/pnas.1706054114] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Calcium influx through the voltage-dependent L-type calcium channel (CaV1.2) rapidly increases in the heart during "fight or flight" through activation of the β-adrenergic and protein kinase A (PKA) signaling pathway. The precise molecular mechanisms of β-adrenergic activation of cardiac CaV1.2, however, are incompletely known, but are presumed to require phosphorylation of residues in α1C and C-terminal proteolytic cleavage of the α1C subunit. We generated transgenic mice expressing an α1C with alanine substitutions of all conserved serine or threonine, which is predicted to be a potential PKA phosphorylation site by at least one prediction tool, while sparing the residues previously shown to be phosphorylated but shown individually not to be required for β-adrenergic regulation of CaV1.2 current (17-mutant). A second line included these 17 putative sites plus the five previously identified phosphoregulatory sites (22-mutant), thus allowing us to query whether regulation requires their contribution in combination. We determined that acute β-adrenergic regulation does not require any combination of potential PKA phosphorylation sites conserved in human, guinea pig, rabbit, rat, and mouse α1C subunits. We separately generated transgenic mice with inducible expression of proteolytic-resistant α1C Prevention of C-terminal cleavage did not alter β-adrenergic stimulation of CaV1.2 in the heart. These studies definitively rule out a role for all conserved consensus PKA phosphorylation sites in α1C in β-adrenergic stimulation of CaV1.2, and show that phosphoregulatory sites on α1C are not redundant and do not each fractionally contribute to the net stimulatory effect of β-adrenergic stimulation. Further, proteolytic cleavage of α1C is not required for β-adrenergic stimulation of CaV1.2.
Collapse
|
31
|
Poomvanicha M, Matthes J, Domes K, Patrucco E, Angermeier E, Laugwitz KL, Schneider T, Hofmann F. Beta-adrenergic regulation of the heart expressing the Ser1700A/Thr1704A mutated Cav1.2 channel. J Mol Cell Cardiol 2017; 111:10-16. [PMID: 28778765 DOI: 10.1016/j.yjmcc.2017.07.119] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/27/2017] [Revised: 07/25/2017] [Accepted: 07/28/2017] [Indexed: 01/07/2023]
Abstract
Beta-adrenergic stimulation of the heart increases ICa. PKA dependent phosphorylation of several amino acids (among them Ser 1700 and Thr 1704 in the carboxy-terminus of the Cav1.2 α1c subunit) has been implicated as decisive for the β-adrenergic up-regulation of cardiac ICa. Mutation of Ser 1700 and Thr 1704 to alanine results in the Cav1.2PKA_P2-/- mice. Cav1.2PKA_P2-/- mice display reduced cardiac L-type current. Fractional shortening and ejection fraction in the intact animal and ICa in isolated cardiomyocytes (CM) are stimulated by isoproterenol. Cardiac specific expression of the mutated Cav1.2PKA_P2-/- gene reduces Cav1.2 α1c protein concentration, ICa, and the β-adrenergic stimulation of L-type ICa in CMs. Single channels were not detected on the CM surface of the cCav1.2PKA_P2-/- hearts. This outcome supports the notion that S1700/1704 is essential for expression of the Cav1.2 channel and that isoproterenol stimulates ICa in Cav1.2PKA_P2-/- CMs.
Collapse
Affiliation(s)
- Montatip Poomvanicha
- Institut für Pharmakologie und Toxikologie, Technische Universität München, Germany
| | - Jan Matthes
- Institut für Pharmakologie und Toxikologie, University Cologne, Germany
| | - Katrin Domes
- Institut für Pharmakologie und Toxikologie, Technische Universität München, Germany
| | - Enrico Patrucco
- Institut für Pharmakologie und Toxikologie, Technische Universität München, Germany
| | - Elisabeth Angermeier
- Institut für Pharmakologie und Toxikologie, Technische Universität München, Germany
| | - Karl-Ludwig Laugwitz
- I. Medizinische Klinik und Poliklinik (Kardiologie, Angiologie & Pneumologie), Klinikum rechts der Isar-Technische Universität München, Ismaninger Straße 22, 81675 München, Germany
| | - Toni Schneider
- Institut für Neurophysiologie, University Cologne, Germany
| | - Franz Hofmann
- Institut für Pharmakologie und Toxikologie, Technische Universität München, Germany.
| |
Collapse
|
32
|
Aromolaran AS, Boutjdir M. Cardiac Ion Channel Regulation in Obesity and the Metabolic Syndrome: Relevance to Long QT Syndrome and Atrial Fibrillation. Front Physiol 2017; 8:431. [PMID: 28680407 PMCID: PMC5479057 DOI: 10.3389/fphys.2017.00431] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2017] [Accepted: 06/06/2017] [Indexed: 01/03/2023] Open
Abstract
Obesity and its associated metabolic dysregulation leading to metabolic syndrome is an epidemic that poses a significant public health problem. More than one-third of the world population is overweight or obese leading to enhanced risk of cardiovascular disease (CVD) incidence and mortality. Obesity predisposes to atrial fibrillation, ventricular, and supraventricular arrhythmias; conditions that are underlain by dysfunction in electrical activity of the heart. To date, current therapeutic options for cardiomyopathy of obesity are limited, suggesting that there is considerable room for development of therapeutic interventions with novel mechanisms of action that will help normalize rhythm in obese patients. Emerging candidates for modulation by obesity are cardiac ion channels and Ca handling proteins. However, the underlying molecular mechanisms of the impact of obesity on these channels/Ca handling proteins remain incompletely understood. Obesity is marked by accumulation of adipose tissue associated with a variety of adverse adaptations including dyslipidemia (or abnormal levels of serum free fatty acids), increased secretion of pro-inflammatory cytokines, fibrosis, hyperglycemia, and insulin resistance, that will cause electrical remodeling and thus predispose to arrhythmias. Further, adipose tissue is also associated with the accumulation of subcutaneous and visceral fat, which are marked by distinct signaling mechanisms. Thus, there may also be functional differences in the outcome of regional distribution of fat deposits on ion channel/Ca handling proteins expression. Evaluating alterations in their functional expression in obesity will lead to progress in the knowledge about the mechanisms responsible for obesity-related arrhythmias. These advances are likely to reveal new targets for pharmacological modulation. The objective of this article is to review cardiac ion channel/Ca handling proteins remodeling that predispose to arrhythmias. Understanding how obesity and related mechanisms lead to cardiac electrical remodeling is likely to have a significant medical and economic impact.
Collapse
Affiliation(s)
- Ademuyiwa S Aromolaran
- Cardiovascular Research Program, VA New York Harbor Healthcare SystemBrooklyn, NY, United States.,Departments of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Medical CenterBrooklyn, NY, United States
| | - Mohamed Boutjdir
- Cardiovascular Research Program, VA New York Harbor Healthcare SystemBrooklyn, NY, United States.,Departments of Medicine, Cell Biology and Pharmacology, State University of New York Downstate Medical CenterBrooklyn, NY, United States.,Department of Medicine, New York University School of MedicineNew York, NY, United States
| |
Collapse
|
33
|
Lyu L, Gao Q, Xu J, Minobe E, Zhu T, Kameyama M. A new interaction between proximal and distal C-terminus of Cav1.2 channels. J Pharmacol Sci 2017; 133:240-246. [DOI: 10.1016/j.jphs.2017.03.002] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Revised: 02/16/2017] [Accepted: 03/03/2017] [Indexed: 11/16/2022] Open
|
34
|
Oz S, Pankonien I, Belkacemi A, Flockerzi V, Klussmann E, Haase H, Dascal N. Protein kinase A regulates C-terminally truncated Ca V 1.2 in Xenopus oocytes: roles of N- and C-termini of the α 1C subunit. J Physiol 2017; 595:3181-3202. [PMID: 28194788 DOI: 10.1113/jp274015] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2017] [Accepted: 02/08/2017] [Indexed: 11/08/2022] Open
Abstract
KEY POINTS β-Adrenergic stimulation enhances Ca2+ entry via L-type CaV 1.2 channels, causing stronger contraction of cardiac muscle cells. The signalling pathway involves activation of protein kinase A (PKA), but the molecular details of PKA regulation of CaV 1.2 remain controversial despite extensive research. We show that PKA regulation of CaV 1.2 can be reconstituted in Xenopus oocytes when the distal C-terminus (dCT) of the main subunit, α1C , is truncated. The PKA upregulation of CaV 1.2 does not require key factors previously implicated in this mechanism: the clipped dCT, the A kinase-anchoring protein 15 (AKAP15), the phosphorylation sites S1700, T1704 and S1928, or the β subunit of CaV 1.2. The gating element within the initial segment of the N-terminus of the cardiac isoform of α1C is essential for the PKA effect. We propose that the regulation described here is one of two or several mechanisms that jointly mediate the PKA regulation of CaV 1.2 in the heart. ABSTRACT β-Adrenergic stimulation enhances Ca2+ currents via L-type, voltage-gated CaV 1.2 channels, strengthening cardiac contraction. The signalling via β-adrenergic receptors (β-ARs) involves elevation of cyclic AMP (cAMP) levels and activation of protein kinase A (PKA). However, how PKA affects the channel remains controversial. Recent studies in heterologous systems and genetically engineered mice stress the importance of the post-translational proteolytic truncation of the distal C-terminus (dCT) of the main (α1C ) subunit. Here, we successfully reconstituted the cAMP/PKA regulation of the dCT-truncated CaV 1.2 in Xenopus oocytes, which previously failed with the non-truncated α1C . cAMP and the purified catalytic subunit of PKA, PKA-CS, injected into intact oocytes, enhanced CaV 1.2 currents by ∼40% (rabbit α1C ) to ∼130% (mouse α1C ). PKA blockers were used to confirm specificity and the need for dissociation of the PKA holoenzyme. The regulation persisted in the absence of the clipped dCT (as a separate protein), the A kinase-anchoring protein AKAP15, and the phosphorylation sites S1700 and T1704, previously proposed as essential for the PKA effect. The CaV β2b subunit was not involved, as suggested by extensive mutagenesis. Using deletion/chimeric mutagenesis, we have identified the initial segment of the cardiac long-N-terminal isoform of α1C as a previously unrecognized essential element involved in PKA regulation. We propose that the observed regulation, that exclusively involves the α1C subunit, is one of several mechanisms underlying the overall PKA action on CaV 1.2 in the heart. We hypothesize that PKA is acting on CaV 1.2, in part, by affecting a structural 'scaffold' comprising the interacting cytosolic N- and C-termini of α1C .
Collapse
Affiliation(s)
- Shimrit Oz
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, 6997801, Israel
| | - Ines Pankonien
- Max Delbrück Center for Molecular Medicine (MDC), D-13092, and the German Centre for Cardiovascular Research (DZHK) partner site, Berlin, Germany
| | - Anouar Belkacemi
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421, Homburg, Germany
| | - Veit Flockerzi
- Experimentelle und Klinische Pharmakologie und Toxikologie, Universität des Saarlandes, 66421, Homburg, Germany
| | - Enno Klussmann
- Max Delbrück Center for Molecular Medicine (MDC), D-13092, and the German Centre for Cardiovascular Research (DZHK) partner site, Berlin, Germany
| | - Hannelore Haase
- Max Delbrück Center for Molecular Medicine (MDC), D-13092, and the German Centre for Cardiovascular Research (DZHK) partner site, Berlin, Germany
| | - Nathan Dascal
- Department of Physiology and Pharmacology, Sackler School of Medicine, Tel Aviv University, Tel Aviv, 6997801, Israel.,Sagol School of Neuroscience, Tel Aviv University, Tel Aviv, 6997801, Israel
| |
Collapse
|
35
|
Minobe E, Mori MX, Kameyama M. Calmodulin and ATP support activity of the Cav1.2 channel through dynamic interactions with the channel. J Physiol 2017; 595:2465-2477. [PMID: 28130847 PMCID: PMC5390892 DOI: 10.1113/jp273736] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2016] [Accepted: 01/06/2017] [Indexed: 11/08/2022] Open
Abstract
Key points Cav1.2 channels maintain activity through interactions with calmodulin (CaM). In this study, activities of the Cav1.2 channel (α1C) and of mutant‐derivatives, C‐terminal deleted (α1CΔ) and α1CΔ linked with CaM (α1CΔCaM), were compared in the inside‐out mode. α1CΔ with CaM, but not without CaM, and α1CΔCaM were active, suggesting that CaM induced channel activity through a dynamic interaction with the channel, even without the distal C‐tail. ATP induced α1C activity with CaM and enhanced activity of the mutant channels. Okadaic acid mimicked the effect of ATP on the wildtype but not mutant channels. These results supported the hypothesis that CaM and ATP maintain activity of Cav1.2 channels through their dynamic interactions. ATP effects involve mechanisms both related and unrelated to channel phosphorylation. CaM‐linked channels are useful tools for investigating Cav1.2 channels in the inside‐out mode; the fast run‐down is prevented by only ATP and the slow run‐down is nearly absent.
Abstract Calmodulin (CaM) plays a critical role in regulation of Cav1.2 Ca2+ channels. CaM binds to the channel directly, maintaining channel activity and regulating it in a Ca2+‐dependent manner. To explore the molecular mechanisms involved, we compared the activity of the wildtype channel (α1C) and mutant derivatives, C‐terminal deleted (α1C∆) and α1C∆ linked to CaM (α1C∆CaM). These were co‐expressed with β2a and α2δ subunits in HEK293 cells. In the inside‐out mode, α1C and α1C∆ showed minimal open‐probabilities in a basic internal solution (run‐down), whereas α1C∆ with CaM and α1C∆CaM maintained detectable channel activity, confirming that CaM was necessary, but not sufficient, for channel activity. Previously, we reported that ATP was required to maintain channel activity of α1C. Unlike α1C, the mutant channels did not require ATP for activation in the early phase (3–5 min). However, α1C∆ with CaM + ATP and α1C∆CaM with ATP maintained activity, even in the late phase (after 7–9 min). These results suggested that CaM and ATP interacted dynamically with the proximal C‐terminal tail of the channel and, thereby, produced channel activity. In addition, okadaic acid, a protein phosphatase inhibitor, could substitute for the effects of ATP on α1C but not on the mutant channels. These results supported the hypothesis that CaM and ATP maintain activity of Cav1.2 channels, further indicating that ATP has dual effects. One maintains phosphorylation of the channel and the other becomes apparent when the distal carboxyl‐terminal tail is removed. Cav1.2 channels maintain activity through interactions with calmodulin (CaM). In this study, activities of the Cav1.2 channel (α1C) and of mutant‐derivatives, C‐terminal deleted (α1CΔ) and α1CΔ linked with CaM (α1CΔCaM), were compared in the inside‐out mode. α1CΔ with CaM, but not without CaM, and α1CΔCaM were active, suggesting that CaM induced channel activity through a dynamic interaction with the channel, even without the distal C‐tail. ATP induced α1C activity with CaM and enhanced activity of the mutant channels. Okadaic acid mimicked the effect of ATP on the wildtype but not mutant channels. These results supported the hypothesis that CaM and ATP maintain activity of Cav1.2 channels through their dynamic interactions. ATP effects involve mechanisms both related and unrelated to channel phosphorylation. CaM‐linked channels are useful tools for investigating Cav1.2 channels in the inside‐out mode; the fast run‐down is prevented by only ATP and the slow run‐down is nearly absent.
Collapse
Affiliation(s)
- Etsuko Minobe
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan
| | - Masayuki X Mori
- Laboratory of Molecular Biology, Department of Synthetic Chemistry and Biological Chemistry, Graduate School of Engineering, Kyoto University, Kyoto, 615-8510, Japan
| | - Masaki Kameyama
- Department of Physiology, Graduate School of Medical and Dental Sciences, Kagoshima University, Kagoshima, 890-8544, Japan
| |
Collapse
|
36
|
Abstract
Unique to striated muscle cells, transverse tubules (t-tubules) are membrane organelles that consist of sarcolemma penetrating into the myocyte interior, forming a highly branched and interconnected network. Mature t-tubule networks are found in mammalian ventricular cardiomyocytes, with the transverse components of t-tubules occurring near sarcomeric z-discs. Cardiac t-tubules contain membrane microdomains enriched with ion channels and signaling molecules. The microdomains serve as key signaling hubs in regulation of cardiomyocyte function. Dyad microdomains formed at the junctional contact between t-tubule membrane and neighboring sarcoplasmic reticulum are critical in calcium signaling and excitation-contraction coupling necessary for beat-to-beat heart contraction. In this review, we provide an overview of the current knowledge in gross morphology and structure, membrane and protein composition, and function of the cardiac t-tubule network. We also review in detail current knowledge on the formation of functional membrane subdomains within t-tubules, with a particular focus on the cardiac dyad microdomain. Lastly, we discuss the dynamic nature of t-tubules including membrane turnover, trafficking of transmembrane proteins, and the life cycles of membrane subdomains such as the cardiac BIN1-microdomain, as well as t-tubule remodeling and alteration in diseased hearts. Understanding cardiac t-tubule biology in normal and failing hearts is providing novel diagnostic and therapeutic opportunities to better treat patients with failing hearts.
Collapse
Affiliation(s)
- TingTing Hong
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California; and Department of Medicine, University of California Los Angeles, Los Angeles, California
| | - Robin M Shaw
- Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, California; and Department of Medicine, University of California Los Angeles, Los Angeles, California
| |
Collapse
|
37
|
Qian H, Patriarchi T, Price JL, Matt L, Lee B, Nieves-Cintrón M, Buonarati OR, Chowdhury D, Nanou E, Nystoriak MA, Catterall WA, Poomvanicha M, Hofmann F, Navedo MF, Hell JW. Phosphorylation of Ser1928 mediates the enhanced activity of the L-type Ca2+ channel Cav1.2 by the β2-adrenergic receptor in neurons. Sci Signal 2017; 10:10/463/eaaf9659. [PMID: 28119465 DOI: 10.1126/scisignal.aaf9659] [Citation(s) in RCA: 79] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
The L-type Ca2+ channel Cav1.2 controls multiple functions throughout the body including heart rate and neuronal excitability. It is a key mediator of fight-or-flight stress responses triggered by a signaling pathway involving β-adrenergic receptors (βARs), cyclic adenosine monophosphate (cAMP), and protein kinase A (PKA). PKA readily phosphorylates Ser1928 in Cav1.2 in vitro and in vivo, including in rodents and humans. However, S1928A knock-in (KI) mice have normal PKA-mediated L-type channel regulation in the heart, indicating that Ser1928 is not required for regulation of cardiac Cav1.2 by PKA in this tissue. We report that augmentation of L-type currents by PKA in neurons was absent in S1928A KI mice. Furthermore, S1928A KI mice failed to induce long-term potentiation in response to prolonged theta-tetanus (PTT-LTP), a form of synaptic plasticity that requires Cav1.2 and enhancement of its activity by the β2-adrenergic receptor (β2AR)-cAMP-PKA cascade. Thus, there is an unexpected dichotomy in the control of Cav1.2 by PKA in cardiomyocytes and hippocampal neurons.
Collapse
Affiliation(s)
- Hai Qian
- Department of Pharmacology, University of Iowa, Iowa City, IA 52242-1109, USA
| | - Tommaso Patriarchi
- Department of Pharmacology, University of California, Davis, CA 95616-8636, USA
| | - Jennifer L Price
- Department of Pharmacology, University of California, Davis, CA 95616-8636, USA
| | - Lucas Matt
- Department of Pharmacology, University of California, Davis, CA 95616-8636, USA
| | - Boram Lee
- Department of Pharmacology, University of California, Davis, CA 95616-8636, USA
| | | | - Olivia R Buonarati
- Department of Pharmacology, University of California, Davis, CA 95616-8636, USA
| | | | - Evanthia Nanou
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280, USA
| | - Matthew A Nystoriak
- Department of Pharmacology, University of California, Davis, CA 95616-8636, USA
| | - William A Catterall
- Department of Pharmacology, University of Washington, Seattle, WA 98195-7280, USA
| | - Montatip Poomvanicha
- Department of Pharmacology and Toxicology, Technical University of Munich, D-80802 Munich, Germany
| | - Franz Hofmann
- Department of Pharmacology and Toxicology, Technical University of Munich, D-80802 Munich, Germany
| | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, CA 95616-8636, USA.
| | - Johannes W Hell
- Department of Pharmacology, University of Iowa, Iowa City, IA 52242-1109, USA. .,Department of Pharmacology, University of California, Davis, CA 95616-8636, USA
| |
Collapse
|
38
|
Loss of β-adrenergic-stimulated phosphorylation of CaV1.2 channels on Ser1700 leads to heart failure. Proc Natl Acad Sci U S A 2016; 113:E7976-E7985. [PMID: 27864509 DOI: 10.1073/pnas.1617116113] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
L-type Ca2+ currents conducted by voltage-gated calcium channel 1.2 (CaV1.2) initiate excitation-contraction coupling in the heart, and altered expression of CaV1.2 causes heart failure in mice. Here we show unexpectedly that reducing β-adrenergic regulation of CaV1.2 channels by mutation of a single PKA site, Ser1700, in the proximal C-terminal domain causes reduced contractile function, cardiac hypertrophy, and heart failure without changes in expression, localization, or function of the CaV1.2 protein in the mutant mice (SA mice). These deficits were aggravated with aging. Dual mutation of Ser1700 and a nearby casein-kinase II site (Thr1704) caused accelerated hypertrophy, heart failure, and death in mice with these mutations (STAA mice). Cardiac hypertrophy was increased by voluntary exercise and by persistent β-adrenergic stimulation. PKA expression was increased, and PKA sites Ser2808 in ryanodine receptor type-2, Ser16 in phospholamban, and Ser23/24 in troponin-I were hyperphosphorylated in SA mice, whereas phosphorylation of substrates for calcium/calmodulin-dependent protein kinase II was unchanged. The Ca2+ pool in the sarcoplasmic reticulum was increased, the activity of calcineurin was elevated, and calcineurin inhibitors improved contractility and ameliorated cardiac hypertrophy. Cardio-specific expression of the SA mutation also caused reduced contractility and hypertrophy. These results suggest engagement of compensatory mechanisms, which initially may enhance the contractility of individual myocytes but eventually contribute to an increased sensitivity to cardiovascular stress and to heart failure in vivo. Our results demonstrate that normal regulation of CaV1.2 channels by phosphorylation of Ser1700 in cardiomyocytes is required for cardiovascular homeostasis and normal physiological regulation in vivo.
Collapse
|
39
|
Huang J, Zamponi GW. Regulation of voltage gated calcium channels by GPCRs and post-translational modification. Curr Opin Pharmacol 2016; 32:1-8. [PMID: 27768908 DOI: 10.1016/j.coph.2016.10.001] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2016] [Revised: 10/03/2016] [Accepted: 10/04/2016] [Indexed: 01/31/2023]
Abstract
Calcium entry via voltage gated calcium channels mediates a wide range of physiological functions, whereas calcium channel dysregulation has been associated with numerous pathophysiological conditions. There are myriad cell signaling pathways that act on voltage gated calcium channels to fine tune their activities and to regulate their cell surface expression. These regulatory mechanisms include the activation of G protein-coupled receptors and downstream phosphorylation events, and their control over calcium channel trafficking through direct physical interactions. Calcium channels also undergo post-translational modifications that alter both function and density of the channels in the plasma membrane. Here we focus on select aspects of these regulatory mechanisms and highlight recent developments.
Collapse
Affiliation(s)
- Junting Huang
- Department of Physiology and Pharmacology, Alberta Children's Hospital Research Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada
| | - Gerald W Zamponi
- Department of Physiology and Pharmacology, Alberta Children's Hospital Research Institute and Hotchkiss Brain Institute, Cumming School of Medicine, University of Calgary, Calgary, Canada.
| |
Collapse
|
40
|
Catterall WA. Regulation of Cardiac Calcium Channels in the Fight-or-Flight Response. Curr Mol Pharmacol 2016; 8:12-21. [PMID: 25966697 DOI: 10.2174/1874467208666150507103417] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Revised: 02/17/2015] [Accepted: 04/20/2015] [Indexed: 11/22/2022]
Abstract
Intracellular calcium transients generated by activation of voltage-gated calcium (CaV) channels generate local signals, which initiate physiological processes such as secretion, synaptic transmission, and excitation-contraction coupling. Regulation of calcium entry through CaV channels is crucial for control of these physiological processes. In this article, I review experimental results that have emerged over several years showing that cardiac CaV1.2 channels form a local signaling complex, in which their proteolytically processed distal C-terminal domain, an A-Kinase Anchoring Protein, and cyclic AMP-dependent protein kinase (PKA) interact directly with the transmembrane core of the ion channel through the proximal C-terminal domain. This signaling complex is the substrate for β-adrenergic up-regulation of the CaV1.2 channel in the heart during the fight-or-flight response. Protein phosphorylation of two sites at the interface between the distal and proximal C-terminal domains contributes importantly to control of basal CaV1.2 channel activity, and phosphorylation of Ser1700 by PKA at that interface up-regulates CaV1.2 activity in response to β-adrenergic signaling. Thus, the intracellular C-terminal domain of CaV1.2 channels serves as a signaling platform, mediating beat-to-beat physiological regulation of channel activity and up-regulation by β-adrenergic signaling in the fight-or-flight response.
Collapse
Affiliation(s)
- William A Catterall
- Department of Pharmacology, Box 357280, University of Washington, Seattle, WA 98195-7280.
| |
Collapse
|
41
|
Dolphin AC. Voltage-gated calcium channels and their auxiliary subunits: physiology and pathophysiology and pharmacology. J Physiol 2016; 594:5369-90. [PMID: 27273705 PMCID: PMC5043047 DOI: 10.1113/jp272262] [Citation(s) in RCA: 208] [Impact Index Per Article: 26.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Accepted: 05/09/2016] [Indexed: 12/22/2022] Open
Abstract
Voltage‐gated calcium channels are essential players in many physiological processes in excitable cells. There are three main subdivisions of calcium channel, defined by the pore‐forming α1 subunit, the CaV1, CaV2 and CaV3 channels. For all the subtypes of voltage‐gated calcium channel, their gating properties are key for the precise control of neurotransmitter release, muscle contraction and cell excitability, among many other processes. For the CaV1 and CaV2 channels, their ability to reach their required destinations in the cell membrane, their activation and the fine tuning of their biophysical properties are all dramatically influenced by the auxiliary subunits that associate with them. Furthermore, there are many diseases, both genetic and acquired, involving voltage‐gated calcium channels. This review will provide a general introduction and then concentrate particularly on the role of auxiliary α2δ subunits in both physiological and pathological processes involving calcium channels, and as a therapeutic target.
![]()
Collapse
Affiliation(s)
- Annette C Dolphin
- Department of Neuroscience, Physiology and Pharmacology, University College London, Gower Street, London, WC1E 6BT, UK.
| |
Collapse
|
42
|
K(ATP) channel gain-of-function leads to increased myocardial L-type Ca(2+) current and contractility in Cantu syndrome. Proc Natl Acad Sci U S A 2016; 113:6773-8. [PMID: 27247394 DOI: 10.1073/pnas.1606465113] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023] Open
Abstract
Cantu syndrome (CS) is caused by gain-of-function (GOF) mutations in genes encoding pore-forming (Kir6.1, KCNJ8) and accessory (SUR2, ABCC9) KATP channel subunits. We show that patients with CS, as well as mice with constitutive (cGOF) or tamoxifen-induced (icGOF) cardiac-specific Kir6.1 GOF subunit expression, have enlarged hearts, with increased ejection fraction and increased contractility. Whole-cell voltage-clamp recordings from cGOF or icGOF ventricular myocytes (VM) show increased basal L-type Ca(2+) current (LTCC), comparable to that seen in WT VM treated with isoproterenol. Mice with vascular-specific expression (vGOF) show left ventricular dilation as well as less-markedly increased LTCC. Increased LTCC in KATP GOF models is paralleled by changes in phosphorylation of the pore-forming α1 subunit of the cardiac voltage-gated calcium channel Cav1.2 at Ser1928, suggesting enhanced protein kinase activity as a potential link between increased KATP current and CS cardiac pathophysiology.
Collapse
|
43
|
Patriarchi T, Qian H, Di Biase V, Malik ZA, Chowdhury D, Price JL, Hammes EA, Buonarati OR, Westenbroek RE, Catterall WA, Hofmann F, Xiang YK, Murphy GG, Chen CY, Navedo MF, Hell JW. Phosphorylation of Cav1.2 on S1928 uncouples the L-type Ca2+ channel from the β2 adrenergic receptor. EMBO J 2016; 35:1330-45. [PMID: 27103070 DOI: 10.15252/embj.201593409] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2015] [Accepted: 03/24/2016] [Indexed: 01/07/2023] Open
Abstract
Agonist-triggered downregulation of β-adrenergic receptors (ARs) constitutes vital negative feedback to prevent cellular overexcitation. Here, we report a novel downregulation of β2AR signaling highly specific for Cav1.2. We find that β2-AR binding to Cav1.2 residues 1923-1942 is required for β-adrenergic regulation of Cav1.2. Despite the prominence of PKA-mediated phosphorylation of Cav1.2 S1928 within the newly identified β2AR binding site, its physiological function has so far escaped identification. We show that phosphorylation of S1928 displaces the β2AR from Cav1.2 upon β-adrenergic stimulation rendering Cav1.2 refractory for several minutes from further β-adrenergic stimulation. This effect is lost in S1928A knock-in mice. Although AMPARs are clustered at postsynaptic sites like Cav1.2, β2AR association with and regulation of AMPARs do not show such dissociation. Accordingly, displacement of the β2AR from Cav1.2 is a uniquely specific desensitization mechanism of Cav1.2 regulation by highly localized β2AR/cAMP/PKA/S1928 signaling. The physiological implications of this mechanism are underscored by our finding that LTP induced by prolonged theta tetanus (PTT-LTP) depends on Cav1.2 and its regulation by channel-associated β2AR.
Collapse
Affiliation(s)
| | - Hai Qian
- Department of Pharmacology, University of Iowa, Iowa City, IA, USA
| | | | - Zulfiquar A Malik
- Department of Pharmacology, University of California, Davis, CA, USA Department of Pharmacology, University of Iowa, Iowa City, IA, USA
| | | | - Jennifer L Price
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Erik A Hammes
- Department of Pharmacology, University of California, Davis, CA, USA
| | | | | | | | - Franz Hofmann
- Department of Pharmacology and Toxicology, Technical University of Munich, Munich, Germany
| | - Yang K Xiang
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Geoffrey G Murphy
- Department of Molecular & Integrative Physiology, Molecular & Behavioral Neuroscience Institute University of Michigan, Ann Arbor, MI, USA
| | - Chao-Ye Chen
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Manuel F Navedo
- Department of Pharmacology, University of California, Davis, CA, USA
| | - Johannes W Hell
- Department of Pharmacology, University of California, Davis, CA, USA Department of Pharmacology, University of Iowa, Iowa City, IA, USA
| |
Collapse
|
44
|
Fu Y, Shaw SA, Naami R, Vuong CL, Basheer WA, Guo X, Hong T. Isoproterenol Promotes Rapid Ryanodine Receptor Movement to Bridging Integrator 1 (BIN1)-Organized Dyads. Circulation 2016; 133:388-97. [PMID: 26733606 DOI: 10.1161/circulationaha.115.018535] [Citation(s) in RCA: 58] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/16/2015] [Accepted: 12/21/2015] [Indexed: 11/16/2022]
Abstract
BACKGROUND The key pathophysiology of human acquired heart failure is impaired calcium transient, which is initiated at dyads consisting of ryanodine receptors (RyRs) at sarcoplasmic reticulum apposing CaV1.2 channels at t-tubules. Sympathetic tone regulates myocardial calcium transients through β-adrenergic receptor (β-AR)-mediated phosphorylation of dyadic proteins. Phosphorylated RyRs (P-RyR) have increased calcium sensitivity and open probability, amplifying calcium transient at a cost of receptor instability. Given that bridging integrator 1 (BIN1) organizes t-tubule microfolds and facilitates CaV1.2 delivery, we explored whether β-AR-regulated RyRs are also affected by BIN1. METHODS AND RESULTS Isolated adult mouse hearts or cardiomyocytes were perfused for 5 minutes with the β-AR agonist isoproterenol (1 µmol/L) or the blockers CGP+ICI (baseline). Using biochemistry and superresolution fluorescent imaging, we identified that BIN1 clusters P-RyR and CaV1.2. Acute β-AR activation increases coimmunoprecipitation between P-RyR and cardiac spliced BIN1+13+17 (with exons 13 and 17). Isoproterenol redistributes BIN1 to t-tubules, recruiting P-RyRs and improving the calcium transient. In cardiac-specific Bin1 heterozygote mice, isoproterenol fails to concentrate BIN1 to t-tubules, impairing P-RyR recruitment. The resultant accumulation of uncoupled P-RyRs increases the incidence of spontaneous calcium release. In human hearts with end-stage ischemic cardiomyopathy, we find that BIN1 is also 50% reduced, with diminished P-RyR association with BIN1. CONCLUSIONS On β-AR activation, reorganization of BIN1-induced microdomains recruits P-RyR into dyads, increasing the calcium transient while preserving electric stability. When BIN1 is reduced as in human acquired heart failure, acute stress impairs microdomain formation, limiting contractility and promoting arrhythmias.
Collapse
Affiliation(s)
- Ying Fu
- From Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (Y.F., S.A.S., R.N., C.L.V., W.A.B., T.H.); Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA (X.G.); and Departments of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, CA (T.H.)
| | - Seiji A Shaw
- From Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (Y.F., S.A.S., R.N., C.L.V., W.A.B., T.H.); Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA (X.G.); and Departments of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, CA (T.H.)
| | - Robert Naami
- From Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (Y.F., S.A.S., R.N., C.L.V., W.A.B., T.H.); Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA (X.G.); and Departments of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, CA (T.H.)
| | - Caresse L Vuong
- From Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (Y.F., S.A.S., R.N., C.L.V., W.A.B., T.H.); Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA (X.G.); and Departments of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, CA (T.H.)
| | - Wassim A Basheer
- From Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (Y.F., S.A.S., R.N., C.L.V., W.A.B., T.H.); Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA (X.G.); and Departments of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, CA (T.H.)
| | - Xiuqing Guo
- From Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (Y.F., S.A.S., R.N., C.L.V., W.A.B., T.H.); Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA (X.G.); and Departments of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, CA (T.H.)
| | - TingTing Hong
- From Cedars-Sinai Heart Institute, Cedars-Sinai Medical Center, Los Angeles, CA (Y.F., S.A.S., R.N., C.L.V., W.A.B., T.H.); Institute for Translational Genomics and Population Sciences, Department of Pediatrics, Los Angeles Biomedical Research Institute at Harbor-UCLA Medical Center, Torrance, CA (X.G.); and Departments of Medicine, Cedars-Sinai Medical Center and UCLA, Los Angeles, CA (T.H.).
| |
Collapse
|
45
|
Hoang-Trong TM, Ullah A, Jafri MS. Calcium Sparks in the Heart: Dynamics and Regulation. ACTA ACUST UNITED AC 2015; 6:203-214. [PMID: 27212876 DOI: 10.2147/rrb.s61495] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
Calcium (Ca2+) plays a central role in the contraction of the heart. It is the bi-directional link between electrical excitation of the heart and contraction. Electrical excitation initiates Ca2+influx across the sarcolemma and T-tubular membrane that triggered calcium release from the sarcoplasmic reticulum. Ca2+sparks are the elementary events of calcium release from the sarcoplasmic reticulum. Therefore, understanding the dynamics of Ca2+sparks is essential for understanding the function of the heart. To this end, numerous experimental and computational studies have focused on this topic, exploring the mechanisms of calcium spark initiation, termination, and regulation and what role these play in normal and patho-physiology. The proper understanding of Ca2+ spark regulation and dynamics serves as the foundation for our insights into a multitude of pathological conditions may develop that can be the result of structural and/or functional changes at the cellular or subcellular level. Computational modeling of Ca2+ spark dynamics has proven to be a useful tool to understand Ca2+ spark dynamics. This review addresses our current understanding of Ca2+ sparks and how synchronized SR Ca2+ release, in which Ca2+ sparks is a major pathway, is linked to the different cardiac diseases, especially arrhythmias.
Collapse
Affiliation(s)
- Tuan M Hoang-Trong
- Department of Molecular Neuroscience, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA 22030
| | - Aman Ullah
- Department of Molecular Neuroscience, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA 22030
| | - M Saleet Jafri
- Department of Molecular Neuroscience, Krasnow Institute for Advanced Study, George Mason University, Fairfax, VA 22030; Biomedical Engineering and Technology, University of Maryland, Baltimore, MD 20201
| |
Collapse
|
46
|
Affiliation(s)
- William A Catterall
- Department of Pharmacology, University of Washington, Seattle, Washington 98195-7280.
| |
Collapse
|
47
|
Zamponi GW, Striessnig J, Koschak A, Dolphin AC. The Physiology, Pathology, and Pharmacology of Voltage-Gated Calcium Channels and Their Future Therapeutic Potential. Pharmacol Rev 2015; 67:821-70. [PMID: 26362469 PMCID: PMC4630564 DOI: 10.1124/pr.114.009654] [Citation(s) in RCA: 704] [Impact Index Per Article: 78.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Voltage-gated calcium channels are required for many key functions in the body. In this review, the different subtypes of voltage-gated calcium channels are described and their physiologic roles and pharmacology are outlined. We describe the current uses of drugs interacting with the different calcium channel subtypes and subunits, as well as specific areas in which there is strong potential for future drug development. Current therapeutic agents include drugs targeting L-type Ca(V)1.2 calcium channels, particularly 1,4-dihydropyridines, which are widely used in the treatment of hypertension. T-type (Ca(V)3) channels are a target of ethosuximide, widely used in absence epilepsy. The auxiliary subunit α2δ-1 is the therapeutic target of the gabapentinoid drugs, which are of value in certain epilepsies and chronic neuropathic pain. The limited use of intrathecal ziconotide, a peptide blocker of N-type (Ca(V)2.2) calcium channels, as a treatment of intractable pain, gives an indication that these channels represent excellent drug targets for various pain conditions. We describe how selectivity for different subtypes of calcium channels (e.g., Ca(V)1.2 and Ca(V)1.3 L-type channels) may be achieved in the future by exploiting differences between channel isoforms in terms of sequence and biophysical properties, variation in splicing in different target tissues, and differences in the properties of the target tissues themselves in terms of membrane potential or firing frequency. Thus, use-dependent blockers of the different isoforms could selectively block calcium channels in particular pathologies, such as nociceptive neurons in pain states or in epileptic brain circuits. Of important future potential are selective Ca(V)1.3 blockers for neuropsychiatric diseases, neuroprotection in Parkinson's disease, and resistant hypertension. In addition, selective or nonselective T-type channel blockers are considered potential therapeutic targets in epilepsy, pain, obesity, sleep, and anxiety. Use-dependent N-type calcium channel blockers are likely to be of therapeutic use in chronic pain conditions. Thus, more selective calcium channel blockers hold promise for therapeutic intervention.
Collapse
Affiliation(s)
- Gerald W Zamponi
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada (G.W.Z.); Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria (J.S., A.K.); and Department of Neuroscience, Physiology, and Pharmacology, Division of Biosciences, University College London, London, United Kingdom (A.C.D.)
| | - Joerg Striessnig
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada (G.W.Z.); Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria (J.S., A.K.); and Department of Neuroscience, Physiology, and Pharmacology, Division of Biosciences, University College London, London, United Kingdom (A.C.D.)
| | - Alexandra Koschak
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada (G.W.Z.); Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria (J.S., A.K.); and Department of Neuroscience, Physiology, and Pharmacology, Division of Biosciences, University College London, London, United Kingdom (A.C.D.)
| | - Annette C Dolphin
- Department of Physiology and Pharmacology, Cumming School of Medicine, University of Calgary, Calgary, Alberta, Canada (G.W.Z.); Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck, Innsbruck, Austria (J.S., A.K.); and Department of Neuroscience, Physiology, and Pharmacology, Division of Biosciences, University College London, London, United Kingdom (A.C.D.)
| |
Collapse
|
48
|
Dema A, Perets E, Schulz MS, Deák VA, Klussmann E. Pharmacological targeting of AKAP-directed compartmentalized cAMP signalling. Cell Signal 2015; 27:2474-87. [PMID: 26386412 DOI: 10.1016/j.cellsig.2015.09.008] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2015] [Revised: 09/08/2015] [Accepted: 09/14/2015] [Indexed: 01/26/2023]
Abstract
The second messenger cyclic adenosine monophosphate (cAMP) can bind and activate protein kinase A (PKA). The cAMP/PKA system is ubiquitous and involved in a wide array of biological processes and therefore requires tight spatial and temporal regulation. Important components of the safeguard system are the A-kinase anchoring proteins (AKAPs), a heterogeneous family of scaffolding proteins defined by its ability to directly bind PKA. AKAPs tether PKA to specific subcellular compartments, and they bind further interaction partners to create local signalling hubs. The recent discovery of new AKAPs and advances in the field that shed light on the relevance of these hubs for human disease highlight unique opportunities for pharmacological modulation. This review exemplifies how interference with signalling, particularly cAMP signalling, at such hubs can reshape signalling responses and discusses how this could lead to novel pharmacological concepts for the treatment of disease with an unmet medical need such as cardiovascular disease and cancer.
Collapse
Affiliation(s)
- Alessandro Dema
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Ekaterina Perets
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Maike Svenja Schulz
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Veronika Anita Deák
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany
| | - Enno Klussmann
- Max Delbrück Center for Molecular Medicine Berlin in the Helmholtz Association (MDC), Robert-Rössle-Straße 10, 13125 Berlin, Germany; DZHK, German Centre for Cardiovascular Research, Oudenarder Straße 16, 13347 Berlin, Germany.
| |
Collapse
|
49
|
Abstract
In this issue of Cell Reports, Murphy et al. and Dittmer et al. present exciting new insight into the regulation of Ca2+ influx via the L-type Ca2+ channel Cav1.2 and how increased Ca2+ influx translates into localized activation of the nuclear transcription factor NFAT upon depolarization in neurons.
Collapse
Affiliation(s)
- Manuel F Navedo
- Department of Pharmacology, University of California, Davis, CA 95615, USA.
| | - Johannes W Hell
- Department of Pharmacology, University of California, Davis, CA 95615, USA.
| |
Collapse
|
50
|
Scharinger A, Eckrich S, Vandael DH, Schönig K, Koschak A, Hecker D, Kaur G, Lee A, Sah A, Bartsch D, Benedetti B, Lieb A, Schick B, Singewald N, Sinnegger-Brauns MJ, Carbone E, Engel J, Striessnig J. Cell-type-specific tuning of Cav1.3 Ca(2+)-channels by a C-terminal automodulatory domain. Front Cell Neurosci 2015; 9:309. [PMID: 26379493 PMCID: PMC4547004 DOI: 10.3389/fncel.2015.00309] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2015] [Accepted: 07/27/2015] [Indexed: 11/13/2022] Open
Abstract
Cav1.3 L-type Ca(2+)-channel function is regulated by a C-terminal automodulatory domain (CTM). It affects channel binding of calmodulin and thereby tunes channel activity by interfering with Ca(2+)- and voltage-dependent gating. Alternative splicing generates short C-terminal channel variants lacking the CTM resulting in enhanced Ca(2+)-dependent inactivation and stronger voltage-sensitivity upon heterologous expression. However, the role of this modulatory domain for channel function in its native environment is unkown. To determine its functional significance in vivo, we interrupted the CTM with a hemagglutinin tag in mutant mice (Cav1.3DCRD(HA/HA)). Using these mice we provide biochemical evidence for the existence of long (CTM-containing) and short (CTM-deficient) Cav1.3 α1-subunits in brain. The long (HA-labeled) Cav1.3 isoform was present in all ribbon synapses of cochlear inner hair cells. CTM-elimination impaired Ca(2+)-dependent inactivation of Ca(2+)-currents in hair cells but increased it in chromaffin cells, resulting in hyperpolarized resting potentials and reduced pacemaking. CTM disruption did not affect hearing thresholds. We show that the modulatory function of the CTM is affected by its native environment in different cells and thus occurs in a cell-type specific manner in vivo. It stabilizes gating properties of Cav1.3 channels required for normal electrical excitability.
Collapse
Affiliation(s)
- Anja Scharinger
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| | - Stephanie Eckrich
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University Homburg, Germany
| | - David H Vandael
- Laboratory of Cellular and Molecular Neuroscience, Department of Drug Science, Nanostructured Interfaces and Surfaces Center, University of Torino Torino, Italy
| | - Kai Schönig
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University Mannheim, Germany
| | - Alexandra Koschak
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| | - Dietmar Hecker
- Department of Otorhinolaryngology, Saarland University Homburg, Germany
| | - Gurjot Kaur
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| | - Amy Lee
- Department of Molecular Physiology and Biophysics, University of Iowa Iowa City, IA, USA
| | - Anupam Sah
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| | - Dusan Bartsch
- Department of Molecular Biology, Central Institute of Mental Health, Medical Faculty Mannheim, Heidelberg University Mannheim, Germany
| | - Bruno Benedetti
- Department of Physiology and Medical Physics, Innsbruck Medical University Innsbruck, Austria
| | - Andreas Lieb
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| | - Bernhard Schick
- Department of Otorhinolaryngology, Saarland University Homburg, Germany
| | - Nicolas Singewald
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| | - Martina J Sinnegger-Brauns
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| | - Emilio Carbone
- Laboratory of Cellular and Molecular Neuroscience, Department of Drug Science, Nanostructured Interfaces and Surfaces Center, University of Torino Torino, Italy
| | - Jutta Engel
- Department of Biophysics, Center for Integrative Physiology and Molecular Medicine, Saarland University Homburg, Germany
| | - Jörg Striessnig
- Department of Pharmacology and Toxicology, Institute of Pharmacy, Center for Molecular Biosciences, University of Innsbruck Innsbruck, Austria
| |
Collapse
|