1
|
Armanious GP, Lemieux MJ, Espinoza-Fonseca LM, Young HS. Missense variants in phospholamban and cardiac myosin binding protein identified in patients with a family history and clinical diagnosis of dilated cardiomyopathy. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2024; 1871:119699. [PMID: 38387507 DOI: 10.1016/j.bbamcr.2024.119699] [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: 05/05/2023] [Revised: 11/07/2023] [Accepted: 02/15/2024] [Indexed: 02/24/2024]
Abstract
As the genetic landscape of cardiomyopathies continues to expand, the identification of missense variants in disease-associated genes frequently leads to a classification of variant of uncertain significance (VUS). For the proper reclassification of such variants, functional characterization is an important contributor to the proper assessment of pathogenic potential. Several missense variants in the calcium transport regulatory protein phospholamban have been associated with dilated cardiomyopathy. However, >40 missense variants in this transmembrane peptide are currently known and most remain classified as VUS with little clinical information. Similarly, missense variants in cardiac myosin binding protein have been associated with hypertrophic cardiomyopathy. However, hundreds of variants are known and many have low penetrance and are often found in control populations. Herein, we focused on novel missense variants in phospholamban, an Ala15-Thr variant found in a 4-year-old female and a Pro21-Thr variant found in a 60-year-old female, both with a family history and clinical diagnosis of dilated cardiomyopathy. The patients also harbored a Val896-Met variant in cardiac myosin binding protein. The phospholamban variants caused defects in the function, phosphorylation, and dephosphorylation of this calcium transport regulatory peptide, and we classified these variants as potentially pathogenic. The variant in cardiac myosin binding protein alters the structure of the protein. While this variant has been classified as benign, it has the potential to be a low-risk susceptibility variant because of the structural change in cardiac myosin binding protein. Our studies provide new biochemical evidence for missense variants previously classified as benign or VUS.
Collapse
Affiliation(s)
- Gareth P Armanious
- Department of Biochemistry, University of Alberta, Edmonton, Alberta T6G 2H7, Canada
| | - 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.
| |
Collapse
|
2
|
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.
Collapse
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
| |
Collapse
|
3
|
Biochemical and molecular-physiological aspects of the nitric oxide action in the utera. UKRAINIAN BIOCHEMICAL JOURNAL 2021. [DOI: 10.15407/ubj93.06.005] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
|
4
|
Sordi G, Goti A, Young HS, Palchetti I, Tadini‐Buoninsegni F. Stimulation of Ca 2+ -ATPase Transport Activity by a Small-Molecule Drug. ChemMedChem 2021; 16:3293-3299. [PMID: 34297466 PMCID: PMC8571031 DOI: 10.1002/cmdc.202100350] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2021] [Revised: 07/19/2021] [Indexed: 11/11/2022]
Abstract
The sarco(endo)plasmic reticulum Ca2+ -ATPase (SERCA) hydrolyzes ATP to transport Ca2+ from the cytoplasm to the sarcoplasmic reticulum (SR) lumen, thereby inducing muscle relaxation. Dysfunctional SERCA has been related to various diseases. The identification of small-molecule drugs that can activate SERCA may offer a therapeutic approach to treat pathologies connected with SERCA malfunction. Herein, we propose a method to study the mechanism of interaction between SERCA and novel SERCA activators, i. e. CDN1163, using a solid supported membrane (SSM) biosensing approach. Native SR vesicles or reconstituted proteoliposomes containing SERCA were adsorbed on the SSM and activated by ATP concentration jumps. We observed that CDN1163 reversibly interacts with SERCA and enhances ATP-dependent Ca2+ translocation. The concentration dependence of the CDN1163 effect provided an EC50 =6.0±0.3 μM. CDN1163 was shown to act directly on SERCA and to exert its stimulatory effect under physiological Ca2+ concentrations. These results suggest that CDN1163 interaction with SERCA can promote a protein conformational state that favors Ca2+ release into the SR lumen.
Collapse
Affiliation(s)
- Giacomo Sordi
- Department of Chemistry “Ugo Schiff”University of FlorenceVia della Lastruccia 3–1350019Sesto FiorentinoItaly
- Present address: PQE Group50066 ReggelloFlorenceItaly
| | - Andrea Goti
- Department of Chemistry “Ugo Schiff”University of FlorenceVia della Lastruccia 3–1350019Sesto FiorentinoItaly
| | - Howard S. Young
- Department of BiochemistryUniversity of AlbertaEdmonton, AlbertaT6G 2H7Canada
| | - Ilaria Palchetti
- Department of Chemistry “Ugo Schiff”University of FlorenceVia della Lastruccia 3–1350019Sesto FiorentinoItaly
| | | |
Collapse
|
5
|
Nothing Regular about the Regulins: Distinct Functional Properties of SERCA Transmembrane Peptide Regulatory Subunits. Int J Mol Sci 2021; 22:ijms22168891. [PMID: 34445594 PMCID: PMC8396278 DOI: 10.3390/ijms22168891] [Citation(s) in RCA: 26] [Impact Index Per Article: 8.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2021] [Revised: 08/10/2021] [Accepted: 08/12/2021] [Indexed: 12/11/2022] Open
Abstract
The sarco-endoplasmic reticulum calcium ATPase (SERCA) is responsible for maintaining calcium homeostasis in all eukaryotic cells by actively transporting calcium from the cytosol into the sarco-endoplasmic reticulum (SR/ER) lumen. Calcium is an important signaling ion, and the activity of SERCA is critical for a variety of cellular processes such as muscle contraction, neuronal activity, and energy metabolism. SERCA is regulated by several small transmembrane peptide subunits that are collectively known as the “regulins”. Phospholamban (PLN) and sarcolipin (SLN) are the original and most extensively studied members of the regulin family. PLN and SLN inhibit the calcium transport properties of SERCA and they are required for the proper functioning of cardiac and skeletal muscles, respectively. Myoregulin (MLN), dwarf open reading frame (DWORF), endoregulin (ELN), and another-regulin (ALN) are newly discovered tissue-specific regulators of SERCA. Herein, we compare the functional properties of the regulin family of SERCA transmembrane peptide subunits and consider their regulatory mechanisms in the context of the physiological and pathophysiological roles of these peptides. We present new functional data for human MLN, ELN, and ALN, demonstrating that they are inhibitors of SERCA with distinct functional consequences. Molecular modeling and molecular dynamics simulations of SERCA in complex with the transmembrane domains of MLN and ALN provide insights into how differential binding to the so-called inhibitory groove of SERCA—formed by transmembrane helices M2, M6, and M9—can result in distinct functional outcomes.
Collapse
|
6
|
Fisher ME, Bovo E, Aguayo-Ortiz R, Cho EE, Pribadi MP, Dalton MP, Rathod N, Lemieux MJ, Espinoza-Fonseca LM, Robia SL, Zima AV, Young HS. Dwarf open reading frame (DWORF) is a direct activator of the sarcoplasmic reticulum calcium pump SERCA. eLife 2021; 10:65545. [PMID: 34075877 PMCID: PMC8203291 DOI: 10.7554/elife.65545] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2020] [Accepted: 06/01/2021] [Indexed: 01/05/2023] Open
Abstract
The sarco-plasmic reticulum calcium pump (SERCA) plays a critical role in the contraction-relaxation cycle of muscle. In cardiac muscle, SERCA is regulated by the inhibitor phospholamban. A new regulator, dwarf open reading frame (DWORF), has been reported to displace phospholamban from SERCA. Here, we show that DWORF is a direct activator of SERCA, increasing its turnover rate in the absence of phospholamban. Measurement of in-cell calcium dynamics supports this observation and demonstrates that DWORF increases SERCA-dependent calcium reuptake. These functional observations reveal opposing effects of DWORF activation and phospholamban inhibition of SERCA. To gain mechanistic insight into SERCA activation, fluorescence resonance energy transfer experiments revealed that DWORF has a higher affinity for SERCA in the presence of calcium. Molecular modeling and molecular dynamics simulations provide a model for DWORF activation of SERCA, where DWORF modulates the membrane bilayer and stabilizes the conformations of SERCA that predominate during elevated cytosolic calcium.
Collapse
Affiliation(s)
- M'Lynn E Fisher
- Department of Biochemistry, University of Alberta, Edmonton, Canada
| | - Elisa Bovo
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, United States
| | - Rodrigo Aguayo-Ortiz
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, United States
| | - Ellen E Cho
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, United States
| | - Marsha P Pribadi
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, United States
| | - Michael P Dalton
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, United States
| | - Nishadh Rathod
- Department of Biochemistry, University of Alberta, Edmonton, Canada
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Edmonton, Canada
| | - L Michel Espinoza-Fonseca
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, United States
| | - Seth L Robia
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, United States
| | - Aleksey V Zima
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, United States
| | - Howard S Young
- Department of Biochemistry, University of Alberta, Edmonton, Canada
| |
Collapse
|
7
|
Raguimova ON, Aguayo-Ortiz R, Robia SL, Espinoza-Fonseca LM. Dynamics-Driven Allostery Underlies Ca 2+-Mediated Release of SERCA Inhibition by Phospholamban. Biophys J 2020; 119:1917-1926. [PMID: 33069270 PMCID: PMC7677127 DOI: 10.1016/j.bpj.2020.09.014] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2020] [Revised: 09/17/2020] [Accepted: 09/18/2020] [Indexed: 12/20/2022] Open
Abstract
Sarcoplasmic reticulum (SR) Ca2+-ATPase (SERCA) and phospholamban (PLB) are essential for intracellular Ca2+ transport in myocytes. Ca2+-dependent activation of SERCA-PLB provides a control function that regulates cytosolic and SR Ca2+ levels. Although experimental and computational studies alone have led to a greater insight into SERCA-PLB regulation, the structural mechanisms for Ca2+ binding reversing inhibition of the complex remain poorly understood. Therefore, we have performed atomistic simulations totaling 32.7 μs and cell-based intramolecular fluorescence resonance energy transfer (FRET) experiments to determine structural changes of PLB-bound SERCA in response to binding of a single Ca2+ ion. Complementary MD simulations and FRET experiments showed that open-to-closed transitions in the structure of the headpiece underlie PLB inhibition of SERCA, and binding of a single Ca2+ ion is sufficient to shift the protein population toward a structurally closed structure of the complex. Closure is accompanied by functional interactions between the N-domain β5-β6 loop and the A-domain and the displacement of the catalytic phosphorylation domain toward a competent structure. We propose that reversal of SERCA-PLB inhibition is achieved by stringing together its controlling modules (A-domain and loop Nβ5-β6) with catalytic elements (P-domain) to regulate function during intracellular Ca2+ signaling. We conclude that binding of a single Ca2+ is a critical mediator of allosteric signaling that dictates structural changes and motions that relieve SERCA inhibition by PLB. Understanding allosteric regulation is of paramount importance to guide therapeutic modulation of SERCA and other evolutionarily related ion-motive ATPases.
Collapse
Affiliation(s)
- Olga N Raguimova
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois
| | - Rodrigo Aguayo-Ortiz
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan
| | - Seth L Robia
- Department of Cell and Molecular Physiology, Stritch School of Medicine, Loyola University Chicago, Maywood, Illinois
| | - L Michel Espinoza-Fonseca
- Center for Arrhythmia Research, Department of Internal Medicine, Division of Cardiovascular Medicine, University of Michigan, Ann Arbor, Michigan.
| |
Collapse
|
8
|
Roczkowsky A, Chan BYH, Lee TYT, Mahmud Z, Hartley B, Julien O, Armanious G, Young HS, Schulz R. Myocardial MMP-2 contributes to SERCA2a proteolysis during cardiac ischaemia-reperfusion injury. Cardiovasc Res 2020; 116:1021-1031. [PMID: 31373602 DOI: 10.1093/cvr/cvz207] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 06/05/2019] [Accepted: 07/31/2019] [Indexed: 01/06/2023] Open
Abstract
AIMS Matrix metalloproteinase-2 (MMP-2) is a zinc-dependent protease which contributes to cardiac contractile dysfunction when activated during myocardial ischaemia-reperfusion (IR) injury. MMP-2 is localized to several subcellular sites inside cardiac myocytes; however, its role in the sarcoplasmic reticulum (SR) is unknown. The Ca2+ ATPase SERCA2a, which pumps cytosolic Ca2+ into the SR to facilitate muscle relaxation, is degraded in cardiac IR injury; however, the protease responsible for this is unclear. We hypothesized that MMP-2 contributes to cardiac contractile dysfunction by proteolyzing SERCA2a, thereby impairing its activity in IR injury. METHODS AND RESULTS Isolated rat hearts were subjected to IR injury in the presence or absence of the selective MMP inhibitor ARP-100, or perfused aerobically as a control. Inhibition of MMP activity with ARP-100 significantly improved the recovery of cardiac mechanical function and prevented the increase of a 70 kDa SERCA2a degradation fragment following IR injury, although 110 kDa SERCA2a and phospholamban levels appeared unchanged. Electrophoresis of IR heart samples followed by LC-MS/MS confirmed the presence of a SERCA2a fragment of ∼70 kDa. MMP-2 activity co-purified with SR-enriched microsomes prepared from the isolated rat hearts. Endogenous SERCA2a in SR-enriched microsomes was proteolyzed to ∼70 kDa products when incubated in vitro with exogenous MMP-2. MMP-2 also cleaved purified porcine SERCA2a in vitro. SERCA activity in SR-enriched microsomes was decreased by IR injury; however, this was not prevented with ARP-100. CONCLUSION This study shows that MMP-2 activity is found in SR-enriched microsomes from heart muscle and that SERCA2a is proteolyzed by MMP-2. The cardioprotective actions of MMP inhibition in myocardial IR injury may include the prevention of SERCA2a degradation.
Collapse
Affiliation(s)
- Andrej Roczkowsky
- Department of Pediatrics, University of Alberta, Mazankowski Alberta Heart Institute, 462 Heritage Medical Research Centre, Edmonton, AB T6G 2S2, Canada.,Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Brandon Y H Chan
- Department of Pediatrics, University of Alberta, Mazankowski Alberta Heart Institute, 462 Heritage Medical Research Centre, Edmonton, AB T6G 2S2, Canada.,Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Tim Y T Lee
- Department of Pediatrics, University of Alberta, Mazankowski Alberta Heart Institute, 462 Heritage Medical Research Centre, Edmonton, AB T6G 2S2, Canada.,Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| | - Zabed Mahmud
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Bridgette Hartley
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Olivier Julien
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Gareth Armanious
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Howard S Young
- Department of Biochemistry, University of Alberta, Edmonton, AB, Canada
| | - Richard Schulz
- Department of Pediatrics, University of Alberta, Mazankowski Alberta Heart Institute, 462 Heritage Medical Research Centre, Edmonton, AB T6G 2S2, Canada.,Department of Pharmacology, University of Alberta, Edmonton, AB, Canada
| |
Collapse
|
9
|
Tadini-Buoninsegni F. Protein Adsorption on Solid Supported Membranes: Monitoring the Transport Activity of P-Type ATPases. Molecules 2020; 25:molecules25184167. [PMID: 32933017 PMCID: PMC7570688 DOI: 10.3390/molecules25184167] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Revised: 09/01/2020] [Accepted: 09/02/2020] [Indexed: 02/07/2023] Open
Abstract
P-type ATPases are a large family of membrane transporters that are found in all forms of life. These enzymes couple ATP hydrolysis to the transport of various ions or phospholipids across cellular membranes, thereby generating and maintaining crucial electrochemical potential gradients. P-type ATPases have been studied by a variety of methods that have provided a wealth of information about the structure, function, and regulation of this class of enzymes. Among the many techniques used to investigate P-type ATPases, the electrical method based on solid supported membranes (SSM) was employed to investigate the transport mechanism of various ion pumps. In particular, the SSM method allows the direct measurement of charge movements generated by the ATPase following adsorption of the membrane-bound enzyme on the SSM surface and chemical activation by a substrate concentration jump. This kind of measurement was useful to identify electrogenic partial reactions and localize ion translocation in the reaction cycle of the membrane transporter. In the present review, we discuss how the SSM method has contributed to investigate some key features of the transport mechanism of P-type ATPases, with a special focus on sarcoplasmic reticulum Ca2+-ATPase, mammalian Cu+-ATPases (ATP7A and ATP7B), and phospholipid flippase ATP8A2.
Collapse
|
10
|
Aguayo-Ortiz R, Espinoza-Fonseca LM. Linking Biochemical and Structural States of SERCA: Achievements, Challenges, and New Opportunities. Int J Mol Sci 2020; 21:ijms21114146. [PMID: 32532023 PMCID: PMC7313052 DOI: 10.3390/ijms21114146] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2020] [Revised: 06/05/2020] [Accepted: 06/08/2020] [Indexed: 02/07/2023] Open
Abstract
Sarcoendoplasmic reticulum calcium ATPase (SERCA), a member of the P-type ATPase family of ion and lipid pumps, is responsible for the active transport of Ca2+ from the cytoplasm into the sarcoplasmic reticulum lumen of muscle cells, into the endoplasmic reticulum (ER) of non-muscle cells. X-ray crystallography has proven to be an invaluable tool in understanding the structural changes of SERCA, and more than 70 SERCA crystal structures representing major biochemical states (defined by bound ligand) have been deposited in the Protein Data Bank. Consequently, SERCA is one of the best characterized components of the calcium transport machinery in the cell. Emerging approaches in the field, including spectroscopy and molecular simulation, now help integrate and interpret this rich structural information to understand the conformational transitions of SERCA that occur during activation, inhibition, and regulation. In this review, we provide an overview of the crystal structures of SERCA, focusing on identifying metrics that facilitate structure-based categorization of major steps along the catalytic cycle. We examine the integration of crystallographic data with different biophysical approaches and computational methods to link biochemical and structural states of SERCA that are populated in the cell. Finally, we discuss the challenges and new opportunities in the field, including structural elucidation of functionally important and novel regulatory complexes of SERCA, understanding the structural basis of functional divergence among homologous SERCA regulators, and bridging the gap between basic and translational research directed toward therapeutic modulation of SERCA.
Collapse
|
11
|
Learning of Signaling Networks: Molecular Mechanisms. Trends Biochem Sci 2020; 45:284-294. [PMID: 32008897 DOI: 10.1016/j.tibs.2019.12.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2019] [Revised: 11/28/2019] [Accepted: 12/31/2019] [Indexed: 01/03/2023]
Abstract
Molecular processes of neuronal learning have been well described. However, learning mechanisms of non-neuronal cells are not yet fully understood at the molecular level. Here, we discuss molecular mechanisms of cellular learning, including conformational memory of intrinsically disordered proteins (IDPs) and prions, signaling cascades, protein translocation, RNAs [miRNA and long noncoding RNA (lncRNA)], and chromatin memory. We hypothesize that these processes constitute the learning of signaling networks and correspond to a generalized Hebbian learning process of single, non-neuronal cells, and we discuss how cellular learning may open novel directions in drug design and inspire new artificial intelligence methods.
Collapse
|
12
|
Rahate K, Bhatt LK, Prabhavalkar KS. SERCA stimulation: A potential approach in therapeutics. Chem Biol Drug Des 2019; 95:5-15. [DOI: 10.1111/cbdd.13620] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Revised: 08/19/2019] [Accepted: 08/26/2019] [Indexed: 12/12/2022]
Affiliation(s)
- Kiran Rahate
- Department of Pharmacology SVKM’s Dr. Bhanuben Nanavati College of Pharmacy Mumbai India
| | - Lokesh Kumar Bhatt
- Department of Pharmacology SVKM’s Dr. Bhanuben Nanavati College of Pharmacy Mumbai India
| | - Kedar S. Prabhavalkar
- Department of Pharmacology SVKM’s Dr. Bhanuben Nanavati College of Pharmacy Mumbai India
| |
Collapse
|
13
|
Song Y, Liu G, Liu S, Chen R, Wang N, Liu Z, Zhang X, Xiao Z, Liu L. Helicobacter pylori upregulates TRPC6 via Wnt/β-catenin signaling to promote gastric cancer migration and invasion. Onco Targets Ther 2019; 12:5269-5279. [PMID: 31308697 PMCID: PMC6613196 DOI: 10.2147/ott.s201025] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Accepted: 05/20/2019] [Indexed: 12/11/2022] Open
Abstract
Background Helicobacter pylori infection is recognized as a major risk factor for gastric cancer (GC) progression; however, the underlying molecular mechanisms have remained to be fully elucidated. Methods qPCR and Western blot were used to detect mRNA level and relative protein expression. Wound healing assay and transwell were used to determine migration and invasion of cells. Calcium imaging was used to determine calcium signaling in cells. Luciferase reporter assay and immunohistochemistry were performed. Results In the present study, it was demonstrated that H. pylori infection in GC is closely associated with the depth of tumor invasion, lymph node metastasis, tumor-nodes-metastasis stage, and distant metastasis. Migration and invasion assays indicated that H. pylori infection enhanced the migration and invasion of GC cells in a Ca2+-dependent manner. Calcium imaging was applied to detect intracellular Ca2+ and revealed that H. pylori induced an increase of intracellular Ca2+ in GC cells through release from Ca2+ stores and extracellular Ca2+ influx. Further study indicated that H. pylori infection led to an upregulation of the expression of transient receptor potential cation channel subfamily C member 6 (TRPC6) and induced an increase of Ca2+ through the TRPC6 channel. Furthermore, H. pylori increased TRPC6 transcription through the Wnt/β-catenin pathway, and Wnt/β-catenin/TRPC6 signaling was identified to be at least in part responsible for H. pylori-induced GC migration and invasion. Finally, it was observed that TRPC6 expression was significantly associated with the H. pylori infection status in GC tissues, and H. pylori infection was associated with metastasis and poor prognosis for GC patients. Conclusion The present results indicate that H. pylori causes an upregulation of TRPC6 expression through the Wnt/β-catenin pathway to promote GC progression, and this interaction may serve as a promising target for GC therapy.
Collapse
Affiliation(s)
- Yang Song
- Center of Clinical Laboratory, First Medical Center of Chinese PLA General Hospital, Sanya, People's Republic of China.,Center of Clinical Laboratory, Hainan Hospital of Chinese PLA General Hospital, Sanya, People's Republic of China
| | - Gao Liu
- Department of Geriatric Cardiology, Second Medical Center of Chinese PLA General Hospital, Beijing, People's Republic of China.,National Centre for Clinical Research on Gerontology, Beijing, People's Republic of China
| | - Shuang Liu
- Center of Clinical Laboratory, Hainan Hospital of Chinese PLA General Hospital, Sanya, People's Republic of China
| | - Rong Chen
- Center of Clinical Laboratory, First Medical Center of Chinese PLA General Hospital, Sanya, People's Republic of China
| | - Na Wang
- Outpatient Comprehensive Treatment Area, First Medical Center of Chinese PLA General Hospital, Sanya, People's Republic of China
| | - Zhaoyu Liu
- Center of Clinical Laboratory, Hainan Hospital of Chinese PLA General Hospital, Sanya, People's Republic of China
| | - Xiao Zhang
- Central Laboratory, Hainan Hospital of Chinese PLA General Hospital, Sanya, People's Republic of China
| | - Zheng Xiao
- Center of Clinical Laboratory, Hainan Hospital of Chinese PLA General Hospital, Sanya, People's Republic of China
| | - Lin Liu
- Department of General Surgery, First Medical Center of Chinese PLA General Hospital, Sanya, People's Republic of China
| |
Collapse
|
14
|
Glaves JP, Primeau JO, Espinoza-Fonseca LM, Lemieux MJ, Young HS. The Phospholamban Pentamer Alters Function of the Sarcoplasmic Reticulum Calcium Pump SERCA. Biophys J 2019; 116:633-647. [PMID: 30712785 DOI: 10.1016/j.bpj.2019.01.013] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 11/30/2018] [Accepted: 01/11/2019] [Indexed: 11/17/2022] Open
Abstract
The interaction of phospholamban (PLN) with the sarco-endoplasmic reticulum Ca2+-ATPase (SERCA) pump is a major regulatory axis in cardiac muscle contractility. The prevailing model involves reversible inhibition of SERCA by monomeric PLN and storage of PLN as an inactive pentamer. However, this paradigm has been challenged by studies demonstrating that PLN remains associated with SERCA and that the PLN pentamer is required for the regulation of cardiac contractility. We have previously used two-dimensional (2D) crystallization and electron microscopy to study the interaction between SERCA and PLN. To further understand this interaction, we compared small helical crystals and large 2D crystals of SERCA in the absence and presence of PLN. In both crystal forms, SERCA molecules are organized into identical antiparallel dimer ribbons. The dimer ribbons pack together with distinct crystal contacts in the helical versus large 2D crystals, which allow PLN differential access to potential sites of interaction with SERCA. Nonetheless, we show that a PLN oligomer interacts with SERCA in a similar manner in both crystal forms. In the 2D crystals, a PLN pentamer interacts with transmembrane segments M3 of SERCA and participates in a crystal contact that bridges neighboring SERCA dimer ribbons. In the helical crystals, an oligomeric form of PLN also interacts with M3 of SERCA, though the PLN oligomer straddles a SERCA-SERCA crystal contact. We conclude that the pentameric form of PLN interacts with M3 of SERCA and that it plays a distinct structural and functional role in SERCA regulation. The interaction of the pentamer places the cytoplasmic domains of PLN at the membrane surface proximal to the calcium entry funnel of SERCA. This interaction may cause localized perturbation of the membrane bilayer as a mechanism for increasing the turnover rate of SERCA.
Collapse
Affiliation(s)
- John Paul Glaves
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Joseph O Primeau
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - L Michel Espinoza-Fonseca
- Center for Arrhythmia Research, Division of Cardiovascular Medicine, Department of Internal Medicine, University of Michigan, Ann Arbor, Michigan
| | - M Joanne Lemieux
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada
| | - Howard S Young
- Department of Biochemistry, University of Alberta, Edmonton, Alberta, Canada.
| |
Collapse
|
15
|
Guo W, Pencina KM, Gagliano-Jucá T, Jasuja R, Morris N, O'Connell KE, Westmoreland S, Bhasin S. Effects of an ActRIIB.Fc Ligand Trap on Cardiac Function in Simian Immunodeficiency Virus-Infected Male Rhesus Macaques. J Endocr Soc 2018; 2:817-831. [PMID: 30019021 PMCID: PMC6041778 DOI: 10.1210/js.2018-00099] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/10/2018] [Accepted: 05/22/2018] [Indexed: 12/13/2022] Open
Abstract
An important safety consideration in the use of antagonists of myostatin and activins is whether these drugs induce myocardial hypertrophy and impair cardiac function. The current study evaluated the effects of a soluble ActRIIB receptor Fc fusion protein (ActRIIB.Fc), a ligand trap for TGF-β/activin family members including myostatin, on myocardial mass and function in simian immunodeficiency virus (SIV)-infected juvenile rhesus macaques (Macaca mulatta). Fourteen pair-housed, juvenile male rhesus macaques were inoculated with SIVmac239; 4 weeks postinoculation, they were treated with weekly injections of 10 mg/kg ActRIIB.Fc or saline for 12 weeks. Myocardial mass and function were evaluated using two-dimensional echocardiography at baseline and after 12 weeks. The administration of ActRIIB.Fc was associated with a significantly greater increase in thickness of left ventricular posterior wall and interventricular septum both in diastole and systole. Cardiac output and cardiac index increased with time, more in animals treated with ActRIIB.Fc than in those treated with saline, but the difference was not statistically significant. The changes in ejection fraction, fractional shortening, and stroke volume did not differ significantly between groups. The changes in end-diastolic and end-systolic volumes did not differ between groups. In addition to a large reduction in IGF1 mRNA expression in the ActRIIB.Fc-treated animals, complex changes were detected in the myocardial expression of proteins related to calcium transport and storage. In conclusion, ActRIIB.Fc administration for 12 weeks was associated with increased myocardial mass but did not adversely affect myocardial function in juvenile SIV-infected rhesus macaques. Further studies are necessary to establish long-term cardiac safety.
Collapse
Affiliation(s)
- Wen Guo
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Karol M Pencina
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Thiago Gagliano-Jucá
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Ravi Jasuja
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| | - Nancy Morris
- Division of Comparative Pathology, New England Primate Research Center, Southborough, Massachusetts
| | - Karyn E O'Connell
- Division of Comparative Pathology, New England Primate Research Center, Southborough, Massachusetts
| | - Susan Westmoreland
- Division of Comparative Pathology, New England Primate Research Center, Southborough, Massachusetts
| | - Shalender Bhasin
- Research Program in Men's Health: Aging and Metabolism, Boston Claude D. Pepper Older Americans Independence Center, Brigham and Women's Hospital, Harvard Medical School, Boston, Massachusetts
| |
Collapse
|