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Hou P, Zhao L, Zhong L, Shi J, Wang HZ, Gao J, Liu H, Zuckerman J, Cohen IS, Cui J. The fully activated open state of KCNQ1 controls the cardiac "fight-or-flight" response. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.07.02.601749. [PMID: 39005479 PMCID: PMC11244952 DOI: 10.1101/2024.07.02.601749] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 07/16/2024]
Abstract
The cardiac KCNQ1+KCNE1 (I Ks ) channel regulates heart rhythm in both normal and stress conditions. Under stress, the β-adrenergic stimulation elevates the intracellular cAMP level, leading to KCNQ1 phosphorylation by protein kinase A and increased I Ks , which shortens action potentials to adapt to accelerated heart rate. An impaired response to the β-adrenergic stimulation due to KCNQ1 mutations is associated with the occurrence of a lethal congenital long QT syndrome (type 1, also known as LQT1). However, the underlying mechanism of β-adrenergic stimulation of I Ks remains unclear, impeding the development of new therapeutics. Here we find that the unique properties of KCNQ1 channel gating with two distinct open states are key to this mechanism. KCNQ1's fully activated open (AO) state is more sensitive to cAMP than its' intermediate open (IO) state. By enhancing the AO state occupancy, the small molecules ML277 and C28 are found to effectively enhance the cAMP sensitivity of the KCNQ1 channel, independent of KCNE1 association. This finding of enhancing AO state occupancy leads to a potential novel strategy to rescue the response of I Ks to β-adrenergic stimulation in LQT1 mutants. The success of this approach is demonstrated in cardiac myocytes and also in a high-risk LQT1 mutation. In conclusion the present study not only uncovers the key role of the AO state in I Ks channel phosphorylation, but also provides a new target for anti-arrhythmic strategy. Significance statement The increase of I Ks potassium currents with adrenalin stimulation is important for "fight-or-flight" responses. Mutations of the IKs channel reducing adrenalin responses are associated with more lethal form of the type-1 long-QT syndrome (LQT). The alpha subunit of the IKs channel, KCNQ1 opens in two distinct open states, the intermediate-open (IO) and activated-open (AO) states, following a two-step voltage sensing domain (VSD) activation process. We found that the AO state, but not the IO state, is responsible for the adrenalin response. Modulators that specifically enhance the AO state occupancy can enhance adrenalin responses of the WT and LQT-associated mutant channels. These results reveal a mechanism of state dependent modulation of ion channels and provide an anti-arrhythmic strategy.
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2
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Wang Y, Liu Z, Bian X, Zhao C, Zhang X, Liu X, Wang N. Function and regulation of ubiquitin-like SUMO system in heart. Front Cell Dev Biol 2023; 11:1294717. [PMID: 38033852 PMCID: PMC10687153 DOI: 10.3389/fcell.2023.1294717] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 11/06/2023] [Indexed: 12/02/2023] Open
Abstract
The small ubiquitin-related modifier (SUMOylation) system is a conserved, reversible, post-translational protein modification pathway covalently attached to the lysine residues of proteins in eukaryotic cells, and SUMOylation is catalyzed by SUMO-specific activating enzyme (E1), binding enzyme (E2) and ligase (E3). Sentrin-specific proteases (SENPs) can cleave the isopeptide bond of a SUMO conjugate and catalyze the deSUMOylation reaction. SUMOylation can regulate the activity of proteins in many important cellular processes, including transcriptional regulation, cell cycle progression, signal transduction, DNA damage repair and protein stability. Biological experiments in vivo and in vitro have confirmed the key role of the SUMO conjugation/deconjugation system in energy metabolism, Ca2+ cycle homeostasis and protein quality control in cardiomyocytes. In this review, we summarized the research progress of the SUMO conjugation/deconjugation system and SUMOylation-mediated cardiac actions based on related studies published in recent years, and highlighted the further research areas to clarify the role of the SUMO system in the heart by using emerging technologies.
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Affiliation(s)
- Ying Wang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
- Central Laboratory, The Fifth Central Hospital of Tianjin, Tianjin, China
| | - Zhihao Liu
- First Teaching Hospital of Tianjin University of Traditional Chinese Medicine, National Clinical Research Center for Chinese Medicine Acupuncture and Moxibustion, Tianjin, China
- State Key Laboratory of Modern Chinese Medicine, Tianjin University of Traditional Chinese Medicine, Tianjin, China
| | - Xiyun Bian
- Central Laboratory, The Fifth Central Hospital of Tianjin, Tianjin, China
- Tianjin Key Laboratory of Epigenetics for Organ Development in Preterm Infants, The Fifth Central Hospital of Tianjin, Tianjin, China
| | - Chenxu Zhao
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Xin Zhang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Xiaozhi Liu
- Central Laboratory, The Fifth Central Hospital of Tianjin, Tianjin, China
- Tianjin Key Laboratory of Epigenetics for Organ Development in Preterm Infants, The Fifth Central Hospital of Tianjin, Tianjin, China
| | - Nan Wang
- College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
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3
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Mandel N, Büttner M, Poschet G, Kuner R, Agarwal N. SUMOylation Modulates Reactive Oxygen Species (ROS) Levels and Acts as a Protective Mechanism in the Type 2 Model of Diabetic Peripheral Neuropathy. Cells 2023; 12:2511. [PMID: 37947589 PMCID: PMC10648122 DOI: 10.3390/cells12212511] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2023] [Revised: 10/06/2023] [Accepted: 10/17/2023] [Indexed: 11/12/2023] Open
Abstract
Diabetic peripheral neuropathy (DPN) is the prevalent type of peripheral neuropathy; it primarily impacts extremity nerves. Its multifaceted nature makes the molecular mechanisms of diabetic neuropathy intricate and incompletely elucidated. Several types of post-translational modifications (PTMs) have been implicated in the development and progression of DPN, including phosphorylation, glycation, acetylation and SUMOylation. SUMOylation involves the covalent attachment of small ubiquitin-like modifier (SUMO) proteins to target proteins, and it plays a role in various cellular processes, including protein localization, stability, and function. While the specific relationship between high blood glucose and SUMOylation is not extensively studied, recent evidence implies its involvement in the development of DPN in type 1 diabetes. In this study, we investigated the impact of SUMOylation on the onset and progression of DPN in a type 2 diabetes model using genetically modified mutant mice lacking SUMOylation, specifically in peripheral sensory neurons (SNS-Ubc9-/-). Behavioural measurement for evoked pain, morphological analyses of nerve fibre loss in the epidermis, measurement of reactive oxygen species (ROS) levels, and antioxidant molecules were analysed over several months in SUMOylation-deficient and control mice. Our longitudinal analysis at 30 weeks post-high-fat diet revealed that SNS-Ubc9-/- mice exhibited earlier and more pronounced thermal and mechanical sensation loss and accelerated intraepidermal nerve fibre loss compared to control mice. Mechanistically, these changes are associated with increased levels of ROS both in sensory neuronal soma and in peripheral axonal nerve endings in SNS-Ubc9-/- mice. In addition, we observed compromised detoxifying potential, impaired respiratory chain complexes, and reduced levels of protective lipids in sensory neurons upon deletion of SUMOylation in diabetic mice. Importantly, we also identified mitochondrial malate dehydrogenase (MDH2) as a SUMOylation target, the activity of which is negatively regulated by SUMOylation. Our results indicate that SUMOylation is an essential neuroprotective mechanism in sensory neurons in type 2 diabetes, the deletion of which causes oxidative stress and an impaired respiratory chain, resulting in energy depletion and subsequent damage to sensory neurons.
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Affiliation(s)
- Nicolas Mandel
- Institute of Pharmacology, Medical Faculty Heidelberg, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany (R.K.)
| | - Michael Büttner
- Centre for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
| | - Gernot Poschet
- Centre for Organismal Studies (COS), University of Heidelberg, Im Neuenheimer Feld 360, 69120 Heidelberg, Germany
| | - Rohini Kuner
- Institute of Pharmacology, Medical Faculty Heidelberg, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany (R.K.)
| | - Nitin Agarwal
- Institute of Pharmacology, Medical Faculty Heidelberg, Heidelberg University, Im Neuenheimer Feld 366, 69120 Heidelberg, Germany (R.K.)
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4
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Chen C, Zhu X, Xie J, Li X, Wan R, Hong K. Human leukocyte antigen F-associated transcript 10 regulates the IKs potassium channel by competing for Kv7.1 ubiquitination. Philos Trans R Soc Lond B Biol Sci 2023; 378:20220167. [PMID: 37122222 PMCID: PMC10150200 DOI: 10.1098/rstb.2022.0167] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2022] [Accepted: 12/28/2022] [Indexed: 05/02/2023] Open
Abstract
The protein expression and function changes from the slow-delayed rectifying K+ current, IKs, are tightly associated with ventricular cardiac arrhythmias. Human leukocyte antigen F-associated transcript 10 (FAT10), a member of the ubiquitin-like-modifier family, exerts a protective effect against myocardial ischaemia. However, whether or how FAT10 influences the function of IKs remains unclear. Here, human-induced pluripotent stem cell-derived cardiomyocytes (hiPSC-CMs) and Fat10 knockout HEK293 (Fat10-/-) cells through CRISPR-Cas9 technology were used to evaluate the novel modulation of FAT10 in IKs function. Patch-clamp studies showed that the overexpression of FAT10 significantly enhanced the current density of IKs both in hiPSC-CMs and HEK293-Fat10-/- cells. In addition, a shortened action potential duration (APD) was seen from hiPSC-CMs transfected with the ad-Fat10 virus. Then, a series of molecular approaches from neonatal rat cardiomyocytes, H9C2 cells and HEK293 cells were used to determine the regulatory mechanism of FAT10 in IKs. First, western blot assays indicated that the expression of Kv7.1, the alpha-subunit of IKs, was increased when FAT10 was overexpressed. Furthermore, immunofluorescence and co-immunoprecipitation assays demonstrated that FAT10 could interact with Kv7.1. Notably, FAT10 impedes Kv7.1 ubiquitination and degradation, thereby stabilizing its expression. Finally, a hypoxia model of hiPSC-CMs was established, and the overexpression of FAT10 showed a protective effect against hypoxia-induced decreases in the current density of IKs. Taken together, these findings revealed a novel role of FAT10 in the regulation of the IKs potassium channel by competing for Kv7.1 ubiquitination, which provides a new electrophysiological insight that FAT10 could modulate Kv7.1. This article is part of the theme issue 'The heartbeat: its molecular basis and physiological mechanisms'.
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Affiliation(s)
- Chen Chen
- Department of Cardiovascular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang of Jiangxi 330006, People's Republic of China
- Jiangxi Key Laboratory of Molecular Medicine, Nanchang of Jiangxi 330006, People's Republic of China
| | - Xin Zhu
- Department of Cardiovascular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang of Jiangxi 330006, People's Republic of China
- Jiangxi Key Laboratory of Molecular Medicine, Nanchang of Jiangxi 330006, People's Republic of China
| | - Jinyan Xie
- Jiangxi Key Laboratory of Molecular Medicine, Nanchang of Jiangxi 330006, People's Republic of China
| | - Xiaoqing Li
- Department of Cardiovascular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang of Jiangxi 330006, People's Republic of China
- Jiangxi Key Laboratory of Molecular Medicine, Nanchang of Jiangxi 330006, People's Republic of China
| | - Rong Wan
- Jiangxi Key Laboratory of Molecular Medicine, Nanchang of Jiangxi 330006, People's Republic of China
| | - Kui Hong
- Department of Cardiovascular Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang of Jiangxi 330006, People's Republic of China
- Department of Genetic Medicine, The Second Affiliated Hospital of Nanchang University, Nanchang of Jiangxi 330006, People's Republic of China
- Jiangxi Key Laboratory of Molecular Medicine, Nanchang of Jiangxi 330006, People's Republic of China
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5
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Kotler O, Khrapunsky Y, Shvartsman A, Dai H, Plant LD, Goldstein SAN, Fleidervish I. SUMOylation of Na V1.2 channels regulates the velocity of backpropagating action potentials in cortical pyramidal neurons. eLife 2023; 12:e81463. [PMID: 36794908 PMCID: PMC10014073 DOI: 10.7554/elife.81463] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2022] [Accepted: 02/15/2023] [Indexed: 02/17/2023] Open
Abstract
Voltage-gated sodium channels located in axon initial segments (AIS) trigger action potentials (AP) and play pivotal roles in the excitability of cortical pyramidal neurons. The differential electrophysiological properties and distributions of NaV1.2 and NaV1.6 channels lead to distinct contributions to AP initiation and propagation. While NaV1.6 at the distal AIS promotes AP initiation and forward propagation, NaV1.2 at the proximal AIS promotes the backpropagation of APs to the soma. Here, we show the small ubiquitin-like modifier (SUMO) pathway modulates Na+ channels at the AIS to increase neuronal gain and the speed of backpropagation. Since SUMO does not affect NaV1.6, these effects were attributed to SUMOylation of NaV1.2. Moreover, SUMO effects were absent in a mouse engineered to express NaV1.2-Lys38Gln channels that lack the site for SUMO linkage. Thus, SUMOylation of NaV1.2 exclusively controls INaP generation and AP backpropagation, thereby playing a prominent role in synaptic integration and plasticity.
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Affiliation(s)
- Oron Kotler
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the NegevBeer ShevaIsrael
| | - Yana Khrapunsky
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the NegevBeer ShevaIsrael
| | - Arik Shvartsman
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the NegevBeer ShevaIsrael
| | - Hui Dai
- Departments of Pediatrics and Physiology and Biophysics, University of California, IrvineIrvineUnited States
| | - Leigh D Plant
- Department of Pharmaceutical Sciences, Northeastern UniversityBostonUnited States
| | - Steven AN Goldstein
- Departments of Pediatrics and Physiology and Biophysics, University of California, IrvineIrvineUnited States
| | - Ilya Fleidervish
- Department of Physiology and Cell Biology, Faculty of Health Sciences, Ben-Gurion University of the NegevBeer ShevaIsrael
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6
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Xu Y, Yang Y, Chandrashekar A, Gada KD, Masotti M, Baggetta AM, Connolly JG, Kawano T, Plant LD. Hypoxia inhibits the cardiac I K1 current through SUMO targeting Kir2.1 activation by PIP 2. iScience 2022; 25:104969. [PMID: 36060074 PMCID: PMC9437851 DOI: 10.1016/j.isci.2022.104969] [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] [Subscribe] [Scholar Register] [Received: 10/13/2021] [Revised: 05/07/2022] [Accepted: 08/12/2022] [Indexed: 11/30/2022] Open
Abstract
Cardiovascular diseases remain the leading cause of death worldwide. Most deaths are sudden and occur secondary to the occlusion of coronary arteries resulting in a rapid decrease in cellular oxygen levels. Acute hypoxia is proarrhythmic, leading to disordered electrical signals, conduction block, and uncoordinated beating of the myocardium. Although acute hypoxia is recognized to perturb the electrophysiology of heart muscle, the mechanistic basis for the effect has remained elusive, hampering the development of targeted therapeutic interventions. Here, we show that acute hypoxia activates the redox-sensitive SUMO pathway in cardiomyocytes, causing rapid inhibition of the inward-rectifying K+ channel, Kir2.1. We find that SUMOylation decreases the activation of Kir2.1 channels by the membrane phospholipid phosphatidylinositol 4,5-bisphosphate (PIP2). These data provide a mechanistic basis for the proarrhythmic effects of acute hypoxia and offer a framework for understanding the central role of PIP2 in mediating the sequelae of hypoxia and SUMOylation in cardiovascular disease.
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Affiliation(s)
- Yu Xu
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University, Boston, MA, USA
| | - Yuchen Yang
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University, Boston, MA, USA
| | - Aishwarya Chandrashekar
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University, Boston, MA, USA
| | - Kirin D. Gada
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University, Boston, MA, USA
| | - Meghan Masotti
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University, Boston, MA, USA
| | - Austin M. Baggetta
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University, Boston, MA, USA
| | - Jenna G. Connolly
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University, Boston, MA, USA
| | - Takeharu Kawano
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University, Boston, MA, USA
| | - Leigh D. Plant
- Department of Pharmaceutical Sciences, School of Pharmacy and Pharmaceutical Sciences, Bouvé College of Health Sciences, Northeastern University, Boston, MA, USA
- Center for Drug Discovery, Northeastern University, Boston, MA, USA
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7
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Abbott GW. Kv Channel Ancillary Subunits: Where Do We Go from Here? Physiology (Bethesda) 2022; 37:0. [PMID: 35797055 PMCID: PMC9394777 DOI: 10.1152/physiol.00005.2022] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2022] [Revised: 04/29/2022] [Accepted: 04/29/2022] [Indexed: 01/10/2023] Open
Abstract
Voltage-gated potassium (Kv) channels each comprise four pore-forming α-subunits that orchestrate essential duties such as voltage sensing and K+ selectivity and conductance. In vivo, however, Kv channels also incorporate regulatory subunits-some Kv channel specific, others more general modifiers of protein folding, trafficking, and function. Understanding all the above is essential for a complete picture of the role of Kv channels in physiology and disease.
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Affiliation(s)
- Geoffrey W Abbott
- Bioelectricity Laboratory, Department of Physiology and Biophysics, School of Medicine, University of California, Irvine, California
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8
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Jeoung SW, Park HS, Ryoo ZY, Cho DH, Lee HS, Ryu HY. SUMOylation and Major Depressive Disorder. Int J Mol Sci 2022; 23:8023. [PMID: 35887370 PMCID: PMC9316168 DOI: 10.3390/ijms23148023] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Revised: 07/19/2022] [Accepted: 07/19/2022] [Indexed: 12/04/2022] Open
Abstract
Since the discovery of the small ubiquitin-like modifier (SUMO) protein in 1995, SUMOylation has been considered a crucial post-translational modification in diverse cellular functions. In neurons, SUMOylation has various roles ranging from managing synaptic transmitter release to maintaining mitochondrial integrity and determining neuronal health. It has been discovered that neuronal dysfunction is a key factor in the development of major depressive disorder (MDD). PubMed and Google Scholar databases were searched with keywords such as 'SUMO', 'neuronal plasticity', and 'depression' to obtain relevant scientific literature. Here, we provide an overview of recent studies demonstrating the role of SUMOylation in maintaining neuronal function in participants suffering from MDD.
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Affiliation(s)
- Seok-Won Jeoung
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, College of National Sciences, Kyungpook National University, Daegu 41566, Korea; (S.-W.J.); (Z.Y.R.); (D.-H.C.); (H.-S.L.)
- Brain Science and Engineering Institute, Kyungpook National University, Daegu 41566, Korea
| | - Hyun-Sun Park
- Department of Biochemistry, Inje University College of Medicine, Busan 50834, Korea;
| | - Zae Young Ryoo
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, College of National Sciences, Kyungpook National University, Daegu 41566, Korea; (S.-W.J.); (Z.Y.R.); (D.-H.C.); (H.-S.L.)
| | - Dong-Hyung Cho
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, College of National Sciences, Kyungpook National University, Daegu 41566, Korea; (S.-W.J.); (Z.Y.R.); (D.-H.C.); (H.-S.L.)
| | - Hyun-Shik Lee
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, College of National Sciences, Kyungpook National University, Daegu 41566, Korea; (S.-W.J.); (Z.Y.R.); (D.-H.C.); (H.-S.L.)
| | - Hong-Yeoul Ryu
- BK21 FOUR KNU Creative BioResearch Group, School of Life Sciences, College of National Sciences, Kyungpook National University, Daegu 41566, Korea; (S.-W.J.); (Z.Y.R.); (D.-H.C.); (H.-S.L.)
- Brain Science and Engineering Institute, Kyungpook National University, Daegu 41566, Korea
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9
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De Oliveira PA, Moreno E, Casajuana-Martin N, Casadó-Anguera V, Cai NS, Camacho-Hernandez GA, Zhu H, Bonifazi A, Hall MD, Weinshenker D, Newman AH, Logothetis DE, Casadó V, Plant LD, Pardo L, Ferré S. Preferential Gs protein coupling of the galanin Gal 1 receptor in the µ-opioid-Gal 1 receptor heterotetramer. Pharmacol Res 2022; 182:106322. [PMID: 35750299 PMCID: PMC9462584 DOI: 10.1016/j.phrs.2022.106322] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 06/18/2022] [Accepted: 06/19/2022] [Indexed: 12/25/2022]
Abstract
Recent studies have proposed that heteromers of µ-opioid receptors (MORs) and galanin Gal1 receptors (Gal1Rs) localized in the mesencephalon mediate the dopaminergic effects of opioids. The present study reports converging evidence, using a peptide-interfering approach combined with biophysical and biochemical techniques, including total internal reflection fluorescence microscopy, for a predominant homodimeric structure of MOR and Gal1R when expressed individually, and for their preference to form functional heterotetramers when co-expressed. Results show that a heteromerization-dependent change in the Gal1R homodimeric interface leads to a switch in G-protein coupling from inhibitory Gi to stimulatory Gs proteins. The MOR-Gal1R heterotetramer, which is thus bound to Gs via the Gal1R homodimer and Gi via the MOR homodimer, provides the framework for a canonical Gs-Gi antagonist interaction at the adenylyl cyclase level. These novel results shed light on the intense debate about the oligomeric quaternary structure of G protein-coupled receptors, their predilection for heteromer formation, and the resulting functional significance.
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Affiliation(s)
| | - Estefanía Moreno
- Laboratory of Molecular Neuropharmacology, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology and Institute of Biomedicine, University of Barcelona, Barcelona, Spain
| | - Nil Casajuana-Martin
- Laboratory of Computational Medicine, Biostatistics Unit, Faculty of Medicine, Autonomous University of Barcelona, Bellaterra, Spain
| | - Verònica Casadó-Anguera
- Laboratory of Molecular Neuropharmacology, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology and Institute of Biomedicine, University of Barcelona, Barcelona, Spain
| | | | - Gisela Andrea Camacho-Hernandez
- Medicinal Chemistry Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Hu Zhu
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - Alessandro Bonifazi
- Medicinal Chemistry Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Matthew D Hall
- Division of Preclinical Innovation, National Center for Advancing Translational Sciences, National Institutes of Health, Rockville, MD, USA
| | - David Weinshenker
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Amy Hauck Newman
- Medicinal Chemistry Section, National Institute on Drug Abuse, Intramural Research Program, National Institutes of Health, Baltimore, MD, USA
| | - Diomedes E Logothetis
- Departments of Pharmaceutical Sciences, Chemistry and Chemical Biology and Center for Drug Discovery, School of Pharmacy at the Bouvé College of Health Sciences and College of Science, Northeastern University, Boston, MA, USA
| | - Vicent Casadó
- Laboratory of Molecular Neuropharmacology, Department of Biochemistry and Molecular Biomedicine, Faculty of Biology and Institute of Biomedicine, University of Barcelona, Barcelona, Spain.
| | - Leigh D Plant
- Departments of Pharmaceutical Sciences, Chemistry and Chemical Biology and Center for Drug Discovery, School of Pharmacy at the Bouvé College of Health Sciences and College of Science, Northeastern University, Boston, MA, USA.
| | - Leonardo Pardo
- Laboratory of Computational Medicine, Biostatistics Unit, Faculty of Medicine, Autonomous University of Barcelona, Bellaterra, Spain.
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10
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An X, Lee J, Kim GH, Kim HJ, Pyo HJ, Kwon I, Cho H. Modulation of I Ks channel-PIP 2 interaction by PRMT1 plays a critical role in the control of cardiac repolarization. J Cell Physiol 2022; 237:3069-3079. [PMID: 35580065 PMCID: PMC9543859 DOI: 10.1002/jcp.30775] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2021] [Revised: 04/18/2022] [Accepted: 04/25/2022] [Indexed: 11/12/2022]
Abstract
Recent studies have shown that protein arginine methyltransferase 1 (PRMT1) is highly expressed in the human heart, and loss of PRMT1 contributes to cardiac remodeling in the heart failure. However, the functional importance of PRMT1 in cardiac ion channels remains uncertain. The slow activating delayed rectifier K+ (IKs) channel is a cardiac K+ channel composed of KCNQ1 and KCNE1 subunits and is a new therapeutic target for treating lethal arrhythmias in many cardiac pathologies, especially heart failure. Here, we demonstrate that PRMT1 is a critical regulator of the IKs channel and cardiac rhythm. In the guinea pig ventricular myocytes, treatment with furamidine, a PRMT1‐specific inhibitor, prolonged the action potential duration (APD). We further show that this APD prolongation was attributable to IKs reduction. In HEK293T cells expressing human KCNQ1 and KCNE1, inhibiting PRMT1 via furamidine reduced IKs and concurrently decreased the arginine methylation of KCNQ1, a pore‐forming α‐subunit. Evidence presented here indicates that furamidine decreased IKs mainly by lowering the affinity of IKs channels for the membrane phospholipid, phosphatidylinositol 4,5‐bisphosphate (PIP2), which is crucial for pore opening. Finally, applying exogenous PIP2 to cardiomyocytes prevented the furamidine‐induced IKs reduction and APD prolongation. Taken together, these results indicate that PRMT1 positively regulated IKs activity through channel–PIP2 interaction, thereby restricting excessive cardiac action potential.
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Affiliation(s)
- Xue An
- Department of Physiology, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Jiwon Lee
- Department of Anatomy and Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Ga Hye Kim
- Department of Anatomy and Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Hyun-Ji Kim
- Department of Physiology, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Hyun-Jeong Pyo
- Department of Physiology, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Ilmin Kwon
- Department of Anatomy and Cell Biology, Sungkyunkwan University School of Medicine, Suwon, Korea
| | - Hana Cho
- Department of Physiology, Sungkyunkwan University School of Medicine, Suwon, Korea
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11
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Jansen LAR, Forster LA, Smith XL, Rubaharan M, Murphy AZ, Baro DJ. Changes in peripheral HCN2 channels during persistent inflammation. Channels (Austin) 2021; 15:165-179. [PMID: 33423595 PMCID: PMC7808421 DOI: 10.1080/19336950.2020.1870086] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2020] [Revised: 12/22/2020] [Accepted: 12/23/2020] [Indexed: 02/01/2023] Open
Abstract
Nociceptor sensitization following nerve injury or inflammation leads to chronic pain. An increase in the nociceptor hyperpolarization-activated current, Ih, is observed in many models of pathological pain. Pharmacological blockade of Ih prevents the mechanical and thermal hypersensitivity that occurs during pathological pain. Alterations in the Hyperpolarization-activated Cyclic Nucleotide-gated ion channel 2 (HCN2) mediate Ih-dependent thermal and mechanical hyperalgesia. Limited knowledge exists regarding the nature of these changes during chronic inflammatory pain. Modifications in HCN2 expression and post-translational SUMOylation have been observed in the Complete Freund's Adjuvant (CFA) model of chronic inflammatory pain. Intra-plantar injection of CFA into the rat hindpaw induces unilateral hyperalgesia that is sustained for up to 14 days following injection. The hindpaw is innervated by primary afferents in lumbar DRG, L4-6. Adjustments in HCN2 expression and SUMOylation have been well-documented for L5 DRG during the first 7 days of CFA-induced inflammation. Here, we examine bilateral L4 and L6 DRG at day 1 and day 3 post-CFA. Using L4 and L6 DRG cryosections, HCN2 expression and SUMOylation were measured with immunohistochemistry and proximity ligation assays, respectively. Our findings indicate that intra-plantar injection of CFA elicited a bilateral increase in HCN2 expression in L4 and L6 DRG at day 1, but not day 3, and enhanced HCN2 SUMOylation in ipsilateral L6 DRG at day 1 and day 3. Changes in HCN2 expression and SUMOylation were transient over this time course. Our study suggests that HCN2 is regulated by multiple mechanisms during CFA-induced inflammation.
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Affiliation(s)
- L-A. R. Jansen
- Department of Biology, Georgia State University, Atlanta, Georgia
| | - L. A. Forster
- Department of Biology, Georgia State University, Atlanta, Georgia
- Neuroscience Institute, Georgia State University, Atlanta, Georgia
| | - X. L. Smith
- Department of Biology, Georgia State University, Atlanta, Georgia
| | - M. Rubaharan
- Neuroscience Institute, Georgia State University, Atlanta, Georgia
| | - A. Z. Murphy
- Neuroscience Institute, Georgia State University, Atlanta, Georgia
| | - D. J. Baro
- Department of Biology, Georgia State University, Atlanta, Georgia
- Neuroscience Institute, Georgia State University, Atlanta, Georgia
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12
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Welch MA, Jansen LAR, Baro DJ. SUMOylation of the Kv4.2 Ternary Complex Increases Surface Expression and Current Amplitude by Reducing Internalization in HEK 293 Cells. Front Mol Neurosci 2021; 14:757278. [PMID: 34795560 PMCID: PMC8593141 DOI: 10.3389/fnmol.2021.757278] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Accepted: 10/05/2021] [Indexed: 11/29/2022] Open
Abstract
Kv4 α-subunits exist as ternary complexes (TC) with potassium channel interacting proteins (KChIP) and dipeptidyl peptidase-like proteins (DPLP); multiple ancillary proteins also interact with the α-subunits throughout the channel’s lifetime. Dynamic regulation of Kv4.2 protein interactions adapts the transient potassium current, IA, mediated by Kv4 α-subunits. Small ubiquitin-like modifier (SUMO) is an 11 kD peptide post-translationally added to lysine (K) residues to regulate protein–protein interactions. We previously demonstrated that when expressed in human embryonic kidney (HEK) cells, Kv4.2 can be SUMOylated at two K residues, K437 and K579. SUMOylation at K437 increased surface expression of electrically silent channels while SUMOylation at K579 reduced IA maximal conductance (Gmax) without altering surface expression. KChIP and DPLP subunits are known to modify the pattern of Kv4.2 post-translational decorations and/or their effects. In this study, co-expressing Kv4.2 with KChIP2a and DPP10c altered the effects of enhanced Kv4.2 SUMOylation. First, the effect of enhanced SUMOylation was the same for a TC containing either the wild-type Kv4.2 or the mutant K437R Kv4.2, suggesting that either the experimental manipulation no longer enhanced K437 SUMOylation or K437 SUMOylation no longer influenced Kv4.2 surface expression. Second, instead of decreasing IA Gmax, enhanced SUMOylation at K579 now produced a significant ∼37–70% increase in IA maximum conductance (Gmax) and a significant ∼30–50% increase in Kv4.2g surface expression that was accompanied by a 65% reduction in TC internalization. Blocking clathrin-mediated endocytosis (CME) in HEK cells expressing the Kv4.2 TC mimicked and occluded the effect of SUMO on IA Gmax; however, the amount of Kv4.2 associated with the major adaptor for constitutive CME, adaptor protein 2 (AP2), was not SUMO dependent. Thus, SUMOylation reduced Kv4.2 internalization by acting downstream of Kv4.2 recruitment into clathrin-coated pits. In sum, the two major findings of this study are: SUMOylation of Kv4.2 at K579 regulates TC internalization most likely by promoting channel recycling. Additionally, there is a reciprocity between Kv4.2 SUMOylation and the Kv4.2 interactome such that SUMOylation regulates the interactome and the interactome influences the pattern and effect of SUMOylation.
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Affiliation(s)
- Meghyn A Welch
- Department of Biology, Georgia State University, Atlanta, GA, United States
| | | | - Deborah J Baro
- Department of Biology, Georgia State University, Atlanta, GA, United States.,Neuroscience Institute, Georgia State University, Atlanta, GA, United States
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13
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Plant LD, Xiong D, Romero J, Dai H, Goldstein SAN. Hypoxia Produces Pro-arrhythmic Late Sodium Current in Cardiac Myocytes by SUMOylation of Na V1.5 Channels. Cell Rep 2021; 30:2225-2236.e4. [PMID: 32075761 PMCID: PMC7054841 DOI: 10.1016/j.celrep.2020.01.025] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 12/03/2019] [Accepted: 01/07/2020] [Indexed: 01/08/2023] Open
Abstract
Acute cardiac hypoxia produces life-threatening elevations in late sodium current (ILATE) in the human heart. Here, we show the underlying mechanism: hypoxia induces rapid SUMOylation of NaV1.5 channels so they reopen when normally inactive, late in the action potential. NaV1.5 is SUMOylated only on lysine 442, and the mutation of that residue, or application of a deSUMOylating enzyme, prevents hypoxic reopenings. The time course of SUMOylation of single channels in response to hypoxia coincides with the increase in ILATE, a reaction that is complete in under 100 s. In human cardiac myocytes derived from pluripotent stem cells, hypoxia-induced ILATE is confirmed to be SUMO-dependent and to produce action potential prolongation, the pro-arrhythmic change observed in patients. The cardiac channel NaV1.5 passes pro-arrhythmic late sodium currents in response to hypoxia. Plant et al. demonstrate the pathophysiological mechanism to be rapid, hypoxia-induced monoSUMOylation of NaV1.5 channels. Blocking SUMOylation of lysine442 prevents hypoxia-induced late currents and attendant prolongation of the action potential in human cardiomyocytes derived from pluripotent stem cells.
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Affiliation(s)
- Leigh D Plant
- Department of Pharmaceutical Sciences, Northeastern University, 360 Huntington Avenue, Boston, MA 02115, USA.
| | - Dazhi Xiong
- Departments of Pediatrics and Physiology & Biophysics, University of California, Irvine, 1001 Health Sciences Road, Irvine Hall, Irvine, CA 92697, USA
| | - Jesus Romero
- Departments of Pediatrics and Physiology & Biophysics, University of California, Irvine, 1001 Health Sciences Road, Irvine Hall, Irvine, CA 92697, USA
| | - Hui Dai
- Departments of Pediatrics and Physiology & Biophysics, University of California, Irvine, 1001 Health Sciences Road, Irvine Hall, Irvine, CA 92697, USA
| | - Steve A N Goldstein
- Departments of Pediatrics and Physiology & Biophysics, University of California, Irvine, 1001 Health Sciences Road, Irvine Hall, Irvine, CA 92697, USA.
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14
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FAT10 protects against ischemia-induced ventricular arrhythmia by decreasing Nedd4-2/Nav1.5 complex formation. Cell Death Dis 2021; 12:25. [PMID: 33414395 PMCID: PMC7790828 DOI: 10.1038/s41419-020-03290-3] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2020] [Revised: 10/19/2020] [Accepted: 10/21/2020] [Indexed: 01/29/2023]
Abstract
The human leukocyte antigen F-associated transcript 10 (FAT10) is a member of the small ubiquitin-like protein family that binds to its target proteins and subjects them to degradation by the ubiquitin-proteasome system (UPS). In the heart, FAT10 plays a cardioprotective role and affects predisposition to cardiac arrhythmias after myocardial ischemia (MI). However, whether and how FAT10 influences cardiac arrhythmias is unknown. We investigated the role of FAT10 in regulating the sodium channel Nav1.5, a major regulator of cardiac arrhythmias. Fat10 was conditionally deleted in cardiac myocytes using Myh6-Cre and Fat10F/F mice (cFat10-/-). Compared with their wild-type littermates, cFat10-/- mice showed prolonged RR, PR, and corrected QT (QTc) intervals, were more likely to develop ventricular arrhythmia, and had increased mortality after MI. Patch-clamp studies showed that the peak Na+ current was reduced, and the late Na+ current was significantly augmented, resulting in a decreased action potential amplitude and delayed depolarization. Immunoblot and immunofluorescence analyses showed that the expression of the membrane protein Nav1.5 was decreased. Coimmunoprecipitation experiments demonstrated that FAT10 stabilized Nav1.5 expression by antagonizing Nav1.5 ubiquitination and degradation. Specifically, FAT10 bound to the lysine residues in the C-terminal fragments of Nav1.5 and decreased the binding of Nav1.5 to the Nedd4-2 protein, a ubiquitin E3 ligase, preventing degradation of the Nav1.5 protein. Collectively, our findings showed that deletion of the Fat10 in cardiac myocytes led to increased cardiac arrhythmias and increased mortality after MI. Thus, FAT10 protects against ischemia-induced ventricular arrhythmia by binding to Nav1.5 and preventing its Neddylation and degradation by the UPS after MI.
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15
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Henley JM, Seager R, Nakamura Y, Talandyte K, Nair J, Wilkinson KA. SUMOylation of synaptic and synapse-associated proteins: An update. J Neurochem 2021; 156:145-161. [PMID: 32538470 PMCID: PMC8218484 DOI: 10.1111/jnc.15103] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2020] [Revised: 04/23/2020] [Accepted: 04/24/2020] [Indexed: 12/13/2022]
Abstract
SUMOylation is a post-translational modification that regulates protein signalling and complex formation by adjusting the conformation or protein-protein interactions of the substrate protein. There is a compelling and rapidly expanding body of evidence that, in addition to SUMOylation of nuclear proteins, SUMOylation of extranuclear proteins contributes to the control of neuronal development, neuronal stress responses and synaptic transmission and plasticity. In this brief review we provide an update of recent developments in the identification of synaptic and synapse-associated SUMO target proteins and discuss the cell biological and functional implications of these discoveries.
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Affiliation(s)
- Jeremy M. Henley
- School of BiochemistryCentre for Synaptic PlasticityUniversity of BristolUniversity WalkBristolUK
| | - Richard Seager
- School of BiochemistryCentre for Synaptic PlasticityUniversity of BristolUniversity WalkBristolUK
| | - Yasuko Nakamura
- School of BiochemistryCentre for Synaptic PlasticityUniversity of BristolUniversity WalkBristolUK
| | - Karolina Talandyte
- School of BiochemistryCentre for Synaptic PlasticityUniversity of BristolUniversity WalkBristolUK
| | - Jithin Nair
- School of BiochemistryCentre for Synaptic PlasticityUniversity of BristolUniversity WalkBristolUK
| | - Kevin A. Wilkinson
- School of BiochemistryCentre for Synaptic PlasticityUniversity of BristolUniversity WalkBristolUK
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16
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Shetty PMV, Rangrez AY, Frey N. SUMO proteins in the cardiovascular system: friend or foe? J Biomed Sci 2020; 27:98. [PMID: 33099299 PMCID: PMC7585181 DOI: 10.1186/s12929-020-00689-0] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/16/2020] [Indexed: 02/07/2023] Open
Abstract
Post-translational modifications (PTMs) are crucial for the adaptation of various signalling pathways to ensure cellular homeostasis and proper adaptation to stress. PTM is a covalent addition of a small chemical functional group such as a phosphate group (phosphorylation), methyl group (methylation), or acetyl group (acetylation); lipids like hydrophobic isoprene polymers (isoprenylation); sugars such as a glycosyl group (glycosylation); or even small peptides such as ubiquitin (ubiquitination), SUMO (SUMOylation), NEDD8 (neddylation), etc. SUMO modification changes the function and/or fate of the protein especially under stress conditions, and the consequences of this conjugation can be appreciated from development to diverse disease processes. The impact of SUMOylation in disease has not been monotonous, rather SUMO is found playing a role on both sides of the coin either facilitating or impeding disease progression. Several recent studies have implicated SUMO proteins as key regulators in various cardiovascular disorders. The focus of this review is thus to summarize the current knowledge on the role of the SUMO family in the pathophysiology of cardiovascular diseases.
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Affiliation(s)
- Prithviraj Manohar Vijaya Shetty
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, Rosalind-Franklin Str. 12, 24105, Kiel, Germany
- Manipal Institute of Regenerative Medicine, MAHE-Bengaluru, Bangalore, India
| | - Ashraf Yusuf Rangrez
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, Rosalind-Franklin Str. 12, 24105, Kiel, Germany.
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Kiel, Germany.
| | - Norbert Frey
- Department of Internal Medicine III (Cardiology, Angiology, Intensive Care), University Medical Center Kiel, Rosalind-Franklin Str. 12, 24105, Kiel, Germany.
- DZHK (German Centre for Cardiovascular Research), Partner Site Hamburg/Kiel/Lübeck, Kiel, Germany.
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17
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Shugg T, Hudmon A, Overholser BR. Neurohormonal Regulation of I Ks in Heart Failure: Implications for Ventricular Arrhythmogenesis and Sudden Cardiac Death. J Am Heart Assoc 2020; 9:e016900. [PMID: 32865116 PMCID: PMC7726975 DOI: 10.1161/jaha.120.016900] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Heart failure (HF) results in sustained alterations in neurohormonal signaling, including enhanced signaling through the sympathetic nervous system and renin-angiotensin-aldosterone system pathways. While enhanced sympathetic nervous system and renin-angiotensin-aldosterone system activity initially help compensate for the failing myocardium, sustained signaling through these pathways ultimately contributes to HF pathophysiology. HF remains a leading cause of mortality, with arrhythmogenic sudden cardiac death comprising a common mechanism of HF-related death. The propensity for arrhythmia development in HF occurs secondary to cardiac electrical remodeling that involves pathological regulation of ventricular ion channels, including the slow component of the delayed rectifier potassium current, that contribute to action potential duration prolongation. To elucidate a mechanistic explanation for how HF-mediated electrical remodeling predisposes to arrhythmia development, a multitude of investigations have investigated the specific regulatory effects of HF-associated stimuli, including enhanced sympathetic nervous system and renin-angiotensin-aldosterone system signaling, on the slow component of the delayed rectifier potassium current. The objective of this review is to summarize the current knowledge related to the regulation of the slow component of the delayed rectifier potassium current in response to HF-associated stimuli, including the intracellular pathways involved and the specific regulatory mechanisms.
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Affiliation(s)
- Tyler Shugg
- Division of Clinical PharmacologyIndiana University School of MedicineIndianapolisIN
| | - Andy Hudmon
- Department of Medicinal Chemistry and Molecular PharmacologyPurdue University College of PharmacyWest LafayetteIN
| | - Brian R. Overholser
- Division of Clinical PharmacologyIndiana University School of MedicineIndianapolisIN
- Department of Pharmacy PracticePurdue University College of PharmacyIndianapolisIN
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18
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Li Y, Yi J, Liu W, Liu Y, Liu J. Gaining insight into cellular cardiac physiology using single particle tracking. J Mol Cell Cardiol 2020; 148:63-77. [PMID: 32871158 DOI: 10.1016/j.yjmcc.2020.08.011] [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] [Received: 01/10/2020] [Revised: 08/18/2020] [Accepted: 08/20/2020] [Indexed: 11/29/2022]
Abstract
Single particle tracking (SPT) is a robust technique to monitor single-molecule behaviors in living cells directly. By this approach, we can uncover the potential biological significance of particle dynamics by statistically characterizing individual molecular behaviors. SPT provides valuable information at the single-molecule level, that could be obscured by simple averaging that is inherent to conventional ensemble measurements. Here, we give a brief introduction to SPT including the commonly used optical implementations, fluorescence labeling strategies, and data analysis methods. We then focus on how SPT has been harnessed to decipher myocardial function. In this context, SPT has provided novel insight into the lateral diffusion of signal receptors and ion channels, the dynamic organization of cardiac nanodomains, subunit composition and stoichiometry of cardiac ion channels, myosin movement along actin filaments, the kinetic features of transcription factors involved in cardiac remodeling, and the intercellular communication by nanotubes. Finally, we speculate on the prospects and challenges of applying SPT to future questions regarding cellular cardiac physiology using SPT.
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Affiliation(s)
- Ying Li
- School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen, 518060, China.
| | - Jing Yi
- School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen, 518060, China.
| | - Wenjuan Liu
- School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen, 518060, China.
| | - Yun Liu
- The Seventh Affiliated Hospital, Sun Yat-sen University, Guangdong Province, China.
| | - Jie Liu
- School of Basic Medical Sciences, Shenzhen University Health Science Center, Shenzhen, 518060, China.
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19
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Forster LA, Jansen LAR, Rubaharan M, Murphy AZ, Baro DJ. Alterations in SUMOylation of the hyperpolarization-activated cyclic nucleotide-gated ion channel 2 during persistent inflammation. Eur J Pain 2020; 24:1517-1536. [PMID: 32446289 PMCID: PMC7496191 DOI: 10.1002/ejp.1606] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2020] [Revised: 04/28/2020] [Accepted: 05/15/2020] [Indexed: 01/08/2023]
Abstract
Background Unilateral injection of Complete Freund's Adjuvant (CFA) into the intra‐plantar surface of the rodent hindpaw elicits chronic inflammation and hyperalgesia in the ipsilateral hindlimb. Mechanisms contributing to this hyperalgesia may act over multiple time courses and can include changes in ion channel expression and post‐translational SUMOylation. Hyperpolarization‐activated, cyclic nucleotide‐gated (HCN) channels mediate the hyperpolarization‐activated current, Ih. An HCN2‐mediated increase in C‐nociceptor Ih contributes to mechanical hyperalgesia in the CFA model of inflammatory pain. Changes in HCN2 post‐translational SUMOylation and protein expression have not been systematically documented for a given dorsal root ganglia (DRG) throughout the time course of inflammation. Methods This study examined HCN2 protein expression and post‐translational SUMOylation in a rat model of CFA‐induced hindpaw inflammation. L5 DRG cryosections were used in immunohistochemistry experiments and proximity ligation assays to investigate HCN2 expression and SUMOylation, respectively, on days 1 and 3 post‐CFA. Results Unilateral CFA injection elicited a significant bilateral increase in HCN2 staining intensity in small diameter DRG neurons on day 1 post‐CFA, and a significant bilateral increase in the number of small neurons expressing HCN2 but not staining intensity on day 3 post‐CFA. HCN2 channels were hyper‐SUMOylated in small diameter neurons of ipsilateral relative to contralateral DRG on days 1 and 3 post‐CFA. Conclusions Unilateral CFA injection elicits unilateral mechanical hyperalgesia, a bilateral increase in HCN2 expression and a unilateral increase in post‐translational SUMOylation. This suggests that enhanced HCN2 expression in L5 DRG is not sufficient for mechanical hyperalgesia in the early stages of inflammation and that hyper‐SUMOylation of HCN2 channels may also be necessary. Significance Nociceptor HCN2 channels mediate an increase in Ih that is necessary for mechanical hyperalgesia in a CFA model of chronic pain, but the mechanisms producing the increase in nociceptor Ih have not been resolved. The data presented here suggest that the increase in Ih during the early stages of inflammation may be mediated by an increase in HCN2 protein expression and post‐translational SUMOylation.
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Affiliation(s)
- Lori A Forster
- Department of Biology, Georgia State University, Atlanta, GA, USA.,Neuroscience Institute, Georgia State University, Atlanta, GA, USA
| | | | | | - Anne Z Murphy
- Neuroscience Institute, Georgia State University, Atlanta, GA, USA
| | - Deborah J Baro
- Department of Biology, Georgia State University, Atlanta, GA, USA.,Neuroscience Institute, Georgia State University, Atlanta, GA, USA
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20
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Du CP, Wang M, Geng C, Hu B, Meng L, Xu Y, Cheng B, Wang N, Zhu QJ, Hou XY. Activity-Induced SUMOylation of Neuronal Nitric Oxide Synthase Is Associated with Plasticity of Synaptic Transmission and Extracellular Signal-Regulated Kinase 1/2 Signaling. Antioxid Redox Signal 2020; 32:18-34. [PMID: 31642335 DOI: 10.1089/ars.2018.7669] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
Abstract
Aims: Neuronal nitric oxide synthase (nNOS) and nitric oxide (NO) signaling have been implicated in learning, memory, and underlying long-lasting synaptic plasticity. In this study, we aimed at detecting whether nNOS is a target protein of SUMOylation in the hippocampus and its contributions to hippocampal long-term potentiation (LTP) of synaptic transmission. Results: We showed that N-methyl-d-aspartate receptor-dependent neuronal activity enhancement induced the attachment of small ubiquitin-like modifier 1 (SUMO1) to nNOS. Protein inhibitor of activated STAT3 (PIAS3) promoted SUMO1 conjugation at K725 and K739 on nNOS, which upregulated NO production and nNOS S1412 phosphorylation (activation). In addition, the N-terminus (amino acids 43-86) of PIAS3 bound nNOS directly. Tat-tagged PIAS3 segment representing amino acids 43-86, a cell-permeable peptide containing PIAS3 residues 43-86, suppressed activity-induced nNOS SUMOylation by disrupting PIAS3-nNOS association. It also decreased LTP-related expression of Arc and brain-derived neurotrophic factor and blocked signaling via extracellular signal-regulated kinase (ERK) 1/2 and Elk-1 in the hippocampus. More importantly, PIAS3-mediated nNOS SUMOylation was required for activity-regulated ERK1/2 activation in nNOS-positive neurons and hippocampal LTP induction. Innovation and Conclusion: These findings indicated that network activity-regulated nNOS SUMOylation underlies excitatory synaptic LTP by facilitating nNOS-NO-ERK1/2 signal cascades.
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Affiliation(s)
- Cai-Ping Du
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China.,State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
| | - Mei Wang
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China
| | - Chi Geng
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China.,State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
| | - Bin Hu
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China
| | - Li Meng
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China
| | - Yan Xu
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China
| | - Bao Cheng
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China
| | - Nan Wang
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China
| | - Qiu-Ju Zhu
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China
| | - Xiao-Yu Hou
- Research Center for Biochemistry and Molecular Biology, Jiangsu Key Laboratory of Brain Disease Bioinformation, Xuzhou Medical University, Xuzhou, China.,State Key Laboratory of Natural Medicines, School of Life Science and Technology, China Pharmaceutical University, Nanjing, China
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21
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Hasan R, Leo MD, Muralidharan P, Mata-Daboin A, Yin W, Bulley S, Fernandez-Peña C, MacKay CE, Jaggar JH. SUMO1 modification of PKD2 channels regulates arterial contractility. Proc Natl Acad Sci U S A 2019; 116:27095-27104. [PMID: 31822608 PMCID: PMC6936352 DOI: 10.1073/pnas.1917264116] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
PKD2 (polycystin-2, TRPP1) channels are expressed in a wide variety of cell types and can regulate functions, including cell division and contraction. Whether posttranslational modification of PKD2 modifies channel properties is unclear. Similarly uncertain are signaling mechanisms that regulate PKD2 channels in arterial smooth muscle cells (myocytes). Here, by studying inducible, cell-specific Pkd2 knockout mice, we discovered that PKD2 channels are modified by SUMO1 (small ubiquitin-like modifier 1) protein in myocytes of resistance-size arteries. At physiological intravascular pressures, PKD2 exists in approximately equal proportions as either nonsumoylated (PKD2) or triple SUMO1-modifed (SUMO-PKD2) proteins. SUMO-PKD2 recycles, whereas unmodified PKD2 is surface-resident. Intravascular pressure activates voltage-dependent Ca2+ influx that stimulates the return of internalized SUMO-PKD2 channels to the plasma membrane. In contrast, a reduction in intravascular pressure, membrane hyperpolarization, or inhibition of Ca2+ influx leads to lysosomal degradation of internalized SUMO-PKD2 protein, which reduces surface channel abundance. Through this sumoylation-dependent mechanism, intravascular pressure regulates the surface density of SUMO-PKD2-mediated Na+ currents (INa) in myocytes to control arterial contractility. We also demonstrate that intravascular pressure activates SUMO-PKD2, not PKD2, channels, as desumoylation leads to loss of INa activation in myocytes and vasodilation. In summary, this study reveals that PKD2 channels undergo posttranslational modification by SUMO1, which enables physiological regulation of their surface abundance and pressure-mediated activation in myocytes and thus control of arterial contractility.
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Affiliation(s)
- Raquibul Hasan
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163
| | - M. Dennis Leo
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163
| | | | - Alejandro Mata-Daboin
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163
| | - Wen Yin
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163
| | - Simon Bulley
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163
| | - Carlos Fernandez-Peña
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163
| | - Charles E. MacKay
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163
| | - Jonathan H. Jaggar
- Department of Physiology, University of Tennessee Health Science Center, Memphis, TN 38163
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22
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Namuduri AV, Heras G, Lauschke VM, Vitadello M, Traini L, Cacciani N, Gorza L, Gastaldello S. Expression of SUMO enzymes is fiber type dependent in skeletal muscles and is dysregulated in muscle disuse. FASEB J 2019; 34:2269-2286. [PMID: 31908008 DOI: 10.1096/fj.201901913r] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2019] [Revised: 11/06/2019] [Accepted: 11/23/2019] [Indexed: 12/27/2022]
Abstract
SUMOylation is a dynamic, reversible, enzymatic drug-targetable post-translational modification (PTM) reaction where the Small Ubiquitin-like Modifier (SUMO) moieties are attached to proteins. This reaction regulates various biological functions like cell growth, differentiation, and it is crucial for maintaining organ homeostasis. However, the actions of SUMO in skeletal muscle pathophysiology are still not investigated. In this study, we quantified the abundance of the SUMO enzymes and determined the distribution of SUMOylated proteins along the fibers of nine different muscles. We find that skeletal muscles contain a distinctive group of SUMO enzymes and SUMOylated proteins in relation to their different metabolism, functions, and fiber type composition. In addition, before the activation of protein degradation pathways, this unique set is quickly altered in response to muscle sedentariness. Finally, we demonstrated that PAX6 acts as an upstream regulator of the SUMO conjugation reaction, which can become a potential therapeutic marker to prevent muscle diseases generated by inactivity.
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Affiliation(s)
| | - Gabriel Heras
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Volker M Lauschke
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | | | - Leonardo Traini
- Helmholtz-University Group "Cell Plasticity and Epigenetic Remodeling", German Cancer Research Center (DKFZ), Heidelberg, Germany.,Institute of Pathology University Hospital, Heidelberg, Germany
| | - Nicola Cacciani
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.,Department of Clinical Neuroscience, Clinical Neurophysiology, Karolinska Institutet, Stockholm, Sweden
| | - Luisa Gorza
- Department of Biomedical Sciences, University of Padova, Padova, Italy
| | - Stefano Gastaldello
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden.,Precision Medicine Research Center, Binzhou Medical University, Yantai, China
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23
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Welch MA, Forster LA, Atlas SI, Baro DJ. SUMOylating Two Distinct Sites on the A-type Potassium Channel, Kv4.2, Increases Surface Expression and Decreases Current Amplitude. Front Mol Neurosci 2019; 12:144. [PMID: 31213982 PMCID: PMC6554448 DOI: 10.3389/fnmol.2019.00144] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2018] [Accepted: 05/17/2019] [Indexed: 12/15/2022] Open
Abstract
Post-translational conjugation of Small Ubiquitin-like Modifier (SUMO) peptides to lysine (K) residues on target proteins alters their interactions. SUMOylation of a target protein can either promote its interaction with other proteins that possess SUMO binding domains, or it can prevent target protein interactions that normally occur in the absence of SUMOylation. One subclass of voltage-gated potassium channels that mediates an A-type current, IA, exists as a ternary complex comprising Kv4 pore-forming subunits, Kv channel interacting proteins (KChIP) and transmembrane dipeptidyl peptidase like proteins (DPPL). SUMOylation could potentially regulate intra- and/or intermolecular interactions within the complex. This study began to test this hypothesis and showed that Kv4.2 channels were SUMOylated in the rat brain and in human embryonic kidney (HEK) cells expressing a GFP-tagged mouse Kv4.2 channel (Kv4.2g). Prediction software identified two putative SUMOylation sites in the Kv4.2 C-terminus at K437 and K579. These sites were conserved across mouse, rat, and human Kv4.2 channels and across mouse Kv4 isoforms. Increasing Kv4.2g SUMOylation at each site by ~30% produced a significant ~22%–50% decrease in IA Gmax, and a ~70%–95% increase in channel surface expression. Site-directed mutagenesis of Kv4.2g showed that K437 SUMOylation regulated channel surface expression, while K579 SUMOylation controlled IA Gmax. The K579R mutation mimicked and occluded the SUMOylation-mediated decrease in IA Gmax, suggesting that SUMOylation at K579 blocked an intra- or inter-protein interaction involving K579. The K437R mutation did not obviously alter channel surface expression or biophysical properties, but it did block the SUMOylation-mediated increase in channel surface expression. Interestingly, enhancing K437 SUMOylation in the K579R mutant roughly doubled channel surface expression, but produced no change in IA Gmax, suggesting that the newly inserted channels were electrically silent. This is the first report that Kv4.2 channels are SUMOylated and that SUMOylation can independently regulate Kv4.2 surface expression and IA Gmax in opposing directions. The next step will be to determine if/how SUMOylation affects Kv4 interactions within the ternary complex.
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Affiliation(s)
- Meghyn A Welch
- Department of Biology, Georgia State University, Atlanta, GA, United States
| | - Lori A Forster
- Neuroscience Institute, Georgia State University, Atlanta, GA, United States
| | - Selin I Atlas
- Department of Biology, Georgia State University, Atlanta, GA, United States
| | - Deborah J Baro
- Department of Biology, Georgia State University, Atlanta, GA, United States.,Neuroscience Institute, Georgia State University, Atlanta, GA, United States
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24
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Modulator-Gated, SUMOylation-Mediated, Activity-Dependent Regulation of Ionic Current Densities Contributes to Short-Term Activity Homeostasis. J Neurosci 2018; 39:596-611. [PMID: 30504282 DOI: 10.1523/jneurosci.1379-18.2018] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 10/23/2018] [Accepted: 11/03/2018] [Indexed: 02/07/2023] Open
Abstract
Neurons operate within defined activity limits, and feedback control mechanisms dynamically tune ionic currents to maintain this optimal range. This study describes a novel, rapid feedback mechanism that uses SUMOylation to continuously adjust ionic current densities according to changes in activity. Small ubiquitin-like modifier (SUMO) is a peptide that can be post-translationally conjugated to ion channels to influence their surface expression and biophysical properties. Neuronal activity can regulate the extent of protein SUMOylation. This study on the single, unambiguously identifiable lateral pyloric neuron (LP), a component of the pyloric network in the stomatogastric nervous system of male and female spiny lobsters (Panulirus interruptus), focused on dynamic SUMOylation in the context of activity homeostasis. There were four major findings: First, neuronal activity adjusted the balance between SUMO conjugation and deconjugation to continuously and bidirectionally fine-tune the densities of two opposing conductances: the hyperpolarization activated current (Ih) and the transient potassium current (IA). Second, tonic 5 nm dopamine (DA) gated activity-dependent SUMOylation to permit and prevent activity-dependent regulation of Ih and IA, respectively. Third, DA-gated, activity-dependent SUMOylation contributed to a feedback mechanism that restored the timing and duration of LP activity during prolonged modulation by 5 μm DA, which initially altered these and other activity features. Fourth, DA modulatory and metamoduatory (gating) effects were tailored to simultaneously alter and stabilize neuronal output. Our findings suggest that modulatory tone may select a subset of rapid activity-dependent mechanisms from a larger menu to achieve homeostasis under varying conditions.SIGNIFICANCE STATEMENT Post-translational SUMOylation of ion channel subunits controls their interactions. When subunit SUMOylation is dysregulated, conductance densities mediated by the channels are distorted, leading to nervous system disorders, such as seizures and chronic pain. Regulation of ion channel SUMOylation is poorly understood. This study demonstrated that neuronal activity can regulate SUMOylation to reconfigure ionic current densities over minutes, and this regulation was gated by tonic nanomolar dopamine. Dynamic SUMOylation was necessary to maintain specific aspects of neuronal output while the neuron was being modulated by high (5 μm) concentrations of dopamine, suggesting that the gating function may ensure neuronal homeostasis during extrinsic modulation of a circuit.
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25
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Role of human Hv1 channels in sperm capacitation and white blood cell respiratory burst established by a designed peptide inhibitor. Proc Natl Acad Sci U S A 2018; 115:E11847-E11856. [PMID: 30478045 DOI: 10.1073/pnas.1816189115] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023] Open
Abstract
Using a de novo peptide inhibitor, Corza6 (C6), we demonstrate that the human voltage-gated proton channel (hHv1) is the main pathway for H+ efflux that allows capacitation in sperm and permits sustained reactive oxygen species (ROS) production in white blood cells (WBCs). C6 was identified by a phage-display strategy whereby ∼1 million novel peptides were fabricated on an inhibitor cysteine knot (ICK) scaffold and sorting on purified hHv1 protein. Two C6 peptides bind to each dimeric channel, one on the S3-S4 loop of each voltage sensor domain (VSD). Binding is cooperative with an equilibrium affinity (K d) of ∼1 nM at -50 mV. As expected for a VSD-directed toxin, C6 inhibits by shifting hHv1 activation to more positive voltages, slowing opening and speeding closure, effects that diminish with membrane depolarization.
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26
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Strigli A, Raab C, Hessler S, Huth T, Schuldt AJT, Alzheimer C, Friedrich T, Burridge PW, Luedde M, Schwake M. Doxorubicin induces caspase-mediated proteolysis of KV7.1. Commun Biol 2018; 1:155. [PMID: 30302399 PMCID: PMC6162258 DOI: 10.1038/s42003-018-0162-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2018] [Accepted: 08/31/2018] [Indexed: 12/13/2022] Open
Abstract
Kv7.1 (KCNQ1) coassembles with KCNE1 to generate the cardiac IKs-channel. Gain- and loss-of-function mutations in KCNQ1 are associated with cardiac arrhthymias, highlighting the importance of modulating IKs activity for cardiac function. Here, we report proteolysis of Kv7.1 as an irreversible posttranslational modification. The identification of two C-terminal fragments of Kv7.1 led us to identify an aspartate critical for the generation of one of the fragments and caspases as responsible for mediating proteolysis. Activating caspases reduces Kv7.1/KCNE1 currents, which is abrogated in cells expressing caspase-resistant channels. Enhanced cleavage of Kv7.1 can be detected for the LQT mutation G460S, which is located adjacent to the cleavage site, whereas a calmodulin-binding-deficient mutation impairs cleavage. Application of apoptotic stimuli or doxorubicin-induced cardiotoxicity provokes caspase-mediated cleavage of endogenous IKs in human cardiomyocytes. In summary, caspases are novel regulatory components of IKs channels that may have important implications for the molecular mechanism of doxorubicin-induced cardiotoxicity. Anne Strigli et al. report that the voltage-gated potassium channel Kv7.1 undergoes caspase-mediated proteolytic cleavage, which reduces its cardiac activity. Their findings implicate caspases as regulators of the IKs channel complex, which may have implications for understanding drug-induced cardiotoxicity.
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Affiliation(s)
- Anne Strigli
- Institute of Biochemistry, Christian Albrechts University of Kiel, Otto-Hahn-Platz 9, 24118, Kiel, Germany
| | - Christian Raab
- Institute of Biochemistry, Christian Albrechts University of Kiel, Otto-Hahn-Platz 9, 24118, Kiel, Germany
| | - Sabine Hessler
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstr. 17, 91054, Erlangen, Germany
| | - Tobias Huth
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstr. 17, 91054, Erlangen, Germany
| | - Adam J T Schuldt
- Department of Pharmacology and Center for Pharmacogenomics, Feinberg School of Medicine, Northwestern University, 320 East Superior Street, Searle Building 8-450, Chicago, IL, 60611, USA
| | - Christian Alzheimer
- Institute of Physiology and Pathophysiology, Friedrich-Alexander-Universität Erlangen-Nürnberg, Universitätsstr. 17, 91054, Erlangen, Germany
| | - Thomas Friedrich
- Institut für Chemie PC 14, Technische Universität Berlin, Straße des 17. Juni 135, 10623, Berlin, Germany
| | - Paul W Burridge
- Department of Pharmacology and Center for Pharmacogenomics, Feinberg School of Medicine, Northwestern University, 320 East Superior Street, Searle Building 8-450, Chicago, IL, 60611, USA
| | - Mark Luedde
- Department of Internal Medicine III, University Hospital Schleswig-Holstein, Campus Kiel, Arnold-Heller-Str. 3, 24105, Kiel, Germany
| | - Michael Schwake
- Institute of Biochemistry, Christian Albrechts University of Kiel, Otto-Hahn-Platz 9, 24118, Kiel, Germany. .,Faculty of Chemistry/Biochemistry III, University of Bielefeld, Universitätsstr. 25, 33615, Bielefeld, Germany. .,Department of Neurology, Northwestern University Feinberg School of Medicine, 303 East Chicago Avenue, Chicago, IL, 60611-4296, USA.
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27
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Bruyneel AAN, McKeithan WL, Feyen DAM, Mercola M. Using iPSC Models to Probe Regulation of Cardiac Ion Channel Function. Curr Cardiol Rep 2018; 20:57. [DOI: 10.1007/s11886-018-1000-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
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28
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Abstract
Post-translational modification of substrate proteins by SUMO conjugation regulates a diverse array of cellular processes. While predominantly a nuclear protein modification, there is a growing appreciation that SUMOylation of proteins outside the nucleus plays direct roles in controlling synaptic transmission, neuronal excitability, and adaptive responses to cell stress. Furthermore, alterations in protein SUMOylation are observed in a wide range of neurological and neurodegenerative diseases, and several extranuclear disease-associated proteins have been shown to be directly SUMOylated. Here, focusing mainly on SUMOylation of synaptic and mitochondrial proteins, we outline recent developments and discoveries, and present our opinion as to the most exciting avenues for future research to define how SUMOylation of extranuclear proteins regulates neuronal and synaptic function.
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Affiliation(s)
- Jeremy M Henley
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK.
| | - Ruth E Carmichael
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK
| | - Kevin A Wilkinson
- School of Biochemistry, Centre for Synaptic Plasticity, Biomedical Sciences Building, University of Bristol, Bristol, BS8 1TD, UK.
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