1
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Sluysmans S, Salmaso A, Rouaud F, Méan I, Brini M, Citi S. The PLEKHA7-PDZD11 complex regulates the localization of the calcium pump PMCA and calcium handling in cultured cells. J Biol Chem 2022; 298:102138. [PMID: 35714771 PMCID: PMC9307954 DOI: 10.1016/j.jbc.2022.102138] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 06/05/2022] [Accepted: 06/06/2022] [Indexed: 01/11/2023] Open
Abstract
The plasma membrane calcium ATPase (PMCA) extrudes calcium from the cytosol to the extracellular space to terminate calcium-dependent signaling. Although the distribution of PMCA is crucial for its function, the molecular mechanisms that regulate the localization of PMCA isoforms are not well understood. PLEKHA7 is implicated by genetic studies in hypertension and the regulation of calcium handling. PLEKHA7 recruits the small adapter protein PDZD11 to adherens junctions, and together they control the trafficking and localization of plasma membrane associated proteins, including the Menkes copper ATPase. Since PDZD11 binds to the C-terminal domain of b-isoforms of PMCA, PDZD11 and its interactor PLEKHA7 could control the localization and activity of PMCA. Here, we test this hypothesis using cultured cell model systems. We show using immunofluorescence microscopy and a surface biotinylation assay that KO of either PLEKHA7 or PDZD11 in mouse kidney collecting duct epithelial cells results in increased accumulation of endogenous PMCA at lateral cell–cell contacts and PDZ-dependent ectopic apical localization of exogenous PMCA4x/b isoform. In HeLa cells, coexpression of PDZD11 reduces membrane accumulation of overexpressed PMCA4x/b, and analysis of cytosolic calcium transients shows that PDZD11 counteracts calcium extrusion activity of overexpressed PMCA4x/b, but not PMCA4x/a, which lacks the PDZ-binding motif. Moreover, KO of PDZD11 in either endothelial (bEnd.3) or epithelial (mouse kidney collecting duct) cells increases the rate of calcium extrusion. Collectively, these results suggest that the PLEKHA7–PDZD11 complex modulates calcium homeostasis by regulating the localization of PMCA.
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Affiliation(s)
- Sophie Sluysmans
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Andrea Salmaso
- Department of Biology, University of Padua, Padua, Italy
| | - Florian Rouaud
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Isabelle Méan
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland
| | - Marisa Brini
- Department of Biology, University of Padua, Padua, Italy.
| | - Sandra Citi
- Department of Molecular and Cellular Biology, University of Geneva, Geneva, Switzerland.
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2
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Naso F, Intartaglia D, Falanga D, Soldati C, Polishchuk E, Giamundo G, Tiberi P, Marrocco E, Scudieri P, Di Malta C, Trapani I, Nusco E, Salierno FG, Surace EM, Galietta LJ, Banfi S, Auricchio A, Ballabio A, Medina DL, Conte I. Light-responsive microRNA miR-211 targets Ezrin to modulate lysosomal biogenesis and retinal cell clearance. EMBO J 2020; 39:e102468. [PMID: 32154600 DOI: 10.15252/embj.2019102468] [Citation(s) in RCA: 26] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2019] [Revised: 02/03/2020] [Accepted: 02/05/2020] [Indexed: 12/16/2022] Open
Abstract
Vertebrate vision relies on the daily phagocytosis and lysosomal degradation of photoreceptor outer segments (POS) within the retinal pigment epithelium (RPE). However, how these events are controlled by light is largely unknown. Here, we show that the light-responsive miR-211 controls lysosomal biogenesis at the beginning of light-dark transitions in the RPE by targeting Ezrin, a cytoskeleton-associated protein essential for the regulation of calcium homeostasis. miR-211-mediated down-regulation of Ezrin leads to Ca2+ influx resulting in the activation of calcineurin, which in turn activates TFEB, the master regulator of lysosomal biogenesis. Light-mediated induction of lysosomal biogenesis and function is impaired in the RPE from miR-211-/- mice that show severely compromised vision. Pharmacological restoration of lysosomal biogenesis through Ezrin inhibition rescued the miR-211-/- phenotype, pointing to a new therapeutic target to counteract retinal degeneration associated with lysosomal dysfunction.
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Affiliation(s)
- Federica Naso
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy
| | | | - Danila Falanga
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy
| | - Chiara Soldati
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy
| | - Elena Polishchuk
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy
| | - Giuliana Giamundo
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy
| | - Paola Tiberi
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy
| | - Elena Marrocco
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy
| | - Paolo Scudieri
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy
| | - Chiara Di Malta
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy
| | - Ivana Trapani
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy
| | - Edoardo Nusco
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy
| | | | - Enrico Maria Surace
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy.,Department of Translational Medicine, University of Naples Federico II, Naples, Italy
| | - Luis Jv Galietta
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy.,Department of Translational Medicine, University of Naples Federico II, Naples, Italy
| | - Sandro Banfi
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy.,Medical Genetics, Department of Biochemistry, Biophysics and General Pathology, University of Campania "L. Vanvitelli", Naples, Italy
| | - Alberto Auricchio
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy.,Department of Translational Medicine, University of Naples Federico II, Naples, Italy
| | - Andrea Ballabio
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy.,Department of Translational Medicine, University of Naples Federico II, Naples, Italy.,Jan and Dan Duncan Neurological Research Institute, Texas Children Hospital, Houston, TX, USA.,Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, TX, USA
| | - Diego Luis Medina
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy
| | - Ivan Conte
- Telethon Institute of Genetics and Medicine, Pozzuoli (Naples), Italy.,Department of Biology, University of Naples Federico II, Naples, Italy
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3
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Hegedűs L, Zámbó B, Pászty K, Padányi R, Varga K, Penniston JT, Enyedi Á. Molecular Diversity of Plasma Membrane Ca2+ Transporting ATPases: Their Function Under Normal and Pathological Conditions. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1131:93-129. [DOI: 10.1007/978-3-030-12457-1_5] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
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4
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Jeong J, Kim W, Hens J, Dann P, Schedin P, Friedman PA, Wysolmerski JJ. NHERF1 Is Required for Localization of PMCA2 and Suppression of Early Involution in the Female Lactating Mammary Gland. Endocrinology 2019; 160:1797-1810. [PMID: 31087002 PMCID: PMC6619491 DOI: 10.1210/en.2019-00230] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/22/2019] [Accepted: 05/07/2019] [Indexed: 12/11/2022]
Abstract
Prior studies have demonstrated that the calcium pump, plasma membrane calcium ATPase 2 (PMCA2), mediates calcium transport into milk and prevents mammary epithelial cell death during lactation. PMCA2 also regulates cell proliferation and cell death in breast cancer cells, in part by maintaining the receptor tyrosine kinase ErbB2/HER2 within specialized plasma membrane domains. Furthermore, the regulation of PMCA2 membrane localization and activity in breast cancer cells requires its interaction with the PDZ domain-containing scaffolding molecule sodium-hydrogen exchanger regulatory factor (NHERF) 1. In this study, we asked whether NHERF1 also interacts with PMCA2 in normal mammary epithelial cells during lactation. Our results demonstrate that NHERF1 expression is upregulated during lactation and that it interacts with PMCA2 at the apical membrane of secretory luminal epithelial cells. Similar to PMCA2, NHERF1 expression is rapidly reduced by milk stasis after weaning. Examining lactating NHERF1 knockout (KO) mice showed that NHERF1 contributes to the proper apical location of PMCA2, for proper apical-basal polarity in luminal epithelial cells, and that it participates in the suppression of Stat3 activation and the prevention of premature mammary gland involution. Additionally, we found that PMCA2 also interacts with the closely related scaffolding molecule, NHERF2, at the apical membrane, which likely maintains PMCA2 at the plasma membrane of mammary epithelial cells in lactating NHERF1KO mice. Based on these data, we conclude that, during lactation, NHERF1 is required for the proper expression and apical localization of PMCA2, which, in turn, contributes to preventing the premature activation of Stat3 and the lysosome-mediated cell death pathway that usually occur only early in mammary involution.
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Affiliation(s)
- Jaekwang Jeong
- Section of Endocrinology and Metabolism, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Wonnam Kim
- Division of Pharmacology, College of Korean Medicine, Semyung University, Jecheon, Republic of Korea
| | - Julie Hens
- Section of Endocrinology and Metabolism, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Pamela Dann
- Section of Endocrinology and Metabolism, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut
| | - Pepper Schedin
- Department of Cell, Developmental, and Cancer Biology, Oregon Health and Science University, Portland, Oregon
| | - Peter A Friedman
- Department of Pharmacology and Chemical Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania
| | - John J Wysolmerski
- Section of Endocrinology and Metabolism, Department of Medicine, Yale University School of Medicine, New Haven, Connecticut
- Correspondence: John J. Wysolmerski, MD, Section of Endocrinology and Metabolism, Department of Internal Medicine, TAC S123a, Yale University School of Medicine, 333 Cedar Street, FMT 102, Box 208020, New Haven, Connecticut 06520. E-mail:
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5
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Moulick A, Heger Z, Milosavljevic V, Richtera L, Barroso-Flores J, Merlos Rodrigo MA, Buchtelova H, Podgajny R, Hynek D, Kopel P, Adam V. Real-Time Visualization of Cell Membrane Damage Using Gadolinium-Schiff Base Complex-Doped Quantum Dots. ACS APPLIED MATERIALS & INTERFACES 2018; 10:35859-35868. [PMID: 30264566 DOI: 10.1021/acsami.8b15868] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/08/2023]
Abstract
Despite the importance of cell membranes for maintenance of integrity of cellular structures, there is still a lack of methods that allow simple real-time visualization of their damage. Herein, we describe gadolinium-Schiff base-doped quantum dots (GdQDs)-based probes for a fast facile spatial labeling of membrane injuries. We found that GdQDs preferentially interact through electron-rich and hydrophobic residues with a specific sequence motif of NHE-RF2 scaffold protein, exposed upon membrane damage. Such interaction results in a fast formation of intensively fluorescent droplets with a higher resolution and in a much shorter time compared to immunofluorescence using organic dye. GdQDs have high stability, brightness, and considerable cytocompatibility, which enable their use in long-term experiments in living cultures. To the best of our knowledge, this is the first report, demonstrating a method allowing real-time monitoring of membrane damage and recovery without any special requirements for instrumentation. Because of intensive brightness and simple signal pattern, GdQDs allow easy examination of interactions between cellular membranes and cell-penetrating peptides or cytostatic drugs. We anticipate that the simple and flexible method will also facilitate the studies dealing with host-pathogen interactions.
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Affiliation(s)
- Amitava Moulick
- Department of Chemistry and Biochemistry , Mendel University in Brno , Zemedelska 1 , CZ-613 00 Brno , Czech Republic
- Central European Institute of Technology , Brno University of Technology , Purkynova 123 , CZ-612 00 Brno , Czech Republic
| | - Zbynek Heger
- Department of Chemistry and Biochemistry , Mendel University in Brno , Zemedelska 1 , CZ-613 00 Brno , Czech Republic
- Central European Institute of Technology , Brno University of Technology , Purkynova 123 , CZ-612 00 Brno , Czech Republic
| | - Vedran Milosavljevic
- Department of Chemistry and Biochemistry , Mendel University in Brno , Zemedelska 1 , CZ-613 00 Brno , Czech Republic
| | - Lukas Richtera
- Department of Chemistry and Biochemistry , Mendel University in Brno , Zemedelska 1 , CZ-613 00 Brno , Czech Republic
- Central European Institute of Technology , Brno University of Technology , Purkynova 123 , CZ-612 00 Brno , Czech Republic
| | - Joaquin Barroso-Flores
- Centro Conjunto de Investigación en Química Sustentable UAEM-UNAM , Carretera Toluca-Atlacomulco Km 14.5, Unidad San Cayetano , CP-50200 Toluca , Estado de México , Mexico
| | - Miguel Angel Merlos Rodrigo
- Department of Chemistry and Biochemistry , Mendel University in Brno , Zemedelska 1 , CZ-613 00 Brno , Czech Republic
- Central European Institute of Technology , Brno University of Technology , Purkynova 123 , CZ-612 00 Brno , Czech Republic
| | - Hana Buchtelova
- Department of Chemistry and Biochemistry , Mendel University in Brno , Zemedelska 1 , CZ-613 00 Brno , Czech Republic
| | - Robert Podgajny
- Faculty of Chemistry , Jagiellonian University , Gronostajowa 2 , PL 30-387 Krakow , Poland
| | - David Hynek
- Department of Chemistry and Biochemistry , Mendel University in Brno , Zemedelska 1 , CZ-613 00 Brno , Czech Republic
- Central European Institute of Technology , Brno University of Technology , Purkynova 123 , CZ-612 00 Brno , Czech Republic
| | - Pavel Kopel
- Department of Chemistry and Biochemistry , Mendel University in Brno , Zemedelska 1 , CZ-613 00 Brno , Czech Republic
- Central European Institute of Technology , Brno University of Technology , Purkynova 123 , CZ-612 00 Brno , Czech Republic
| | - Vojtech Adam
- Department of Chemistry and Biochemistry , Mendel University in Brno , Zemedelska 1 , CZ-613 00 Brno , Czech Republic
- Central European Institute of Technology , Brno University of Technology , Purkynova 123 , CZ-612 00 Brno , Czech Republic
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6
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Romero-Lorca A, Gaibar M, Armesilla AL, Fernandez-Santander A, Novillo A. Differential expression of PMCA2 mRNA isoforms in a cohort of Spanish patients with breast tumor types. Oncol Lett 2018; 16:6950-6959. [PMID: 30546427 PMCID: PMC6256341 DOI: 10.3892/ol.2018.9540] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 05/29/2018] [Indexed: 01/01/2023] Open
Abstract
The present study examined the mRNA expression levels of different isoforms of the plasma membrane calcium ATPase 2 (PMCA2) gene generated by alternative splicing at the first intracellular loop (site A) and C-terminal region (site C) in 85 human breast cancer tumor and 69 adjacent non-tumor tissues. Associations were identified between the expression of PMCA2 splice isoforms and the following clinical variables: Estrogen receptor (ER), progesterone receptor (PR) and human epidermal growth factor receptor 2 (HER2) status, tumor size, staging and histological classification, and lymph node status. Transcripts including splice site A or splice site C were amplified by reverse transcription-quantitative polymerase chain reaction using PMCA2 isoform-specific primers. Tumor and adjacent tissues were determined to express the different PMCA2 splice isoforms 2w, 2× and 2z (site A), and 2b (site C). The mRNA levels for these variants indicated high biological variability, but increased expression was observed in breast tumor tissues, compared with in adjacent tissues. Significantly increased PMCA2×/b expression levels were detected in breast tumor tissues histologically classified as lobulillar, compared with in ductal-types breast tumor tissues (P<0.028). Furthermore, PMCA2z expression was significantly associated with PR status (P<0.024, compared with in PR-negative tumor tissues), and PMCA2w expression was significantly associated with ER status (P<0.048, increased in ER-positive tumor tissues, compared with ER-negative tumor tissues). Finally, PMCA2b was overexpressed in HER2-positive tumor tissues, compared with in HER2-negative tumor tissues (P<0.014). The data demonstrated the differential mRNA expression of a number of splice site A and C variants of PMCA2 in breast tumor and adjacent tissues, depending on tumor hormone receptor status and histological classification. In agreement with previous data, PMCA2b was overexpressed in HER2-positive tumor tissues, indicating that high mRNA levels of this variant could be a marker of poor prognosis.
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Affiliation(s)
- Alicia Romero-Lorca
- Department of Basic Biomedical Sciences, Faculty of Biomedical and Health Sciences, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid 28670, Spain
| | - Maria Gaibar
- Department of Basic Biomedical Sciences, Faculty of Biomedical and Health Sciences, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid 28670, Spain
| | - Angel Luis Armesilla
- Faculty of Science and Engineering, School of Pharmacy, University of Wolverhampton, Wolverhampton, West Midlands WV1 1LY, UK
| | - Ana Fernandez-Santander
- Department of Basic Biomedical Sciences, Faculty of Biomedical and Health Sciences, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid 28670, Spain
| | - Apolonia Novillo
- Department of Basic Biomedical Sciences, Faculty of Biomedical and Health Sciences, Universidad Europea de Madrid, Villaviciosa de Odón, Madrid 28670, Spain
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7
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Vinaiphat A, Thongboonkerd V. Characterizations of PMCA2-interacting complex and its role as a calcium oxalate crystal-binding protein. Cell Mol Life Sci 2018; 75:1461-1482. [PMID: 29085954 PMCID: PMC11105569 DOI: 10.1007/s00018-017-2699-2] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2017] [Revised: 10/24/2017] [Accepted: 10/26/2017] [Indexed: 12/27/2022]
Abstract
Three isoforms of plasma membrane Ca2+-ATPase (PMCA) are expressed in the kidney. While PMCA1 and PMCA4 play major role in regulating Ca2+ reabsorption, the role for PMCA2 remains vaguely defined. To define PMCA2 function, PMCA2-interacting complex was characterized by immunoprecipitation followed by nanoLC-ESI-Qq-TripleTOF MS/MS (IP-MS). After subtracting non-specific binders using isotype-controlled IP-MS, 474 proteins were identified as PMCA2-interacting partners. Among these, eight were known and 20 were potential PMCA2-interacting partners based on bioinformatic prediction, whereas other 446 were novel and had not been previously reported/predicted. Quantitative immuno-co-localization assay confirmed the association of PMCA2 with these partners. Gene ontology analysis revealed binding activity as the major molecular function of PMCA2-interacting complex. Functional validation using calcium oxalate monohydrate (COM) crystal-protein binding, crystal-cell adhesion, and crystal internalization assays together with neutralization by anti-PMCA2 antibody compared to isotype-controlled IgG and blank control, revealed a novel role of PMCA2 as a COM crystal-binding protein that was crucial for crystal retention and uptake. In summary, a large number of novel PMCA2-interacting proteins have been defined and a novel function of PMCA2 as a COM crystal-binding protein sheds light onto its involvement, at least in part, in kidney stone pathogenesis.
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Affiliation(s)
- Arada Vinaiphat
- Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, 6th Floor-SiMR Building, 2 Wanglang Road, Bangkoknoi, Bangkok, 10700, Thailand
- Center for Research in Complex Systems Science, Mahidol University, Bangkok, Thailand
| | - Visith Thongboonkerd
- Medical Proteomics Unit, Office for Research and Development, Faculty of Medicine Siriraj Hospital, Mahidol University, 6th Floor-SiMR Building, 2 Wanglang Road, Bangkoknoi, Bangkok, 10700, Thailand.
- Center for Research in Complex Systems Science, Mahidol University, Bangkok, Thailand.
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8
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Regulation of the Plasma Membrane Calcium ATPases by the actin cytoskeleton. Biochem Biophys Res Commun 2017; 506:347-354. [PMID: 29180009 DOI: 10.1016/j.bbrc.2017.11.151] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2017] [Accepted: 11/22/2017] [Indexed: 01/08/2023]
Abstract
Associations between the cortical cytoskeleton and the components of the plasma membrane are no longer considered to be merely of structural and mechanical nature but are nowadays recognized as dynamic interactions that modulate a plethora of cellular responses. Reorganization of actin filaments upon diverse stimuli - among which is the rise in cytosolic Ca2+ - is involved in cell motility and adhesion, phagocytosis, cytokinesis, and secretion. Actin dynamics also participates in the regulation of ion transport across the membranes where it not only plays a key role in the delivery and stabilization of channels and transporters in the plasma membrane but also in the regulation of their activity. The recently described functional interaction between actin and the Plasma Membrane Ca2+-ATPase (PMCA) represents a novel regulatory mechanism of the pump at the time that unveils a new pathway by which the cortical actin cytoskeleton participates in the regulation of cytosolic Ca2+ homeostasis. In this review, we summarize the current knowledge on the interaction between the cortical actin cytoskeleton and the PMCA and discuss the possible mechanisms that may explain the pump's modulation.
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9
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Ip YK, Hiong KC, Goh EJK, Boo MV, Choo CYL, Ching B, Wong WP, Chew SF. The Whitish Inner Mantle of the Giant Clam, Tridacna squamosa, Expresses an Apical Plasma Membrane Ca 2+-ATPase (PMCA) Which Displays Light-Dependent Gene and Protein Expressions. Front Physiol 2017; 8:781. [PMID: 29066980 PMCID: PMC5641333 DOI: 10.3389/fphys.2017.00781] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2017] [Accepted: 09/25/2017] [Indexed: 12/16/2022] Open
Abstract
Giant clams live in symbiosis with extracellular zooxanthellae and display high rates of growth and shell formation (calcification) in light. Light-enhanced calcification requires an increase in the supply of Ca2+ to, and simultaneously an augmented removal of H+ from, the extrapallial fluid where shell formation occurs. We have obtained the complete coding cDNA sequence of Plasma Membrane Ca2+-ATPase (PMCA) from the thin and whitish inner mantle, which is in touch with the extrapallial fluid, of the giant clam Tridacna squamosa. The deduced PMCA sequence consisted of an apical targeting element. Immunofluorescence microscopy confirmed that PMCA had an apical localization in the shell-facing epithelium of the inner mantle, whereby it can actively secrete Ca2+ in exchange for H+. More importantly, the apical PMCA-immunofluorescence of the shell-facing epithelium of the inner mantle increased significantly after 12 h of exposure to light. The transcript and protein levels of PMCA/PMCA also increased significantly in the inner mantle after 6 or 12 h of light exposure. These results offer insights into a light-dependable mechanism of shell formation in T. squamosa and a novel explanation of light-enhanced calcification in general. As the inner mantle normally lacks light sensitive pigments, our results support a previous proposition that symbiotic zooxanthellae, particularly those in the colorful and extensible outer mantle, may act as light-sensing elements for the host clam.
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Affiliation(s)
- Yuen K Ip
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore.,The Tropical Marine Science Institute, National University of Singapore, Singapore, Singapore
| | - Kum C Hiong
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Enan J K Goh
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Mel V Boo
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Celine Y L Choo
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Biyun Ching
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Wai P Wong
- Department of Biological Sciences, National University of Singapore, Singapore, Singapore
| | - Shit F Chew
- Natural Sciences and Science Education, National Institute of Education, Nanyang Technological University, Singapore, Singapore
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10
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Jeong J, VanHouten JN, Kim W, Dann P, Sullivan C, Choi J, Sneddon WB, Friedman PA, Wysolmerski JJ. The scaffolding protein NHERF1 regulates the stability and activity of the tyrosine kinase HER2. J Biol Chem 2017; 292:6555-6568. [PMID: 28235801 DOI: 10.1074/jbc.m116.770883] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2016] [Revised: 02/02/2017] [Indexed: 12/19/2022] Open
Abstract
We examined whether the scaffolding protein sodium-hydrogen exchanger regulatory factor 1 (NHERF1) interacts with the calcium pump PMCA2 and the tyrosine kinase receptor ErbB2/HER2 in normal mammary epithelial cells and breast cancer cells. NHERF1 interacts with the PDZ-binding motif in PMCA2 in both normal and malignant breast cells. NHERF1 expression is increased in HER2-positive breast cancers and correlates with HER2-positive status in human ductal carcinoma in situ (DCIS) lesions and invasive breast cancers as well as with increased mortality in patients. NHERF1 is part of a multiprotein complex that includes PMCA2, HSP90, and HER2 within specific actin-rich and lipid raft-rich membrane signaling domains. Knocking down NHERF1 reduces PMCA2 and HER2 expression, inhibits HER2 signaling, dissociates HER2 from HSP90, and causes the internalization, ubiquitination, and degradation of HER2. These results demonstrate that NHERF1 acts with PMCA2 to regulate HER2 signaling and membrane retention in breast cancers.
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Affiliation(s)
- Jaekwang Jeong
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine
| | - Joshua N VanHouten
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine
| | - Wonnam Kim
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine
| | - Pamela Dann
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine
| | | | - Jungmin Choi
- Department of Genetics, Yale University School of Medicine, New Haven, Connecticut 06520
| | - W Bruce Sneddon
- the Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, and
| | - Peter A Friedman
- the Laboratory for GPCR Biology, Department of Pharmacology and Chemical Biology, and.,Department of Structural Biology,University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania 15261
| | - John J Wysolmerski
- From the Section of Endocrinology and Metabolism, Department of Internal Medicine,
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11
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Walsh DR, Nolin TD, Friedman PA. Drug Transporters and Na+/H+ Exchange Regulatory Factor PSD-95/Drosophila Discs Large/ZO-1 Proteins. Pharmacol Rev 2016; 67:656-80. [PMID: 26092975 DOI: 10.1124/pr.115.010728] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Drug transporters govern the absorption, distribution, and elimination of pharmacologically active compounds. Members of the solute carrier and ATP binding-cassette drug transporter family mediate cellular drug uptake and efflux processes, thereby coordinating the vectorial movement of drugs across epithelial barriers. To exert their physiologic and pharmacological function in polarized epithelia, drug transporters must be targeted and stabilized to appropriate regions of the cell membrane (i.e., apical versus basolateral). Despite the critical importance of drug transporter membrane targeting, the mechanisms that underlie these processes are largely unknown. Several clinically significant drug transporters possess a recognition sequence that binds to PSD-95/Drosophila discs large/ZO-1 (PDZ) proteins. PDZ proteins, such as the Na(+)/H(+) exchanger regulatory factor (NHERF) family, act to stabilize and organize membrane targeting of multiple transmembrane proteins, including many clinically relevant drug transporters. These PDZ proteins are normally abundant at apical membranes, where they tether membrane-delimited transporters. NHERF expression is particularly high at the apical membrane in polarized tissue such as intestinal, hepatic, and renal epithelia, tissues important to drug disposition. Several recent studies have highlighted NHERF proteins as determinants of drug transporter function secondary to their role in controlling membrane abundance and localization. Mounting evidence strongly suggests that NHERF proteins may have clinically significant roles in pharmacokinetics and pharmacodynamics of several pharmacologically active compounds and may affect drug action in cancer and chronic kidney disease. For these reasons, NHERF proteins represent a novel class of post-translational mediators of drug transport and novel targets for new drug development.
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Affiliation(s)
- Dustin R Walsh
- Laboratory for G Protein-Coupled Receptor Biology, Department of Pharmacology and Chemical Biology, and Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (P.A.F.); and Center for Clinical Pharmaceutical Sciences, Department of Pharmacy and Therapeutics, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania (D.R.W., T.D.N.)
| | - Thomas D Nolin
- Laboratory for G Protein-Coupled Receptor Biology, Department of Pharmacology and Chemical Biology, and Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (P.A.F.); and Center for Clinical Pharmaceutical Sciences, Department of Pharmacy and Therapeutics, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania (D.R.W., T.D.N.)
| | - Peter A Friedman
- Laboratory for G Protein-Coupled Receptor Biology, Department of Pharmacology and Chemical Biology, and Structural Biology, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania (P.A.F.); and Center for Clinical Pharmaceutical Sciences, Department of Pharmacy and Therapeutics, University of Pittsburgh School of Pharmacy, Pittsburgh, Pennsylvania (D.R.W., T.D.N.)
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12
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PMCA2 regulates HER2 protein kinase localization and signaling and promotes HER2-mediated breast cancer. Proc Natl Acad Sci U S A 2016; 113:E282-90. [PMID: 26729871 DOI: 10.1073/pnas.1516138113] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022] Open
Abstract
In the lactating mammary gland, the plasma membrane calcium ATPase2 (PMCA2) transports milk calcium. Its expression is activated in breast cancers, where high tumor levels predict increased mortality. We find that PMCA2 expression correlates with HER2 levels in breast cancers and that PMCA2 interacts with HER2 in specific actin-rich membrane domains. Knocking down PMCA2 increases intracellular calcium, disrupts interactions between HER2 and HSP-90, inhibits HER2 signaling, and results in internalization and degradation of HER2. Manipulating PMCA2 levels regulates the growth of breast cancer cells, and knocking out PMCA2 inhibits the formation of tumors in mouse mammary tumor virus (MMTV)-Neu mice. These data reveal previously unappreciated molecular interactions regulating HER2 localization, membrane retention, and signaling, as well as the ability of HER2 to generate breast tumors, suggesting that interactions between PMCA2 and HER2 may represent therapeutic targets for breast cancer.
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13
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Multifaceted plasma membrane Ca(2+) pumps: From structure to intracellular Ca(2+) handling and cancer. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1863:1351-63. [PMID: 26707182 DOI: 10.1016/j.bbamcr.2015.12.011] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Revised: 11/25/2015] [Accepted: 12/12/2015] [Indexed: 11/20/2022]
Abstract
Plasma membrane Ca(2+) ATPases (PMCAs) are intimately involved in the control of intracellular Ca(2+) concentration. They reduce Ca(2+) in the cytosol not only by direct ejection, but also by controlling the formation of inositol-1,4,5-trisphosphate and decreasing Ca(2+) release from the endoplasmic reticulum Ca(2+) pool. In mammals four genes (PMCA1-4) are expressed, and alternative RNA splicing generates more than twenty variants. The variants differ in their regulatory characteristics. They localize into highly specialized membrane compartments and respond to the incoming Ca(2+) with distinct temporal resolution. The expression pattern of variants depends on cell type; a change in this pattern can result in perturbed Ca(2+) homeostasis and thus altered cell function. Indeed, PMCAs undergo remarkable changes in their expression pattern during tumorigenesis that might significantly contribute to the unbalanced Ca(2+) homeostasis of cancer cells. This article is part of a Special Issue entitled: Calcium and Cell Fate. Guest Editors: Jacques Haiech, Claus Heizmann, Joachim Krebs, Thierry Capiod and Olivier Mignen.
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14
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Strehler EE. Plasma membrane calcium ATPases: From generic Ca(2+) sump pumps to versatile systems for fine-tuning cellular Ca(2.). Biochem Biophys Res Commun 2015; 460:26-33. [PMID: 25998731 DOI: 10.1016/j.bbrc.2015.01.121] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 01/21/2015] [Indexed: 10/23/2022]
Abstract
The plasma membrane calcium ATPases (PMCAs) are ATP-driven primary ion pumps found in all eukaryotic cells. They are the major high-affinity calcium extrusion system for expulsion of Ca(2+) ions from the cytosol and help restore the low resting levels of intracellular [Ca(2+)] following the temporary elevation of Ca(2+) generated during Ca(2+) signaling. Due to their essential role in the maintenance of cellular Ca(2+) homeostasis they were initially thought to be "sump pumps" for Ca(2+) removal needed by all cells to avoid eventual calcium overload. The discovery of multiple PMCA isoforms and alternatively spliced variants cast doubt on this simplistic assumption, and revealed instead that PMCAs are integral components of highly regulated multi-protein complexes fulfilling specific roles in calcium-dependent signaling originating at the plasma membrane. Biochemical, genetic, and physiological studies in gene-manipulated and mutant animals demonstrate the important role played by specific PMCAs in distinct diseases including those affecting the peripheral and central nervous system, cardiovascular disease, and osteoporosis. Human PMCA gene mutations and allelic variants associated with specific disorders continue to be discovered and underline the crucial role of different PMCAs in particular cells, tissues and organs.
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Affiliation(s)
- Emanuel E Strehler
- Department of Biochemistry and Molecular Biology, Guggenheim 16-11A1, Mayo Clinic College of Medicine, 200 First Street SW, Rochester, MN 55905, USA.
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15
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Holcomb J, Jiang Y, Lu G, Trescott L, Brunzelle J, Sirinupong N, Li C, Naren AP, Yang Z. Structural insights into PDZ-mediated interaction of NHERF2 and LPA(2), a cellular event implicated in CFTR channel regulation. Biochem Biophys Res Commun 2014; 446:399-403. [PMID: 24613836 DOI: 10.1016/j.bbrc.2014.02.128] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2014] [Accepted: 02/27/2014] [Indexed: 12/22/2022]
Abstract
The formation of CFTR-NHERF2-LPA2 macromolecular complex in airway epithelia regulates CFTR channel function and plays an important role in compartmentalized cAMP signaling. We previously have shown that disruption of the PDZ-mediated NHERF2-LPA2 interaction abolishes the LPA inhibitory effect and augments CFTR Cl(-) channel activity in vitro and in vivo. Here we report the first crystal structure of the NHERF2 PDZ1 domain in complex with the C-terminal LPA2 sequence. The structure reveals that the PDZ1-LPA2 binding specificity is achieved by numerous hydrogen bonds and hydrophobic contacts with the last four LPA2 residues contributing to specific interactions. Comparison of the PDZ1-LPA2 structure to the structure of PDZ1 in complex with a different peptide provides insights into the diverse nature of PDZ1 substrate recognition and suggests that the conformational flexibility in the ligand binding pocket is involved in determining the broad substrate specificity of PDZ1. In addition, the structure reveals a small surface pocket adjacent to the ligand-binding site, which may have therapeutic implications. This study provides an understanding of the structural basis for the PDZ-mediated NHERF2-LPA2 interaction that could prove valuable in selective drug design against CFTR-related human diseases.
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Affiliation(s)
- Joshua Holcomb
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Yuanyuan Jiang
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Guorong Lu
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Laura Trescott
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI, USA
| | | | - Nualpun Sirinupong
- Nutraceuticals and Functional Food Research and Development Center, Prince of Songkla University, Hat-Yai, Songkhla, Thailand
| | - Chunying Li
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI, USA
| | - Anjaparavanda P Naren
- Department of Pediatrics, Cincinnati Children's Hospital Medical Center, Cincinnati, OH, USA.
| | - Zhe Yang
- Department of Biochemistry and Molecular Biology, Wayne State University School of Medicine, Detroit, MI, USA.
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16
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Antalffy G, Pászty K, Varga K, Hegedűs L, Enyedi Á, Padányi R. A C-terminal di-leucine motif controls plasma membrane expression of PMCA4b. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2013; 1833:2561-2572. [PMID: 23830917 DOI: 10.1016/j.bbamcr.2013.06.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2013] [Revised: 06/18/2013] [Accepted: 06/24/2013] [Indexed: 01/17/2023]
Abstract
Recent evidences show that the localization of different plasma membrane Ca(2+) ATPases (PMCAs) is regulated in various complex, cell type-specific ways. Here we show that in low-density epithelial and endothelial cells PMCA4b localized mostly in intracellular compartments and its plasma membrane localization was enhanced upon increasing density of cells. In good correlation with the enhanced plasma membrane localization a significantly more efficient Ca(2+) clearance was observed in confluent versus non-confluent HeLa cell cultures expressing mCherry-PMCA4b. We analyzed the subcellular localization and function of various C-terminally truncated PMCA4b variants and found that a truncated mutant PMCA4b-ct24 was mostly intracellular while another mutant, PMCA4b-ct48, localized more to the plasma membrane, indicating that a protein sequence corresponding to amino acid residues 1158-1181 contained a signal responsible for the intracellular retention of PMCA4b in non-confluent cultures. Alteration of three leucines to alanines at positions 1167-1169 resulted in enhanced cell surface expression and an appropriate Ca(2+) transport activity of both wild type and truncated pumps, suggesting that the di-leucine-like motif (1167)LLL was crucial in targeting PMCA4b. Furthermore, upon loss of cell-cell contact by extracellular Ca(2+) removal, the wild-type pump was translocated to the early endosomal compartment. Targeting PMCA4b to early endosomes was diminished by the L(1167-69)A mutation, and the mutant pump accumulated in long tubular cytosolic structures. In summary, we report a di-leucine-like internalization signal at the C-tail of PMCA4b and suggest an internalization-mediated loss of function of the pump upon low degree of cell-cell contact.
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Affiliation(s)
- Géza Antalffy
- Molecular Biophysics Research Group of the Hungarian Academy of Sciences and Department of Biophysics, Semmelweis University, Budapest, Hungary
| | - Katalin Pászty
- Molecular Biophysics Research Group of the Hungarian Academy of Sciences and Department of Biophysics, Semmelweis University, Budapest, Hungary
| | - Karolina Varga
- Institute of Molecular Pharmacology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Luca Hegedűs
- Institute of Molecular Pharmacology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Ágnes Enyedi
- Hungarian National Blood Transfusion Service, Budapest, Hungary; Institute of Molecular Pharmacology, Research Centre for Natural Sciences, Hungarian Academy of Sciences, Budapest, Hungary
| | - Rita Padányi
- Hungarian National Blood Transfusion Service, Budapest, Hungary.
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17
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Vanagas L, de La Fuente MC, Dalghi M, Ferreira-Gomes M, Rossi RC, Strehler EE, Mangialavori IC, Rossi JPFC. Differential effects of G- and F-actin on the plasma membrane calcium pump activity. Cell Biochem Biophys 2013; 66:187-98. [PMID: 23152090 PMCID: PMC3894748 DOI: 10.1007/s12013-012-9467-6] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/27/2022]
Abstract
We have previously shown that plasma membrane calcium ATPase (PMCA) pump activity is affected by the membrane protein concentration (Vanagas et al., Biochim Biophys Acta 1768:1641-1644, 2007). The results of this study provided evidence for the involvement of the actin cytoskeleton. In this study, we explored the relationship between the polymerization state of actin and its effects on purified PMCA activity. Our results show that PMCA associates with the actin cytoskeleton and this interaction causes a modulation of the catalytic activity involving the phosphorylated intermediate of the pump. The state of actin polymerization determines whether it acts as an activator or an inhibitor of the pump: G-actin and/or short oligomers activate the pump, while F-actin inhibits it. The effects of actin on PMCA are the consequence of direct interaction as demonstrated by immunoblotting and cosedimentation experiments. Taken together, these findings suggest that interactions with actin play a dynamic role in the regulation of PMCA-mediated Ca(2+) extrusion through the membrane. Our results provide further evidence of the activation-inhibition phenomenon as a property of many cytoskeleton-associated membrane proteins where the cytoskeleton is no longer restricted to a mechanical function but is dynamically involved in modulating the activity of integral proteins with which it interacts.
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Affiliation(s)
- Laura Vanagas
- IQUIFIB, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956 (1113), Buenos Aires, Argentina
| | | | - Marianela Dalghi
- IQUIFIB, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956 (1113), Buenos Aires, Argentina
| | - Mariela Ferreira-Gomes
- IQUIFIB, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956 (1113), Buenos Aires, Argentina
| | - Rolando C. Rossi
- IQUIFIB, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956 (1113), Buenos Aires, Argentina
| | - Emanuel E. Strehler
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905, USA
| | - Irene C. Mangialavori
- IQUIFIB, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956 (1113), Buenos Aires, Argentina
| | - Juan P. F. C. Rossi
- IQUIFIB, Facultad de Farmacia y Bioquímica, Universidad de Buenos Aires, Junín 956 (1113), Buenos Aires, Argentina
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18
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Yang J, Singh V, Cha B, Chen TE, Sarker R, Murtazina R, Jin S, Zachos NC, Patterson GH, Tse CM, Kovbasnjuk O, Li X, Donowitz M. NHERF2 protein mobility rate is determined by a unique C-terminal domain that is also necessary for its regulation of NHE3 protein in OK cells. J Biol Chem 2013; 288:16960-16974. [PMID: 23612977 DOI: 10.1074/jbc.m113.470799] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Na(+)/H(+) exchanger regulatory factor (NHERF) proteins are a family of PSD-95/Discs-large/ZO-1 (PDZ)-scaffolding proteins, three of which (NHERFs 1-3) are localized to the brush border in kidney and intestinal epithelial cells. All NHERF proteins are involved in anchoring membrane proteins that contain PDZ recognition motifs to form multiprotein signaling complexes. In contrast to their predicted immobility, NHERF1, NHERF2, and NHERF3 were all shown by fluorescence recovery after photobleaching/confocal microscopy to be surprisingly mobile in the microvilli of the renal proximal tubule OK cell line. Their diffusion coefficients, although different among the three, were all of the same magnitude as that of the transmembrane proteins, suggesting they are all anchored in the microvilli but to different extents. NHERF3 moves faster than NHERF1, and NHERF2 moves the slowest. Several chimeras and mutants of NHERF1 and NHERF2 were made to determine which part of NHERF2 confers the slower mobility rate. Surprisingly, the slower mobility rate of NHERF2 was determined by a unique C-terminal domain, which includes a nonconserved region along with the ezrin, radixin, moesin (ERM) binding domain. Also, this C-terminal domain of NHERF2 determined its greater detergent insolubility and was necessary for the formation of larger multiprotein NHERF2 complexes. In addition, this NHERF2 domain was functionally significant in NHE3 regulation, being necessary for stimulation by lysophosphatidic acid of activity and increased mobility of NHE3, as well as necessary for inhibition of NHE3 activity by calcium ionophore 4-Br-A23187. Thus, multiple functions of NHERF2 require involvement of an additional domain in this protein.
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Affiliation(s)
- Jianbo Yang
- Department of Medicine, Division of Gastroenterology, Baltimore, Maryland 21205
| | - Varsha Singh
- Department of Medicine, Division of Gastroenterology, Baltimore, Maryland 21205
| | - Boyoung Cha
- Department of Medicine, Division of Gastroenterology, Baltimore, Maryland 21205
| | - Tian-E Chen
- Department of Medicine, Division of Gastroenterology, Baltimore, Maryland 21205
| | - Rafiquel Sarker
- Department of Medicine, Division of Gastroenterology, Baltimore, Maryland 21205
| | - Rakhilya Murtazina
- Department of Medicine, Division of Gastroenterology, Baltimore, Maryland 21205
| | - Shi Jin
- Department of Medicine, Division of Gastroenterology, Baltimore, Maryland 21205
| | - Nicholas C Zachos
- Department of Medicine, Division of Gastroenterology, Baltimore, Maryland 21205
| | - George H Patterson
- Biophotonics Section, National Institute of Biomedical Imaging and Bioengineering, NIH, Bethesda, Maryland 20892
| | - C Ming Tse
- Department of Medicine, Division of Gastroenterology, Baltimore, Maryland 21205
| | - Olga Kovbasnjuk
- Department of Medicine, Division of Gastroenterology, Baltimore, Maryland 21205
| | - Xuhang Li
- Department of Medicine, Division of Gastroenterology, Baltimore, Maryland 21205
| | - Mark Donowitz
- Department of Medicine, Division of Gastroenterology, Baltimore, Maryland 21205; Department of Physiology, The Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
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19
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Hu Z, Hu J, Zhang Z, Shen WJ, Yun CC, Berlot CH, Kraemer FB, Azhar S. Regulation of expression and function of scavenger receptor class B, type I (SR-BI) by Na+/H+ exchanger regulatory factors (NHERFs). J Biol Chem 2013; 288:11416-35. [PMID: 23482569 DOI: 10.1074/jbc.m112.437368] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Scavenger receptor class B, type I (SR-BI) binds HDL and mediates selective delivery of cholesteryl esters (CEs) to the liver, adrenals, and gonads for product formation (bile acids and steroids). Because relatively little is known about SR-BI posttranslational regulation in steroidogenic cells, we examined the roles of Na(+)/H(+) exchanger regulatory factors (NHERFs) in regulating SR-BI expression, SR-BI-mediated selective CE uptake, and steroidogenesis. NHERF1 and NHERF2 mRNA and protein are expressed at varying levels in model steroidogenic cell lines and the adrenal, with only low expression of PDZK1 (NHERF3) and NHERF4. Dibutyryl cyclic AMP decreased NHERF1 and NHERF2 and increased SR-BI mRNA expression in primary rat granulosa cells and MLTC-1 cells, whereas ACTH had no effect on NHERF1 and NHERF2 mRNA levels but decreased their protein levels in rat adrenals. Co-immunoprecipitation, colocalization, bimolecular fluorescence complementation, and mutational analysis indicated that SR-BI associates with NHERF1 and NHERF2. NHERF1 and NHERF2 down-regulated SR-BI protein expression through inhibition of its de novo synthesis. NHERF1 and NHERF2 also inhibited SR-BI-mediated selective CE transport and steroidogenesis, which were markedly attenuated by partial deletions of the PDZ1 or PDZ2 domain of NHERF1, the PDZ2 domain of NHERF2, or the MERM domains of NHERF1/2 or by gene silencing of NHERF1/2. Moreover, an intact COOH-terminal PDZ recognition motif (EAKL) in SR-BI is needed. Transient transfection of hepatic cell lines with NHERF1 or NHERF2 caused a significant reduction in endogenous protein levels of SR-BI. Collectively, these data establish NHERF1 and NHERF2 as SR-BI protein binding partners that play a negative role in the regulation of SR-BI expression, selective CE transport, and steroidogenesis.
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Affiliation(s)
- Zhigang Hu
- Geriatric Research, Education and Clinical Center, Veterans Affairs Palo Alto Health Care System, Palo Alto, California 94304, USA
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20
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Activated ERM protein plays a critical role in drug resistance of MOLT4 cells induced by CCL25. PLoS One 2013; 8:e52384. [PMID: 23326330 PMCID: PMC3541277 DOI: 10.1371/journal.pone.0052384] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2012] [Accepted: 11/12/2012] [Indexed: 11/19/2022] Open
Abstract
We have previously demonstrated that the CCR9/CCL25 signaling pathway plays an important role in drug resistance in human acute T-lymphocytic leukemia (T-ALL) by inducing activation of ERM protein with polarized distribution in T-ALL cell line MOLT4. However, the mechanism of action of the activated ERM protein in the drug resistance of MOLT4 cells induced by CCL25 remains uncharacterized. Here we investigated the mechanism of CCR9/CCL25-initiated drug resistance in CCR9-high-expressing T-ALL cells. Our results showed that 1) the function of P-gp was increased after treatment with CCL25; 2) P-gp colocalized and co-immunoprecipitated with p-ERM and F-actin in CCL25 treated cells; and 3) ERM-shRNA conferred drug sensitivity coincident with release of ERM interactions with P-gp and F-actin after treatment with CCL25. These data suggest it is pivotal that P-gp associate with the F-actin cytoskeleton through p-ERM in CCR9/CCL25 induced multidrug resistance of T-ALL cells. Strategies aimed at inhibiting P-gp-F-actin cytoskeleton association may be helpful in increasing the efficiency of therapies in T-ALL.
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21
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Strehler EE. Plasma membrane calcium ATPases as novel candidates for therapeutic agent development. JOURNAL OF PHARMACY & PHARMACEUTICAL SCIENCES : A PUBLICATION OF THE CANADIAN SOCIETY FOR PHARMACEUTICAL SCIENCES, SOCIETE CANADIENNE DES SCIENCES PHARMACEUTIQUES 2013; 16:190-206. [PMID: 23958189 PMCID: PMC3869240 DOI: 10.18433/j3z011] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/24/2022]
Abstract
Plasma membrane Ca2+ ATPases (PMCAs) are highly regulated transporters responsible for Ca2+ extrusion from all eukaryotic cells. Different PMCA isoforms are implicated in various tasks of Ca2+ regulation including bulk Ca2+ transport and localized Ca2+ signaling in specific membrane microdomains. Accumulating evidence shows that loss, mutation or inappropriate expression of different PMCAs is associated with pathologies ranging from hypertension, low bone density and male infertility to hearing loss and cerebellar ataxia. Compared to Ca2+ influx channels, PMCAs have lagged far behind as targets for drug development, mainly due to the lack of detailed understanding of their structure and specific function. This is rapidly changing thanks to integrated efforts combining biochemical, structural, cellular and physiological studies suggesting that selective modulation of PMCA isoforms may be of therapeutic value in the management of different and complex diseases. Both structurally informed rational design and high-throughput small molecule library screenings are promising strategies that are expected to lead to specific and isoform-selective modulators of PMCA function. This short review will provide an overview of the diverse roles played by PMCA isoforms in different cells and tissues and their emerging involvement in pathophysiological processes, summarize recent progress in obtaining structural information on the PMCAs, and discuss current and future strategies to develop specific PMCA inhibitors and activators for potential therapeutic applications.
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Affiliation(s)
- Emanuel E Strehler
- Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN, USA.
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22
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The plasma membrane potential and the organization of the actin cytoskeleton of epithelial cells. Int J Cell Biol 2012; 2012:121424. [PMID: 22315611 PMCID: PMC3272338 DOI: 10.1155/2012/121424] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2011] [Accepted: 10/08/2011] [Indexed: 12/22/2022] Open
Abstract
The establishment and maintenance of the polarized epithelial phenotype require a characteristic organization of the cytoskeletal components. There are many cellular effectors involved in the regulation of the cytoskeleton of epithelial cells. Recently, modifications in the plasma membrane potential (PMP) have been suggested to participate in the modulation of the cytoskeletal organization of epithelia. Here, we review evidence showing that changes in the PMP of diverse epithelial cells promote characteristic modifications in the cytoskeletal organization, with a focus on the actin cytoskeleton. The molecular paths mediating these effects may include voltage-sensitive integral membrane proteins and/or peripheral proteins sensitive to surface potentials. The voltage dependence of the cytoskeletal organization seems to have implications in several physiological processes, including epithelial wound healing and apoptosis.
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23
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Plasma membrane calcium pump (PMCA) isoform 4 is targeted to the apical membrane by the w-splice insert from PMCA2. Cell Calcium 2012; 51:171-8. [PMID: 22252018 DOI: 10.1016/j.ceca.2011.12.010] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Revised: 11/23/2011] [Accepted: 12/13/2011] [Indexed: 11/24/2022]
Abstract
Local Ca(2+) signaling requires proper targeting of the Ca(2+) signaling toolkit to specific cellular locales. Different isoforms of the plasma membrane Ca(2+) pump (PMCA) are responsible for Ca(2+) extrusion at the apical and basolateral membrane of polarized epithelial cells, but the mechanisms and signals for differential targeting of the PMCAs are not well understood. Recent work demonstrated that the alternatively spliced w-insert in PMCA2 directs this pump to the apical membrane. We now show that inserting the w-insert into the corresponding location of the PMCA4 isoform confers apical targeting to this normally basolateral pump. Mutation of a di-leucine motif in the C-tail thought to be important for basolateral targeting did not enhance apical localization of the chimeric PMCA4(2w)/b. In contrast, replacing the C-terminal Val residue by Leu to optimize the PDZ ligand site for interaction with the scaffolding protein NHERF2 enhanced the apical localization of PMCA4(2w)/b, but not of PMCA4x/b. Functional studies showed that both apical PMCA4(2w)/b and basolateral PMCA4x/b handled ATP-induced Ca(2+) signals with similar kinetics, suggesting that isoform-specific functional characteristics are retained irrespective of membrane targeting. Our results demonstrate that the alternatively spliced w-insert provides autonomous apical targeting information in the PMCA without altering its functional characteristics.
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Tanimura A, Yamada F, Saito A, Ito M, Kimura T, Anzai N, Horie D, Yamamoto H, Miyamoto KI, Taketani Y, Takeda E. Analysis of different complexes of type IIa sodium-dependent phosphate transporter in rat renal cortex using blue-native polyacrylamide gel electrophoresis. THE JOURNAL OF MEDICAL INVESTIGATION 2011; 58:140-7. [PMID: 21372499 DOI: 10.2152/jmi.58.140] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Abstract
Type IIa sodium-dependent phosphate transporter (NaPi-IIa) can be localized in the apical plasma membrane of renal proximal tubule to carry out a rate-limiting step of phosphate reabsorption. For the apical localization, NaPi-IIa is required to form a macromolecular complex with some adaptor proteins such as Na(+)/H(+) exchanger regulatory factor 1 (NHERF-1) and ezrin. However, the detail of macromolecular complex containing NaPi-IIa in the apical membrane of the renal proximal tubular cells has not been clarified. In this study, we identified at least four different complexes (220, 480, 920, 1,100 kDa) containing NaPi-IIa by using blue-native polyacrylamide gel electrophoresis. Interestingly, LC-MS/MS analysis and immunoprecipitation analysis reveal that megalin is a component of larger complexes (920 and 1,100 kDa). In addition, NaPi-IIa can be heterogeneously co-localized with ezrin and megalin on the apical membrane of renal proximal tubuler cells by fluorescence microscopy analysis. These results suggest that NaPi-IIa can form some different complexes on the apical plasma membrane of renal proximal tubular cells.
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Affiliation(s)
- Ayako Tanimura
- Department of Clinical Nutrition, Institute of Health Biosciences, University of Tokushima Graduate School, Tokushima, Japan
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25
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Apical localization of PMCA2w/b is enhanced in terminally polarized MDCK cells. Biochem Biophys Res Commun 2011; 410:322-7. [PMID: 21672522 DOI: 10.1016/j.bbrc.2011.05.147] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2011] [Accepted: 05/31/2011] [Indexed: 11/23/2022]
Abstract
The "w" splice forms of PMCA2 localize to distinct membrane compartments such as the apical membrane of the lactating mammary epithelium, the stereocilia of inner ear hair cells or the post-synaptic density of hippocampal neurons. Previous studies indicated that PMCA2w/b was not fully targeted to the apical domain of MDCK cells but distributed more evenly to the lateral and apical membrane compartments. Overexpression of the apical scaffold protein NHERF2, however, greatly increased the amount of the pump in the apical membrane of these epithelial cells. We generated a stable MDCK cell line expressing non-tagged, full-length PMCA2w/b to further study the localization and function of this protein. Here we demonstrate that PMCA2w/b is highly active and shows enhanced apical localization in terminally polarized MDCK cells grown on semi-permeable filters. Reversible surface biotinylation combined with confocal microscopy of fully polarized cells show that the pump is stabilized in the apical membrane via the apical membrane cytoskeleton with the help of endogenous NHERF2 and ezrin. Disruption of the actin cytoskeleton removed the pump from the apical actin patches without provoking its internalization. Our data suggest that full polarization is a prerequisite for proper positioning of the PMCA2w variants in the apical membrane domain of polarized cells.
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Strehler EE. Emanuel Strehler’s work on calcium pumps and calcium signaling. World J Biol Chem 2011; 2:67-72. [PMID: 21537475 PMCID: PMC3083948 DOI: 10.4331/wjbc.v2.i4.67] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 03/16/2011] [Accepted: 03/23/2011] [Indexed: 02/05/2023] Open
Abstract
Cells are equipped with mechanisms to control tightly the influx, efflux and resting level of free calcium (Ca2+). Inappropriate Ca2+ signaling and abnormal Ca2+ levels are involved in many clinical disorders including heart disease, Alzheimer’s disease and stroke. Ca2+ also plays a major role in cell growth, differentiation and motility; disturbances in these processes underlie cell transformation and the progression of cancer. Accordingly, research in the Strehler laboratory is focused on a better understanding of the molecular “toolkit” needed to ensure proper Ca2+ homeostasis in the cell, as well as on the mechanisms of localized Ca2+ signaling. A long-term focus has been on the plasma membrane calcium pumps (PMCAs), which are linked to multiple disorders including hearing loss, neurodegeneration, and heart disease. Our work over the past 20 years or more has revealed a surprising complexity of PMCA isoforms with different functional characteristics, regulation, and cellular localization. Emerging evidence shows how specific PMCAs contribute not only to setting basal intracellular Ca2+ levels, but also to local Ca2+ signaling and vectorial Ca2+ transport. A second major research area revolves around the calcium sensor protein calmodulin and an enigmatic calmodulin-like protein (CALML3) that is linked to epithelial differentiation. One of the cellular targets of CALML3 is the unconventional motor protein myosin-10, which raises new questions about the role of CALML3 and myosin-10 in cell adhesion and migration in normal cell differentiation and cancer.
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Affiliation(s)
- Emanuel E Strehler
- Emanuel E Strehler, Biochemistry and Molecular Biology, Department of Biochemistry and Molecular Biology, Mayo Clinic College of Medicine, Rochester, MN 55905, United States
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