1
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Weber DK, Reddy UV, Robia SL, Veglia G. Pathological mutations in the phospholamban cytoplasmic region affect its topology and dynamics modulating the extent of SERCA inhibition. BIOCHIMICA ET BIOPHYSICA ACTA. BIOMEMBRANES 2024; 1866:184370. [PMID: 38986894 DOI: 10.1016/j.bbamem.2024.184370] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/10/2024] [Revised: 06/26/2024] [Accepted: 07/02/2024] [Indexed: 07/12/2024]
Abstract
Phospholamban (PLN) is a 52 amino acid regulin that allosterically modulates the activity of the sarco(endo)plasmic reticulum Ca2+-ATPase (SERCA) in the heart muscle. In its unphosphorylated form, PLN binds SERCA within its transmembrane (TM) domains, approximately 20 Å away from the Ca2+ binding site, reducing SERCA's apparent Ca2+ affinity (pKCa) and decreasing cardiac contractility. During the enzymatic cycle, the inhibitory TM domain of PLN remains anchored to SERCA, whereas its cytoplasmic region transiently binds the ATPase's headpiece. Phosphorylation of PLN at Ser16 by protein kinase A increases the affinity of its cytoplasmic domain to SERCA, weakening the TM interactions with the ATPase, reversing its inhibitory function, and augmenting muscle contractility. How the structural changes caused by pathological mutations in the PLN cytoplasmic region are transmitted to its inhibitory TM domain is still unclear. Using solid-state NMR spectroscopy and activity assays, we analyzed the structural and functional effects of a series of mutations and their phosphorylated forms located in the PLN cytoplasmic region and linked to dilated cardiomyopathy. We found that these missense mutations affect the overall topology and dynamics of PLN and ultimately modulate its inhibitory potency. Also, the changes in the TM tilt angle and cytoplasmic dynamics of PLN caused by these mutations correlate well with the extent of SERCA inhibition. Our study unveils new molecular determinants for designing variants of PLN that outcompete endogenous PLN to regulate SERCA in a tunable manner.
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Affiliation(s)
- Daniel K Weber
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - U Venkateswara Reddy
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - Seth L Robia
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL, USA
| | - Gianluigi Veglia
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA.
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2
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Berta B, Tordai H, Lukács GL, Papp B, Enyedi Á, Padányi R, Hegedűs T. SARS-CoV-2 envelope protein alters calcium signaling via SERCA interactions. Sci Rep 2024; 14:21200. [PMID: 39261533 PMCID: PMC11391011 DOI: 10.1038/s41598-024-71144-5] [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: 03/06/2024] [Accepted: 08/26/2024] [Indexed: 09/13/2024] Open
Abstract
The clinical management of severe COVID-19 cases is not yet well resolved. Therefore, it is important to identify and characterize cell signaling pathways involved in virus pathogenesis that can be targeted therapeutically. Envelope (E) protein is a structural protein of the virus, which is known to be highly expressed in the infected host cell and is a key virulence factor; however, its role is poorly characterized. The E protein is a single-pass transmembrane protein that can assemble into a pentamer forming a viroporin, perturbing Ca2+ homeostasis. Because it is structurally similar to regulins such as, for example, phospholamban, that regulate the sarco/endoplasmic reticulum calcium ATPases (SERCA), we investigated whether the SARS-CoV-2 E protein affects the SERCA system as an exoregulin. Using FRET experiments we demonstrate that E protein can form oligomers with regulins, and thus can alter the monomer/multimer regulin ratio and consequently influence their interactions with SERCAs. We also confirm that a direct interaction between E protein and SERCA2b results in a decrease in SERCA-mediated ER Ca2+ reload. Structural modeling of the complexes indicates an overlapping interaction site for E protein and endogenous regulins. Our results reveal novel links in the host-virus interaction network that play an important role in viral pathogenesis and may provide a new therapeutic target for managing severe inflammatory responses induced by SARS-CoV-2.
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Affiliation(s)
- Blanka Berta
- Institute of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Hedvig Tordai
- Institute of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary
| | - Gergely L Lukács
- Department of Physiology, McGill University, Montréal, QC, Canada
| | - Béla Papp
- INSERM UMR U976, Hôpital Saint-Louis, Paris, France
- Institut de Recherche Saint-Louis, Hôpital Saint-Louis, Université de Paris, Paris, France
- CEA, DRF-Institut Francois Jacob, Department of Hemato-Immunology Research, Hôpital Saint-Louis, Paris, France
| | - Ágnes Enyedi
- Department of Transfusiology, Semmelweis University, Budapest, Hungary
| | - Rita Padányi
- Institute of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary.
| | - Tamás Hegedűs
- Institute of Biophysics and Radiation Biology, Semmelweis University, Budapest, Hungary.
- HUN-REN-SU Biophysical Virology Research Group, Eötvös Loránd Research Network, Budapest, Hungary.
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3
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Rathod N, Lemieux MJ, Chipot C, Roux B, Young HS. Probing the formation of a hetero-dimeric membrane transport complex with dual in vitro and in silico mutagenesis. Chem Sci 2024:d4sc02915a. [PMID: 39156929 PMCID: PMC11322925 DOI: 10.1039/d4sc02915a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2024] [Accepted: 08/05/2024] [Indexed: 08/20/2024] Open
Abstract
The reversible association of transmembrane helices is a fundamental mechanism in how living cells convey information and respond to physiological events. The cardiac calcium transport regulator phospholamban (PLN) is an example of a single-span transmembrane protein that populates a variety of reversible and competing oligomeric states. PLN primarily forms monomers and pentamers in the membrane, where the PLN pentamer is a storage form and the PLN monomer forms a hetero-dimeric inhibitory complex with SERCA. The binding affinity and free-energy of formation of the SERCA-PLN complex in a membrane have not been determined. As is the case for most transmembrane protein interactions, measuring these quantities experimentally is extremely challenging. In this study, we estimated binding affinities by employing in silico alchemical free-energy calculations for all PLN transmembrane alanine substitutions in a membrane bilayer. The binding affinities were calculated separately for the SERCA-PLN complex, a PLN monomer, and a PLN pentamer and compared to in vitro functional measurements of SERCA regulation by the PLN alanine substitutions. Initially, the changes in SERCA inhibition by PLN alanine substitutions were compared to the changes in free energy for the SERCA-PLN complex formed from the PLN monomer. However, the functional data for the PLN alanine substitutions were better explained by the formation of the SERCA-PLN complex directly from the PLN pentamer. This finding points to an inhibitory mechanism favoring conformational selection of SERCA and the interaction of a PLN pentamer with SERCA for 'delivery' of a PLN monomer to the inhibitory site. The implications of these findings suggest that the energetics of helix exchange between homo- and hetero-oligomeric signaling complexes is favored over an intermediate involving a free monomeric helix in the membrane bilayer.
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Affiliation(s)
- Nishadh Rathod
- Department of Biochemistry, University of Alberta Edmonton Alberta Canada T6G 2H7 +1 (780) 492-3931 +1 (780) 492-3931
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta Edmonton Alberta Canada T6G 2H7 +1 (780) 492-3931 +1 (780) 492-3931
| | - Christophe Chipot
- Department of Biochemistry and Molecular Biology, University of Chicago Chicago USA 60637
- Laboratoire International Associé Centre National de la Recherche Scientifique et University of Illinois at Urbana-Champaign, Unité Mixte de Recherche no. 7019, Université de Lorraine B.P. 70239, 54506 Vandœuvre-lès-Nancy Cedex France
- Theoretical and Computational Biophysics Group, Beckman Institute, Department of Physics, University of Illinois at Urbana-Champaign Urbana Illinois 61801 USA
| | - Benoît Roux
- Department of Biochemistry and Molecular Biology, University of Chicago Chicago USA 60637
| | - Howard S Young
- Department of Biochemistry, University of Alberta Edmonton Alberta Canada T6G 2H7 +1 (780) 492-3931 +1 (780) 492-3931
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4
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Roopnarine O, Thomas DD. Structural Dynamics of Protein Interactions Using Site-Directed Spin Labeling of Cysteines to Measure Distances and Rotational Dynamics with EPR Spectroscopy. APPLIED MAGNETIC RESONANCE 2024; 55:79-100. [PMID: 38371230 PMCID: PMC10868710 DOI: 10.1007/s00723-023-01623-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/14/2023] [Revised: 09/19/2023] [Accepted: 09/22/2023] [Indexed: 02/20/2024]
Abstract
Here we review applications of site-directed spin labeling (SDSL) with engineered cysteines in proteins, to study the structural dynamics of muscle and non-muscle proteins, using and developing the electron paramagnetic resonance (EPR) spectroscopic techniques of dipolar EPR, double electron electron resonance (DEER), saturation transfer EPR (STEPR), and orientation measured by EPR. The SDSL technology pioneered by Wayne Hubbell and collaborators has greatly expanded the use of EPR, including the measurement of distances between spin labels covalently attached to proteins and peptides. The Thomas lab and collaborators have applied these techniques to elucidate dynamic interactions in the myosin-actin complex, myosin-binding protein C, calmodulin, ryanodine receptor, phospholamban, utrophin, dystrophin, β-III-spectrin, and Aurora kinase. The ability to design and engineer cysteines in proteins for site-directed covalent labeling has enabled the use of these powerful EPR techniques to measure distances, while showing that they are complementary with optical spectroscopy measurements.
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Affiliation(s)
- Osha Roopnarine
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
| | - David D. Thomas
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN 55455, USA
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5
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Kanazawa Y, Takahashi T, Nagano M, Koinuma S, Shigeyoshi Y. The Effects of Aging on Sarcoplasmic Reticulum-Related Factors in the Skeletal Muscle of Mice. Int J Mol Sci 2024; 25:2148. [PMID: 38396828 PMCID: PMC10889371 DOI: 10.3390/ijms25042148] [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: 12/30/2023] [Revised: 02/04/2024] [Accepted: 02/06/2024] [Indexed: 02/25/2024] Open
Abstract
The pathogenesis of sarcopenia includes the dysfunction of calcium homeostasis associated with the sarcoplasmic reticulum; however, the localization in sarcoplasmic reticulum-related factors and differences by myofiber type remain unclear. Here, we investigated the effects of aging on sarcoplasmic reticulum-related factors in the soleus (slow-twitch) and gastrocnemius (fast-twitch) muscles of 3- and 24-month-old male C57BL/6J mice. There were no notable differences in the skeletal muscle weight of these 3- and 24-month-old mice. The expression of Atp2a1, Atp2a2, Sln, and Pln increased with age in the gastrocnemius muscles, but not in the soleus muscles. Subsequently, immunohistochemical analysis revealed ectopic sarcoplasmic reticulum calcium ion ATPase (SERCA) 1 and SERCA2a immunoreactivity only in the gastrocnemius muscles of old mice. Histochemical and transmission electron microscope analysis identified tubular aggregate (TA), an aggregation of the sarcoplasmic reticulum, in the gastrocnemius muscles of old mice. Dihydropyridine receptor α1, ryanodine receptor 1, junctophilin (JPH) 1, and JPH2, which contribute to sarcoplasmic reticulum function, were also localized in or around the TA. Furthermore, JPH1 and JPH2 co-localized with matrix metalloproteinase (MMP) 2 around the TA. These results suggest that sarcoplasmic reticulum-related factors are localized in or around TAs that occur in fast-twitch muscle with aging, but some of them might be degraded by MMP2.
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Affiliation(s)
- Yuji Kanazawa
- Department of Physical Therapy, Hokuriku University, Kanazawa 920-1180, Ishikawa, Japan
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama 589-8511, Osaka, Japan; (M.N.); (S.K.); (Y.S.)
| | - Tatsuo Takahashi
- Department of Clinical Pharmacology, Hokuriku University, Kanazawa 920-1181, Ishikawa, Japan;
| | - Mamoru Nagano
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama 589-8511, Osaka, Japan; (M.N.); (S.K.); (Y.S.)
| | - Satoshi Koinuma
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama 589-8511, Osaka, Japan; (M.N.); (S.K.); (Y.S.)
| | - Yasufumi Shigeyoshi
- Department of Anatomy and Neurobiology, Faculty of Medicine, Kindai University, Osakasayama 589-8511, Osaka, Japan; (M.N.); (S.K.); (Y.S.)
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Gasch K, Hykollari A, Habe M, Haubensak P, Painer-Gigler J, Smith S, Stalder G, Arnold W. Summer fades, deer change: Photoperiodic control of cellular seasonal acclimatization of skeletal muscle. iScience 2024; 27:108619. [PMID: 38155774 PMCID: PMC10753075 DOI: 10.1016/j.isci.2023.108619] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2023] [Revised: 10/23/2023] [Accepted: 11/30/2023] [Indexed: 12/30/2023] Open
Abstract
We found major seasonal changes of polyunsaturated fatty acids (PUFAs) in muscular phospholipids (PL) in a large non-hibernating mammal, the red deer (Cervus elaphus). Dietary supply of essential linoleic acid (LA) and α-linolenic acid (ALA) had no, or only weak influence, respectively. We further found correlations of PL PUFA concentrations with the activity of key metabolic enzymes, independent of higher winter expression. Activity of the sarcoplasmic reticulum (SR) Ca++-ATPase increased with SR PL concentrations of n-6 PUFA, and of cytochrome c oxidase and citrate synthase, indicators of ATP-production, with concentrations of eicosapentaenoic acid in mitochondrial PL. All detected cyclic molecular changes were controlled by photoperiod and are likely of general relevance for mammals living in seasonal environments, including humans. During winter, these changes at the molecular level presumably compensate for Arrhenius effects in the colder peripheral body parts and thus enable a thrifty life at lower body temperature.
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Affiliation(s)
- Kristina Gasch
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
| | - Alba Hykollari
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
| | - Manuela Habe
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
| | - Patricia Haubensak
- Konrad Lorenz Institute of Ethology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
| | - Johanna Painer-Gigler
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
| | - Steve Smith
- Konrad Lorenz Institute of Ethology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
| | - Gabrielle Stalder
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
| | - Walter Arnold
- Research Institute of Wildlife Ecology, Department of Interdisciplinary Life Science, University of Veterinary Medicine Vienna, 1160 Vienna, Austria
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7
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Rathod N, Guerrero-Serna G, Young HS, Espinoza-Fonseca LM. Replacement of Lys27 by asparagine in the SERCA regulator myoregulin: A Ca 2+ affinity modulator or a catalytic activity switch? BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119613. [PMID: 37918638 DOI: 10.1016/j.bbamcr.2023.119613] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/04/2023] [Revised: 09/06/2023] [Accepted: 10/16/2023] [Indexed: 11/04/2023]
Abstract
Myoregulin (MLN) is a protein that regulates the activity of the sarcoplasmic reticulum Ca2+-ATPase (SERCA) without affecting its affinity for Ca2+. MLN's residue Lys27 is located at a site where other SERCA regulators control Ca2+ affinity. Therefore, we conducted atomistic simulations and ATPase activity experiments to determine whether replacing Lys27 with asparagine, a conserved residue found in various muscle SERCA regulators, would enable MLN to modulate both the Ca2+ affinity and catalytic activity of SERCA. Our findings indicate that replacing Lys27 with Asn significantly enhances the inhibitory potency of MLN, but it does not affect SERCA's affinity for Ca2+. We suggest that the SERCA site modulating Ca2+ affinity also acts as a catalytic activity switch. Therefore, this site is a key element contributing to the functional divergence among homologous SERCA regulators. This study paves the way for future investigations to explore how biological function diverges during the evolution of the SERCA regulator family.
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Affiliation(s)
- Nishadh Rathod
- Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - Guadalupe Guerrero-Serna
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Howard S Young
- Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - L Michel Espinoza-Fonseca
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA.
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8
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Šeflová J, Cruz-Cortés C, Guerrero-Serna G, Robia SL, Espinoza-Fonseca LM. Mechanisms for cardiac calcium pump activation by its substrate and a synthetic allosteric modulator using fluorescence lifetime imaging. PNAS NEXUS 2024; 3:pgad453. [PMID: 38222469 PMCID: PMC10785037 DOI: 10.1093/pnasnexus/pgad453] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 06/20/2023] [Accepted: 12/15/2023] [Indexed: 01/16/2024]
Abstract
The discovery of allosteric modulators is an emerging paradigm in drug discovery, and signal transduction is a subtle and dynamic process that is challenging to characterize. We developed a time-correlated single photon-counting imaging approach to investigate the structural mechanisms for small-molecule activation of the cardiac sarcoplasmic reticulum Ca2+-ATPase, a pharmacologically important pump that transports Ca2+ at the expense of adenosine triphosphate (ATP) hydrolysis. We first tested whether the dissociation of sarcoplasmic reticulum Ca2+-ATPase from its regulatory protein phospholamban is required for small-molecule activation. We found that CDN1163, a validated sarcoplasmic reticulum Ca2+-ATPase activator, does not have significant effects on the stability of the sarcoplasmic reticulum Ca2+-ATPase-phospholamban complex. Time-correlated single photon-counting imaging experiments using the nonhydrolyzable ATP analog β,γ-Methyleneadenosine 5'-triphosphate (AMP-PCP) showed ATP is an allosteric modulator of sarcoplasmic reticulum Ca2+-ATPase, increasing the fraction of catalytically competent structures at physiologically relevant Ca2+ concentrations. Unlike ATP, CDN1163 alone has no significant effects on the Ca2+-dependent shifts in the structural populations of sarcoplasmic reticulum Ca2+-ATPase, and it does not increase the pump's affinity for Ca2+ ions. However, we found that CDN1163 enhances the ATP-mediated modulatory effects to increase the population of catalytically competent sarcoplasmic reticulum Ca2+-ATPase structures. Importantly, this structural shift occurs within the physiological window of Ca2+ concentrations at which sarcoplasmic reticulum Ca2+-ATPase operates. We demonstrated that ATP is both a substrate and modulator of sarcoplasmic reticulum Ca2+-ATPase and showed that CDN1163 and ATP act synergistically to populate sarcoplasmic reticulum Ca2+-ATPase structures that are primed for phosphorylation. This study provides novel insights into the structural mechanisms for sarcoplasmic reticulum Ca2+-ATPase activation by its substrate and a synthetic allosteric modulator.
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Affiliation(s)
- Jaroslava Šeflová
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL 60153, USA
| | - Carlos Cruz-Cortés
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Guadalupe Guerrero-Serna
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Seth L Robia
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL 60153, USA
| | - L Michel Espinoza-Fonseca
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
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9
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Sahgal A, Uversky V, Davé V. Microproteins transitioning into a new Phase: Defining the undefined. Methods 2023; 220:38-54. [PMID: 37890707 DOI: 10.1016/j.ymeth.2023.10.009] [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: 09/01/2023] [Revised: 10/19/2023] [Accepted: 10/21/2023] [Indexed: 10/29/2023] Open
Abstract
Recent advancements in omics technologies have unveiled a hitherto unknown group of short polypeptides called microproteins (miPs). Despite their size, accumulating evidence has demonstrated that miPs exert varied and potent biological functions. They act in paracrine, juxtracrine, and endocrine fashion, maintaining cellular physiology and driving diseases. The present study focuses on biochemical and biophysical analysis and characterization of twenty-four human miPs using distinct computational methods, including RIDAO, AlphaFold2, D2P2, FuzDrop, STRING, and Emboss Pep wheel. miPs often lack well-defined tertiary structures and may harbor intrinsically disordered regions (IDRs) that play pivotal roles in cellular functions. Our analyses define the physicochemical properties of an essential subset of miPs, elucidating their structural characteristics and demonstrating their propensity for driving or participating in liquid-liquid phase separation (LLPS) and intracellular condensate formation. Notably, miPs such as NoBody and pTUNAR revealed a high propensity for LLPS, implicating their potential involvement in forming membrane-less organelles (MLOs) during intracellular LLPS and condensate formation. The results of our study indicate that miPs have functionally profound implications in cellular compartmentalization and signaling processes essential for regulating normal cellular functions. Taken together, our methodological approach explains and highlights the biological importance of these miPs, providing a deeper understanding of the unusual structural landscape and functionality of these newly defined small proteins. Understanding their functions and biological behavior will aid in developing targeted therapies for diseases that involve miPs.
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Affiliation(s)
- Aayushi Sahgal
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, United States; Biotechnology Graduate Program, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, United States
| | - Vladimir Uversky
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, United States; USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, United States
| | - Vrushank Davé
- Department of Molecular Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, United States; Biotechnology Graduate Program, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, United States; Department of Pathology and Cell Biology, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, United States; Department of Oncologic Sciences, Morsani College of Medicine, University of South Florida, Tampa, FL 33612, United States.
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10
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Fan RF, Chen XW, Cui H, Fu HY, Xu WX, Li JZ, Lin H. Selenoprotein K knockdown induces apoptosis in skeletal muscle satellite cells via calcium dyshomeostasis-mediated endoplasmic reticulum stress. Poult Sci 2023; 102:103053. [PMID: 37716231 PMCID: PMC10507440 DOI: 10.1016/j.psj.2023.103053] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/06/2023] [Revised: 08/17/2023] [Accepted: 08/17/2023] [Indexed: 09/18/2023] Open
Abstract
Skeletal muscle satellite cells (SMSCs), known as muscle stem cells, play an important role in muscle embryonic development, post-birth growth, and regeneration after injury. Selenoprotein K (SELENOK), an endoplasmic reticulum (ER) resident selenoprotein, is known to regulate calcium ion (Ca2+) flux and ER stress (ERS). SELENOK deficiency is involved in dietary selenium deficiency-induced muscle injury, but the regulatory mechanisms of SELENOK in SMSCs development remain poorly explored in chicken. Here, we established a SELENOK deficient model to explore the role of SELENOK in SMSCs. SELENOK knockdown inhibited SMSCs proliferation and differentiation by regulating the protein levels of paired box 7 (Pax7), myogenic factor 5 (Myf5), CyclinD1, myogenic differentiation (MyoD), and Myf6. Further analysis exhibited that SELENOK knockdown markedly activated the ERS signaling pathways, which ultimately induced apoptosis in SMSCs. SELENOK knockdown-induced ERS is related with ER Ca2+ ([Ca2+]ER) overload via decreasing the protein levels of STIM2, Orai1, palmitoylation of inositol 1,4,5-trisphosphate receptor 1 (IP3R1), phospholamban (PLN), and plasma membrane Ca2+-ATPase (PMCA) while increasing the protein levels of sarco/endoplasmic Ca2+-ATPase 1 (SERCA1) and Na+/Ca2+ exchanger 1 (NCX1). Moreover, thimerosal, an activator of IP3R1, reversed the overload of [Ca2+]ER, ERS, and subsequent apoptosis caused by SELENOK knockdown. These findings indicated that SELENOK knockdown triggered ERS driven by intracellular Ca2+ dyshomeostasis and further induced apoptosis, which ultimately inhibited SMSCs proliferation and differentiation.
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Affiliation(s)
- Rui-Feng Fan
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China
| | - Xue-Wei Chen
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China
| | - Han Cui
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China
| | - Hong-Yu Fu
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China
| | - Wan-Xue Xu
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China
| | - Jiu-Zhi Li
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China
| | - Hai Lin
- College of Animal Science and Veterinary Medicine, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; Shandong Provincial Engineering Technology Research Center of Animal Disease Control and Prevention, Shandong Agricultural University, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China; State Key Laboratory of Crop Biology, College of Life Sciences, 61 Daizong Street, Tai'an City, Shandong Province, 271018, China.
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11
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Dowling P, Swandulla D, Ohlendieck K. Biochemical and proteomic insights into sarcoplasmic reticulum Ca 2+-ATPase complexes in skeletal muscles. Expert Rev Proteomics 2023; 20:125-142. [PMID: 37668143 DOI: 10.1080/14789450.2023.2255743] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2023] [Revised: 07/07/2023] [Accepted: 08/14/2023] [Indexed: 09/06/2023]
Abstract
INTRODUCTION Skeletal muscles contain large numbers of high-molecular-mass protein complexes in elaborate membrane systems. Integral membrane proteins are involved in diverse cellular functions including the regulation of ion handling, membrane homeostasis, energy metabolism and force transmission. AREAS COVERED The proteomic profiling of membrane proteins and large protein assemblies in skeletal muscles are outlined in this article. This includes a critical overview of the main biochemical separation techniques and the mass spectrometric approaches taken to study membrane proteins. As an illustrative example of an analytically challenging large protein complex, the proteomic detection and characterization of the Ca2+-ATPase of the sarcoplasmic reticulum is discussed. The biological role of this large protein complex during normal muscle functioning, in the context of fiber type diversity and in relation to mechanisms of physiological adaptations and pathophysiological abnormalities is evaluated from a proteomics perspective. EXPERT OPINION Mass spectrometry-based muscle proteomics has decisively advanced the field of basic and applied myology. Although it is technically challenging to study membrane proteins, innovations in protein separation methodology in combination with sensitive mass spectrometry and improved systems bioinformatics has allowed the detailed proteomic detection and characterization of skeletal muscle membrane protein complexes, such as Ca2+-pump proteins of the sarcoplasmic reticulum.
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Affiliation(s)
- Paul Dowling
- Department of Biology, Maynooth University, National University of Ireland, Maynooth Kildare, Ireland
- Kathleen Lonsdale Institute for Human Health Research, Maynooth University, Maynooth Kildare, Ireland
| | - Dieter Swandulla
- Institute of Physiology, Medical Faculty, University of Bonn, Bonn, Germany
| | - Kay Ohlendieck
- Department of Biology, Maynooth University, National University of Ireland, Maynooth Kildare, Ireland
- Kathleen Lonsdale Institute for Human Health Research, Maynooth University, Maynooth Kildare, Ireland
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12
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Roopnarine O, Yuen SL, Thompson AR, Roelike LN, Rebbeck RT, Bidwell PA, Aldrich CC, Cornea RL, Thomas DD. Fluorescence lifetime FRET assay for live-cell high-throughput screening of the cardiac SERCA pump yields multiple classes of small-molecule allosteric modulators. Sci Rep 2023; 13:10673. [PMID: 37393380 PMCID: PMC10314922 DOI: 10.1038/s41598-023-37704-x] [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: 02/16/2023] [Accepted: 06/26/2023] [Indexed: 07/03/2023] Open
Abstract
We have used FRET-based biosensors in live cells, in a robust high-throughput screening (HTS) platform, to identify small-molecules that alter the structure and activity of the cardiac sarco/endoplasmic reticulum calcium ATPase (SERCA2a). Our primary aim is to discover drug-like small-molecule activators that improve SERCA's function for the treatment of heart failure. We have previously demonstrated the use of an intramolecular FRET biosensor, based on human SERCA2a, by screening two different small validation libraries using novel microplate readers that detect the fluorescence lifetime or emission spectrum with high speed, precision, and resolution. Here we report results from FRET-HTS of 50,000 compounds using the same biosensor, with hit compounds functionally evaluated using assays for Ca2+-ATPase activity and Ca2+-transport. We focused on 18 hit compounds, from which we identified eight structurally unique scaffolds and four scaffold classes as SERCA modulators, approximately half of which are activators and half are inhibitors. Five of these compounds were identified as promising SERCA activators, one of which activates Ca2+-transport even more than Ca2+-ATPase activity thus improving SERCA efficiency. While both activators and inhibitors have therapeutic potential, the activators establish the basis for future testing in heart disease models and lead development, toward pharmaceutical therapy for heart failure.
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Affiliation(s)
- Osha Roopnarine
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
| | - Samantha L Yuen
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Andrew R Thompson
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Lauren N Roelike
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Robyn T Rebbeck
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - Philip A Bidwell
- Department of Medicine, Cardiovascular Division, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Courtney C Aldrich
- Department of Medicinal Chemistry, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Razvan L Cornea
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology and Biophysics, University of Minnesota, Minneapolis, MN, USA.
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13
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Hassel KR, Brito-Estrada O, Makarewich CA. Microproteins: Overlooked regulators of physiology and disease. iScience 2023; 26:106781. [PMID: 37213226 PMCID: PMC10199267 DOI: 10.1016/j.isci.2023.106781] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/23/2023] Open
Abstract
Ongoing efforts to generate a complete and accurate annotation of the genome have revealed a significant blind spot for small proteins (<100 amino acids) originating from short open reading frames (sORFs). The recent discovery of numerous sORF-encoded proteins, termed microproteins, that play diverse roles in critical cellular processes has ignited the field of microprotein biology. Large-scale efforts are currently underway to identify sORF-encoded microproteins in diverse cell-types and tissues and specialized methods and tools have been developed to aid in their discovery, validation, and functional characterization. Microproteins that have been identified thus far play important roles in fundamental processes including ion transport, oxidative phosphorylation, and stress signaling. In this review, we discuss the optimized tools available for microprotein discovery and validation, summarize the biological functions of numerous microproteins, outline the promise for developing microproteins as therapeutic targets, and look forward to the future of the field of microprotein biology.
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Affiliation(s)
- Keira R. Hassel
- The Heart Institute, Division of Molecular Cardiovascular Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
- University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Omar Brito-Estrada
- The Heart Institute, Division of Molecular Cardiovascular Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
- University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
| | - Catherine A. Makarewich
- The Heart Institute, Division of Molecular Cardiovascular Biology, Cincinnati Children’s Hospital Medical Center, Cincinnati, OH 45229, USA
- Department of Pediatrics, University of Cincinnati College of Medicine, Cincinnati, OH 45229, USA
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14
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Pierantozzi E, Raucci L, Buonocore S, Rubino EM, Ding Q, Laurino A, Fiore F, Soldaini M, Chen J, Rossi D, Vangheluwe P, Chen H, Sorrentino V. Skeletal muscle overexpression of sAnk1.5 in transgenic mice does not predispose to type 2 diabetes. Sci Rep 2023; 13:8195. [PMID: 37210436 PMCID: PMC10199891 DOI: 10.1038/s41598-023-35393-0] [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: 01/09/2023] [Accepted: 05/17/2023] [Indexed: 05/22/2023] Open
Abstract
Genome-wide association studies (GWAS) and cis-expression quantitative trait locus (cis-eQTL) analyses indicated an association of the rs508419 single nucleotide polymorphism (SNP) with type 2 diabetes (T2D). rs508419 is localized in the muscle-specific internal promoter (P2) of the ANK1 gene, which drives the expression of the sAnk1.5 isoform. Functional studies showed that the rs508419 C/C variant results in increased transcriptional activity of the P2 promoter, leading to higher levels of sAnk1.5 mRNA and protein in skeletal muscle biopsies of individuals carrying the C/C genotype. To investigate whether sAnk1.5 overexpression in skeletal muscle might predispose to T2D development, we generated transgenic mice (TgsAnk1.5/+) in which the sAnk1.5 coding sequence was selectively overexpressed in skeletal muscle tissue. TgsAnk1.5/+ mice expressed up to 50% as much sAnk1.5 protein as wild-type (WT) muscles, mirroring the difference reported between individuals with the C/C or T/T genotype at rs508419. However, fasting glucose levels, glucose tolerance, insulin levels and insulin response in TgsAnk1.5/+ mice did not differ from those of age-matched WT mice monitored over a 12-month period. Even when fed a high-fat diet, TgsAnk1.5/+ mice only presented increased caloric intake, but glucose disposal, insulin tolerance and weight gain were comparable to those of WT mice fed a similar diet. Altogether, these data indicate that sAnk1.5 overexpression in skeletal muscle does not predispose mice to T2D susceptibility.
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Affiliation(s)
- E Pierantozzi
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - L Raucci
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - S Buonocore
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - E M Rubino
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - Q Ding
- Department of Cardio-Thoracic Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, 210008, Jiangsu, China
| | - A Laurino
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - F Fiore
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - M Soldaini
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
| | - J Chen
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, Katholieke Universiteit Leuven (KU Leuven), 3000, Leuven, Belgium
| | - D Rossi
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy
- Interdepartmental Program of Molecular Diagnosis and Pathogenetic Mechanisms of Rare Genetic Diseases, Azienda Ospedaliera Universitaria Senese, 53100, Siena, Italy
| | - P Vangheluwe
- Laboratory of Cellular Transport Systems, Department of Cellular and Molecular Medicine, Katholieke Universiteit Leuven (KU Leuven), 3000, Leuven, Belgium
| | - H Chen
- Department of Cardio-Thoracic Surgery, Nanjing Drum Tower Hospital, Nanjing University Medical School, Nanjing, 210008, Jiangsu, China
- Programme in Cardiovascular and Metabolic Disorders, Duke-NUS Medical School, 8 College Road, Singapore, 169857, Singapore
| | - V Sorrentino
- Department of Molecular and Developmental Medicine, University of Siena, 53100, Siena, Italy.
- Interdepartmental Program of Molecular Diagnosis and Pathogenetic Mechanisms of Rare Genetic Diseases, Azienda Ospedaliera Universitaria Senese, 53100, Siena, Italy.
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15
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Zanotti S, Ripolone M, Napoli L, Velardo D, Salani S, Ciscato P, Priori S, Kukavica D, Mazzanti A, Diamanti L, Vegezzi E, Moggio M, Corti S, Comi G, Sciacco M. Characterization of Skeletal Muscle Biopsy and Derived Myoblasts in a Patient Carrying Arg14del Mutation in Phospholamban Gene. Cells 2023; 12:1405. [PMID: 37408239 DOI: 10.3390/cells12101405] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2023] [Revised: 05/10/2023] [Accepted: 05/15/2023] [Indexed: 07/07/2023] Open
Abstract
Phospholamban is involved in the regulation of the activity and storage of calcium in cardiac muscle. Several mutations have been identified in the PLN gene causing cardiac disease associated with arrhythmogenic and dilated cardiomyopathy. The patho-mechanism underlying PLN mutations is not fully understood and a specific therapy is not yet available. PLN mutated patients have been deeply investigated in cardiac muscle, but very little is known about the effect of PLN mutations in skeletal muscle. In this study, we investigated both histological and functional features in skeletal muscle tissue and muscle-derived myoblasts from an Italian patient carrying the Arg14del mutation in PLN. The patient has a cardiac phenotype, but he also reported lower limb fatigability, cramps and fasciculations. The evaluation of a skeletal muscle biopsy showed histological, immunohistochemical and ultrastructural alterations. In particular, we detected an increase in the number of centronucleated fibers and a reduction in the fiber cross sectional area, an alteration in p62, LC3 and VCP proteins and the formation of perinuclear aggresomes. Furthermore, the patient's myoblasts showed a greater propensity to form aggresomes, even more marked after proteasome inhibition compared with control cells. Further genetic and functional studies are necessary to understand whether a definition of PLN myopathy, or cardiomyopathy plus, can be introduced for selected cases with clinical evidence of skeletal muscle involvement. Including skeletal muscle examination in the diagnostic process of PLN-mutated patients can help clarify this issue.
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Affiliation(s)
- Simona Zanotti
- Neuromuscular and Rare Disease Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
| | - Michela Ripolone
- Neuromuscular and Rare Disease Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
| | - Laura Napoli
- Neuromuscular and Rare Disease Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
| | - Daniele Velardo
- Neuromuscular and Rare Disease Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
| | - Sabrina Salani
- Neurology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
| | - Patrizia Ciscato
- Neuromuscular and Rare Disease Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
| | - Silvia Priori
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Department of Molecular Cardiology, IRCCS ICS Maugeri, 27100 Pavia, Italy
- Laboratory of Molecular Cardiology, Centro Nacional de Investigaciones Cardiovasculares Carlos III, 28029 Madrid, Spain
| | - Deni Kukavica
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Department of Molecular Cardiology, IRCCS ICS Maugeri, 27100 Pavia, Italy
- Laboratory of Molecular Cardiology, Centro Nacional de Investigaciones Cardiovasculares Carlos III, 28029 Madrid, Spain
| | - Andrea Mazzanti
- Department of Molecular Medicine, University of Pavia, 27100 Pavia, Italy
- Department of Molecular Cardiology, IRCCS ICS Maugeri, 27100 Pavia, Italy
- Laboratory of Molecular Cardiology, Centro Nacional de Investigaciones Cardiovasculares Carlos III, 28029 Madrid, Spain
| | - Luca Diamanti
- Neuroncology Unit, IRCCS Mondino Foundation, 27100 Pavia, Italy
| | - Elisa Vegezzi
- Department of Brain and Behavioral Sciences, University of Pavia, 27100 Pavia, Italy
- IRCCS Mondino Foundation, 27100 Pavia, Italy
| | - Maurizio Moggio
- Neuromuscular and Rare Disease Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
| | - Stefania Corti
- Neurology Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, 20122 Milan, Italy
- Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), University of Milan, 20122 Milan, Italy
| | - Giacomo Comi
- Neuromuscular and Rare Disease Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
- Dino Ferrari Centre, Department of Pathophysiology and Transplantation (DEPT), University of Milan, 20122 Milan, Italy
| | - Monica Sciacco
- Neuromuscular and Rare Disease Unit, Fondazione IRCCS Ca' Granda Ospedale Maggiore Policlinico, Via Francesco Sforza 35, 20122 Milan, Italy
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16
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Galis P, Bartosova L, Farkasova V, Szobi A, Horvath C, Kovacova D, Adameova A, Rajtik T. Intermittent Hypoxic Preconditioning Plays a Cardioprotective Role in Doxorubicin-Induced Cardiomyopathy. Cardiovasc Toxicol 2023:10.1007/s12012-023-09793-7. [PMID: 37119387 DOI: 10.1007/s12012-023-09793-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2022] [Accepted: 04/14/2023] [Indexed: 05/01/2023]
Abstract
Intermittent hypoxic preconditioning (IHP) is a well-established cardioprotective intervention in models of ischemia/reperfusion injury. Nevertheless, the significance of IHP in different cardiac pathologies remains elusive. In order to investigate the role of IHP and its effects on calcium-dependent signalization in HF, we employed a model of cardiomyopathy induced by doxorubicin (Dox), a widely used drug from the class of cardiotoxic antineoplastics, which was i.p. injected to Wistar rats (4 applications of 4 mg/kg/week). IHP-treated group was exposed to IHP for 2 weeks prior to Dox administration. IHP ameliorated Dox-induced reduction in cardiac output. Western blot analysis revealed increased expression of sarco/endoplasmic reticulum Ca2+-ATPase (SERCA2a) while the expression of hypoxia inducible factor (HIF)-1-α, which is a crucial regulator of hypoxia-inducible genes, was not changed. Animals administered with Dox had further decreased expression of TRPV1 and TRPV4 (transient receptor potential, vanilloid subtype) ion channels along with suppressed Ca2+/calmodulin-dependent protein kinase II (CaMKII) activation. In summary, IHP-mediated improvement in cardiac output in the model of Dox-induced cardiomyopathy is likely a result of increased SERCA2a expression which could implicate IHP as a potential protective intervention in Dox cardiomyopathy, however, further analysis of observed effects is still required.
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Affiliation(s)
- Peter Galis
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University, Odbojárov 10, 832 32, Bratislava, Slovakia
| | - Linda Bartosova
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University, Odbojárov 10, 832 32, Bratislava, Slovakia
| | - Veronika Farkasova
- Institute for Heart Research, Slovak Academy of Sciences, Dúbravská Cesta 9, 841 04, Bratislava, Slovakia
| | - Adrian Szobi
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University, Odbojárov 10, 832 32, Bratislava, Slovakia
| | - Csaba Horvath
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University, Odbojárov 10, 832 32, Bratislava, Slovakia
| | - Dominika Kovacova
- Faculty of Medicine, Institute of Pathophysiology, Comenius University, Špitálska 24, 813 72, Bratislava, Slovakia
| | - Adriana Adameova
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University, Odbojárov 10, 832 32, Bratislava, Slovakia
- Institute for Heart Research, Slovak Academy of Sciences, Dúbravská Cesta 9, 841 04, Bratislava, Slovakia
| | - Tomas Rajtik
- Department of Pharmacology and Toxicology, Faculty of Pharmacy, Comenius University, Odbojárov 10, 832 32, Bratislava, Slovakia.
- Institute for Heart Research, Slovak Academy of Sciences, Dúbravská Cesta 9, 841 04, Bratislava, Slovakia.
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17
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Chen Z, Watanabe S, Hashida H, Inoue M, Daigaku Y, Kikkawa M, Inaba K. Cryo-EM structures of human SPCA1a reveal the mechanism of Ca 2+/Mn 2+ transport into the Golgi apparatus. SCIENCE ADVANCES 2023; 9:eadd9742. [PMID: 36867705 PMCID: PMC9984183 DOI: 10.1126/sciadv.add9742] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2022] [Accepted: 01/27/2023] [Indexed: 06/02/2023]
Abstract
Secretory pathway Ca2+/Mn2+ ATPase 1 (SPCA1) actively transports cytosolic Ca2+ and Mn2+ into the Golgi lumen, playing a crucial role in cellular calcium and manganese homeostasis. Detrimental mutations of the ATP2C1 gene encoding SPCA1 cause Hailey-Hailey disease. Here, using nanobody/megabody technologies, we determined cryo-electron microscopy structures of human SPCA1a in the ATP and Ca2+/Mn2+-bound (E1-ATP) state and the metal-free phosphorylated (E2P) state at 3.1- to 3.3-Å resolutions. The structures revealed that Ca2+ and Mn2+ share the same metal ion-binding pocket with similar but notably different coordination geometries in the transmembrane domain, corresponding to the second Ca2+-binding site in sarco/endoplasmic reticulum Ca2+-ATPase (SERCA). In the E1-ATP to E2P transition, SPCA1a undergoes similar domain rearrangements to those of SERCA. Meanwhile, SPCA1a shows larger conformational and positional flexibility of the second and sixth transmembrane helices, possibly explaining its wider metal ion specificity. These structural findings illuminate the unique mechanisms of SPCA1a-mediated Ca2+/Mn2+ transport.
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Affiliation(s)
- Zhenghao Chen
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Satoshi Watanabe
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Hironori Hashida
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Michio Inoue
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
| | - Yasukazu Daigaku
- Cancer Institute, Japanese Foundation for Cancer Research (JFCR), Tokyo 135-8550, Japan
| | - Masahide Kikkawa
- Graduate School of Medicine, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-0033, Japan
| | - Kenji Inaba
- Institute of Multidisciplinary Research for Advanced Materials, Tohoku University, Sendai, Miyagi 980-8577, Japan
- Department of Molecular and Chemical Life Sciences, Graduate School of Life Sciences, Tohoku University, Sendai, Miyagi 980-8577, Japan
- Department of Chemistry, Graduate School of Science, Tohoku University, Sendai, Miyagi 980-8578, Japan
- Core Research for Evolutional Science and Technology (CREST), Japan Agency for Medical Research and Development (AMED), Tokyo, Japan
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18
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Roopnarine O, Yuen SL, Thompson AR, Roelike LN, Rebbeck RT, Bidwell PA, Aldrich CC, Cornea RL, Thomas DD. FRET assay for live-cell high-throughput screening of the cardiac SERCA pump yields multiple classes of small-molecule allosteric modulators. RESEARCH SQUARE 2023:rs.3.rs-2596384. [PMID: 36909610 PMCID: PMC10002828 DOI: 10.21203/rs.3.rs-2596384/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/04/2023]
Abstract
We have used FRET-based biosensors in live cells, in a robust high-throughput screening (HTS) platform, to identify small-molecules that alter the structure and activity of the cardiac sarco/endoplasmic reticulum calcium ATPase (SERCA2a). Our primary aim is to discover drug-like small-molecule activators that improve SERCA’s function for the treatment of heart failure. We have previously demonstrated the use of an intramolecular FRET biosensor, based on human SERCA2a, by screening a small validation library using novel microplate readers that can detect the fluorescence lifetime or emission spectrum with high speed, precision, and resolution. Here we report results from a 50,000-compound screen using the same biosensor, with hit compounds functionally evaluated using Ca 2+ -ATPase and Ca 2+ -transport assays. We focused on 18 hit compounds, from which we identified eight structurally unique compounds and four compound classes as SERCA modulators, approximately half of which are activators and half are inhibitors. While both activators and inhibitors have therapeutic potential, the activators establish the basis for future testing in heart disease models and lead development, toward pharmaceutical therapy for heart failure.
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19
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Zádor E. The Meeting of Micropeptides with Major Ca 2+ Pumps in Inner Membranes-Consideration of a New Player, SERCA1b. MEMBRANES 2023; 13:274. [PMID: 36984661 PMCID: PMC10058886 DOI: 10.3390/membranes13030274] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/21/2022] [Revised: 02/20/2023] [Accepted: 02/23/2023] [Indexed: 06/18/2023]
Abstract
Calcium is a major signalling bivalent cation within the cell. Compartmentalization is essential for regulation of calcium mediated processes. A number of players contribute to intracellular handling of calcium, among them are the sarco/endoplasmic reticulum calcium ATP-ases (SERCAs). These molecules function in the membrane of ER/SR pumping Ca2+ from cytoplasm into the lumen of the internal store. Removal of calcium from the cytoplasm is essential for signalling and for relaxation of skeletal muscle and heart. There are three genes and over a dozen isoforms of SERCA in mammals. These can be potentially influenced by small membrane peptides, also called regulins. The discovery of micropeptides has increased in recent years, mostly because of the small ORFs found in long RNAs, annotated formerly as noncoding (lncRNAs). Several excellent works have analysed the mechanism of interaction of micropeptides with each other and with the best known SERCA1a (fast muscle) and SERCA2a (heart, slow muscle) isoforms. However, the array of tissue and developmental expressions of these potential regulators raises the question of interaction with other SERCAs. For example, the most abundant calcium pump in neonatal and regenerating skeletal muscle, SERCA1b has never been looked at with scrutiny to determine whether it is influenced by micropeptides. Further details might be interesting on the interaction of these peptides with the less studied SERCA1b isoform.
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Affiliation(s)
- Ernő Zádor
- Institute of Biochemistry, Albert Szent-Györgyi Faculty of Medicine, University of Szeged, Dóm tér 9, H-6720 Szeged, Hungary
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20
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Roopnarine O, Yuen SL, Thompson AR, Roelike LN, Rebbeck RT, Bidwell PA, Aldrich CC, Cornea RL, Thomas DD. FRET assay for live-cell high-throughput screening of the cardiac SERCA pump yields multiple classes of small-molecule allosteric modulators. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.02.22.529557. [PMID: 36865289 PMCID: PMC9980093 DOI: 10.1101/2023.02.22.529557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/24/2023]
Abstract
We have used FRET-based biosensors in live cells, in a robust high-throughput screening (HTS) platform, to identify small-molecules that alter the structure and activity of the cardiac sarco/endoplasmic reticulum calcium ATPase (SERCA2a). Our primary aim is to discover drug-like small-molecule activators that improve SERCA’s function for the treatment of heart failure. We have previously demonstrated the use of an intramolecular FRET biosensor, based on human SERCA2a, by screening a small validation library using novel microplate readers that can detect the fluorescence lifetime or emission spectrum with high speed, precision, and resolution. Here we report results from a 50,000-compound screen using the same biosensor, with hit compounds functionally evaluated using Ca 2+ -ATPase and Ca 2+ -transport assays. We focused on 18 hit compounds, from which we identified eight structurally unique compounds and four compound classes as SERCA modulators, approximately half of which are activators and half are inhibitors. While both activators and inhibitors have therapeutic potential, the activators establish the basis for future testing in heart disease models and lead development, toward pharmaceutical therapy for heart failure.
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21
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Rustad MD, Roopnarine O, Cornea RL, Thomas DD. Interaction of DWORF with SERCA and PLB as determined by EPR spectroscopy. Biochem Biophys Res Commun 2023; 645:97-102. [PMID: 36682333 PMCID: PMC9951557 DOI: 10.1016/j.bbrc.2023.01.041] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Accepted: 01/13/2023] [Indexed: 01/15/2023]
Abstract
Insufficient sarco/endoplasmic reticulum calcium ATPase (SERCA) activity significantly contributes to heart failure, which is a leading cause of death worldwide. A characteristic pathology of cardiac disease is the slow and incomplete Ca2+ removal from the myocyte cytoplasm in diastole, which is primarily driven by SERCA, the integral transmembrane Ca2+ pump. Phospholamban (PLB) allosterically inhibits SERCA by reducing its apparent Ca2+ affinity. Recently, the 34-codon novel dwarf open reading frame (DWORF) micropeptide has been identified as a muscle-specific SERCA effector, capable of reversing the inhibitory effects of PLB and independently activating SERCA in the absence of PLB. However, the structural basis for these functions has not yet been determined in a system of defined molecular components. We have used electron paramagnetic resonance (EPR) spectroscopy to investigate the protein-protein interactions of DWORF, co-reconstituted in proteoliposomes with SERCA and spin-labeled PLB. We analyzed the change of PLB rotational mobility in response to varying DWORF concentration, to quantify competitive binding of DWORF and PLB. We determined that DWORF competes with PLB for binding to SERCA at low [Ca2+], although the measured affinity of DWORF for SERCA is an order of magnitude weaker than that of PLB for SERCA, indicating cooperativity. The sensitivity of EPR to structural dynamics, using stereospecifically attached spin labels, allows us to obtain new information needed to refine the molecular model for regulation of SERCA activity, as needed for development of novel therapeutic remedies against cardiac pathologies.
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Affiliation(s)
- Mark D Rustad
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA; School of Physics and Astronomy, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Osha Roopnarine
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - Razvan L Cornea
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA
| | - David D Thomas
- Department of Biochemistry, Molecular Biology, and Biophysics, University of Minnesota, Minneapolis, MN, 55455, USA.
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22
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The Essentials on microRNA-Encoded Peptides from Plants to Animals. Biomolecules 2023; 13:biom13020206. [PMID: 36830576 PMCID: PMC9953219 DOI: 10.3390/biom13020206] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 01/06/2023] [Accepted: 01/08/2023] [Indexed: 01/22/2023] Open
Abstract
Primary transcripts of microRNAs (pri-miRNAs) were initially defined as long non-coding RNAs that host miRNAs further processed by the microRNA processor complex. A few years ago, however, it was discovered in plants that pri-miRNAs actually contain functional open reading frames (sORFs) that translate into small peptides called miPEPs, for microRNA-encoded peptides. Initially detected in Arabidopsis thaliana and Medicago truncatula, recent studies have revealed the presence of miPEPs in other pri-miRNAs as well as in other species ranging from various plant species to animals. This suggests that miPEP numbers remain largely underestimated and that they could be a common signature of pri-miRNAs. Here we present the most recent advances in miPEPs research and discuss how their discovery has broadened our vision of the regulation of gene expression by miRNAs, and how miPEPs could be interesting tools in sustainable agriculture or the treatment of certain human diseases.
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23
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Valentim M, Brahmbhatt A, Tupling A. Skeletal and cardiac muscle calcium transport regulation in health and disease. Biosci Rep 2022; 42:BSR20211997. [PMID: 36413081 PMCID: PMC9744722 DOI: 10.1042/bsr20211997] [Citation(s) in RCA: 10] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 11/04/2022] [Accepted: 11/22/2022] [Indexed: 11/23/2022] Open
Abstract
In healthy muscle, the rapid release of calcium ions (Ca2+) with excitation-contraction (E-C) coupling, results in elevations in Ca2+ concentrations which can exceed 10-fold that of resting values. The sizable transient changes in Ca2+ concentrations are necessary for the activation of signaling pathways, which rely on Ca2+ as a second messenger, including those involved with force generation, fiber type distribution and hypertrophy. However, prolonged elevations in intracellular Ca2+ can result in the unwanted activation of Ca2+ signaling pathways that cause muscle damage, dysfunction, and disease. Muscle employs several calcium handling and calcium transport proteins that function to rapidly return Ca2+ concentrations back to resting levels following contraction. This review will detail our current understanding of calcium handling during the decay phase of intracellular calcium transients in healthy skeletal and cardiac muscle. We will also discuss how impairments in Ca2+ transport can occur and how mishandling of Ca2+ can lead to the pathogenesis and/or progression of skeletal muscle myopathies and cardiomyopathies.
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Affiliation(s)
- Mark A. Valentim
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
| | - Aditya N. Brahmbhatt
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
| | - A. Russell Tupling
- Department of Kinesiology and Health Sciences, University of Waterloo, Waterloo, Ontario, N2L 3G1, Canada
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24
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A Large-Scale High-Throughput Screen for Modulators of SERCA Activity. Biomolecules 2022; 12:biom12121789. [PMID: 36551215 PMCID: PMC9776381 DOI: 10.3390/biom12121789] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2022] [Revised: 11/21/2022] [Accepted: 11/25/2022] [Indexed: 12/03/2022] Open
Abstract
The sarco/endoplasmic reticulum Ca-ATPase (SERCA) is a P-type ion pump that transports Ca2+ from the cytosol into the endoplasmic/sarcoplasmic reticulum (ER/SR) in most mammalian cells. It is critically important in muscle, facilitating relaxation and enabling subsequent contraction. Increasing SERCA expression or specific activity can alleviate muscle dysfunction, most notably in the heart, and we seek to develop small-molecule drug candidates that activate SERCA. Therefore, we adapted an NADH-coupled assay, measuring Ca-dependent ATPase activity of SERCA, to high-throughput screening (HTS) format, and screened a 46,000-compound library of diverse chemical scaffolds. This HTS platform yielded numerous hits that reproducibly alter SERCA Ca-ATPase activity, with few false positives. The top 19 activating hits were further tested for effects on both Ca-ATPase and Ca2+ transport, in both cardiac and skeletal SR. Nearly all hits increased Ca2+ uptake in both cardiac and skeletal SR, with some showing isoform specificity. Furthermore, dual analysis of both activities identified compounds with a range of effects on Ca2+-uptake and ATPase, which fit into distinct classifications. Further study will be needed to identify which classifications are best suited for therapeutic use. These results reinforce the need for robust secondary assays and criteria for selection of lead compounds, before undergoing HTS on a larger scale.
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25
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Phillips TA, Robia SL. Regulation of the regulator: Endopeptidase cleavage controls the expression of a micropeptide that regulates SERCA. Cell Calcium 2022; 107:102655. [PMID: 36179466 DOI: 10.1016/j.ceca.2022.102655] [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: 08/31/2022] [Accepted: 09/20/2022] [Indexed: 11/16/2022]
Abstract
Micropeptides regulate cellular calcium handling by modulating the function of the calcium transporter SERCA. In a recent Nature Communications paper [4] authors Schiemann et al. describe regulation of an invertebrate SERCA-active micropeptide, sarcolamban, by an endopeptidase called neprilysin 4 (NEP4). NEP4 activity limits sarcolamban expression by cleavage of luminal residues near the micropeptide's c-terminus. This cleavage event liberates sarcolamban from the membrane, reduces its oligomerization, and prevents it from inhibiting SERCA. The study reveals a novel mechanism for "regulation of the regulator" that may be a general feature of micropeptide/SERCA physiology.
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Affiliation(s)
- Taylor A Phillips
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood 60153, IL, United States of America
| | - Seth L Robia
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood 60153, IL, United States of America.
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26
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Bolaños P, Calderón JC. Excitation-contraction coupling in mammalian skeletal muscle: Blending old and last-decade research. Front Physiol 2022; 13:989796. [PMID: 36117698 PMCID: PMC9478590 DOI: 10.3389/fphys.2022.989796] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2022] [Accepted: 08/08/2022] [Indexed: 11/13/2022] Open
Abstract
The excitation–contraction coupling (ECC) in skeletal muscle refers to the Ca2+-mediated link between the membrane excitation and the mechanical contraction. The initiation and propagation of an action potential through the membranous system of the sarcolemma and the tubular network lead to the activation of the Ca2+-release units (CRU): tightly coupled dihydropyridine and ryanodine (RyR) receptors. The RyR gating allows a rapid, massive, and highly regulated release of Ca2+ from the sarcoplasmic reticulum (SR). The release from triadic places generates a sarcomeric gradient of Ca2+ concentrations ([Ca2+]) depending on the distance of a subcellular region from the CRU. Upon release, the diffusing Ca2+ has multiple fates: binds to troponin C thus activating the contractile machinery, binds to classical sarcoplasmic Ca2+ buffers such as parvalbumin, adenosine triphosphate and, experimentally, fluorescent dyes, enters the mitochondria and the SR, or is recycled through the Na+/Ca2+ exchanger and store-operated Ca2+ entry (SOCE) mechanisms. To commemorate the 7th decade after being coined, we comprehensively and critically reviewed “old”, historical landmarks and well-established concepts, and blended them with recent advances to have a complete, quantitative-focused landscape of the ECC. We discuss the: 1) elucidation of the CRU structures at near-atomic resolution and its implications for functional coupling; 2) reliable quantification of peak sarcoplasmic [Ca2+] using fast, low affinity Ca2+ dyes and the relative contributions of the Ca2+-binding mechanisms to the whole concert of Ca2+ fluxes inside the fibre; 3) articulation of this novel quantitative information with the unveiled structural details of the molecular machinery involved in mitochondrial Ca2+ handing to understand how and how much Ca2+ enters the mitochondria; 4) presence of the SOCE machinery and its different modes of activation, which awaits understanding of its magnitude and relevance in situ; 5) pharmacology of the ECC, and 6) emerging topics such as the use and potential applications of super-resolution and induced pluripotent stem cells (iPSC) in ECC. Blending the old with the new works better!
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Affiliation(s)
- Pura Bolaños
- Laboratory of Cellular Physiology, Centre of Biophysics and Biochemistry, Venezuelan Institute for Scientific Research (IVIC), Caracas, Venezuela
| | - Juan C. Calderón
- Physiology and Biochemistry Research Group-PHYSIS, Faculty of Medicine, University of Antioquia, Medellín, Colombia
- *Correspondence: Juan C. Calderón,
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27
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Bak JJ, Aguayo-Ortiz R, Rathod N, Primeau JO, Khan MB, Robia SL, Lemieux MJ, Espinoza-Fonseca LM, Young HS. Primitive Phospholamban- and Sarcolipin-like Peptides Inhibit the Sarcoplasmic Reticulum Calcium Pump SERCA. Biochemistry 2022; 61:1419-1430. [PMID: 35771007 PMCID: PMC10588654 DOI: 10.1021/acs.biochem.2c00246] [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] [Indexed: 01/09/2023]
Abstract
Intracellular calcium signaling is essential for all kingdoms of life. An important part of this process is the sarco-endoplasmic reticulum Ca2+-ATPase (SERCA), which maintains the low cytosolic calcium levels required for intracellular calcium homeostasis. In higher organisms, SERCA is regulated by a series of tissue-specific transmembrane subunits such as phospholamban in cardiac muscles and sarcolipin in skeletal muscles. These regulatory axes are so important for muscle contractility that SERCA, phospholamban, and sarcolipin are practically invariant across mammalian species. With the recent discovery of the arthropod sarcolambans, the family of calcium pump regulatory subunits appears to span more than 550 million years of evolutionary divergence from arthropods to humans. This evolutionary divergence is reflected in the peptide sequences, which vary enormously from one another and only vaguely resemble phospholamban and sarcolipin. The discovery of the sarcolambans allowed us to address two questions. How much sequence variation is tolerated in the regulation of mammalian SERCA activity by the transmembrane peptides? Do divergent peptide sequences mimic phospholamban or sarcolipin in their regulatory activities despite limited sequence similarity? We expressed and purified recombinant sarcolamban peptides from three different arthropods. The peptides were coreconstituted into proteoliposomes with mammalian SERCA1a and the effect of each peptide on the apparent calcium affinity and maximal activity of SERCA was measured. All three peptides were superinhibitors of SERCA, exhibiting either phospholamban-like or sarcolipin-like characteristics. Molecular modeling, protein-protein docking, and molecular dynamics simulations revealed novel features of the divergent peptides and their SERCA regulatory properties.
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Affiliation(s)
- Jessi J. Bak
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - Rodrigo Aguayo-Ortiz
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Nishadh Rathod
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - Joseph O. Primeau
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - Muhammad Bashir Khan
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - Seth L. Robia
- Department of Cell and Molecular Physiology, Loyola University Chicago, Maywood, IL 60153, USA
| | - M. Joanne Lemieux
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
| | - L. Michel Espinoza-Fonseca
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, MI 48109, USA
| | - Howard S. Young
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, T6G 2H7, Canada
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28
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Guarnieri AR, Benson TW, Tranter M. Calcium cycling as a mediator of thermogenic metabolism in adipose tissue. Mol Pharmacol 2022; 102:MOLPHARM-MR-2021-000465. [PMID: 35504660 PMCID: PMC9341262 DOI: 10.1124/molpharm.121.000465] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2021] [Revised: 04/20/2022] [Accepted: 04/23/2022] [Indexed: 11/22/2022] Open
Abstract
Canonical non-shivering thermogenesis (NST) in brown and beige fat relies on uncoupling protein 1 (UCP1)-mediated heat generation, although alternative mechanisms of NST have been identified, including sarcoplasmic reticulum (SR)-calcium cycling. Intracellular calcium is a crucial cell signaling molecule for which compartmentalization is tightly regulated, and the sarco-endoplasmic calcium ATPase (SERCA) actively pumps calcium from the cytosol into the SR. In this review, we discuss the capacity of SERCA-mediated calcium cycling as a significant mediator of thermogenesis in both brown and beige adipocytes. Here, we suggest two primary mechanisms of SR calcium mediated thermogenesis. The first mechanism is through direct uncoupling of the ATPase and calcium pump activity of SERCA, resulting in the energy of ATP catalysis being expended as heat in the absence of calcium transport. Regulins, a class of SR membrane proteins, act to decrease the calcium affinity of SERCA and uncouple the calcium transport function from ATPase activity, but remain largely unexplored in adipose tissue thermogenesis. A second mechanism is through futile cycling of SR calcium whereby SERCA-mediated SR calcium influx is equally offset by SR calcium efflux, resulting in ATP consumption without a net change in calcium compartmentalization. A fuller understanding of the functional and mechanistic role of calcium cycling as a mediator of adipose tissue thermogenesis and how manipulation of these pathways can be harnessed for therapeutic gain remains unexplored. Significance Statement Enhancing thermogenic metabolism in brown or beige adipose tissue may be of broad therapeutic utility to reduce obesity and metabolic syndrome. Canonical BAT-mediated thermogenesis occurs via uncoupling protein 1 (UCP1). However, UCP1-independent pathways of thermogenesis, such as sarcoplasmic (SR) calcium cycling, have also been identified, but the regulatory mechanisms and functional significance of these pathways remain largely unexplored. Thus, this mini-review discusses the state of the field with regard to calcium cycling as a thermogenic mediator in adipose tissue.
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Affiliation(s)
| | - Tyler W Benson
- University of Cincinnati College of Medicine, United States
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29
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Braun JL, Messner HN, Cleverdon REG, Baranowski RW, Hamstra SI, Geromella MS, Stuart JA, Fajardo VA. Heterozygous SOD2 deletion selectively impairs SERCA function in the soleus of female mice. Physiol Rep 2022; 10:e15285. [PMID: 35581738 PMCID: PMC9114654 DOI: 10.14814/phy2.15285] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2022] [Revised: 04/05/2022] [Accepted: 04/08/2022] [Indexed: 06/15/2023] Open
Abstract
The sarco(endo)plasmic reticulum Ca2+ ATPase (SERCA) restores intracellular Ca2+ ([Ca2+ ]i ) to resting levels after muscle contraction, ultimately eliciting relaxation. SERCA pumps are highly susceptible to tyrosine (T)-nitration, impairing their ability to take up Ca2+ resulting in reduced muscle function and increased [Ca2+ ]i and cellular damage. The mitochondrial antioxidant enzyme, superoxide dismutase 2 (SOD2), converts superoxide radicals into less reactive H2 O2 . Heterozygous deletion of SOD2 (Sod2+/- ) in mice increases mitochondrial oxidative stress; however, the consequences of reduced SOD2 expression in skeletal and cardiac muscle, specifically the effect on SERCA pumps, has yet to be investigated. We obtained soleus, extensor digitorum longus (EDL), and left ventricle (LV) muscles from 6 to 7 month-old wild-type (WT) and Sod2+/- female C57BL/6J mice. Ca2+ -dependent SERCA activity assays were performed to assess SERCA function. Western blotting was conducted to examine the protein content of SERCA, phospholamban, and sarcolipin; and immunoprecipitation experiments were done to assess SERCA2a- and SERCA1a-specific T-nitration. Heterozygous SOD2 deletion did not alter SERCA1a or SERCA2a expression in the soleus or LV but reduced SERCA2a in the EDL compared with WT, though this was not statistically significant. Soleus muscles from Sod2+/- mice showed a significant reduction in SERCA's apparent affinity for Ca2+ when compared to WT, corresponding with significantly elevated SERCA2a T-nitration in the soleus. No effect was seen in the EDL or the LV. This is the first study to investigate the effects of SOD2 deficiency on muscle SERCA function and shows that it selectively impairs SERCA function in the soleus.
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Affiliation(s)
- Jessica L. Braun
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
- Centre for NeuroscienceBrock UniversitySt. CatharinesOntarioCanada
| | - Holt N. Messner
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
- Department of Biological SciencesBrock UniversitySt. CatharinesOntarioCanada
| | - Riley E. G. Cleverdon
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
| | - Ryan W. Baranowski
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
| | - Sophie I. Hamstra
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
| | - Mia S. Geromella
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
| | - Jeffrey A. Stuart
- Department of Biological SciencesBrock UniversitySt. CatharinesOntarioCanada
| | - Val A. Fajardo
- Department of KinesiologyBrock UniversitySt. CatharinesOntarioCanada
- Centre for Bone and Muscle HealthBrock UniversitySt. CatharinesOntarioCanada
- Centre for NeuroscienceBrock UniversitySt. CatharinesOntarioCanada
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