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Karmazyn M, Pierce GN, Fliegel L. The Remaining Conundrum of the Role of the Na +/H + Exchanger Isoform 1 (NHE1) in Cardiac Physiology and Pathology: Can It Be Rectified? Rev Cardiovasc Med 2022; 23:284. [PMID: 39076631 PMCID: PMC11266974 DOI: 10.31083/j.rcm2308284] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 06/29/2022] [Accepted: 07/08/2022] [Indexed: 07/31/2024] Open
Abstract
The mammalian Na + /H + exchanger (NHE) is a family of ubiquitous membrane proteins present in humans. Isoform one (NHE1) is present on the plasma membrane and regulates intracellular pH by removal of one intracellular proton in exchange for one extracellular sodium thus functioning as an electroneutral process. Human NHE1 has a 500 amino acid membrane domain plus a C-terminal 315 amino acid, regulatory cytosolic tail. It is regulated through a cytosolic regulatory C-terminal tail which is subject to phosphorylation and is modulated by proteins and lipids. Substantial evidence has implicated NHE1 activity in both myocardial ischemia and reperfusion damage and myocardial remodeling resulting in heart failure. Experimental data show excellent cardioprotection with NHE1 inhibitors although results from clinical results have been mixed. In cardiac surgery patients receiving the NHE1 inhibitor cariporide, subgroups showed beneficial effects of treatment. However, in one trial this was associated with a significantly increased incidence of ischemic strokes. This likely reflected both inappropriate dosing regimens as well as overly high drug doses. We suggest that further progress towards NHE1 inhibition as a treatment for cardiovascular disease is warranted through the development of novel compounds to inhibit NHE1 that are structurally different than those previously used in compromised clinical trials. Some novel pyrazinoyl guanidine inhibitors of NHE1 are already in development and the recent elucidation of the three-dimensional structure of the NHE1 protein and identity of the inhibitor binding site may facilitate development. An alternative approach may also be to control the endogenous regulation of activity of NHE1, which is activated in disease.
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Affiliation(s)
- Morris Karmazyn
- Department of Physiology and Pharmacology, University of Western Ontario, London, ON N6A 5C1, Canada
| | - Grant N. Pierce
- Institute of Cardiovascular Sciences, Albrechtsen Research Centre, St. Boniface Hospital, and Department of Physiology and Pathophysiology, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R2H 2A6, Canada
| | - Larry Fliegel
- Department of Biochemistry, University Alberta, Edmonton, AB T6G 2H7, Canada
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2
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Nag A, Gupta K, Dubey N, Mishra SK, Panigrahi J. Genomic characterization of ZIP genes in pigeonpea ( CcZIP) and their expression analysis among the genotypes with contrasting host response to pod borer. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2021; 27:2787-2804. [PMID: 35035136 PMCID: PMC8720128 DOI: 10.1007/s12298-021-01111-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2021] [Revised: 12/05/2021] [Accepted: 12/07/2021] [Indexed: 06/14/2023]
Abstract
UNLABELLED Zinc (Zn) is a vital micronutrient from the perspective of biofortification and biotic stress endurance in pigeonpea. The ZIP transporters with domain (Pfam: PF02535) regulate uptake and transport of metal ions, including Zn, in consonance with plant metal homeostasis. Genome-wide analysis in pigeonpea identified 19 non-redundant members of ZIP family (CcZIP) that were analyzed for gene structure, conserved motifs and homology besides other structural and biochemical parameters. Intra-specific as well as the inter-specific phylogenetic relationships of these 19 CcZIPs were elucidated by comparison with ZIP proteins of Arabidopsis thaliana, Medicago truncatula, Phaseolus vulgaris and Glycine max. In addition to gene structure, the cis-regulatory elements (CREs) in the promoter region were also identified. It revealed several stress responsive CREs that might be regulatory for differential expression of CcZIP proteins. Expression analysis showed that both CcZIP3 and CcZIP15, having zinc deficiency responsive element, up-regulated in the reproductive leaf tissues and down-regulated in matured green pods of the pod borer resistant genotypes with higher zinc content. Alternately, the expression of CcZIP6 and CcZIP13 was higher in matured green pods than reproductive leaves of the resistant genotypes. These findings on differential expression indicate the possible role of these CcZIPs on the mobilization of Zn from leaves to pods, phloem loading and unloading, and higher accumulation of seed zinc in pod borer resistant genotypes used in this study. Further functional characterization of CcZIP genes could shed light on their role in bio-fortification and genetic improvement to inhibit the pod borer herbivory in pigeonpea. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1007/s12298-021-01111-1.
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Affiliation(s)
- Atul Nag
- Department of Biosciences and Bioinformatics, Berhampur University, Bhanja Bihar, Berhampur, Odisha 760007 India
- Department of Biotechnology and Bioinformatics, Sambalpur University, Jyoti vihar, Odisha 768019 India
| | - Kapil Gupta
- Department of Biotechnology, School of Life Sciences, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817 India
- Department of Biotechnology, Sidhharth University, Kapilvastu, Siddharth Nagar, UP 272202 India
| | - Neeraj Dubey
- Department of Biotechnology, School of Life Sciences, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817 India
| | - Sujit K. Mishra
- Department of Biotechnology and Bioinformatics, Sambalpur University, Jyoti vihar, Odisha 768019 India
- Department of Zoology, Centurion University of Technology and Management, R. Sitapur, Odisha India
| | - Jogeswar Panigrahi
- Department of Biosciences and Bioinformatics, Berhampur University, Bhanja Bihar, Berhampur, Odisha 760007 India
- Department of Biotechnology and Bioinformatics, Sambalpur University, Jyoti vihar, Odisha 768019 India
- Department of Biotechnology, School of Life Sciences, Central University of Rajasthan, NH-8, Bandarsindri, Ajmer, Rajasthan 305817 India
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Blawn KT, Kellohen KL, Galloway EA, Wahl J, Vivek A, Verkhovsky VG, Barker NK, Cottier KE, Vallecillo TG, Langlais PR, Liktor-Busa E, Vanderah TW, Largent-Milnes TM. Sex hormones regulate NHE1 functional expression and brain endothelial proteome to control paracellular integrity of the blood endothelial barrier. Brain Res 2021; 1763:147448. [PMID: 33771519 PMCID: PMC10494867 DOI: 10.1016/j.brainres.2021.147448] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2020] [Revised: 03/18/2021] [Accepted: 03/19/2021] [Indexed: 01/31/2023]
Abstract
BACKGROUND Sex hormones have been implicated in pH regulation of numerous physiological systems. One consistent factor of these studies is the sodium-hydrogen exchanger 1 (NHE1). NHE1 has been associated with pH homeostasis at epithelial barriers. Hormone fluctuations have been implicated in protection and risk for breaches in blood brain barrier (BBB)/blood endothelial barrier (BEB) integrity. Few studies, however, have investigated BBB/BEB integrity in neurological disorders in the context of sex-hormone regulation of pH homeostasis. METHODS//RESULTS Physiologically relevant concentrations of 17-β-estradiol (E2, 294 pM), progesterone (P, 100 nM), and testosterone (T,3.12 nM) were independently applied to cultured immortalized bEnd.3 brain endothelial cells to study the BEB. Individual gonadal hormones showed preferential effects on extracellular pH (E2), 14C-sucrose uptake (T), stimulated paracellular breaches (P) with dependence on functional NHE1 expression without impacting transendothelial resistance (TEER) or total protein expression. While total NHE1 expression was not changed as determined via whole cell lysate and subcellular fractionation experiment, biotinylation of NHE1 for surface membrane expression showed E2 reduced functional expression. Quantitative proteomic analysis revealed divergent effects of 17-β-estradiol and testosterone on changes in protein abundance in bEnd.3 endothelial cells as compared to untreated controls. CONCLUSIONS These data suggest that circulating levels of sex hormones may independently control BEB integrity by 1) regulating pH homeostasis through NHE1 functional expression and 2) modifying the endothelial proteome.
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Affiliation(s)
- Kiera T Blawn
- University of Arizona, Department of Pharmacology, Tucson, AZ, USA
| | | | - Emily A Galloway
- University of Arizona, Department of Pharmacology, Tucson, AZ, USA
| | - Jared Wahl
- University of Arizona, Department of Pharmacology, Tucson, AZ, USA
| | - Anjali Vivek
- University of Arizona, Department of Pharmacology, Tucson, AZ, USA
| | | | - Natalie K Barker
- University of Arizona, Department of Medicine, Division of Endocrinology, College of Medicine, Tucson, AZ, USA
| | | | | | - Paul R Langlais
- University of Arizona, Department of Medicine, Division of Endocrinology, College of Medicine, Tucson, AZ, USA
| | | | - Todd W Vanderah
- University of Arizona, Department of Pharmacology, Tucson, AZ, USA
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4
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Role of Host-Mediated Post-Translational Modifications (PTMs) in RNA Virus Pathogenesis. Int J Mol Sci 2020; 22:ijms22010323. [PMID: 33396899 PMCID: PMC7796338 DOI: 10.3390/ijms22010323] [Citation(s) in RCA: 50] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2020] [Revised: 12/11/2020] [Accepted: 12/16/2020] [Indexed: 12/17/2022] Open
Abstract
Being opportunistic intracellular pathogens, viruses are dependent on the host for their replication. They hijack host cellular machinery for their replication and survival by targeting crucial cellular physiological pathways, including transcription, translation, immune pathways, and apoptosis. Immediately after translation, the host and viral proteins undergo a process called post-translational modification (PTM). PTMs of proteins involves the attachment of small proteins, carbohydrates/lipids, or chemical groups to the proteins and are crucial for the proteins’ functioning. During viral infection, host proteins utilize PTMs to control the virus replication, using strategies like activating immune response pathways, inhibiting viral protein synthesis, and ultimately eliminating the virus from the host. PTM of viral proteins increases solubility, enhances antigenicity and virulence properties. However, RNA viruses are devoid of enzymes capable of introducing PTMs to their proteins. Hence, they utilize the host PTM machinery to promote their survival. Proteins from viruses belonging to the family: Togaviridae, Flaviviridae, Retroviridae, and Coronaviridae such as chikungunya, dengue, zika, HIV, and coronavirus are a few that are well-known to be modified. This review discusses various host and virus-mediated PTMs that play a role in the outcome during the infection.
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Pedersen SF, Counillon L. The SLC9A-C Mammalian Na +/H + Exchanger Family: Molecules, Mechanisms, and Physiology. Physiol Rev 2019; 99:2015-2113. [PMID: 31507243 DOI: 10.1152/physrev.00028.2018] [Citation(s) in RCA: 103] [Impact Index Per Article: 20.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Na+/H+ exchangers play pivotal roles in the control of cell and tissue pH by mediating the electroneutral exchange of Na+ and H+ across cellular membranes. They belong to an ancient family of highly evolutionarily conserved proteins, and they play essential physiological roles in all phyla. In this review, we focus on the mammalian Na+/H+ exchangers (NHEs), the solute carrier (SLC) 9 family. This family of electroneutral transporters constitutes three branches: SLC9A, -B, and -C. Within these, each isoform exhibits distinct tissue expression profiles, regulation, and physiological roles. Some of these transporters are highly studied, with hundreds of original articles, and some are still only rudimentarily understood. In this review, we present and discuss the pioneering original work as well as the current state-of-the-art research on mammalian NHEs. We aim to provide the reader with a comprehensive view of core knowledge and recent insights into each family member, from gene organization over protein structure and regulation to physiological and pathophysiological roles. Particular attention is given to the integrated physiology of NHEs in the main organ systems. We provide several novel analyses and useful overviews, and we pinpoint main remaining enigmas, which we hope will inspire novel research on these highly versatile proteins.
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Affiliation(s)
- S F Pedersen
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
| | - L Counillon
- Section for Cell Biology and Physiology, Department of Biology, University of Copenhagen, Copenhagen, Denmark; and Université Côte d'Azur, CNRS, Laboratoire de Physiomédecine Moléculaire, LP2M, France, and Laboratories of Excellence Ion Channel Science and Therapeutics, Nice, France
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6
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Fuchs S, Hansen SC, Markones M, Mymrikov EV, Heerklotz H, Hunte C. Calcineurin B homologous protein 3 binds with high affinity to the CHP binding domain of the human sodium/proton exchanger NHE1. Sci Rep 2018; 8:14837. [PMID: 30287853 PMCID: PMC6172220 DOI: 10.1038/s41598-018-33096-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2018] [Accepted: 09/21/2018] [Indexed: 12/26/2022] Open
Abstract
The Na+/H+ exchanger NHE1 is critical for cell vitality as it controls intracellular pH and cell volume. Its functionality is influenced by calcineurin B homologous proteins (CHPs). The human isoform CHP3 is important for transport of NHE1 to the plasma membrane and for its activity. Here, we characterized the binding interaction of human CHP3 with the regulatory domain of NHE1. The exact binding site of CHP3 was previously debated. CHP3 as well as both regions of NHE1 in question were produced and purified. CHP3 specifically formed stable complexes with the CHP-binding region (CBD) of NHE1 (residues 503-545) in size-exclusion chromatography (SEC), but not with the C-terminal region (CTD, residues 633-815). CTD was functional as shown by Ca2+-dependent binding of calmodulin in SEC analysis. CHP3 bound with high affinity to CBD with an equilibrium dissociation constant (KD) of 56 nM determined by microscale thermophoresis. The high affinity was substantiated by isothermal calorimetry analysis (KD = 3 nM), which also revealed that the interaction with CBD is strongly exothermic (ΔG° = -48.6 kJ/mol, ΔH = -75.3 kJ/mol, -TΔS° = 26.7 kJ/mol). The data provide insights in the molecular mechanisms that underlie the regulatory interaction of CHP3 and NHE1 and more general of calcineurin homologous proteins with their target proteins.
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Affiliation(s)
- Simon Fuchs
- Institute for Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, D-79104, Freiburg, Germany
- Faculty of Biology, University of Freiburg, D-79104, Freiburg, Germany
| | - Sierra C Hansen
- Institute for Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, D-79104, Freiburg, Germany
| | - Marie Markones
- Department of Pharmaceutical Technology and Biopharmacy, University of Freiburg, D-79104, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, D-79104, Freiburg, Germany
| | - Evgeny V Mymrikov
- Institute for Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, D-79104, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, D-79104, Freiburg, Germany
| | - Heiko Heerklotz
- Department of Pharmaceutical Technology and Biopharmacy, University of Freiburg, D-79104, Freiburg, Germany
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, D-79104, Freiburg, Germany
- Leslie Dan Faculty of Pharmacy, University of Toronto, Toronto, Canada
| | - Carola Hunte
- Institute for Biochemistry and Molecular Biology, ZBMZ, Faculty of Medicine, University of Freiburg, D-79104, Freiburg, Germany.
- BIOSS Centre for Biological Signalling Studies, University of Freiburg, D-79104, Freiburg, Germany.
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7
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Jiang H, Zhang X, Chen X, Aramsangtienchai P, Tong Z, Lin H. Protein Lipidation: Occurrence, Mechanisms, Biological Functions, and Enabling Technologies. Chem Rev 2018; 118:919-988. [PMID: 29292991 DOI: 10.1021/acs.chemrev.6b00750] [Citation(s) in RCA: 286] [Impact Index Per Article: 47.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Protein lipidation, including cysteine prenylation, N-terminal glycine myristoylation, cysteine palmitoylation, and serine and lysine fatty acylation, occurs in many proteins in eukaryotic cells and regulates numerous biological pathways, such as membrane trafficking, protein secretion, signal transduction, and apoptosis. We provide a comprehensive review of protein lipidation, including descriptions of proteins known to be modified and the functions of the modifications, the enzymes that control them, and the tools and technologies developed to study them. We also highlight key questions about protein lipidation that remain to be answered, the challenges associated with answering such questions, and possible solutions to overcome these challenges.
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Affiliation(s)
- Hong Jiang
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Xiaoyu Zhang
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Xiao Chen
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Pornpun Aramsangtienchai
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Zhen Tong
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
| | - Hening Lin
- Howard Hughes Medical Institute, Department of Chemistry and Chemical Biology, Cornell University , Ithaca, New York 14853, United States
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Takamatsu G, Katagiri C, Tomoyuki T, Shimizu-Okabe C, Nakamura W, Nakamura-Higa M, Hayakawa T, Wakabayashi S, Kondo T, Takayama C, Matsushita M. Tescalcin is a potential target of class I histone deacetylase inhibitors in neurons. Biochem Biophys Res Commun 2016; 482:1327-1333. [PMID: 27939885 DOI: 10.1016/j.bbrc.2016.12.036] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2016] [Accepted: 12/06/2016] [Indexed: 10/20/2022]
Abstract
Class I histone deacetylase (HDAC) inhibitors are believed to have positive effects on neurite outgrowth, synaptic plasticity, and neurogenesis in adult brain. However, the downstream molecular targets of class I HDAC inhibitors in neurons are not clear. Although class I HDAC inhibitors are thought to broadly promote transcription of many neuronal genes through enhancement of histone acetylation, the affected gene set may include unidentified genes that are essential for neuronal survival and function. To identify novel genes that are targets of class I HDAC inhibitors, we used a microarray to screen transcripts from neuronal cultures and evaluated changes in protein and mRNA expression following treatment with four HDAC inhibitors. We identified tescalcin (Tesc) as the most strongly up-regulated gene following treatment with class I HDAC inhibitors in neurons. Moreover, hippocampal neurons overexpressing TESC showed a greater than 5-fold increase in the total length of neurites and number of branch points compared with controls. These findings highlight a potentially important role for TESC in mediating the neuroprotective effect of class I HDAC inhibitors. TESC may also be involved in the development of brain and neurodegenerative diseases through epigenetic mechanisms.
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Affiliation(s)
- Gakuya Takamatsu
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, 903-0215 Okinawa, Japan; Department of Neuropsychiatry, Graduate School of Medicine, University of the Ryukyus, 903-0215 Okinawa, Japan
| | - Chiaki Katagiri
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, 903-0215 Okinawa, Japan; Department of Neurosurgery, Graduate School of Medicine, University of the Ryukyus, 903-0215 Okinawa, Japan
| | - Tsumuraya Tomoyuki
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, 903-0215 Okinawa, Japan
| | - Chigusa Shimizu-Okabe
- Department of Molecular Anatomy, Graduate School of Medicine, University of the Ryukyus, 903-0215 Okinawa, Japan
| | - Wakako Nakamura
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, 903-0215 Okinawa, Japan
| | - Mariko Nakamura-Higa
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, 903-0215 Okinawa, Japan
| | - Tomoko Hayakawa
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, 903-0215 Okinawa, Japan
| | - Shigeo Wakabayashi
- Department of Pharmacology, Faculty of Medicine, Osaka Medical College, 569-8686 Osaka, Japan
| | - Tsuyoshi Kondo
- Department of Neuropsychiatry, Graduate School of Medicine, University of the Ryukyus, 903-0215 Okinawa, Japan
| | - Chitoshi Takayama
- Department of Molecular Anatomy, Graduate School of Medicine, University of the Ryukyus, 903-0215 Okinawa, Japan
| | - Masayuki Matsushita
- Department of Molecular and Cellular Physiology, Graduate School of Medicine, University of the Ryukyus, 903-0215 Okinawa, Japan.
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9
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Takakuwa S, Mizuno N, Takano T, Asakawa S, Sato T, Hiratsuka M, Hirasawa N. Down-regulation of Na +/H + exchanger 1 by Toll-like receptor stimulation in macrophages. Immunobiology 2016; 222:176-182. [PMID: 27771174 DOI: 10.1016/j.imbio.2016.10.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2016] [Revised: 10/07/2016] [Accepted: 10/07/2016] [Indexed: 12/17/2022]
Abstract
The role of Na+/H+ exchanger 1 (NHE1) in various cell types, including inflammatory cells, has been extensively studied. However, regulation of NHE1 protein level in activated inflammatory cells is yet to be characterized. In this study, we investigated whether Toll-like receptor (TLR) ligands can regulate NHE1 protein level in the mouse macrophage-like RAW 264 cell line. We found that lipopolysaccharide (LPS), a TLR4 ligand, lowered NHE1 level and activity in RAW 264 cells and in primary murine macrophages. Other TLR ligands, such as zymosan A and poly(I:C), also displayed reduced NHE1 level. LPS promoted NHE1 ubiquitination and reduced the expression of calcineurin homologous protein 1 (CHP1), a regulator of NHE1 activity and stability. These responses were inhibited by c-Jun N-terminal kinase (JNK) inhibitor SP600125 and dexamethasone. A proteasome inhibitor, but not caspase-3 or lysosomal inhibitors, blocked the LPS-induced NHE1 down-regulation. These results suggested that LPS promotes the degranulation of NHE1 mediated by the ubiquitin-proteasome system and CHP1 downregulation resulting from activation of JNK.
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Affiliation(s)
- Shiho Takakuwa
- Laboratory of Pharmacotherapy of Lifestyle Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Natsumi Mizuno
- Laboratory of Pharmacotherapy of Lifestyle Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Takayuki Takano
- Laboratory of Pharmacotherapy of Lifestyle Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Sanki Asakawa
- Laboratory of Pharmacotherapy of Lifestyle Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Taiki Sato
- Laboratory of Pharmacotherapy of Lifestyle Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Masahiro Hiratsuka
- Laboratory of Pharmacotherapy of Lifestyle Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan
| | - Noriyasu Hirasawa
- Laboratory of Pharmacotherapy of Lifestyle Related Diseases, Graduate School of Pharmaceutical Sciences, Tohoku University, Sendai, Miyagi 980-8578, Japan.
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10
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Kolobynina KG, Solovyova VV, Levay K, Rizvanov AA, Slepak VZ. Emerging roles of the single EF-hand Ca2+ sensor tescalcin in the regulation of gene expression, cell growth and differentiation. J Cell Sci 2016; 129:3533-3540. [PMID: 27609838 DOI: 10.1242/jcs.191486] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
Tescalcin (TESC, also known as calcineurin-homologous protein 3, CHP3) is a 24-kDa EF-hand Ca2+-binding protein that has recently emerged as a regulator of cell differentiation and growth. The TESC gene has also been linked to human brain abnormalities, and high expression of tescalcin has been found in several cancers. The expression level of tescalcin changes dramatically during development and upon signal-induced cell differentiation. Recent studies have shown that tescalcin is not only subjected to up- or down-regulation, but also has an active role in pathways that drive cell growth and differentiation programs. At the molecular level, there is compelling experimental evidence showing that tescalcin can directly interact with and regulate the activities of the Na+/H+ exchanger NHE1, subunit 4 of the COP9 signalosome (CSN4) and protein kinase glycogen-synthase kinase 3 (GSK3). In hematopoetic precursor cells, tescalcin has been shown to couple activation of the extracellular signal-regulated kinase (ERK) cascade to the expression of transcription factors that control cell differentiation. The purpose of this Commentary is to summarize recent efforts that have served to characterize the biochemical, genetic and physiological attributes of tescalcin, and its unique role in the regulation of various cellular functions.
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Affiliation(s)
- Ksenia G Kolobynina
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Republic of Tatarstan, 420000, Russian Federation
| | - Valeria V Solovyova
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Republic of Tatarstan, 420000, Russian Federation
| | - Konstantin Levay
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Albert A Rizvanov
- Institute of Fundamental Medicine and Biology, Kazan Federal University, Kazan, Republic of Tatarstan, 420000, Russian Federation
| | - Vladlen Z Slepak
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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11
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Allman E, Wang Q, Walker RL, Austen M, Peters MA, Nehrke K. Calcineurin homologous proteins regulate the membrane localization and activity of sodium/proton exchangers in C. elegans. Am J Physiol Cell Physiol 2015; 310:C233-42. [PMID: 26561640 DOI: 10.1152/ajpcell.00291.2015] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2015] [Accepted: 11/09/2015] [Indexed: 11/22/2022]
Abstract
Calcineurin B homologous proteins (CHP) are N-myristoylated, EF-hand Ca(2+)-binding proteins that bind to and regulate Na(+)/H(+) exchangers, which occurs through a variety of mechanisms whose relative significance is incompletely understood. Like mammals, Caenorhabditis elegans has three CHP paralogs, but unlike mammals, worms can survive CHP loss-of-function. However, mutants for the CHP ortholog PBO-1 are unfit, and PBO-1 has been shown to be required for proton signaling by the basolateral Na(+)/H(+) exchanger NHX-7 and for proton-coupled intestinal nutrient uptake by the apical Na(+)/H(+) exchanger NHX-2. Here, we have used this genetic model organism to interrogate PBO-1's mechanism of action. Using fluorescent tags to monitor Na(+)/H(+) exchanger trafficking and localization, we found that loss of either PBO-1 binding or activity caused NHX-7 to accumulate in late endosomes/lysosomes. In contrast, NHX-2 was stabilized at the apical membrane by a nonfunctional PBO-1 protein and was only internalized following its complete loss. Additionally, two pbo-1 paralogs were identified, and their expression patterns were analyzed. One of these contributed to the function of the excretory cell, which acts like a kidney in worms, establishing an alternative model for testing the role of this protein in membrane transporter trafficking and regulation. These results lead us to conclude that the role of CHP in Na(+)/H(+) exchanger regulation differs between apical and basolateral transporters. This further emphasizes the importance of proper targeting of Na(+)/H(+) exchangers and the critical role of CHP family proteins in this process.
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Affiliation(s)
- Erik Allman
- Departments of Pharmacology and Physiology and Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York; Department of Biochemistry and Molecular Biology, Pennsylvania State University, University Park, Pennsylvania
| | - Qian Wang
- Departments of Pharmacology and Physiology and Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York
| | - Rachel L Walker
- Departments of Pharmacology and Physiology and Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York
| | - Molly Austen
- Departments of Pharmacology and Physiology and Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York
| | | | - Keith Nehrke
- Departments of Pharmacology and Physiology and Medicine, University of Rochester School of Medicine and Dentistry, Rochester, New York;
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12
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Odunewu-Aderibigbe A, Fliegel L. The Na+/H+exchanger and pH regulation in the heart. IUBMB Life 2014; 66:679-85. [DOI: 10.1002/iub.1323] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2014] [Accepted: 10/15/2014] [Indexed: 11/11/2022]
Affiliation(s)
| | - Larry Fliegel
- Department of Biochemistry; University of Alberta; Edmonton AB Canada
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13
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A novel tescalcin-sodium/hydrogen exchange axis underlying sorafenib resistance in FLT3-ITD+ AML. Blood 2014; 123:2530-9. [DOI: 10.1182/blood-2013-07-512194] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Key Points
A novel TESC-NEH1 pathway is involved in FLT3-ITD+ AML pathogenesis. Inhibition of NHE1 overcomes sorafenib resistance in FLT3-ITD+AML.
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14
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Levay K, Slepak VZ. Regulation of Cop9 signalosome activity by the EF-hand Ca2+-binding protein tescalcin. J Cell Sci 2014; 127:2448-59. [PMID: 24659803 DOI: 10.1242/jcs.139592] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The Ca(2+)-binding protein tescalcin is known to be involved in hematopoietic cell differentiation; however, this mechanism is poorly understood. Here, we identify CSN4 (subunit 4 of the COP9 signalosome) as a novel binding partner of tescalcin. The COP9 signalosome (CSN) is a multiprotein complex that is essential for development in all eukaryotes. This interaction is selective, Ca(2+)-dependent and involves the PCI domain of CSN4 subunit. We then investigated tescalcin and CSN activity in human erythroleukemia HEL and promyelocytic leukemia K562 cells and find that phorbol 12-myristate 13-acetate (PMA)-induced differentiation, resulting in the upregulation of tescalcin, coincides with reduced deneddylation of cullin-1 (Cul1) and stabilization of p27(Kip1) - molecular events that are associated with CSN activity. The knockdown of tescalcin led to an increase in Cul1 deneddylation, expression of F-box protein Skp2 and the transcription factor c-Jun, whereas the levels of cell cycle regulators p27(Kip1) and p53 decreased. These effects are consistent with the hypothesis that tescalcin might play a role as a negative regulator of CSN activity towards Cul1 in the process of induced cell differentiation.
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Affiliation(s)
- Konstantin Levay
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA
| | - Vladlen Z Slepak
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL 33136, USA Neuroscience Program, University of Miami Miller School of Medicine, Miami, FL 33136, USA
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15
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Hendus-Altenburger R, Kragelund BB, Pedersen SF. Structural dynamics and regulation of the mammalian SLC9A family of Na⁺/H⁺ exchangers. CURRENT TOPICS IN MEMBRANES 2014; 73:69-148. [PMID: 24745981 DOI: 10.1016/b978-0-12-800223-0.00002-5] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Mammalian Na⁺/H⁺ exchangers of the SLC9A family are widely expressed and involved in numerous essential physiological processes. Their primary function is to mediate the 1:1 exchange of Na⁺ for H⁺ across the membrane in which they reside, and they play central roles in regulation of body, cellular, and organellar pH. Their function is tightly regulated through mechanisms involving interactions with multiple protein and lipid-binding partners, phosphorylations, and other posttranslational modifications. Biochemical and mutational analyses indicate that the SLC9As have a short intracellular N-terminus, 12 transmembrane (TM) helices necessary and sufficient for ion transport, and a C-terminal cytoplasmic tail region with essential regulatory roles. No high-resolution structures of the SLC9As exist; however, models based on crystal structures of the bacterial NhaAs support the 12 TM organization and suggest that TMIV and XI may form a central part of the ion-translocation pathway, whereas pH sensing may involve TMII, TMIX, and several intracellular loops. Similar to most ion transporters studied, SLC9As likely exist as coupled dimers in the membrane, and this appears to be important for the well-studied cooperativity of H⁺ binding. The aim of this work is to summarize and critically discuss the currently available evidence on the structural dynamics, regulation, and binding partner interactions of SLC9As, focusing in particular on the most widely studied isoform, SLC9A1/NHE1. Further, novel bioinformatic and structural analyses are provided that to some extent challenge the existing paradigm on how ions are transported by mammalian SLC9As.
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Affiliation(s)
- Ruth Hendus-Altenburger
- Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Copenhagen, Denmark; Section for Cell and Developmental Biology, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Birthe B Kragelund
- Section for Biomolecular Sciences, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Stine Falsig Pedersen
- Section for Cell and Developmental Biology, Department of Biology, University of Copenhagen, Copenhagen, Denmark.
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16
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Babich V, Vadnagara K, Di Sole F. The biophysical and molecular basis of intracellular pH sensing by Na+/H+ exchanger-3. FASEB J 2013; 27:4646-58. [PMID: 23934281 DOI: 10.1096/fj.12-225466] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Epithelial Na(+)/H(+) exchanger-3 (NHE3) transport is fundamental for renal and intestinal sodium reabsorption. Cytoplasmic protons are thought to serve as allosteric modifiers of the exchanger and to trigger its transport through protein conformational change. This effect presupposes an intracellular pH (pHi) dependence of NHE3 activity, although the biophysical and molecular basis of NHE3 pHi sensitivity have not been defined. NHE3, when complexed with the calcineurin homologous protein-1 (CHP1), had a shift in pHi sensitivity (0.4 units) toward the acidic side in comparison with NHE3 alone, as measured by oscillating pH electrodes combined with whole-cell patch clamping. Indeed, CHP1 interaction with NHE3 inhibited NHE3 transport in a pHi -dependent manner. CHP1 binding to NHE3 also affected its acute regulation. Intracellular perfusion of peptide from the CHP1 binding region (or pHi modification to reduce the CHP1 amount bound to NHE3) was permissive and cooperative for dopamine inhibition of NHE3 but reversed that of adenosine. Thus, CHP1 interaction with NHE3 apparently establishes the exchanger set point for pHi, and modification in this set point is effective in the hormonal stimuli-mediated regulation of NHE3. CHP1 may serve as a regulatory cofactor for NHE3 conformational change, dependent on intracellular protonation.
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Affiliation(s)
- Victor Babich
- 1Department of Medicine, University of Maryland School of Medicine, 20 Penn Street, HSFII, Suite S005, Baltimore, MD 21201, USA.
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17
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Regulation of the cardiac Na⁺/H⁺ exchanger in health and disease. J Mol Cell Cardiol 2013; 61:68-76. [PMID: 23429007 DOI: 10.1016/j.yjmcc.2013.02.007] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Revised: 02/07/2013] [Accepted: 02/11/2013] [Indexed: 11/21/2022]
Abstract
The Na(+) gradient produced across the cardiac sarcolemma by the ATP-dependent Na(+)-pump is a constant source of energy for Na(+)-dependent transporters. The plasma membrane Na(+)/H(+) exchanger (NHE) is one such secondary active transporter, regulating intracellular pH, Na(+) concentration, and cell volume. NHE1, the major isoform found in the heart, is activated in response to a variety of stimuli such as hormones and mechanical stress. This important characteristic of NHE1 is intimately linked to heart diseases, including maladaptive cardiac hypertrophy and subsequent heart failure, as well as acute ischemic-reperfusion injury. NHE1 activation results in elevation of pH and intracellular Na(+) concentration, which potentially enhance downstream signaling cascades in the myocardium. Therefore, in addition to determining the mechanism underlying regulation of NHE1 activity, it is important to understand how the ionic signal produced by NHE1 is transmitted to the downstream targets. Extensive studies have identified many accessory factors that interact with NHE1. Here, we have summarized the recent progress on understanding the molecular mechanism underlying NHE1 regulation and have shown a possible signaling pathway leading to cardiac remodeling, which is initiated from NHE1. This article is part of a Special Issue entitled "Na(+) Regulation in Cardiac Myocytes".
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