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Nishimura T, Araki H, Higuchi K, Noguchi S, Saito K, Hara K, Yagishita H, Akashi R, Obata S, Tomi M. Involvement of GAT2/Slc6a13 in hypotaurine uptake at fetal-facing plasma membrane of syncytiotrophoblasts at mid-to-late gestation in rats and mice. Placenta 2024; 147:59-67. [PMID: 38325050 DOI: 10.1016/j.placenta.2024.01.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/25/2023] [Revised: 01/11/2024] [Accepted: 01/30/2024] [Indexed: 02/09/2024]
Abstract
INTRODUCTION Hypotaurine, a precursor to taurine, is known for its antioxidant properties and is prominently present in fetal plasma and the placenta. Our previous research revealed that ezrin-knockout mice experience fetal growth retardation, coinciding with reduced hypotaurine levels in fetal plasma. This study aims to elucidate the expression and role of hypotaurine transporters within the placenta. METHODS We employed quantitative RT-PCR to measure mRNA expression of GAT transporter family members in the placenta during mid-to-late gestation. LC/MS/MS was used to analyze the distribution of hypotaurine in different placental subregions. Immunohistochemistry was utilized to examine the localization of GAT2 in mice. Placental hypotaurine uptake from fetal circulation was studied via umbilical perfusion in rats. RESULTS Among hypotaurine transporters, GAT2 exhibited increased mRNA and protein expression in murine placenta during mid-to-late gestation. Notably, GAT2/Slc6a13 mRNA and hypotaurine were most concentrated in the labyrinth of murine placenta. In contrast, enzymes responsible for hypotaurine synthesis, such as cysteine dioxygenase, cysteine sulfinic acid decarboxylase, and 2-aminoethanethiol dioxygenase, showed minimal expression in the labyrinth. These findings suggest that GAT2 is a key determinant of hypotaurine levels in the placental labyrinth. Immunohistochemical examination unveiled that GAT2 was predominantly localized on the fetal-facing plasma membrane within syncytiotrophoblasts, which co-localized with ezrin. In rat umbilical perfusion experiments, the GAT2/3 and TauT inhibitor, SNAP-5114, significantly reduced hypotaurine extraction from fetal circulation to the placenta. DISCUSSION The results suggest that GAT2 plays a pivotal role in the concentrative uptake of hypotaurine from fetal plasma within syncytiotrophoblasts of the placenta.
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Affiliation(s)
- Tomohiro Nishimura
- Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan
| | - Hikari Araki
- Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan
| | - Kei Higuchi
- School of Pharmacy, Tokyo University of Pharmacy and Life Sciences, 1432-1 Horinouchi, Hachioji, Tokyo, 192-0392, Japan
| | - Saki Noguchi
- Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan
| | - Kei Saito
- Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan
| | - Kanako Hara
- Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan
| | - Haruya Yagishita
- Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan
| | - Risa Akashi
- Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan
| | - Sakiko Obata
- Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan
| | - Masatoshi Tomi
- Faculty of Pharmacy, Keio University, 1-5-30 Shibakoen, Minato-ku, Tokyo, 105-8512, Japan.
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Lombardo AT, Mitchell CAR, Zaman R, McDermitt DJ, Bretscher A. ARHGAP18-ezrin functions as an autoregulatory module for RhoA in the assembly of distinct actin-based structures. eLife 2024; 13:e83526. [PMID: 38193818 PMCID: PMC10830128 DOI: 10.7554/elife.83526] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2022] [Accepted: 01/08/2024] [Indexed: 01/10/2024] Open
Abstract
The location of different actin-based structures is largely regulated by Rho GTPases through specific effectors. We use the apical aspect of epithelial cells as a model system to investigate how RhoA is locally regulated to contribute to two distinct adjacent actin-based structures. Assembly of the non-muscle myosin-2 filaments in the terminal web is dependent on RhoA activity, and assembly of the microvilli also requires active RhoA for phosphorylation and activation of ezrin. We show that the RhoGAP, ARHGAP18, is localized by binding active microvillar ezrin, and this interaction enhances ARHGAP18's RhoGAP activity. We present a model where ezrin-ARHGAP18 acts as a negative autoregulatory module to locally reduce RhoA activity in microvilli. Consistent with this model, loss of ARHGAP18 results in disruption of the distinction between microvilli and the terminal web including aberrant assembly of myosin-2 filaments forming inside microvilli. Thus, ARHGAP18, through its recruitment and activation by ezrin, fine-tunes the local level of RhoA to allow for the appropriate distribution of actin-based structures between the microvilli and terminal web. As RhoGAPs vastly outnumber Rho GTPases, this may represent a general mechanism whereby individual Rho effectors drive specific actin-based structures.
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Affiliation(s)
- Andrew T Lombardo
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
| | - Cameron AR Mitchell
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
| | - Riasat Zaman
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
| | - David J McDermitt
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
| | - Anthony Bretscher
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell UniversityIthacaUnited States
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Tabrizi MEA, Gupta JK, Gross SR. Ezrin and Its Phosphorylated Thr567 Form Are Key Regulators of Human Extravillous Trophoblast Motility and Invasion. Cells 2023; 12:cells12050711. [PMID: 36899847 PMCID: PMC10000480 DOI: 10.3390/cells12050711] [Citation(s) in RCA: 3] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Revised: 02/16/2023] [Accepted: 02/17/2023] [Indexed: 02/27/2023] Open
Abstract
The protein ezrin has been shown to enhance cancer cell motility and invasion leading to malignant behaviours in solid tumours, but a similar regulatory function in the early physiological reproduction state is, however, much less clear. We speculated that ezrin may play a key role in promoting first-trimester extravillous trophoblast (EVT) migration/invasion. Ezrin, as well as its Thr567 phosphorylation, were found in all trophoblasts studied, whether primary cells or lines. Interestingly, the proteins were seen in a distinct cellular localisation in long, extended protrusions in specific regions of cells. Loss-of-function experiments were carried out in EVT HTR8/SVneo and Swan71, as well as primary cells, using either ezrin siRNAs or the phosphorylation Thr567 inhibitor NSC668394, resulting in significant reductions in both cell motility and cellular invasion, albeit with differences between the cells used. Our analysis further demonstrated that an increase in focal adhesion was, in part, able to explain some of the molecular mechanisms involved. Data collected using human placental sections and protein lysates further showed that ezrin expression was significantly higher during the early stage of placentation and, importantly, clearly seen in the EVT anchoring columns, further supporting the potential role of ezrin in regulating migration and invasion in vivo.
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Affiliation(s)
| | - Janesh K. Gupta
- Institute of Metabolism and Systems Research, University of Birmingham, Birmingham B15 2TT, UK
- Fetal Medicine Centre, Birmingham Women’s NHS Foundation Trust, Birmingham B15 2TT, UK
| | - Stephane R. Gross
- School of Life and Health Sciences, Aston University, Birmingham B4 7ET, UK
- Correspondence: ; Tel.: +44-0121-204-3467
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Hartmann C, Thüring EM, Greune L, Michels BE, Pajonczyk D, Leußink S, Brinkmann F, Glaesner-Ebnet M, Wardelmann E, Zobel T, Schmidt MA, Janssen KP, Gerke V, Ebnet K. Intestinal brush border formation requires a TMIGD1-based intermicrovillar adhesion complex. Sci Signal 2022; 15:eabm2449. [PMID: 36099341 DOI: 10.1126/scisignal.abm2449] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Intestinal epithelial cells absorb nutrients through the brush border, composed of dense arrays of highly ordered microvilli at their apical membranes. A protocadherin-based intermicrovillar adhesion complex localized at microvilli tips mediates microvilli packing and organization. Here, we identified a second adhesion complex localized at the proximal base region of microvilli. This complex contained the immunoglobulin superfamily member TMIGD1, which directly interacted with the microvillar scaffolding proteins EBP50 and E3KARP. Complex formation with EBP50 required the activation of EBP50 by the actin-binding protein ezrin and was enhanced by the dephosphorylation of Ser162 in the PDZ2 domain of EBP50 by the phosphatase PP1α. Binding of the EBP50-ezrin complex to TMIGD1 enhanced the dynamic turnover of EBP50 at microvilli. Enterocyte-specific inactivation of Tmigd1 in mice resulted in microvillar blebbing, loss of intermicrovillar adhesion, and perturbed brush border formation. Thus, we identified a second adhesion complex in microvilli and propose a mechanism that promotes microvillar formation and dynamics.
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Affiliation(s)
- Christian Hartmann
- Institute-associated Research Group "Cell adhesion and cell polarity", ZMBE, University of Münster, D-48149 Münster, Germany.,Institute of Medical Biochemistry, ZMBE, University of Münster, D-48149 Münster, Germany
| | - Eva-Maria Thüring
- Institute-associated Research Group "Cell adhesion and cell polarity", ZMBE, University of Münster, D-48149 Münster, Germany.,Institute of Medical Biochemistry, ZMBE, University of Münster, D-48149 Münster, Germany
| | - Lilo Greune
- Institute of Infectiology, ZMBE, University of Münster, D-48149 Münster, Germany
| | - Birgitta E Michels
- Institute-associated Research Group "Cell adhesion and cell polarity", ZMBE, University of Münster, D-48149 Münster, Germany.,Institute of Medical Biochemistry, ZMBE, University of Münster, D-48149 Münster, Germany
| | - Denise Pajonczyk
- Institute-associated Research Group "Cell adhesion and cell polarity", ZMBE, University of Münster, D-48149 Münster, Germany.,Institute of Medical Biochemistry, ZMBE, University of Münster, D-48149 Münster, Germany
| | - Sophia Leußink
- Institute-associated Research Group "Cell adhesion and cell polarity", ZMBE, University of Münster, D-48149 Münster, Germany.,Institute of Medical Biochemistry, ZMBE, University of Münster, D-48149 Münster, Germany
| | - Frauke Brinkmann
- Institute-associated Research Group "Cell adhesion and cell polarity", ZMBE, University of Münster, D-48149 Münster, Germany.,Institute of Medical Biochemistry, ZMBE, University of Münster, D-48149 Münster, Germany
| | - Mark Glaesner-Ebnet
- Institute-associated Research Group "Cell adhesion and cell polarity", ZMBE, University of Münster, D-48149 Münster, Germany.,Institute of Medical Biochemistry, ZMBE, University of Münster, D-48149 Münster, Germany
| | - Eva Wardelmann
- Gerhard-Domagk-Institute of Pathology, University Hospital Münster, D-48149 Münster, Germany
| | - Thomas Zobel
- Imaging Network Microscopy, University of Münster, D-48149 Münster, Germany
| | - M Alexander Schmidt
- Institute of Infectiology, ZMBE, University of Münster, D-48149 Münster, Germany
| | | | - Volker Gerke
- Institute of Medical Biochemistry, ZMBE, University of Münster, D-48149 Münster, Germany.,Cells-in-Motion Interfaculty Center (CiMIC), University of Münster, D-48419 Münster, Germany
| | - Klaus Ebnet
- Institute-associated Research Group "Cell adhesion and cell polarity", ZMBE, University of Münster, D-48149 Münster, Germany.,Institute of Medical Biochemistry, ZMBE, University of Münster, D-48149 Münster, Germany.,Cells-in-Motion Interfaculty Center (CiMIC), University of Münster, D-48419 Münster, Germany.,Interdisciplinary Center for Clinical Research (IZKF), University of Münster, D-48149 Münster, Germany
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5
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Yuan O, Ugale A, de Marchi T, Anthonydhason V, Konturek-Ciesla A, Wan H, Eldeeb M, Drabe C, Jassinskaja M, Hansson J, Hidalgo I, Velasco-Hernandez T, Cammenga J, Magee JA, Niméus E, Bryder D. A somatic mutation in moesin drives progression into acute myeloid leukemia. SCIENCE ADVANCES 2022; 8:eabm9987. [PMID: 35442741 PMCID: PMC9020775 DOI: 10.1126/sciadv.abm9987] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 03/01/2022] [Indexed: 06/14/2023]
Abstract
Acute myeloid leukemia (AML) arises when leukemia-initiating cells, defined by a primary genetic lesion, acquire subsequent molecular changes whose cumulative effects bypass tumor suppression. The changes that underlie AML pathogenesis not only provide insights into the biology of transformation but also reveal novel therapeutic opportunities. However, backtracking these events in transformed human AML samples is challenging, if at all possible. Here, we approached this question using a murine in vivo model with an MLL-ENL fusion protein as a primary molecular event. Upon clonal transformation, we identified and extensively verified a recurrent codon-changing mutation (Arg295Cys) in the ERM protein moesin that markedly accelerated leukemogenesis. Human cancer-associated moesin mutations at the conserved arginine-295 residue similarly enhanced MLL-ENL-driven leukemogenesis. Mechanistically, the mutation interrupted the stability of moesin and conferred a neomorphic activity to the protein, which converged on enhanced extracellular signal-regulated kinase activity. Thereby, our studies demonstrate a critical role of ERM proteins in AML, with implications also for human cancer.
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Affiliation(s)
- Ouyang Yuan
- Division of Molecular Hematology, Department of Laboratory Medicine, Lund Stem Cell Center, Faculty of Medical, Lund University, 221 84 Lund, Sweden
| | - Amol Ugale
- Division of Molecular Hematology, Department of Laboratory Medicine, Lund Stem Cell Center, Faculty of Medical, Lund University, 221 84 Lund, Sweden
- Department of Microbiology, Immunobiology and Genetics, Center for Molecular Biology of the University of Vienna, Max F. Perutz Laboratories, Vienna Biocenter (VBC), 1030 Vienna, Austria
| | - Tommaso de Marchi
- Division of Surgery, Oncology, and Pathology, Department of Clinical Sciences, Lund University, Solvegatan 19, 223 62, Lund, Sweden
| | - Vimala Anthonydhason
- Sahlgrenska Center for Cancer Research, University of Gothenburg, Medicinaregatan 1F, 413 90, Gothenburg, Sweden
| | - Anna Konturek-Ciesla
- Division of Molecular Hematology, Department of Laboratory Medicine, Lund Stem Cell Center, Faculty of Medical, Lund University, 221 84 Lund, Sweden
| | - Haixia Wan
- Division of Molecular Hematology, Department of Laboratory Medicine, Lund Stem Cell Center, Faculty of Medical, Lund University, 221 84 Lund, Sweden
| | - Mohamed Eldeeb
- Division of Molecular Hematology, Department of Laboratory Medicine, Lund Stem Cell Center, Faculty of Medical, Lund University, 221 84 Lund, Sweden
| | - Caroline Drabe
- Division of Molecular Hematology, Department of Laboratory Medicine, Lund Stem Cell Center, Faculty of Medical, Lund University, 221 84 Lund, Sweden
| | - Maria Jassinskaja
- Division of Molecular Hematology, Department of Laboratory Medicine, Lund Stem Cell Center, Faculty of Medical, Lund University, 221 84 Lund, Sweden
- York Biomedical Research Institute, Department of Biology, University of York, Wentworth Way, York YO10 5DD, UK
| | - Jenny Hansson
- Division of Molecular Hematology, Department of Laboratory Medicine, Lund Stem Cell Center, Faculty of Medical, Lund University, 221 84 Lund, Sweden
| | - Isabel Hidalgo
- Division of Molecular Hematology, Department of Laboratory Medicine, Lund Stem Cell Center, Faculty of Medical, Lund University, 221 84 Lund, Sweden
| | | | - Jörg Cammenga
- Division of Molecular Hematology, Department of Laboratory Medicine, Lund Stem Cell Center, Faculty of Medical, Lund University, 221 84 Lund, Sweden
| | - Jeffrey A. Magee
- Department of Pediatrics, Division of Hematology and Oncology, Washington University School of Medicine, St. Louis, MO 63110, USA
- Department of Genetics, Washington University School of Medicine, St. Louis, MO 63110, USA
| | - Emma Niméus
- Division of Surgery, Oncology, and Pathology, Department of Clinical Sciences, Lund University, Solvegatan 19, 223 62, Lund, Sweden
- Department of Surgery, Skåne University Hospital, Entrégatan 7, 222 42 Lund, Sweden
| | - David Bryder
- Division of Molecular Hematology, Department of Laboratory Medicine, Lund Stem Cell Center, Faculty of Medical, Lund University, 221 84 Lund, Sweden
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Abstract
Several tissues contain cells with multiple motile cilia that generate a fluid or particle flow to support development and organ functions; defective motility causes human disease. Developmental cues orient motile cilia, but how cilia are locked into their final position to maintain a directional flow is not understood. Here we find that the actin cytoskeleton is highly dynamic during early development of multiciliated cells (MCCs). While apical actin bundles become increasingly more static, subapical actin filaments are nucleated from the distal tip of ciliary rootlets. Anchorage of these subapical actin filaments requires the presence of microridge-like structures formed during MCC development, and the activity of Nonmuscle Myosin II. Optogenetic manipulation of Ezrin, a core component of the microridge actin-anchoring complex, or inhibition of Myosin Light Chain Kinase interfere with rootlet anchorage and orientation. These observations identify microridge-like structures as an essential component of basal body rootlet anchoring in MCCs. Motile cilia beat in a defined direction to orchestrate developmental programs, but also to execute janitorial tasks such as clearing airways. Here they show that motile cilia of the Xenopus epidermis are anchored to microridge-like membrane protrusions to maintain their directionality.
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Cotranslational interaction of human EBP50 and ezrin overcomes masked binding site during complex assembly. Proc Natl Acad Sci U S A 2022; 119:2115799119. [PMID: 35140182 PMCID: PMC8851480 DOI: 10.1073/pnas.2115799119] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 12/23/2021] [Indexed: 12/13/2022] Open
Abstract
Multiprotein assemblages are the intracellular workhorses of many physiological processes. Assembly of constituents into complexes can be driven by stochastic, domain-dependent, posttranslational events in which mature, folded proteins specifically interact. However, inaccessibility of interacting surfaces in mature proteins (e.g., due to "buried" domains) can obstruct complex formation. Mechanisms by which multiprotein complex constituents overcome topological impediments remain enigmatic. For example, the heterodimeric complex formed by EBP50 and ezrin must address this issue as the EBP50-interacting domain in ezrin is obstructed by a self-interaction that occupies the EBP50 binding site. Here, we show that the EBP50-ezrin complex is formed by a cotranslational mechanism in which the C terminus of mature, fully formed EBP50 binds the emerging, ribosome-bound N-terminal FERM domain of ezrin during EZR mRNA translation. Consistent with this observation, a C-terminal EBP50 peptide mimetic reduces the cotranslational interaction and abrogates EBP50-ezrin complex formation. Phosphorylation of EBP50 at Ser339 and Ser340 abrogates the cotranslational interaction and inhibits complex formation. In summary, we show that the function of eukaryotic mRNA translation extends beyond "simple" generation of a linear peptide chain that folds into a tertiary structure, potentially for subsequent complex assembly; importantly, translation can facilitate interactions with sterically inaccessible domains to form functional multiprotein complexes.
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A biophysical perspective of the regulatory mechanisms of ezrin/radixin/moesin proteins. Biophys Rev 2022; 14:199-208. [PMID: 35340609 PMCID: PMC8921360 DOI: 10.1007/s12551-021-00928-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2021] [Accepted: 12/14/2021] [Indexed: 02/08/2023] Open
Abstract
Many signal transductions resulting from ligand-receptor interactions occur at the cell surface. These signaling pathways play essential roles in cell polarization, membrane morphogenesis, and the modulation of membrane tension at the cell surface. However, due to the large number of membrane-binding proteins, including actin-membrane linkers, and transmembrane proteins present at the cell surface, the molecular mechanisms underlying the regulation at the cell surface are yet unclear. Here, we describe the molecular functions of one of the key players at the cell surface, ezrin/radixin/moesin (ERM) proteins from a biophysical point of view. We focus our discussion on biophysical properties of ERM proteins revealed by using biophysical tools in live cells and in vitro reconstitution systems. We first describe the structural properties of ERM proteins and then discuss the interactions of ERM proteins with PI(4,5)P2 and the actin cytoskeleton. These properties of ERM proteins revealed by using biophysical approaches have led to a better understanding of their physiological functions in cells and tissues. Supplementary Information The online version contains supplementary material available at 10.1007/s12551-021-00928-0.
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9
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Contribution of Ezrin on the Cell Surface Plasma Membrane Localization of Programmed Cell Death Ligand-1 in Human Choriocarcinoma JEG-3 Cells. Pharmaceuticals (Basel) 2021; 14:ph14100963. [PMID: 34681187 PMCID: PMC8540387 DOI: 10.3390/ph14100963] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2021] [Revised: 09/01/2021] [Accepted: 09/22/2021] [Indexed: 12/26/2022] Open
Abstract
Immune checkpoint blockade (ICB) antibodies targeting programmed cell death ligand-1 (PD-L1) and programmed cell death-1 (PD-1) have improved survival in patients with conventional single agent chemotherapy-resistant gestational trophoblastic neoplasia (GTN). However, many patients are resistant to ICB therapy, the mechanisms of which are poorly understood. Unraveling the regulatory mechanism for PD-L1 expression may provide a new strategy to improve ICB therapy in patients with GTN. Here, we investigated whether the ezrin/radixin/moesin (ERM) family, i.e., a group of scaffold proteins that crosslink actin cytoskeletons with several plasma membrane proteins, plays a role in the regulation of PD-L1 expression using JEG-3 cells, a representative human choriocarcinoma cell line. Our results demonstrate mRNA and protein expressions of ezrin, radixin, and PD-L1, as well as their colocalization in the plasma membrane. Intriguingly, immunoprecipitation experiments revealed that PD-L1 interacted with both ezrin and radixin and the actin cytoskeleton. Moreover, gene silencing of ezrin but not radixin strongly diminished the cell surface expression of PD-L1 without altering the mRNA level. These results indicate that ezrin may contribute to the cell surface localization of PD-L1 as a scaffold protein in JEG-3 cells, highlighting a potential therapeutic target to improve the current ICB therapy in GTN.
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Abstract
Bleb-driven cell migration plays important roles in diverse biological processes. Here, we present the mechanism for polarity establishment and maintenance in blebbing cells in vivo. We show that actin polymerization defines the leading edge, the position where blebs form. We show that the cell front can direct the formation of the rear by facilitating retrograde flow of proteins that limit the generation of blebs at the opposite aspect of the cell. Conversely, localization of bleb-inhibiting proteins at one aspect of the cell results in the establishment of the cell front at the opposite side. These antagonistic interactions result in robust polarity that can be initiated in a random direction, or oriented by a chemokine gradient. To study the mechanisms controlling front-rear polarity in migrating cells, we used zebrafish primordial germ cells (PGCs) as an in vivo model. We find that polarity of bleb-driven migrating cells can be initiated at the cell front, as manifested by actin accumulation at the future leading edge and myosin-dependent retrograde actin flow toward the other side of the cell. In such cases, the definition of the cell front, from which bleb-inhibiting proteins such as Ezrin are depleted, precedes the establishment of the cell rear, where those proteins accumulate. Conversely, following cell division, the accumulation of Ezrin at the cleavage plane is the first sign for cell polarity and this aspect of the cell becomes the cell back. Together, the antagonistic interactions between the cell front and back lead to a robust polarization of the cell. Furthermore, we show that chemokine signaling can bias the establishment of the front-rear axis of the cell, thereby guiding the migrating cells toward sites of higher levels of the attractant. We compare these results to a theoretical model according to which a critical value of actin treadmilling flow can initiate a positive feedback loop that leads to the generation of the front-rear axis and to stable cell polarization. Together, our in vivo findings and the mathematical model, provide an explanation for the observed nonoriented migration of primordial germ cells in the absence of the guidance cue, as well as for the directed migration toward the region where the gonad develops.
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Shang P, Stepicheva N, Teel K, McCauley A, Fitting CS, Hose S, Grebe R, Yazdankhah M, Ghosh S, Liu H, Strizhakova A, Weiss J, Bhutto IA, Lutty GA, Jayagopal A, Qian J, Sahel JA, Samuel Zigler J, Handa JT, Sergeev Y, Rajala RVS, Watkins S, Sinha D. βA3/A1-crystallin regulates apical polarity and EGFR endocytosis in retinal pigmented epithelial cells. Commun Biol 2021; 4:850. [PMID: 34239035 PMCID: PMC8266859 DOI: 10.1038/s42003-021-02386-6] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Accepted: 06/24/2021] [Indexed: 12/20/2022] Open
Abstract
The retinal pigmented epithelium (RPE) is a monolayer of multifunctional cells located at the back of the eye. High membrane turnover and polarization, including formation of actin-based apical microvilli, are essential for RPE function and retinal health. Herein, we demonstrate an important role for βA3/A1-crystallin in RPE. βA3/A1-crystallin deficiency leads to clathrin-mediated epidermal growth factor receptor (EGFR) endocytosis abnormalities and actin network disruption at the apical side that result in RPE polarity disruption and degeneration. We found that βA3/A1-crystallin binds to phosphatidylinositol transfer protein (PITPβ) and that βA3/A1-crystallin deficiency diminishes phosphatidylinositol 4,5-biphosphate (PI(4,5)P2), thus probably decreasing ezrin phosphorylation, EGFR activation, internalization, and degradation. We propose that βA3/A1-crystallin acquired its RPE function before evolving as a structural element in the lens, and that in the RPE, it modulates the PI(4,5)P2 pool through PITPβ/PLC signaling axis, coordinates EGFR activation, regulates ezrin phosphorylation and ultimately the cell polarity.
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Affiliation(s)
- Peng Shang
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Nadezda Stepicheva
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Kenneth Teel
- Dean McGee Eye Institute, University of Oklahoma Health Science Center, Oklahoma City, OK, USA
| | - Austin McCauley
- Dean McGee Eye Institute, University of Oklahoma Health Science Center, Oklahoma City, OK, USA
| | | | - Stacey Hose
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Rhonda Grebe
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Meysam Yazdankhah
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Sayan Ghosh
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Haitao Liu
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Anastasia Strizhakova
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Joseph Weiss
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Imran A Bhutto
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Gerard A Lutty
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | | | - Jiang Qian
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - José-Alain Sahel
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
- Institut de la Vision, INSERM, CNRS, Sorbonne Université, Paris, France
| | - J Samuel Zigler
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - James T Handa
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Yuri Sergeev
- National Eye Institute, National Institutes of Health, Bethesda, MD, USA
| | - Raju V S Rajala
- Dean McGee Eye Institute, University of Oklahoma Health Science Center, Oklahoma City, OK, USA
| | - Simon Watkins
- Department of Cell Biology and Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA
| | - Debasish Sinha
- Department of Ophthalmology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
- Wilmer Eye Institute, The Johns Hopkins University School of Medicine, Baltimore, MD, USA.
- Department of Cell Biology and Center for Biologic Imaging, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
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12
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Guo W, Gao H, Pan W, Yu P, Che G. High glucose induces Nox4 expression and podocyte apoptosis through the Smad3/ezrin/PKA pathway. Biol Open 2021; 10:bio.055012. [PMID: 33046439 PMCID: PMC8181897 DOI: 10.1242/bio.055012] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 09/28/2020] [Indexed: 12/27/2022] Open
Abstract
Podocytes are the major target in proteinuric kidney diseases such as diabetic nephropathy. The underlying molecular mechanisms by which high glucose (HG) results in podocyte damage remain unclear. This study investigated the regulatory role of Smad3, ezrin, and protein kinase A (PKA) in NADPH oxidase (Nox4) expression, reactive oxidative species (ROS) production, and apoptosis in HG-treated podocytes. A human podocyte cell line was cultured and differentiated, then treated with 30 mM HG. Apoptosis and intracellular ROS levels were assessed using TUNEL and DCF assays, respectively. Expressions of Nox4, phospho-Smad3Ser423/425, phospho-PKAThr197, and phospho-ezrinThr567 were evaluated using western blotting. ELISA was used to quantify intracellular cAMP concentration and PKA activity. Knockdown assay was used to inhibit the expressions of Smad3, Nox4, and ezrin by lentiviral shRNA. In HG-treated podocytes, the level of phospho-Smad3Ser423/425 and phospho-ezrinThr567 was increased significantly, which was accompanied by the reduction of cAMP and phospho-PKAThr197. HG-induced apoptosis was significantly prevented by the Smad3-inhibitor SIS3 or shRNA-Smad3. In podocytes expressing shRNA-ezrin or shRNA-Nox4, apoptosis was remarkably mitigated following HG treatment. HG-induced upregulation of phospho-ezrinThr567 and downregulation of phospho-PKAThr197 was significantly prevented by SIS3, shRNA-ezrin or shRNA-Smad3. Forskolin, a PKA activator, significantly inhibited HG-mediated upregulation of Nox4 expression, ROS generation, and apoptosis. Additionally, an increase in the ROS level was prohibited in HG-treated podocytes with the knockdown of Nox4, Smad3, or ezrin. Taken together, our findings provided evidence that Smad3-mediated ezrin activation upregulates Nox4 expression and ROS production, by suppressing PKA activity, which may at least in part contribute to HG-induced podocyte apoptosis. Summary: The actin-membrane linker protein ezrin-related signaling plays a critical role in podocyte apoptosis through regulation of Nox4 expression and ROS production.
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Affiliation(s)
- Wanxu Guo
- Department of Pediatrics, Second Hospital, Jilin University, Changchun, 130041, China
| | - Hang Gao
- The Key Laboratory of Pathobiology, Ministry of Education, Norman Bethune College of Medicine, Jilin University, Changchun 130021, China
| | - Wei Pan
- Department of Pediatrics, Second Hospital, Jilin University, Changchun, 130041, China
| | - Panapn Yu
- Department of Pediatrics, Second Hospital, Jilin University, Changchun, 130041, China
| | - Guanghua Che
- Department of Pediatrics, Second Hospital, Jilin University, Changchun, 130041, China
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13
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Robertson TF, Chengappa P, Gomez Atria D, Wu CF, Avery L, Roy NH, Maillard I, Petrie RJ, Burkhardt JK. Lymphocyte egress signal sphingosine-1-phosphate promotes ERM-guided, bleb-based migration. J Cell Biol 2021; 220:211919. [PMID: 33764397 PMCID: PMC8006814 DOI: 10.1083/jcb.202007182] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2020] [Revised: 02/07/2021] [Accepted: 03/03/2021] [Indexed: 02/04/2023] Open
Abstract
Ezrin, radixin, and moesin (ERM) family proteins regulate cytoskeletal responses by tethering the plasma membrane to the underlying actin cortex. Mutations in ERM proteins lead to severe combined immunodeficiency, but the function of these proteins in T cells remains poorly defined. Using mice in which T cells lack all ERM proteins, we demonstrate a selective role for these proteins in facilitating S1P-dependent egress from lymphoid organs. ERM-deficient T cells display defective S1P-induced migration in vitro, despite normal responses to standard protein chemokines. Analysis of these defects revealed that S1P promotes a fundamentally different mode of migration than chemokines, characterized by intracellular pressurization and bleb-based motility. ERM proteins facilitate this process, controlling directional migration by limiting blebbing to the leading edge. We propose that the distinct modes of motility induced by S1P and chemokines are specialized to allow T cell migration across lymphatic barriers and through tissue stroma, respectively.
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Affiliation(s)
- Tanner F Robertson
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, PA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | | | - Daniela Gomez Atria
- Division of Hematology-Oncology, Department of Medicine, Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Christine F Wu
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, PA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Lyndsay Avery
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, PA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Nathan H Roy
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, PA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
| | - Ivan Maillard
- Division of Hematology-Oncology, Department of Medicine, Abramson Family Cancer Research Institute, University of Pennsylvania Perelman School of Medicine, Philadelphia, PA
| | - Ryan J Petrie
- Department of Biology, Drexel University, Philadelphia, PA
| | - Janis K Burkhardt
- Department of Pathology and Laboratory Medicine, Children's Hospital of Philadelphia Research Institute, Philadelphia, PA.,Perelman School of Medicine, University of Pennsylvania, Philadelphia, PA
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14
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Ramalho JJ, Sepers JJ, Nicolle O, Schmidt R, Cravo J, Michaux G, Boxem M. C-terminal phosphorylation modulates ERM-1 localization and dynamics to control cortical actin organization and support lumen formation during Caenorhabditiselegans development. Development 2020; 147:dev188011. [PMID: 32586975 PMCID: PMC10755404 DOI: 10.1242/dev.188011] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 06/13/2020] [Indexed: 12/31/2023]
Abstract
ERM proteins are conserved regulators of cortical membrane specialization that function as membrane-actin linkers and molecular hubs. The activity of ERM proteins requires a conformational switch from an inactive cytoplasmic form into an active membrane- and actin-bound form, which is thought to be mediated by sequential PIP2 binding and phosphorylation of a conserved C-terminal threonine residue. Here, we use the single Caenorhabditiselegans ERM ortholog, ERM-1, to study the contribution of these regulatory events to ERM activity and tissue formation in vivo Using CRISPR/Cas9-generated erm-1 mutant alleles, we demonstrate that a PIP2-binding site is crucially required for ERM-1 function. By contrast, dynamic regulation of C-terminal T544 phosphorylation is not essential but modulates ERM-1 apical localization and dynamics in a tissue-specific manner, to control cortical actin organization and support lumen formation in epithelial tubes. Our work highlights the dynamic nature of ERM protein regulation during tissue morphogenesis and the importance of C-terminal phosphorylation in fine-tuning ERM activity in a tissue-specific context.
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Affiliation(s)
- João J Ramalho
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Jorian J Sepers
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Ophélie Nicolle
- Univ Rennes, CNRS, IGDR (Institut de Génétique et de Développement de Rennes), UMR 6290, F-35000 Rennes, France
| | - Ruben Schmidt
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Janine Cravo
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
| | - Grégoire Michaux
- Univ Rennes, CNRS, IGDR (Institut de Génétique et de Développement de Rennes), UMR 6290, F-35000 Rennes, France
| | - Mike Boxem
- Division of Developmental Biology, Institute of Biodynamics and Biocomplexity, Department of Biology, Faculty of Science, Utrecht University, Padualaan 8, 3584 CH, Utrecht, The Netherlands
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15
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Medvedev A, Kopylov A, Buneeva O, Kurbatov L, Tikhonova O, Ivanov A, Zgoda V. A Neuroprotective Dose of Isatin Causes Multilevel Changes Involving the Brain Proteome: Prospects for Further Research. Int J Mol Sci 2020; 21:ijms21114187. [PMID: 32545384 PMCID: PMC7313464 DOI: 10.3390/ijms21114187] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2020] [Revised: 06/08/2020] [Accepted: 06/09/2020] [Indexed: 12/18/2022] Open
Abstract
Isatin (indole-2,3-dione) is an endogenous regulator, exhibiting a wide range of biological and pharmacological activities. At doses of 100 mg/kg and above, isatin is neuroprotective in different experimental models of neurodegeneration. Good evidence exists that its effects are realized via interaction with numerous isatin-binding proteins identified in the brain and peripheral tissues studied. In this study, we investigated the effect of a single dose administration of isatin to mice (100 mg/kg, 24 h) on differentially expressed proteins and a profile of the isatin-binding proteins in brain hemispheres. Isatin administration to mice caused downregulation of 31 proteins. However, these changes cannot be attributed to altered expression of corresponding genes. Although at this time point isatin influenced the expression of more than 850 genes in brain hemispheres (including 433 upregulated and 418 downregulated genes), none of them could account for the changes in the differentially expressed proteins. Comparative proteomic analysis of brain isatin-binding proteins of control and isatin-treated mice revealed representative groups of proteins sensitive to isatin administration. Control-specific proteins (n = 55) represent specific targets that interact directly with isatin. Appearance of brain isatin-binding proteins specific to isatin-treated mice (n = 94) may be attributed to the formation of new clusters of protein–protein interactions and/or novel binding sites induced by a high concentration of this regulator (ligand-induced binding sites). Thus, isatin administration produces multiple effects in the brain, which include changes in gene expression and also profiles of isatin-binding proteins and their interactomes. Further studies are needed for deeper insight into the mechanisms of the multilevel changes in the brain proteome induced by isatin. In the context of the neuroprotective action, these changes may be aimed at interruption of pathological links that begin to form after initiation of pathological processes.
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16
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Rainey L, Deevi RK, McClements J, Khawaja H, Watson CJ, Roudier M, Van Schaeybroeck S, Campbell FC. Fundamental control of grade-specific colorectal cancer morphology by Src regulation of ezrin-centrosome engagement. J Pathol 2020; 251:310-322. [PMID: 32315081 DOI: 10.1002/path.5452] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2019] [Revised: 02/27/2020] [Accepted: 04/07/2020] [Indexed: 11/11/2022]
Abstract
The phenotypic spectrum of colorectal cancer (CRC) is remarkably diverse, with seemingly endless variations in cell shape, mitotic figures and multicellular configurations. Despite this morphological complexity, histological grading of collective phenotype patterns provides robust prognostic stratification in CRC. Although mechanistic understanding is incomplete, previous studies have shown that the cortical protein ezrin controls diversification of cell shape, mitotic figure geometry and multicellular architecture, in 3D organotypic CRC cultures. Because ezrin is a substrate of Src tyrosine kinase that is frequently overexpressed in CRC, we investigated Src regulation of ezrin and morphogenic growth in 3D CRC cultures. Here we show that Src perturbations disrupt CRC epithelial spatial organisation. Aberrant Src activity suppresses formation of the cortical ezrin cap that anchors interphase centrosomes. In CRC cells with a normal centrosome number, these events lead to mitotic spindle misorientation, perturbation of cell cleavage, abnormal epithelial stratification, apical membrane misalignment, multilumen formation and evolution of cribriform multicellular morphology, a feature of low-grade cancer. In isogenic CRC cells with centrosome amplification, aberrant Src signalling promotes multipolar mitotic spindle formation, pleomorphism and morphological features of high-grade cancer. Translational studies in archival human CRC revealed associations between Src intensity, multipolar mitotic spindle frequency and high-grade cancer morphology. Collectively, our study reveals Src regulation of CRC morphogenic growth via ezrin-centrosome engagement and uncovers combined perturbations underlying transition to high-grade CRC morphology. © 2020 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Lisa Rainey
- Centre for Cancer Research and Cell Biology, Queen's University Belfast and Belfast Health and Social Care Trust, Belfast, UK
| | - Ravi K Deevi
- Centre for Cancer Research and Cell Biology, Queen's University Belfast and Belfast Health and Social Care Trust, Belfast, UK
| | - Jane McClements
- Centre for Cancer Research and Cell Biology, Queen's University Belfast and Belfast Health and Social Care Trust, Belfast, UK
| | - Hajrah Khawaja
- Centre for Cancer Research and Cell Biology, Queen's University Belfast and Belfast Health and Social Care Trust, Belfast, UK
| | - Chris J Watson
- Wellcome Wolfson Institute for Experimental Medicine, Queen's University Belfast, Belfast, UK
| | - Martine Roudier
- Molecular Pathology Laboratory, AstraZeneca Oncology Translational Science, Cambridge, UK
| | - Sandra Van Schaeybroeck
- Centre for Cancer Research and Cell Biology, Queen's University Belfast and Belfast Health and Social Care Trust, Belfast, UK
| | - Frederick C Campbell
- Centre for Cancer Research and Cell Biology, Queen's University Belfast and Belfast Health and Social Care Trust, Belfast, UK
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17
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Roberts RE, Dewitt S, Hallett MB. Membrane Tension and the Role of Ezrin During Phagocytosis. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2020; 1246:83-102. [PMID: 32399827 DOI: 10.1007/978-3-030-40406-2_6] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/03/2022]
Abstract
During phagocytosis, there is an apparent expansion of the plasma membrane to accommodate the target within a phagosome. This is accompanied (or driven by) a change in membrane tension. It is proposed that the wrinkled topography of the phagocyte surface, by un-wrinkling, provides the additional available membrane and that this explains the changes in membrane tension. There is no agreement as to the mechanism by which unfolding of cell surface wrinkles occurs during phagocytosis, but there is a good case building for the involvement of the actin-plasma membrane crosslinking protein ezrin. Not only have direct measurements of membrane tension strongly implicated ezrin as the key component in establishing membrane tension, but the cortical location of ezrin changes at the phagocytic cup, suggesting that it is locally signalled. This chapter therefore attempts to synthesise our current state of knowledge about ezrin and membrane tension with phagocytosis to provide a coherent hypothesis.
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Affiliation(s)
| | - Sharon Dewitt
- School of Dentistry, Cardiff University, Cardiff, UK
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18
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Uretmen Kagiali ZC, Saner N, Akdag M, Sanal E, Degirmenci BS, Mollaoglu G, Ozlu N. CLIC4 and CLIC1 bridge plasma membrane and cortical actin network for a successful cytokinesis. Life Sci Alliance 2019; 3:3/2/e201900558. [PMID: 31879279 PMCID: PMC6933522 DOI: 10.26508/lsa.201900558] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2019] [Revised: 12/20/2019] [Accepted: 12/20/2019] [Indexed: 11/24/2022] Open
Abstract
CLIC members are required for the progression of cytokinesis by coupling the plasma membrane and cortical actin network at the cleavage furrow and polar cortex. CLIC4 and CLIC1 are members of the well-conserved chloride intracellular channel proteins (CLICs) structurally related to glutathione-S-transferases. Here, we report new roles of CLICs in cytokinesis. At the onset of cytokinesis, CLIC4 accumulates at the cleavage furrow and later localizes to the midbody in a RhoA-dependent manner. The cell cycle–dependent localization of CLIC4 is abolished when its glutathione S-transferase activity–related residues (C35A and F37D) are mutated. Ezrin, anillin, and ALIX are identified as interaction partners of CLIC4 at the cleavage furrow and midbody. Strikingly, CLIC4 facilitates the activation of ezrin at the cleavage furrow and reciprocally inhibition of ezrin activation diminishes the translocation of CLIC4 to the cleavage furrow. Furthermore, knockouts of CLIC4and CLIC1 cause abnormal blebbing at the polar cortex and regression of the cleavage furrow at late cytokinesis leading to multinucleated cells. We conclude that CLIC4 and CLIC1 function together with ezrin where they bridge plasma membrane and actin cytoskeleton at the polar cortex and cleavage furrow to promote cortical stability and successful completion of cytokinesis in mammalian cells.
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Affiliation(s)
| | - Nazan Saner
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Mehmet Akdag
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Erdem Sanal
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | | | - Gurkan Mollaoglu
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey
| | - Nurhan Ozlu
- Department of Molecular Biology and Genetics, Koç University, Istanbul, Turkey .,Koç University Research Center for Translational Medicine (KUTTAM), Istanbul, Turkey
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19
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Neutrophil Cell Shape Change: Mechanism and Signalling during Cell Spreading and Phagocytosis. Int J Mol Sci 2019; 20:ijms20061383. [PMID: 30893856 PMCID: PMC6471475 DOI: 10.3390/ijms20061383] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2019] [Revised: 03/12/2019] [Accepted: 03/14/2019] [Indexed: 12/16/2022] Open
Abstract
Perhaps the most important feature of neutrophils is their ability to rapidly change shape. In the bloodstream, the neutrophils circulate as almost spherical cells, with the ability to deform in order to pass along narrower capillaries. Upon receiving the signal to extravasate, they are able to transform their morphology and flatten onto the endothelium surface. This transition, from a spherical to a flattened morphology, is the first key step which neutrophils undergo before moving out of the blood and into the extravascular tissue space. Once they have migrated through tissues towards sites of infection, neutrophils carry out their primary role-killing infecting microbes by performing phagocytosis and producing toxic reactive oxygen species within the microbe-containing phagosome. Phagocytosis involves the second key morphology change that neutrophils undergo, with the formation of pseudopodia which capture the microbe within an internal vesicle. Both the spherical to flattened stage and the phagocytic capture stage are rapid, each being completed within 100 s. Knowing how these rapid cell shape changes occur in neutrophils is thus fundamental to understanding neutrophil behaviour. This article will discuss advances in our current knowledge of this process, and also identify an important regulated molecular event which may represent an important target for anti-inflammatory therapy.
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20
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Pelaseyed T, Bretscher A. Regulation of actin-based apical structures on epithelial cells. J Cell Sci 2018; 131:131/20/jcs221853. [PMID: 30333133 DOI: 10.1242/jcs.221853] [Citation(s) in RCA: 59] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Cells of transporting epithelia are characterized by the presence of abundant F-actin-based microvilli on their apical surfaces. Likewise, auditory hair cells have highly reproducible rows of apical stereocilia (giant microvilli) that convert mechanical sound into an electrical signal. Analysis of mutations in deaf patients has highlighted the critical components of tip links between stereocilia, and related structures that contribute to the organization of microvilli on epithelial cells have been found. Ezrin/radixin/moesin (ERM) proteins, which are activated by phosphorylation, provide a critical link between the plasma membrane and underlying actin cytoskeleton in surface structures. Here, we outline recent insights into how microvilli and stereocilia are built, and the roles of tip links. Furthermore, we highlight how ezrin is locally regulated by phosphorylation, and that this is necessary to maintain polarity. Localized phosphorylation is achieved through an intricate coincidence detection mechanism that requires the membrane lipid phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] and the apically localized ezrin kinase, lymphocyte-oriented kinase (LOK, also known as STK10) or Ste20-like kinase (SLK). We also discuss how ezrin-binding scaffolding proteins regulate microvilli and how, despite these significant advances, it remains to be discovered how the cell polarity program ultimately interfaces with these processes.
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Affiliation(s)
- Thaher Pelaseyed
- Institute of Biomedicine, Department of Medical Biochemistry and Cell Biology, University of Gothenburg, SE-405 30 Gothenburg, Sweden
| | - Anthony Bretscher
- Weill Institute for Cell and Molecular Biology, Department of Molecular Biology and Genetics, Cornell University, Ithaca, NY 14853, USA
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21
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Deevi RK, Javadi A, McClements J, Vohhodina J, Savage K, Loughrey MB, Evergren E, Campbell FC. Protein kinase C zeta suppresses low- or high-grade colorectal cancer (CRC) phenotypes by interphase centrosome anchoring. J Pathol 2018; 244:445-459. [PMID: 29520890 PMCID: PMC5873423 DOI: 10.1002/path.5035] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/14/2017] [Revised: 12/20/2017] [Accepted: 01/01/2018] [Indexed: 01/05/2023]
Abstract
Histological grading provides prognostic stratification of colorectal cancer (CRC) by scoring heterogeneous phenotypes. Features of aggressiveness include aberrant mitotic spindle configurations, chromosomal breakage, and bizarre multicellular morphology, but pathobiology is poorly understood. Protein kinase C zeta (PKCz) controls mitotic spindle dynamics, chromosome segregation, and multicellular patterns, but its role in CRC phenotype evolution remains unclear. Here, we show that PKCz couples genome segregation to multicellular morphology through control of interphase centrosome anchoring. PKCz regulates interdependent processes that control centrosome positioning. Among these, interaction between the cytoskeletal linker protein ezrin and its binding partner NHERF1 promotes the formation of a localized cue for anchoring interphase centrosomes to the cell cortex. Perturbation of these phenomena induced different outcomes in cells with single or extra centrosomes. Defective anchoring of a single centrosome promoted bipolar spindle misorientation, multi-lumen formation, and aberrant epithelial stratification. Collectively, these disturbances induce cribriform multicellular morphology that is typical of some categories of low-grade CRC. By contrast, defective anchoring of extra centrosomes promoted multipolar spindle formation, chromosomal instability (CIN), disruption of glandular morphology, and cell outgrowth across the extracellular matrix interface characteristic of aggressive, high-grade CRC. Because PKCz enhances apical NHERF1 intensity in 3D epithelial cultures, we used an immunohistochemical (IHC) assay of apical NHERF1 intensity as an indirect readout of PKCz activity in translational studies. We show that apical NHERF1 IHC intensity is inversely associated with multipolar spindle frequency and high-grade morphology in formalin-fixed human CRC samples. To conclude, defective PKCz control of interphase centrosome anchoring may underlie distinct categories of mitotic slippage that shape the development of low- or high-grade CRC phenotypes. © 2018 The Authors. The Journal of Pathology published by John Wiley & Sons Ltd on behalf of Pathological Society of Great Britain and Ireland.
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Affiliation(s)
- Ravi Kiran Deevi
- Centre for Cancer Research and Cell BiologyQueen's University of BelfastBelfastUK
| | - Arman Javadi
- Centre for Cancer Research and Cell BiologyQueen's University of BelfastBelfastUK
| | - Jane McClements
- Centre for Cancer Research and Cell BiologyQueen's University of BelfastBelfastUK
| | - Jekaterina Vohhodina
- Centre for Cancer Research and Cell BiologyQueen's University of BelfastBelfastUK
| | - Kienan Savage
- Centre for Cancer Research and Cell BiologyQueen's University of BelfastBelfastUK
| | - Maurice Bernard Loughrey
- Northern Ireland Molecular Pathology Laboratory, Centre for Cancer Research and Cell BiologyQueen's University Belfast and Belfast Health and Social Care TrustBelfastUK
| | - Emma Evergren
- Centre for Cancer Research and Cell BiologyQueen's University of BelfastBelfastUK
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22
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Lubart Q, Vitet H, Dalonneau F, Le Roy A, Kowalski M, Lourdin M, Ebel C, Weidenhaupt M, Picart C. Role of Phosphorylation in Moesin Interactions with PIP 2-Containing Biomimetic Membranes. Biophys J 2018; 114:98-112. [PMID: 29320700 PMCID: PMC5912500 DOI: 10.1016/j.bpj.2017.10.041] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2017] [Revised: 10/08/2017] [Accepted: 10/17/2017] [Indexed: 12/26/2022] Open
Abstract
Moesin, a protein of the ezrin, radixin, and moesin family, which links the plasma membrane to the cytoskeleton, is involved in multiple physiological and pathological processes, including viral budding and infection. Its interaction with the plasma membrane occurs via a key phosphoinositide, the phosphatidyl(4,5)inositol-bisphosphate (PIP2), and phosphorylation of residue T558, which has been shown to contribute, in cellulo, to a conformationally open protein. We study the impact of a double phosphomimetic mutation of moesin (T235D, T558D), which mimics the phosphorylation state of the protein, on protein/PIP2/microtubule interactions. Analytical ultracentrifugation in the micromolar range showed moesin in the monomer and dimer forms, with wild-type (WT) moesin containing a slightly larger fraction (∼30%) of dimers than DD moesin (10-20%). Only DD moesin was responsive to PIP2 in its micellar form. Quantitative cosedimentation assays using large unilamellar vesicles and quartz crystal microbalance on supported lipid bilayers containing PIP2 reveal a specific cooperative interaction for DD moesin with an ability to bind two PIP2 molecules simultaneously, whereas WT moesin was able to bind only one. In addition, DD moesin could subsequently interact with microtubules, whereas WT moesin was unable to do so. Altogether, our results point to an important role of these two phosphorylation sites in the opening of moesin: since DD moesin is intrinsically in a more open conformation than WT moesin, this intermolecular interaction is reinforced by its binding to PIP2. We also highlight important differences between moesin and ezrin, which appear to be finely regulated and to exhibit distinct molecular behaviors.
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Affiliation(s)
- Quentin Lubart
- CNRS UMR 5628 (LMGP), University Grenoble Alpes, CEA, CNRS, Grenoble, France; Institut National Polytechnique de Grenoble, University Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Helene Vitet
- CNRS UMR 5628 (LMGP), University Grenoble Alpes, CEA, CNRS, Grenoble, France; Institut National Polytechnique de Grenoble, University Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Fabien Dalonneau
- CNRS UMR 5628 (LMGP), University Grenoble Alpes, CEA, CNRS, Grenoble, France; Institut National Polytechnique de Grenoble, University Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Aline Le Roy
- Institut de Biologie Structurale (IBS), University Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Mathieu Kowalski
- CNRS UMR 5628 (LMGP), University Grenoble Alpes, CEA, CNRS, Grenoble, France; Institut National Polytechnique de Grenoble, University Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Morgane Lourdin
- CNRS UMR 5628 (LMGP), University Grenoble Alpes, CEA, CNRS, Grenoble, France; Institut National Polytechnique de Grenoble, University Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Christine Ebel
- Institut de Biologie Structurale (IBS), University Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Marianne Weidenhaupt
- CNRS UMR 5628 (LMGP), University Grenoble Alpes, CEA, CNRS, Grenoble, France; Institut National Polytechnique de Grenoble, University Grenoble Alpes, CEA, CNRS, Grenoble, France
| | - Catherine Picart
- CNRS UMR 5628 (LMGP), University Grenoble Alpes, CEA, CNRS, Grenoble, France; Institut National Polytechnique de Grenoble, University Grenoble Alpes, CEA, CNRS, Grenoble, France.
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23
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Argenzio E, Moolenaar WH. Emerging biological roles of Cl- intracellular channel proteins. J Cell Sci 2017; 129:4165-4174. [PMID: 27852828 DOI: 10.1242/jcs.189795] [Citation(s) in RCA: 67] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Cl- intracellular channels (CLICs) are a family of six evolutionary conserved cytosolic proteins that exist in both soluble and membrane-associated forms; however, their functions have long been elusive. Soluble CLICs adopt a glutathione S-transferase (GST)-fold, can induce ion currents in artificial membranes and show oxidoreductase activity in vitro, but there is no convincing evidence of CLICs having such activities in vivo. Recent studies have revealed a role for CLIC proteins in Rho-regulated cortical actin dynamics as well as vesicular trafficking and integrin recycling, the latter of which are under the control of Rab GTPases. In this Commentary, we discuss the emerging roles of CLIC proteins in these processes and the lessons learned from gene-targeting studies. We also highlight outstanding questions regarding the molecular function(s) of these important but still poorly understood proteins.
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Affiliation(s)
- Elisabetta Argenzio
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam 1066CX, The Netherlands
| | - Wouter H Moolenaar
- Division of Cell Biology, The Netherlands Cancer Institute, Amsterdam 1066CX, The Netherlands
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24
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Oh YS, Heo K, Kim EK, Jang JH, Bae SS, Park JB, Kim YH, Song M, Kim SR, Ryu SH, Kim IH, Suh PG. Dynamic relocalization of NHERF1 mediates chemotactic migration of ovarian cancer cells toward lysophosphatidic acid stimulation. Exp Mol Med 2017; 49:e351. [PMID: 28684865 PMCID: PMC5565956 DOI: 10.1038/emm.2017.88] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Revised: 12/28/2016] [Accepted: 01/09/2017] [Indexed: 01/05/2023] Open
Abstract
NHERF1/EBP50 (Na+/H+ exchanger regulating
factor 1; Ezrin-binding phosphoprotein of 50 kDa) organizes stable
protein complexes beneath the apical membrane of polar epithelial cells. By
contrast, in cancer cells without any fixed polarity, NHERF1 often localizes in
the cytoplasm. The regulation of cytoplasmic NHERF1 and its role in cancer
progression remain unclear. In this study, we found that, upon lysophosphatidic
acid (LPA) stimulation, cytoplasmic NHERF1 rapidly translocated to the plasma
membrane, and subsequently to cortical protrusion structures, of ovarian cancer
cells. This movement depended on direct binding of NHERF1 to C-terminally
phosphorylated ERM proteins (cpERMs). Moreover, NHERF1 depletion downregulated
cpERMs and further impaired cpERM-dependent remodeling of the cell cortex,
suggesting reciprocal regulation between these proteins. The LPA-induced protein
complex was highly enriched in migratory pseudopodia, whose formation was
impaired by overexpression of NHERF1 truncation mutants. Consistent with this,
NHERF1 depletion in various types of cancer cells abolished chemotactic cell
migration toward a LPA gradient. Taken together, our findings suggest that the
high dynamics of cytosolic NHERF1 provide cancer cells with a means of
controlling chemotactic migration. This capacity is likely to be essential for
ovarian cancer progression in tumor microenvironments containing LPA.
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Affiliation(s)
- Yong-Seok Oh
- Department of Brain-Cognitive Science, Daegu-Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Kyun Heo
- Research Institute, National Cancer Center, Goyang, Republic of Korea
| | - Eung-Kyun Kim
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
| | - Jin-Hyeok Jang
- Department of Brain-Cognitive Science, Daegu-Gyeongbuk Institute of Science and Technology (DGIST), Daegu, Republic of Korea
| | - Sun Sik Bae
- MRC for Ischemic Tissue Regeneration, Department of Pharmacology, School of Medicine, Pusan National University, Yangsan, Republic of Korea
| | - Jong Bae Park
- Research Institute, National Cancer Center, Goyang, Republic of Korea.,Graduate School of Cancer Science and Policy, National Cancer Center, Goyang, Republic of Korea
| | - Yun Hee Kim
- Research Institute, National Cancer Center, Goyang, Republic of Korea.,Graduate School of Cancer Science and Policy, National Cancer Center, Goyang, Republic of Korea
| | - Minseok Song
- Synaptic Circuit Plasticity Laboratory, Department of Structure and Function of Neural Network, Korea Brain Research Institute, Daegu, Republic of Korea
| | - Sang Ryong Kim
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Institute of Life Science and Biotechnology, Kyungpook National University, Daegu, Republic of Korea
| | - Sung Ho Ryu
- Division of Molecular and Life Science, Department of Life Science, Pohang University of Science and Technology, Pohang, Republic of Korea
| | - In-Hoo Kim
- Research Institute, National Cancer Center, Goyang, Republic of Korea.,Graduate School of Cancer Science and Policy, National Cancer Center, Goyang, Republic of Korea
| | - Pann-Ghill Suh
- Department of Biological Sciences, Ulsan National Institute of Science and Technology (UNIST), Ulsan, Republic of Korea
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25
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Pelaseyed T, Viswanatha R, Sauvanet C, Filter JJ, Goldberg ML, Bretscher A. Ezrin activation by LOK phosphorylation involves a PIP 2-dependent wedge mechanism. eLife 2017; 6. [PMID: 28430576 PMCID: PMC5400502 DOI: 10.7554/elife.22759] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 03/27/2017] [Indexed: 12/15/2022] Open
Abstract
How cells specify morphologically distinct plasma membrane domains is poorly understood. Prior work has shown that restriction of microvilli to the apical aspect of epithelial cells requires the localized activation of the membrane-F-actin linking protein ezrin. Using an in vitro system, we now define a multi-step process whereby the kinase LOK specifically phosphorylates ezrin to activate it. Binding of PIP2 to ezrin induces a conformational change permitting the insertion of the LOK C-terminal domain to wedge apart the membrane and F-actin-binding domains of ezrin. The N-terminal LOK kinase domain can then access a site 40 residues distal from the consensus sequence that collectively direct phosphorylation of the appropriate threonine residue. We suggest that this elaborate mechanism ensures that ezrin is only phosphorylated at the plasma membrane, and with high specificity by the apically localized kinase LOK. DOI:http://dx.doi.org/10.7554/eLife.22759.001
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Affiliation(s)
- Thaher Pelaseyed
- Weill Institute for Molecular and Cell Biology, Cornell University, Ithaca, United States.,Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Raghuvir Viswanatha
- Weill Institute for Molecular and Cell Biology, Cornell University, Ithaca, United States.,Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States.,Department of Genetics, Harvard Medical School, Boston, United States
| | - Cécile Sauvanet
- Weill Institute for Molecular and Cell Biology, Cornell University, Ithaca, United States.,Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Joshua J Filter
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Michael L Goldberg
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
| | - Anthony Bretscher
- Weill Institute for Molecular and Cell Biology, Cornell University, Ithaca, United States.,Department of Molecular Biology and Genetics, Cornell University, Ithaca, United States
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26
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Antoine-Bertrand J, Duquette PM, Alchini R, Kennedy TE, Fournier AE, Lamarche-Vane N. p120RasGAP Protein Mediates Netrin-1 Protein-induced Cortical Axon Outgrowth and Guidance. J Biol Chem 2015; 291:4589-602. [PMID: 26710849 DOI: 10.1074/jbc.m115.674846] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2015] [Indexed: 12/23/2022] Open
Abstract
The receptor deleted in colorectal cancer (DCC) mediates the attraction of growing axons to netrin-1 during brain development. In response to netrin-1 stimulation, DCC becomes a signaling platform to recruit proteins that promote axon outgrowth and guidance. The Ras GTPase-activating protein (GAP) p120RasGAP inhibits Ras activity and mediates neurite retraction and growth cone collapse in response to repulsive guidance cues. Here we show an interaction between p120RasGAP and DCC that positively regulates netrin-1-mediated axon outgrowth and guidance in embryonic cortical neurons. In response to netrin-1, p120RasGAP is recruited to DCC in growth cones and forms a multiprotein complex with focal adhesion kinase and ERK. We found that Ras/ERK activities are elevated aberrantly in p120RasGAP-deficient neurons. Moreover, the expression of p120RasGAP Src homology 2 (SH2)-SH3-SH2 domains, which interact with the C-terminal tail of DCC, is sufficient to restore netrin-1-dependent axon outgrowth in p120RasGAP-deficient neurons. We provide a novel mechanism that exploits the scaffolding properties of the N terminus of p120RasGAP to tightly regulate netrin-1/DCC-dependent axon outgrowth and guidance.
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Affiliation(s)
- Judith Antoine-Bertrand
- From the Department of Anatomy and Cell Biology and Cancer Research Program, Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, H4A 3J1 Canada and
| | - Philippe M Duquette
- From the Department of Anatomy and Cell Biology and Cancer Research Program, Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, H4A 3J1 Canada and
| | - Ricardo Alchini
- the Department of Neurology and Neurosurgery, Montreal Neurological Institute, Montreal, Quebec, H3A 2B4 Canada
| | - Timothy E Kennedy
- the Department of Neurology and Neurosurgery, Montreal Neurological Institute, Montreal, Quebec, H3A 2B4 Canada
| | - Alyson E Fournier
- the Department of Neurology and Neurosurgery, Montreal Neurological Institute, Montreal, Quebec, H3A 2B4 Canada
| | - Nathalie Lamarche-Vane
- From the Department of Anatomy and Cell Biology and Cancer Research Program, Research Institute of McGill University Health Centre, McGill University, Montreal, Quebec, H4A 3J1 Canada and
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27
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Sauvanet C, Wayt J, Pelaseyed T, Bretscher A. Structure, Regulation, and Functional Diversity of Microvilli on the Apical Domain of Epithelial Cells. Annu Rev Cell Dev Biol 2015; 31:593-621. [DOI: 10.1146/annurev-cellbio-100814-125234] [Citation(s) in RCA: 110] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Cécile Sauvanet
- Department of Molecular Biology and Genetics and Weill Institute for Molecular and Cell Biology, Cornell University, Ithaca, New York 14853;
| | - Jessica Wayt
- Department of Molecular Biology and Genetics and Weill Institute for Molecular and Cell Biology, Cornell University, Ithaca, New York 14853;
| | - Thaher Pelaseyed
- Department of Molecular Biology and Genetics and Weill Institute for Molecular and Cell Biology, Cornell University, Ithaca, New York 14853;
| | - Anthony Bretscher
- Department of Molecular Biology and Genetics and Weill Institute for Molecular and Cell Biology, Cornell University, Ithaca, New York 14853;
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28
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Abstract
The function of scaffolding proteins is to bring together two or more proteins in a relatively stable configuration, hence their name. Numerous scaffolding proteins are found in nature, many having multiple protein–protein interaction modules. Over the past decade, examples of scaffolding complexes long thought to be stable have instead been found to be surprisingly dynamic. These studies are scattered among different biological systems, and so the concept that scaffolding complexes might not always represent stable entities and that their dynamics can be regulated has not garnered general attention. We became aware of this issue in our studies of a scaffolding protein in microvilli, which forced us to reevaluate its contribution to their structure. The purpose of this Perspective is to draw attention to this phenomenon and discuss why complexes might show regulated dynamics. We also wish to encourage more studies on the dynamics of “stable” complexes and to provide a word of caution about how functionally important dynamic associations may be missed in biochemical and proteomic studies.
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Affiliation(s)
- Damien Garbett
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
| | - Anthony Bretscher
- Department of Molecular Biology and Genetics, Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, NY 14853
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29
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Haeger JD, Hambruch N, Dantzer V, Hoelker M, Schellander K, Klisch K, Pfarrer C. Changes in endometrial ezrin and cytokeratin 18 expression during bovine implantation and in caruncular endometrial spheroids in vitro. Placenta 2015; 36:821-31. [DOI: 10.1016/j.placenta.2015.06.001] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 05/19/2015] [Accepted: 06/06/2015] [Indexed: 11/25/2022]
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30
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Nygren PJ, Scott JD. Therapeutic strategies for anchored kinases and phosphatases: exploiting short linear motifs and intrinsic disorder. Front Pharmacol 2015; 6:158. [PMID: 26283967 PMCID: PMC4516873 DOI: 10.3389/fphar.2015.00158] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2015] [Accepted: 07/16/2015] [Indexed: 12/17/2022] Open
Abstract
Phosphorylation events that occur in response to the second messenger cAMP are controlled spatially and temporally by protein kinase A (PKA) interacting with A-kinase anchoring proteins (AKAPs). Recent advances in understanding the structural basis for this interaction have reinforced the hypothesis that AKAPs create spatially constrained signaling microdomains. This has led to the realization that the PKA/AKAP interface is a potential drug target for modulating a plethora of cell-signaling events. Pharmacological disruption of kinase–AKAP interactions has previously been explored for disease treatment and remains an interesting area of research. However, disrupting or enhancing the association of phosphatases with AKAPs is a therapeutic concept of equal promise, particularly since they oppose the actions of many anchored kinases. Accordingly, numerous AKAPs bind phosphatases such as protein phosphatase 1 (PP1), calcineurin (PP2B), and PP2A. These multimodal signaling hubs are equally able to control the addition of phosphate groups onto target substrates, as well as the removal of these phosphate groups. In this review, we describe recent advances in structural analysis of kinase and phosphatase interactions with AKAPs, and suggest future possibilities for targeting these interactions for therapeutic benefit.
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Affiliation(s)
- Patrick J Nygren
- Department of Pharmacology, University of Washington Seattle, WA, USA ; Howard Hughes Medical Institute Chevy Chase, MD, USA
| | - John D Scott
- Department of Pharmacology, University of Washington Seattle, WA, USA ; Howard Hughes Medical Institute Chevy Chase, MD, USA
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31
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Ezrin Binds to DEAD-Box RNA Helicase DDX3 and Regulates Its Function and Protein Level. Mol Cell Biol 2015; 35:3145-62. [PMID: 26149384 DOI: 10.1128/mcb.00332-15] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2015] [Accepted: 06/21/2015] [Indexed: 12/30/2022] Open
Abstract
Ezrin is a key regulator of cancer metastasis that links the extracellular matrix to the actin cytoskeleton and regulates cell morphology and motility. We discovered a small-molecule inhibitor, NSC305787, that directly binds to ezrin and inhibits its function. In this study, we used a nano-liquid chromatography-tandem mass spectrometry (nano-LC-MS-MS)-based proteomic approach to identify ezrin-interacting proteins that are competed away by NSC305787. A large number of the proteins that interact with ezrin were implicated in protein translation and stress granule dynamics. We validated direct interaction between ezrin and the RNA helicase DDX3, and NSC305787 blocked this interaction. Downregulation or long-term pharmacological inhibition of ezrin led to reduced DDX3 protein levels without changes in DDX3 mRNA. Ectopic overexpression of ezrin in low-ezrin-expressing osteosarcoma cells caused a notable increase in DDX3 protein levels. Ezrin inhibited the RNA helicase activity of DDX3 but increased its ATPase activity. Our data suggest that ezrin controls the translation of mRNAs preferentially with a structured 5' untranslated region, at least in part, by sustaining the protein level of DDX3 and/or regulating its function. Therefore, our findings suggest a novel function for ezrin in regulation of gene translation that is distinct from its canonical role as a cytoskeletal scaffold at the cell membrane.
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32
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The NHERF2 sequence adjacent and upstream of the ERM-binding domain affects NHERF2-ezrin binding and dexamethasone stimulated NHE3 activity. Biochem J 2015; 470:77-90. [PMID: 26251448 PMCID: PMC4613507 DOI: 10.1042/bj20150238] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2015] [Accepted: 06/16/2015] [Indexed: 12/19/2022]
Abstract
The microvillar localization of Na+-H+ exchanger regulatory factor (NHERF)1/2 requires not only ezrin, radixin and moesin (ERM)-binding domain (EBD) but also a newly defined ERM-binding regulatory sequence (EBRS) that modulates NHERF1/2–ezrin binding. NHERF2 EBRS is also regulated by phosphorylation, which affects NHE3 (Na+-H+ exchanger 3) stimulation by dexamethasone. In the brush border of intestinal and kidney epithelial cells, scaffolding proteins ezrin, Na+-H+ exchanger regulatory factor (NHERF)1 and NHERF2 play important roles in linking transmembrane proteins to the cytoskeleton and assembling signalling regulatory complexes. The last 30 carboxyl residues of NHERF1 and NHERF2 form the EBDs [ezrin, radixin and moesin (ERM)-binding domain]. The current study found that NHERF1/2 contain an ERM-binding regulatory sequence (EBRS), which facilitates the interaction between the EBD and ezrin. The EBRSs are located within 24 and 19 residues immediately upstream of EBDs for NHERF1 and NHERF2 respectively. In OK (opossum kidney) epithelial cells, EBRSs are necessary along with the EBD to distribute NHERF1 and NHERF2 exclusively to the apical domain. Furthermore, phosphorylation of Ser303 located in the EBRS of NHERF2, decreases the binding affinity for ezrin, dislocates apical NHERF2 into the cytosol and increases the NHERF2 microvillar mobility rate. Moreover, increased phosphorylation of Ser303 was functionally significant preventing acute stimulation of NHE3 (Na+-H+ exchanger 3) activity by dexamethasone.
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33
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Al-Momany A, Li L, Alexander RT, Ballermann BJ. Clustered PI(4,5)P₂ accumulation and ezrin phosphorylation in response to CLIC5A. J Cell Sci 2014; 127:5164-78. [PMID: 25344252 DOI: 10.1242/jcs.147744] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
CLIC5A (encoded by CLIC5) is a component of the ezrin-NHERF2-podocalyxin complex in renal glomerular podocyte foot processes. We explored the mechanism(s) by which CLIC5A regulates ezrin function. In COS-7 cells, CLIC5A augmented ezrin phosphorylation without changing ezrin abundance, increased the association of ezrin with the cytoskeletal fraction and enhanced actin polymerization and the formation of cell surface projections. CLIC5A caused the phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2] reporter RFP-PH-PLC to translocate from the cytosol to discrete plasma membrane clusters at the cell surface, where it colocalized with CLIC5A. Transiently expressed HA-PIP5Kα colocalized with GFP-CLIC5A and was pulled from cell lysates by GST-CLIC5A, and silencing of endogenous PIP5Kα abrogated CLIC5A-dependent ERM phosphorylation. N- and C-terminal deletion mutants of CLIC5A, which failed to associate with the plasma membrane, failed to colocalize with PIP5Kα, did not alter the abundance of PI(4,5)P2 plasma membrane clusters and failed to enhance ezrin phosphorylation. Relative to wild-type mice, in CLIC5-deficient mice, the phosphorylation of glomerular ezrin was diminished and the cytoskeletal association of both ezrin and NHERF2 was reduced. Therefore, the mechanism of CLIC5A action involves clustered plasma membrane PI(4,5)P2 accumulation through an interaction of CLIC5A with PI(4,5)P2-generating kinases, in turn facilitating ezrin activation and actin-dependent cell surface remodeling.
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Affiliation(s)
- Abass Al-Momany
- Department of Physiology, University of Alberta, Edmonton, AL T6G 2V2, Canada
| | - Laiji Li
- Department of Medicine (Nephrology), University of Alberta, Edmonton, AL T6G 2V2, Canada
| | - R Todd Alexander
- Department of Pediatrics, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, AL T6G 2V2, Canada
| | - Barbara J Ballermann
- Department of Physiology, University of Alberta, Edmonton, AL T6G 2V2, Canada Department of Medicine (Nephrology), University of Alberta, Edmonton, AL T6G 2V2, Canada
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34
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Dynamics of ezrin and EBP50 in regulating microvilli on the apical aspect of epithelial cells. Biochem Soc Trans 2014; 42:189-94. [PMID: 24450650 DOI: 10.1042/bst20130263] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
Microvilli are found on the apical surface of epithelial cells. Recent studies on the microvillar proteins ezrin and EBP50 (ezrin/radixin/moesin-binding phosphoprotein of 50 kDa) have revealed both the dynamics and the regulation of microvillar components, and how a dynamic ezrin phosphocycle is necessary to confine microvilli to the apical membrane. In the present review, we first summarize the background to allow us to place these advances in context.
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35
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Abstract
The cell cortex is a dynamic and heterogeneous structure that governs cell identity and behavior. The ERM proteins (ezrin, radixin and moesin) are major architects of the cell cortex, and they link plasma membrane phospholipids and proteins to the underlying cortical actin cytoskeleton. Recent studies in several model systems have uncovered surprisingly dynamic and complex molecular activities of the ERM proteins and have provided new mechanistic insight into how they build and maintain cortical domains. Among many well-established and essential functions of ERM proteins, this Cell Science at a Glance article and accompanying poster will focus on the role of ERMs in organizing the cell cortex during cell division and apical morphogenesis. These examples highlight an emerging appreciation that the ERM proteins both locally alter the mechanical properties of the cell cortex, and control the spatial distribution and activity of key membrane complexes, establishing the ERM proteins as a nexus for the physical and functional organization of the cell cortex and making it clear that they are much more than scaffolds. This article is part of a Minifocus on Establishing polarity.
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Affiliation(s)
- Andrea I McClatchey
- Massachusetts General Hospital Center for Cancer Research, Harvard Medical School Department of Pathology, 149 13th Street, Charlestown, MA 02129, USA
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36
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Kohli P, Bartram MP, Habbig S, Pahmeyer C, Lamkemeyer T, Benzing T, Schermer B, Rinschen MM. Label-free quantitative proteomic analysis of the YAP/TAZ interactome. Am J Physiol Cell Physiol 2014; 306:C805-18. [PMID: 24573087 DOI: 10.1152/ajpcell.00339.2013] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The function of an individual protein is typically defined by protein-protein interactions orchestrating the formation of large complexes critical for a wide variety of biological processes. Over the last decade the analysis of purified protein complexes by mass spectrometry became a key technique to identify protein-protein interactions. We present a fast and straightforward approach for analyses of interacting proteins combining a Flp-in single-copy cellular integration system and single-step affinity purification with single-shot mass spectrometry analysis. We applied this protocol to the analysis of the YAP and TAZ interactome. YAP and TAZ are the downstream effectors of the mammalian Hippo tumor suppressor pathway. Our study provides comprehensive interactomes for both YAP and TAZ and does not only confirm the majority of previously described interactors but, strikingly, revealed uncharacterized interaction partners that affect YAP/TAZ TEAD-dependent transcription. Among these newly identified candidates are Rassf8, thymopoetin, and the transcription factors CCAAT/enhancer-binding protein (C/EBP)β/δ and core-binding factor subunit β (Cbfb). In addition, our data allowed insights into complex stoichiometry and uncovered discrepancies between the YAP and TAZ interactomes. Taken together, the stringent approach presented here could help to significantly sharpen the understanding of protein-protein networks.
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Affiliation(s)
- Priyanka Kohli
- Department II of Internal Medicine and Center for Molecular Medicine, University of Cologne, Cologne, Germany
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