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Chen L, Qian Z, Zheng Y, Zhang J, Sun J, Zhou C, Xiao H. Structural analysis of PTPN21 reveals a dominant-negative effect of the FERM domain on its phosphatase activity. SCIENCE ADVANCES 2024; 10:eadi7404. [PMID: 38416831 PMCID: PMC10901363 DOI: 10.1126/sciadv.adi7404] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/15/2023] [Accepted: 01/24/2024] [Indexed: 03/01/2024]
Abstract
PTPN21 belongs to the four-point-one, ezrin, radixin, moesin (FERM) domain-containing protein tyrosine phosphatases (PTP) and plays important roles in cytoskeleton-associated cellular processes like cell adhesion, motility, and cargo transport. Because of the presence of a WPE loop instead of a WPD loop in the phosphatase domain, it is often considered to lack phosphatase activity. However, many of PTPN21's biological functions require its catalytic activity. To reconcile these findings, we have determined the structures of individual PTPN21 FERM, PTP domains, and a complex between FERM-PTP. Combined with biochemical analysis, we have found that PTPN21 PTP is weakly active and is autoinhibited by association with its FERM domain. Disruption of FERM-PTP interaction results in enhanced ERK activation. The oncogenic HPV18 E7 protein binds to PTP at the same location as PTPN21 FERM, indicating that it may act by displacing the FERM domain from PTP. Our results provide mechanistic insight into PTPN21 and benefit functional studies of PTPN21-mediated processes.
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Affiliation(s)
- Lu Chen
- Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310016, China
- School of Public Health, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Zijun Qian
- Department of Hematology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310016, China
| | - Yuyuan Zheng
- School of Public Health, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Jie Zhang
- Department of Hematology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310016, China
| | - Jie Sun
- Department of Cell Biology, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Chun Zhou
- Department of Pathology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310016, China
- School of Public Health, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310058, China
| | - Haowen Xiao
- Department of Hematology of Sir Run Run Shaw Hospital, Zhejiang University School of Medicine, Hangzhou, Zhejiang 310016, China
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2
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Hofbrucker-MacKenzie SA, Seemann E, Westermann M, Qualmann B, Kessels MM. Long-term depression in neurons involves temporal and ultra-structural dynamics of phosphatidylinositol-4,5-bisphosphate relying on PIP5K, PTEN and PLC. Commun Biol 2023; 6:366. [PMID: 37012315 PMCID: PMC10070498 DOI: 10.1038/s42003-023-04726-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/21/2022] [Accepted: 03/17/2023] [Indexed: 04/05/2023] Open
Abstract
Synaptic plasticity involves proper establishment and rearrangement of structural and functional microdomains. Yet, visualization of the underlying lipid cues proved challenging. Applying a combination of rapid cryofixation, membrane freeze-fracturing, immunogold labeling and electron microscopy, we visualize and quantitatively determine the changes and the distribution of phosphatidylinositol-4,5-bisphosphate (PIP2) in the plasma membrane of dendritic spines and subareas thereof at ultra-high resolution. These efforts unravel distinct phases of PIP2 signals during induction of long-term depression (LTD). During the first minutes PIP2 rapidly increases in a PIP5K-dependent manner forming nanoclusters. PTEN contributes to a second phase of PIP2 accumulation. The transiently increased PIP2 signals are restricted to upper and middle spine heads. Finally, PLC-dependent PIP2 degradation provides timely termination of PIP2 cues during LTD induction. Together, this work unravels the spatial and temporal cues set by PIP2 during different phases after LTD induction and dissects the molecular mechanisms underlying the observed PIP2 dynamics.
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Affiliation(s)
- Sarah A Hofbrucker-MacKenzie
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Eric Seemann
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Martin Westermann
- Center for Electron Microscopy, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany
| | - Britta Qualmann
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany.
| | - Michael M Kessels
- Institute of Biochemistry I, Jena University Hospital - Friedrich Schiller University Jena, 07743, Jena, Germany.
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Zhao S, Luo J, Hu J, Wang H, Zhao N, Cao M, Zhang C, Hu R, Liu L. Role of Ezrin in Asthma-Related Airway Inflammation and Remodeling. Mediators Inflamm 2022; 2022:6255012. [PMID: 36530558 PMCID: PMC9750775 DOI: 10.1155/2022/6255012] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2022] [Revised: 11/22/2022] [Accepted: 11/22/2022] [Indexed: 08/13/2023] Open
Abstract
Ezrin is an actin binding protein connecting the cell membrane and the cytoskeleton, which is crucial to maintaining cell morphology, intercellular adhesion, and cytoskeleton remodeling. Asthma involves dysfunction of inflammatory cells, cytokines, and airway structural cells. Recent studies have shown that ezrin, whose function is affected by extensive phosphorylation and protein interactions, is closely associated with asthma, may be a therapeutic target for asthma treatment. In this review, we summarize studies on ezrin and discuss its role in asthma-related airway inflammation and remodeling.
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Affiliation(s)
- Shumei Zhao
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Chinese Medicine, Nanjing 210029, China
- Nanjing University of Chinese Medicine, Nanjing 210029, China
| | - Jiaqi Luo
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Chinese Medicine, Nanjing 210029, China
- Nanjing University of Chinese Medicine, Nanjing 210029, China
| | - Jun Hu
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Chinese Medicine, Nanjing 210029, China
- Nanjing University of Chinese Medicine, Nanjing 210029, China
| | - Hesheng Wang
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Chinese Medicine, Nanjing 210029, China
- Nanjing University of Chinese Medicine, Nanjing 210029, China
| | - Ningwei Zhao
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Chinese Medicine, Nanjing 210029, China
- Shimadzu Biomedical Research Laboratory, Shanghai 200233, China
| | - Meng Cao
- Nanjing University of Chinese Medicine, Nanjing 210029, China
- Affiliated Hospital of Integrated Traditional Chinese and Western Medicine Nanjing University of Chinese Medicine, Nanjing 210028, China
| | - Cong Zhang
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Chinese Medicine, Nanjing 210029, China
- Nanjing University of Chinese Medicine, Nanjing 210029, China
| | - Rongkui Hu
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Chinese Medicine, Nanjing 210029, China
- Nanjing University of Chinese Medicine, Nanjing 210029, China
| | - Lanying Liu
- Affiliated Hospital of Nanjing University of Chinese Medicine, Jiangsu Province Hospital of Chinese Medicine, Nanjing 210029, China
- Nanjing University of Chinese Medicine, Nanjing 210029, China
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4
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Wei X, Min Y, Feng Y, He D, Zeng X, Huang Y, Fan S, Chen H, Chen J, Xiang K, Luo H, Yin G, Hu D. Development and validation of an individualized nomogram for predicting the high-volume (> 5) central lymph node metastasis in papillary thyroid microcarcinoma. J Endocrinol Invest 2022; 45:507-515. [PMID: 34491546 DOI: 10.1007/s40618-021-01675-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/10/2021] [Accepted: 09/03/2021] [Indexed: 01/30/2023]
Abstract
PURPOSE Papillary thyroid microcarcinoma (PTMC) frequently presents a favorable clinical outcome, while aggressive invasiveness can also be found in some of this population. Identifying the risk clinical factors of high-volume (> 5) central lymph node metastasis (CLNM) in PTMC patients could help oncologists make a better-individualized clinical decision. METHODS We retrospectively reviewed the clinical characteristics of adult patients with PTC in the Surveillance, Epidemiology, and End Results (SEER) database between Jan 2010 and Dec 2015 and in one medical center affiliated to Chongqing Medical University between Jan 2018 and Oct 2020. Univariate and multivariate logistic regression analyses were used to determine the risk factors for high volume of CLNM in PTMC patients. RESULTS The male gender (OR = 2.02, 95% CI 1.46-2.81), larger tumor size (> 5 mm, OR = 1.64, 95% CI 1.13-2.38), multifocality (OR = 1.87, 95% CI 1.40-2.51), and extrathyroidal invasion (OR = 3.67; 95% CI 2.64-5.10) were independent risk factors in promoting high-volume of CLNM in PTMC patients. By contrast, elderly age (≥ 55 years) at diagnosis (OR = 0.57, 95% CI 0.40-0.81) and PTMC-follicular variate (OR = 0.60, 95% CI 0.42-0.87) were determined as the protective factors. Based on these indicators, a nomogram was further constructed with a good concordance index (C-index) of 0.702, supported by an external validating cohort with a promising C-index of 0.811. CONCLUSION A nomogram was successfully established and validated with six clinical indicators. This model could help surgeons to make a better-individualized clinical decision on the management of PTMC patients, especially in terms of whether prophylactic central lymph node dissection and postoperative radiotherapy should be warranted.
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Affiliation(s)
- X Wei
- Department of Internal Cardiology, The Second Affiliated Hospital, Chongqing Medical University, No. 74, Linjiang Rd, Yuzhong Dist, Chongqing, 404100, People's Republic of China
| | - Y Min
- Department of Breast and Thyroid Surgery, The Second Affiliated Hospital of Chongqing Medical University, No. 74, Linjiang Rd, Yuzhong Dist, Chongqing, 404100, People's Republic of China
| | - Y Feng
- Department of Breast and Thyroid Surgery, The Second Affiliated Hospital of Chongqing Medical University, No. 74, Linjiang Rd, Yuzhong Dist, Chongqing, 404100, People's Republic of China
| | - D He
- Department of Breast and Thyroid Surgery, The Second Affiliated Hospital of Chongqing Medical University, No. 74, Linjiang Rd, Yuzhong Dist, Chongqing, 404100, People's Republic of China
| | - X Zeng
- Department of Oncology, The Second Affiliated Hospital, Chongqing Medical University, No. 74, Linjiang Rd, Yuzhong Dist, Chongqing, 404100, People's Republic of China
| | - Y Huang
- Department of Pathology, The Second Affiliated Hospital of Chongqing Medical University, No. 74, Linjiang Rd, Yuzhong Dist, Chongqing, 404100, People's Republic of China
| | - S Fan
- Department of Breast and Thyroid Surgery, The Second Affiliated Hospital of Chongqing Medical University, No. 74, Linjiang Rd, Yuzhong Dist, Chongqing, 404100, People's Republic of China
| | - H Chen
- Department of Breast and Thyroid Surgery, The Second Affiliated Hospital of Chongqing Medical University, No. 74, Linjiang Rd, Yuzhong Dist, Chongqing, 404100, People's Republic of China
| | - J Chen
- Department of Breast and Thyroid Surgery, The Second Affiliated Hospital of Chongqing Medical University, No. 74, Linjiang Rd, Yuzhong Dist, Chongqing, 404100, People's Republic of China
| | - K Xiang
- Department of Breast and Thyroid Surgery, The Second Affiliated Hospital of Chongqing Medical University, No. 74, Linjiang Rd, Yuzhong Dist, Chongqing, 404100, People's Republic of China
| | - H Luo
- Department of Breast and Thyroid Surgery, The Second Affiliated Hospital of Chongqing Medical University, No. 74, Linjiang Rd, Yuzhong Dist, Chongqing, 404100, People's Republic of China
| | - G Yin
- Department of Breast and Thyroid Surgery, The Second Affiliated Hospital of Chongqing Medical University, No. 74, Linjiang Rd, Yuzhong Dist, Chongqing, 404100, People's Republic of China.
| | - D Hu
- Department of Breast and Thyroid Surgery, The Second Affiliated Hospital of Chongqing Medical University, No. 74, Linjiang Rd, Yuzhong Dist, Chongqing, 404100, People's Republic of China.
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Bommanavar S, Kanetkar SR, Datkhile KD, More AL. Membrane-organizing extension spike protein and its role as an emerging biomarker in oral squamous cell carcinoma. J Oral Maxillofac Pathol 2022; 26:82-86. [PMID: 35571321 PMCID: PMC9106235 DOI: 10.4103/jomfp.jomfp_182_21] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2021] [Accepted: 09/05/2021] [Indexed: 12/02/2022] Open
Abstract
Oral squamous cell carcinoma (OSCC) is the most malignant tumor worldwide with a relatively poor prognosis. This can be due to lack of using new specific biomarkers as a mode of pristine interventional therapy for detecting the lesions at an early stage, thereby not allowing it to proceed to a severe advanced stage. Biomarkers, being the products of malignant cells, can prove to be promising prognostic factors in understanding the molecular pathogenesis of oral cancer. One such biomarker is membrane-organizing extension spike protein (MOESIN). Belonging to the family of ezrin/radixin/MOESIN proteins, MOESIN acts as a structural linker between plasma membrane and actin filament of the cell moiety and is involved in regulating many fundamental cellular processes such as cell morphology, adhesion and motility. This narrative review is a systematic compilation on MOESIN and its role as an emerging biomarker in OSCC.
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Affiliation(s)
- Sushma Bommanavar
- Department of Oral Pathology and Microbiology, School of Dental Sciences, KIMSDU, Karad, Maharashtra, India
| | - Sujata R Kanetkar
- Department of Pathology, Krishna Institute of Medical Sciences, Karad, Maharashtra, India
| | - Kailas D Datkhile
- Department of Molecular Biology and Genetics, KIMSDU, Karad, Maharashtra, India
| | - Ashwini L More
- Department of Molecular Biology and Genetics, KIMSDU, Karad, Maharashtra, India
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Leguay K, Decelle B, He YY, Pagniez A, Hogue M, Kobayashi H, Le Gouill C, Bouvier M, Carréno S. Development of conformational BRET biosensors that monitor ezrin, radixin and moesin activation in real time. J Cell Sci 2021; 134:237806. [PMID: 33712451 DOI: 10.1242/jcs.255307] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2020] [Accepted: 03/01/2021] [Indexed: 11/20/2022] Open
Abstract
Ezrin, radixin and moesin compose the family of ERM proteins. They link actin filaments and microtubules to the plasma membrane to control signaling and cell morphogenesis. Importantly, their activity promotes invasive properties of metastatic cells from different cancer origins. Therefore, a precise understanding of how these proteins are regulated is important for the understanding of the mechanism controlling cell shape, as well as providing new opportunities for the development of innovative cancer therapies. Here, we developed and characterized novel bioluminescence resonance energy transfer (BRET)-based conformational biosensors, compatible with high-throughput screening, that monitor individual ezrin, radixin or moesin activation in living cells. We showed that these biosensors faithfully monitor ERM activation and can be used to quantify the impact of small molecules, mutation of regulatory amino acids or depletion of upstream regulators on their activity. The use of these biosensors allowed us to characterize the activation process of ERMs that involves a pool of closed-inactive ERMs stably associated with the plasma membrane. Upon stimulation, we discovered that this pool serves as a cortical reserve that is rapidly activated before the recruitment of cytoplasmic ERMs.
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Affiliation(s)
- Kévin Leguay
- Cellular Mechanisms of Morphogenesis during Mitosis and Cell Motility lab, Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, P.O. Box 6128, Station Centre-Ville, Montréal, QC H3C 3J7, Canada
| | - Barbara Decelle
- Cellular Mechanisms of Morphogenesis during Mitosis and Cell Motility lab, Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, P.O. Box 6128, Station Centre-Ville, Montréal, QC H3C 3J7, Canada
| | - Yu Yan He
- Cellular Mechanisms of Morphogenesis during Mitosis and Cell Motility lab, Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, P.O. Box 6128, Station Centre-Ville, Montréal, QC H3C 3J7, Canada.,Molecular pharmacology lab, Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, P.O. Box 6128, Station Centre-Ville, Montréal, QC H3C 3J7, Canada
| | - Anthony Pagniez
- Cellular Mechanisms of Morphogenesis during Mitosis and Cell Motility lab, Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, P.O. Box 6128, Station Centre-Ville, Montréal, QC H3C 3J7, Canada
| | - Mireille Hogue
- Molecular pharmacology lab, Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, P.O. Box 6128, Station Centre-Ville, Montréal, QC H3C 3J7, Canada
| | - Hiroyuki Kobayashi
- Molecular pharmacology lab, Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, P.O. Box 6128, Station Centre-Ville, Montréal, QC H3C 3J7, Canada
| | - Christian Le Gouill
- Molecular pharmacology lab, Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, P.O. Box 6128, Station Centre-Ville, Montréal, QC H3C 3J7, Canada
| | - Michel Bouvier
- Molecular pharmacology lab, Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, P.O. Box 6128, Station Centre-Ville, Montréal, QC H3C 3J7, Canada.,Department of Biochemistry and Molecular Medicine, Université de Montréal, Montréal, Québec H3C 3J7, Canada
| | - Sébastien Carréno
- Cellular Mechanisms of Morphogenesis during Mitosis and Cell Motility lab, Institute for Research in Immunology and Cancer (IRIC), Université de Montréal, P.O. Box 6128, Station Centre-Ville, Montréal, QC H3C 3J7, Canada.,Department of Pathology and Cell Biology, Université de Montréal, Montréal, Québec H3C 3J7, Canada
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Conventional and Unconventional Mechanisms by which Exocytosis Proteins Oversee β-cell Function and Protection. Int J Mol Sci 2021; 22:ijms22041833. [PMID: 33673206 PMCID: PMC7918544 DOI: 10.3390/ijms22041833] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2021] [Revised: 02/02/2021] [Accepted: 02/08/2021] [Indexed: 02/06/2023] Open
Abstract
Type 2 diabetes (T2D) is one of the prominent causes of morbidity and mortality in the United States and beyond, reaching global pandemic proportions. One hallmark of T2D is dysfunctional glucose-stimulated insulin secretion from the pancreatic β-cell. Insulin is secreted via the recruitment of insulin secretory granules to the plasma membrane, where the soluble N-ethylmaleimide-sensitive factor attachment protein receptors (SNAREs) and SNARE regulators work together to dock the secretory granules and release insulin into the circulation. SNARE proteins and their regulators include the Syntaxins, SNAPs, Sec1/Munc18, VAMPs, and double C2-domain proteins. Recent studies using genomics, proteomics, and biochemical approaches have linked deficiencies of exocytosis proteins with the onset and progression of T2D. Promising results are also emerging wherein restoration or enhancement of certain exocytosis proteins to β-cells improves whole-body glucose homeostasis, enhances β-cell function, and surprisingly, protection of β-cell mass. Intriguingly, overexpression and knockout studies have revealed novel functions of certain exocytosis proteins, like Syntaxin 4, suggesting that exocytosis proteins can impact a variety of pathways, including inflammatory signaling and aging. In this review, we present the conventional and unconventional functions of β-cell exocytosis proteins in normal physiology and T2D and describe how these insights might improve clinical care for T2D.
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Zhu M, Cornwall-Scoones J, Wang P, Handford CE, Na J, Thomson M, Zernicka-Goetz M. Developmental clock and mechanism of de novo polarization of the mouse embryo. Science 2021; 370:370/6522/eabd2703. [PMID: 33303584 DOI: 10.1126/science.abd2703] [Citation(s) in RCA: 48] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Accepted: 10/14/2020] [Indexed: 12/31/2022]
Abstract
Embryo polarization is critical for mouse development; however, neither the regulatory clock nor the molecular trigger that it activates is known. Here, we show that the embryo polarization clock reflects the onset of zygotic genome activation, and we identify three factors required to trigger polarization. Advancing the timing of transcription factor AP-2 gamma (Tfap2c) and TEA domain transcription factor 4 (Tead4) expression in the presence of activated Ras homolog family member A (RhoA) induces precocious polarization as well as subsequent cell fate specification and morphogenesis. Tfap2c and Tead4 induce expression of actin regulators that control the recruitment of apical proteins on the membrane, whereas RhoA regulates their lateral mobility, allowing the emergence of the apical domain. Thus, Tfap2c, Tead4, and RhoA are regulators for the onset of polarization and cell fate segregation in the mouse.
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Affiliation(s)
- Meng Zhu
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK
| | - Jake Cornwall-Scoones
- Division of Biology and Biological Engineering, California Institute of Technology (Caltech), Pasadena, CA 91125, USA
| | - Peizhe Wang
- Centre for Stem Cell Biology and Regenerative Medicine, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Charlotte E Handford
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK.,Centre for Trophoblast Research, University of Cambridge, Cambridge CB2 3EG, UK
| | - Jie Na
- Centre for Stem Cell Biology and Regenerative Medicine, School of Medicine, Tsinghua University, Beijing 100084, China
| | - Matt Thomson
- Division of Biology and Biological Engineering, California Institute of Technology (Caltech), Pasadena, CA 91125, USA
| | - Magdalena Zernicka-Goetz
- Department of Physiology, Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK. .,Division of Biology and Biological Engineering, California Institute of Technology (Caltech), Pasadena, CA 91125, USA.,Centre for Trophoblast Research, University of Cambridge, Cambridge CB2 3EG, UK
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Wen Y, Vogt VM, Feigenson GW. PI(4,5)P 2 Clustering and Its Impact on Biological Functions. Annu Rev Biochem 2021; 90:681-707. [PMID: 33441034 DOI: 10.1146/annurev-biochem-070920-094827] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Located at the inner leaflet of the plasma membrane (PM), phosphatidyl-inositol 4,5-bisphosphate [PI(4,5)P2] composes only 1-2 mol% of total PM lipids. With its synthesis and turnover both spatially and temporally regulated, PI(4,5)P2 recruits and interacts with hundreds of cellular proteins to support a broad spectrum of cellular functions. Several factors contribute to the versatile and dynamic distribution of PI(4,5)P2 in membranes. Physiological multivalent cations such as Ca2+ and Mg2+ can bridge between PI(4,5)P2 headgroups, forming nanoscopic PI(4,5)P2-cation clusters. The distinct lipid environment surrounding PI(4,5)P2 affects the degree of PI(4,5)P2 clustering. In addition, diverse cellular proteins interacting with PI(4,5)P2 can further regulate PI(4,5)P2 lateral distribution and accessibility. This review summarizes the current understanding of PI(4,5)P2 behavior in both cells and model membranes, with emphasis on both multivalent cation- and protein-induced PI(4,5)P2 clustering. Understanding the nature of spatially separated pools of PI(4,5)P2 is fundamental to cell biology.
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Affiliation(s)
- Yi Wen
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14850, USA; , ,
| | - Volker M Vogt
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14850, USA; , ,
| | - Gerald W Feigenson
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York 14850, USA; , ,
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10
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Annunziata MC, Parisi M, Esposito G, Fabbrocini G, Ammendola R, Cattaneo F. Phosphorylation Sites in Protein Kinases and Phosphatases Regulated by Formyl Peptide Receptor 2 Signaling. Int J Mol Sci 2020; 21:ijms21113818. [PMID: 32471307 PMCID: PMC7312799 DOI: 10.3390/ijms21113818] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2020] [Revised: 05/22/2020] [Accepted: 05/25/2020] [Indexed: 12/19/2022] Open
Abstract
FPR1, FPR2, and FPR3 are members of Formyl Peptides Receptors (FPRs) family belonging to the GPCR superfamily. FPR2 is a low affinity receptor for formyl peptides and it is considered the most promiscuous member of this family. Intracellular signaling cascades triggered by FPRs include the activation of different protein kinases and phosphatase, as well as tyrosine kinase receptors transactivation. Protein kinases and phosphatases act coordinately and any impairment of their activation or regulation represents one of the most common causes of several human diseases. Several phospho-sites has been identified in protein kinases and phosphatases, whose role may be to expand the repertoire of molecular mechanisms of regulation or may be necessary for fine-tuning of switch properties. We previously performed a phospho-proteomic analysis in FPR2-stimulated cells that revealed, among other things, not yet identified phospho-sites on six protein kinases and one protein phosphatase. Herein, we discuss on the selective phosphorylation of Serine/Threonine-protein kinase N2, Serine/Threonine-protein kinase PRP4 homolog, Serine/Threonine-protein kinase MARK2, Serine/Threonine-protein kinase PAK4, Serine/Threonine-protein kinase 10, Dual specificity mitogen-activated protein kinase kinase 2, and Protein phosphatase 1 regulatory subunit 14A, triggered by FPR2 stimulation. We also describe the putative FPR2-dependent signaling cascades upstream to these specific phospho-sites.
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Affiliation(s)
- Maria Carmela Annunziata
- Department of Clinical Medicine and Surgery, School of Medicine, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (M.C.A.); (M.P.); (G.F.)
| | - Melania Parisi
- Department of Clinical Medicine and Surgery, School of Medicine, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (M.C.A.); (M.P.); (G.F.)
| | - Gabriella Esposito
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (G.E.); (R.A.)
| | - Gabriella Fabbrocini
- Department of Clinical Medicine and Surgery, School of Medicine, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (M.C.A.); (M.P.); (G.F.)
| | - Rosario Ammendola
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (G.E.); (R.A.)
| | - Fabio Cattaneo
- Department of Molecular Medicine and Medical Biotechnology, School of Medicine, University of Naples Federico II, Via S. Pansini 5, 80131 Naples, Italy; (G.E.); (R.A.)
- Correspondence: ; Fax: +39-081-7464-359
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11
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Xie YH, Li LY, He JZ, Xu XE, Liao LD, Zhang Q, Xie JJ, Xu LY, Li EM. Heat shock protein family B member 1 facilitates ezrin activation to control cell migration in esophageal squamous cell carcinoma. Int J Biochem Cell Biol 2019; 112:79-87. [PMID: 31082616 DOI: 10.1016/j.biocel.2019.05.005] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2019] [Revised: 05/06/2019] [Accepted: 05/08/2019] [Indexed: 02/05/2023]
Abstract
Ezrin plays an important role in the development and progression of human esophageal squamous cell carcinoma (ESCC), providing a link between the cortical actin cytoskeleton and the plasma membrane to govern membrane structure and protrusions. However, the mechanism by which ezrin is activated still remains unknown in ESCC. Here, we identify a novel interaction between ezrin and heat shock protein family B (small) member 1 (HSPB1) in ESCC cells by mass spectroscopy and co-immunoprecipitation. HSPB1 only interacts with inactive ezrin and binds to the α-helical coiled coil region of ezrin. Knockdown of HSPB1 resulted to the decline of phosphorylation at ezrin Thr567, markedly suppressing the ability of ezrin to bind to the actin cytoskeleton and migration of ESCC cells. Furthermore, neither the constitutively active phosphomimetic ezrin T567D, nor inactivated ezrin T567A could restore cell migration following HSPB1 knockdown. Low HSPB1 expression was associated with favorable overall survival of ESCC patients. Taken together, HSPB1, as an important partner, participates in the activation of ezrin and merits further evaluation as a novel therapeutic target against human ESCC.
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Affiliation(s)
- Ying-Hua Xie
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, PR China; Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, Guangdong, PR China
| | - Li-Yan Li
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, PR China; Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, Guangdong, PR China
| | - Jian-Zhong He
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, PR China; Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, Guangdong, PR China
| | - Xiu-E Xu
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, PR China; Institute of Oncologic Pathology, Shantou University Medical College, Shantou 515041, Guangdong, PR China
| | - Lian-Di Liao
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, PR China; Institute of Oncologic Pathology, Shantou University Medical College, Shantou 515041, Guangdong, PR China
| | - Qiang Zhang
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, PR China; Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, Guangdong, PR China
| | - Jian-Jun Xie
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, PR China; Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, Guangdong, PR China
| | - Li-Yan Xu
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, PR China; Institute of Oncologic Pathology, Shantou University Medical College, Shantou 515041, Guangdong, PR China.
| | - En-Min Li
- The Key Laboratory of Molecular Biology for High Cancer Incidence Coastal Chaoshan Area, Shantou University Medical College, Shantou 515041, Guangdong, PR China; Department of Biochemistry and Molecular Biology, Shantou University Medical College, Shantou 515041, Guangdong, PR China.
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12
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Molecular Dynamics of the Association of L-Selectin and FERM Regulated by PIP2. Biophys J 2019; 114:1858-1868. [PMID: 29694864 DOI: 10.1016/j.bpj.2018.02.034] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/27/2017] [Revised: 02/05/2018] [Accepted: 02/20/2018] [Indexed: 11/22/2022] Open
Abstract
Phosphatidylinositol 4,5-bisphosphate (PIP2) acts as a signaling lipid, mediating membrane trafficking and recruitment of proteins to membranes. A key example is the PIP2-dependent regulation of the adhesion of L-selectin to the cytoskeleton adaptors of the N-terminal subdomain of ezrin-radixin-moesin (FERM). The molecular details of the mediating behavior of multivalent anionic PIP2 lipids in this process, however, remain unclear. Here, we use coarse-grained molecular dynamics simulation to explore the mechanistic details of PIP2 in the transformation, translocation, and association of the FERM/L-selectin complex. We compare membranes of different compositions and find that anionic phospholipids are necessary for both FERM and the cytoplasmic domain of L-selectin to absorb on the membrane surface. The subsequent formation of the FERM/L-selectin complex is strongly favored by the presence of PIP2, which clusters around both proteins and triggers a conformational transition in the cytoplasmic domain of L-selectin. We are able to quantify the effect of PIP2 on the association free energy of the complex by means of a potential of mean force. We conclude that PIP2 behaves as an adhesive agent to enhance the stability of the FERM/L-selectin complex and identify key residues involved. The molecular information revealed in this study highlights the specific role of membrane lipids such as PIP2 in protein translocation and potential signaling.
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13
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Ivetic A, Hoskins Green HL, Hart SJ. L-selectin: A Major Regulator of Leukocyte Adhesion, Migration and Signaling. Front Immunol 2019; 10:1068. [PMID: 31139190 PMCID: PMC6527602 DOI: 10.3389/fimmu.2019.01068] [Citation(s) in RCA: 250] [Impact Index Per Article: 50.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2019] [Accepted: 04/26/2019] [Indexed: 12/12/2022] Open
Abstract
L-selectin (CD62L) is a type-I transmembrane glycoprotein and cell adhesion molecule that is expressed on most circulating leukocytes. Since its identification in 1983, L-selectin has been extensively characterized as a tethering/rolling receptor. There is now mounting evidence in the literature to suggest that L-selectin plays a role in regulating monocyte protrusion during transendothelial migration (TEM). The N-terminal calcium-dependent (C-type) lectin domain of L-selectin interacts with numerous glycans, including sialyl Lewis X (sLex) for tethering/rolling and proteoglycans for TEM. Although the signals downstream of L-selectin-dependent adhesion are poorly understood, they will invariably involve the short 17 amino acid cytoplasmic tail. In this review we will detail the expression of L-selectin in different immune cell subsets, and its influence on cell behavior. We will list some of the diverse glycans known to support L-selectin-dependent adhesion, within luminal and abluminal regions of the vessel wall. We will describe how each domain within L-selectin contributes to adhesion, migration and signal transduction. A significant focus on the L-selectin cytoplasmic tail and its proposed contribution to signaling via the ezrin-radixin-moesin (ERM) family of proteins will be outlined. Finally, we will discuss how ectodomain shedding of L-selectin during monocyte TEM is essential for the establishment of front-back cell polarity, bestowing emigrated cells the capacity to chemotax toward sites of damage.
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Affiliation(s)
- Aleksandar Ivetic
- King's College London, School of Cardiovascular Medicine and Sciences, BHF Center of Research Excellence, London, United Kingdom
| | - Hannah Louise Hoskins Green
- King's College London, School of Cardiovascular Medicine and Sciences, BHF Center of Research Excellence, London, United Kingdom
| | - Samuel James Hart
- King's College London, School of Cardiovascular Medicine and Sciences, BHF Center of Research Excellence, London, United Kingdom
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14
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Michie KA, Bermeister A, Robertson NO, Goodchild SC, Curmi PMG. Two Sides of the Coin: Ezrin/Radixin/Moesin and Merlin Control Membrane Structure and Contact Inhibition. Int J Mol Sci 2019; 20:ijms20081996. [PMID: 31018575 PMCID: PMC6515277 DOI: 10.3390/ijms20081996] [Citation(s) in RCA: 42] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2019] [Revised: 04/16/2019] [Accepted: 04/19/2019] [Indexed: 12/21/2022] Open
Abstract
The merlin-ERM (ezrin, radixin, moesin) family of proteins plays a central role in linking the cellular membranes to the cortical actin cytoskeleton. Merlin regulates contact inhibition and is an integral part of cell–cell junctions, while ERM proteins, ezrin, radixin and moesin, assist in the formation and maintenance of specialized plasma membrane structures and membrane vesicle structures. These two protein families share a common evolutionary history, having arisen and separated via gene duplication near the origin of metazoa. During approximately 0.5 billion years of evolution, the merlin and ERM family proteins have maintained both sequence and structural conservation to an extraordinary level. Comparing crystal structures of merlin-ERM proteins and their complexes, a picture emerges of the merlin-ERM proteins acting as switchable interaction hubs, assembling protein complexes on cellular membranes and linking them to the actin cytoskeleton. Given the high level of structural conservation between the merlin and ERM family proteins we speculate that they may function together.
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Affiliation(s)
- Katharine A Michie
- School of Physics, University of New South Wales, Sydney 2052, Australia.
| | - Adam Bermeister
- School of Physics, University of New South Wales, Sydney 2052, Australia.
| | - Neil O Robertson
- School of Physics, University of New South Wales, Sydney 2052, Australia.
| | - Sophia C Goodchild
- Department of Molecular Sciences, Macquarie University, Sydney 2109, Australia.
| | - Paul M G Curmi
- School of Physics, University of New South Wales, Sydney 2052, Australia.
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15
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Li J, Yin W, Jing Y, Kang D, Yang L, Cheng J, Yu Z, Peng Z, Li X, Wen Y, Sun X, Ren B, Liu C. The Coordination Between B Cell Receptor Signaling and the Actin Cytoskeleton During B Cell Activation. Front Immunol 2019; 9:3096. [PMID: 30687315 PMCID: PMC6333714 DOI: 10.3389/fimmu.2018.03096] [Citation(s) in RCA: 46] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2018] [Accepted: 12/13/2018] [Indexed: 01/27/2023] Open
Abstract
B-cell activation plays a crucial part in the immune system and is initiated via interaction between the B cell receptor (BCR) and specific antigens. In recent years with the help of modern imaging techniques, it was found that the cortical actin cytoskeleton changes dramatically during B-cell activation. In this review, we discuss how actin-cytoskeleton reorganization regulates BCR signaling in different stages of B-cell activation, specifically when stimulated by antigens, and also how this reorganization is mediated by BCR signaling molecules. Abnormal BCR signaling is associated with the progression of lymphoma and immunological diseases including autoimmune disorders, and recent studies have proved that impaired actin cytoskeleton can devastate the normal activation of B cells. Therefore, to figure out the coordination between the actin cytoskeleton and BCR signaling may reveal an underlying mechanism of B-cell activation, which has potential for new treatments for B-cell associated diseases.
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Affiliation(s)
- Jingwen Li
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Wei Yin
- Wuhan Children's Hospital, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yukai Jing
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Danqing Kang
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Lu Yang
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Jiali Cheng
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Ze Yu
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Zican Peng
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xingbo Li
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Yue Wen
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Xizi Sun
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
| | - Boxu Ren
- Department of Immunology, School of Medicine, Yangtze University, Jingzhou, China
- Clinical Molecular Immunology Center, School of Medicine, Yangtze University, Jingzhou, China
| | - Chaohong Liu
- Department of Microbiology, School of Basic Medicine, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, China
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16
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Ahmad R. Steroidal glycoalkaloids from Solanum nigrum target cytoskeletal proteins: an in silico analysis. PeerJ 2019; 7:e6012. [PMID: 30627484 PMCID: PMC6321755 DOI: 10.7717/peerj.6012] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 10/26/2018] [Indexed: 12/03/2022] Open
Abstract
Background Solanum nigrum (black nightshade; S. nigrum), a member of family Solanaceae, has been endowed with a heterogeneous array of secondary metabolites of which the steroidal glycoalkaloids (SGAs) and steroidal saponins (SS) have vast potential to serve as anticancer agents. Since there has been much controversy regarding safety of use of glycoalkaloids as anticancer agents, this area has remained more or less unexplored. Cytoskeletal proteins like actin play an important role in maintaining cell shape, synchronizing cell division, cell motility, etc. and along with their accessory proteins may also serve as important therapeutic targets for potential anticancer candidates. In the present study, glycoalkaloids and saponins from S. nigrum were screened for their interaction and binding affinity to cytoskeletal proteins, using molecular docking. Methods Bioactivity score and Prediction of Activity Spectra for Substances (PASS) analysis were performed using softwares Molinspiration and Osiris Data Explorer respectively, to assess the feasibility of selected phytoconstituents as potential drug candidates. The results were compared with two standard reference drugs doxorubicin hydrochloride (anticancer) and tetracycline (antibiotic). Multivariate data obtained were analyzed using principal component analysis (PCA). Results Docking analysis revealed that the binding affinities of the phytoconstituents towards the target cytoskeletal proteins decreased in the order coronin>villin>ezrin>vimentin>gelsolin>thymosin>cofilin. Glycoalkaloid solasonine displayed the greatest binding affinity towards the target proteins followed by alpha-solanine whereas amongst the saponins, nigrumnin-I showed maximum binding affinity. PASS Analysis of the selected phytoconstituents revealed 1 to 3 violations of Lipinski’s parameters indicating the need for modification of their structure-activity relationship (SAR) for improvement of their bioactivity and bioavailability. Glycoalkaloids and saponins all had bioactivity scores between −5.0 and 0.0 with respect to various receptor proteins and target enzymes. Solanidine, solasodine and solamargine had positive values of druglikeness which indicated that these compounds have the potential for development into future anticancer drugs. Toxicity potential evaluation revealed that glycoalkaloids and saponins had no toxicity, tumorigenicity or irritant effect(s). SAR analysis revealed that the number, type and location of sugar or the substitution of hydroxyl group on alkaloid backbone had an effect on the activity and that the presence of α-L-rhamnopyranose sugar at C-2 was critical for a compound to exhibit anticancer activity. Conclusion The present study revealed some cytoskeletal target(s) for S. nigrum phytoconstituents by docking analysis that have not been previously reported and thus warrant further investigations both in vitro and in vivo.
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Affiliation(s)
- Rumana Ahmad
- Department of Biochemisty, Era's Lucknow Medical College and Hospital, Era University, Lucknow, Uttar Pradesh, India
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17
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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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18
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Mu L, Tu Z, Miao L, Ruan H, Kang N, Hei Y, Chen J, Wei W, Gong F, Wang B, Du Y, Ma G, Amerein MW, Xia T, Shi Y. A phosphatidylinositol 4,5-bisphosphate redistribution-based sensing mechanism initiates a phagocytosis programing. Nat Commun 2018; 9:4259. [PMID: 30323235 PMCID: PMC6189171 DOI: 10.1038/s41467-018-06744-7] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2018] [Accepted: 09/20/2018] [Indexed: 12/30/2022] Open
Abstract
Phagocytosis is one of the earliest cellular functions, developing approximately 2 billion years ago. Although FcR-based phagocytic signaling is well-studied, how it originated from ancient phagocytosis is unknown. Lipid redistribution upregulates a phagocytic program recapitulating FcR-based phagocytosis with complete dependence on Src family kinases, Syk, and phosphoinositide 3-kinases (PI3K). Here we show that in phagocytes, an atypical ITAM sequence in the ancient membrane anchor protein Moesin transduces signal without receptor activation. Plasma membrane deformation created by solid structure binding generates phosphatidylinositol 4,5-bisphosphate (PIP2) accumulation at the contact site, which binds the Moesin FERM domain and relocalizes Syk to the membrane via the ITAM motif. Phylogenic analysis traces this signaling using PI3K and Syk to 0.8 billion years ago, earlier than immune receptor signaling. The proposed general model of solid structure phagocytosis implies a preexisting lipid redistribution-based activation platform collecting intracellular signaling components for the emergence of immune receptors.
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Affiliation(s)
- Libing Mu
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Institute for Immunology and Department of Basic Medical Sciences, Beijing Key Lab for Immunological Research on Chronic Diseases, School of Medicine; Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Zhongyuan Tu
- Department of Microbiology, Immunology & Infectious Diseases and Snyder Institute, University of Calgary, Calgary, T2N 4N1, AB, Canada
| | - Lin Miao
- Institute for Immunology and Department of Basic Medical Sciences, Beijing Key Lab for Immunological Research on Chronic Diseases, School of Medicine; Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China
- School of Life Sciences, Peking-Tsinghua Center for Life Sciences, Peking University, Beijing, 100871, China
| | - Hefei Ruan
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Institute for Immunology and Department of Basic Medical Sciences, Beijing Key Lab for Immunological Research on Chronic Diseases, School of Medicine; Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Ning Kang
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Institute for Immunology and Department of Basic Medical Sciences, Beijing Key Lab for Immunological Research on Chronic Diseases, School of Medicine; Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Yongzhen Hei
- Institute for Immunology and Department of Basic Medical Sciences, Beijing Key Lab for Immunological Research on Chronic Diseases, School of Medicine; Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Jiahuan Chen
- School of Life Sciences, Tsinghua University, Beijing, 100084, China
- Institute for Immunology and Department of Basic Medical Sciences, Beijing Key Lab for Immunological Research on Chronic Diseases, School of Medicine; Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China
| | - Wei Wei
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
| | - Fangling Gong
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
| | - Bingjie Wang
- Department of Biomedical Engineering, School of Medicine, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Tsinghua University, Beijing, 100084, China
| | - Yanan Du
- Department of Biomedical Engineering, School of Medicine, Collaborative Innovation Center for Diagnosis and Treatment of Infectious Diseases, Tsinghua University, Beijing, 100084, China
| | - Guanghui Ma
- State Key Laboratory of Biochemical Engineering, Institute of Process Engineering, Chinese Academy of Sciences, Beijing, 100190, China
| | - Matthias W Amerein
- Department of Cell Biology and Anatomy, University of Calgary, Calgary, T2N 4N1, AB, Canada
- Snyder Institute of Chronic Diseases, University of Calgary, Calgary, T2N 4N1, AB, Canada
| | - Tie Xia
- School of Life Sciences, Tsinghua University, Beijing, 100084, China.
- Institute for Immunology and Department of Basic Medical Sciences, Beijing Key Lab for Immunological Research on Chronic Diseases, School of Medicine; Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China.
| | - Yan Shi
- School of Life Sciences, Tsinghua University, Beijing, 100084, China.
- Institute for Immunology and Department of Basic Medical Sciences, Beijing Key Lab for Immunological Research on Chronic Diseases, School of Medicine; Tsinghua-Peking Center for Life Sciences, Tsinghua University, Beijing, 100084, China.
- Department of Microbiology, Immunology & Infectious Diseases and Snyder Institute, University of Calgary, Calgary, T2N 4N1, AB, Canada.
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19
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Xu W, Jin M, Huang W, Wang H, Hu R, Li J, Cao Y. Apical PtdIns(4,5)P
2
is required for ciliogenesis and suppression of polycystic kidney disease. FASEB J 2018; 33:2848-2857. [DOI: 10.1096/fj.201800385rrr] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Affiliation(s)
- Wenyan Xu
- Clinical and Translational Research Center of ShanghaiFirst Maternity and Infant HospitalSchool of Life Sciences and TechnologyTongji UniversityShanghaiChina
| | - Miaomiao Jin
- Clinical and Translational Research Center of ShanghaiFirst Maternity and Infant HospitalSchool of Life Sciences and TechnologyTongji UniversityShanghaiChina
| | - Weilai Huang
- Clinical and Translational Research Center of ShanghaiFirst Maternity and Infant HospitalSchool of Life Sciences and TechnologyTongji UniversityShanghaiChina
| | - Hong Wang
- Clinical and Translational Research Center of ShanghaiFirst Maternity and Infant HospitalSchool of Life Sciences and TechnologyTongji UniversityShanghaiChina
| | - Ruikun Hu
- Clinical and Translational Research Center of ShanghaiFirst Maternity and Infant HospitalSchool of Life Sciences and TechnologyTongji UniversityShanghaiChina
| | - Jingyu Li
- Clinical and Translational Research Center of ShanghaiFirst Maternity and Infant HospitalSchool of Life Sciences and TechnologyTongji UniversityShanghaiChina
| | - Ying Cao
- Clinical and Translational Research Center of ShanghaiFirst Maternity and Infant HospitalSchool of Life Sciences and TechnologyTongji UniversityShanghaiChina
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20
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Janmey PA, Bucki R, Radhakrishnan R. Regulation of actin assembly by PI(4,5)P2 and other inositol phospholipids: An update on possible mechanisms. Biochem Biophys Res Commun 2018; 506:307-314. [PMID: 30139519 DOI: 10.1016/j.bbrc.2018.07.155] [Citation(s) in RCA: 72] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 06/21/2018] [Accepted: 07/31/2018] [Indexed: 01/15/2023]
Abstract
Actin cytoskeleton dynamics depend on a tight regulation of actin filament formation from an intracellular pool of monomers, followed by their linkage to each other or to cell membranes, followed by their depolymerization into a fresh pool of actin monomers. The ubiquitous requirement for continuous actin remodeling that is necessary for many cellular functions is orchestrated in large part by actin binding proteins whose affinity for actin is altered by inositol phospholipids, most prominently PI(4,5)P2 (phosphatidylinositol 4,5-bisphosphate). The kinetics of PI(4,5)P2 synthesis and hydrolysis, its lateral distribution within the lipid bilayer, and coincident detection of PI(4,5)P2 and another signal, all play a role in determining when and where a particular PI(4,5)P2-regulated protein is inactivated or activated to exert its effect on the actin cytoskeleton. This review summarizes a range of models that have been developed to explain how PI(4,5)P2 might function in the complex chemical and structural environment of the cell based on a combination of experiment and computational studies.
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Affiliation(s)
- Paul A Janmey
- Department of Physiology, University of Pennsylvania, Philadelphia, PA, USA; Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, USA.
| | - Robert Bucki
- Institute for Medicine and Engineering, University of Pennsylvania, Philadelphia, PA, USA; Department of Microbiological and Nanobiomedical Engineering, Medical University of Bialystok, Bialystok, Poland
| | - Ravi Radhakrishnan
- Department of Bioengineering, University of Pennsylvania, Philadelphia, PA, USA
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21
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Rey-Gallardo A, Tomlins H, Joachim J, Rahman I, Kitscha P, Frudd K, Parsons M, Ivetic A. Sequential binding of ezrin and moesin to L-selectin regulates monocyte protrusive behaviour during transendothelial migration. J Cell Sci 2018; 131:jcs.215541. [PMID: 29777033 PMCID: PMC6051341 DOI: 10.1242/jcs.215541] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2018] [Accepted: 05/02/2018] [Indexed: 01/21/2023] Open
Abstract
Leukocyte transendothelial migration (TEM) is absolutely fundamental to the inflammatory response, and involves initial pseudopod protrusion and subsequent polarised migration across inflamed endothelium. Ezrin/radixin/moesin (ERM) proteins are expressed in leukocytes and mediate cell shape changes and polarity. The spatio-temporal organisation of ERM proteins with their targets, and their individual contribution to protrusion during TEM, has never been explored. Here, we show that blocking binding of moesin to phosphatidylinositol 4,5-bisphosphate (PIP2) reduces its C-terminal phosphorylation during monocyte TEM, and that on–off cycling of ERM activity is essential for pseudopod protrusion into the subendothelial space. Reactivation of ERM proteins within transmigrated pseudopods re-establishes their binding to targets, such as L-selectin. Knockdown of ezrin, but not moesin, severely impaired the recruitment of monocytes to activated endothelial monolayers under flow, suggesting that this protein plays a unique role in the early recruitment process. Ezrin binds preferentially to L-selectin in resting cells and during early TEM. The moesin–L-selectin interaction increases within transmigrated pseudopods as TEM proceeds, facilitating localised L-selectin ectodomain shedding. In contrast, a non-cleavable L-selectin mutant binds selectively to ezrin, driving multi-pseudopodial extensions. Taken together, these results show that ezrin and moesin play mutually exclusive roles in modulating L-selectin signalling and shedding to control protrusion dynamics and polarity during monocyte TEM. Summary: Ezrin and moesin co-ordinate binding to L-selectin in monocytes to, respectively, regulate pseudopod protrusion and ectodomain shedding during transendothelial migration.
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Affiliation(s)
- Angela Rey-Gallardo
- School of Cardiovascular Medicine and Sciences, James Black Centre, BHF Centre of Research Excellence, 125 Coldharbour Lane, King's College London, London SE5 9NU, UK
| | - Hannah Tomlins
- School of Cardiovascular Medicine and Sciences, James Black Centre, BHF Centre of Research Excellence, 125 Coldharbour Lane, King's College London, London SE5 9NU, UK
| | - Justin Joachim
- School of Cardiovascular Medicine and Sciences, James Black Centre, BHF Centre of Research Excellence, 125 Coldharbour Lane, King's College London, London SE5 9NU, UK
| | - Izajur Rahman
- School of Cardiovascular Medicine and Sciences, James Black Centre, BHF Centre of Research Excellence, 125 Coldharbour Lane, King's College London, London SE5 9NU, UK
| | - Phoebe Kitscha
- School of Cardiovascular Medicine and Sciences, James Black Centre, BHF Centre of Research Excellence, 125 Coldharbour Lane, King's College London, London SE5 9NU, UK
| | - Karen Frudd
- School of Cardiovascular Medicine and Sciences, James Black Centre, BHF Centre of Research Excellence, 125 Coldharbour Lane, King's College London, London SE5 9NU, UK
| | - Maddy Parsons
- School of Basic & Medical Biosciences, Randall Division of Cell & Molecular Biophysics, New Hunt's House, London, SE1 1UL, UK
| | - Aleksandar Ivetic
- School of Cardiovascular Medicine and Sciences, James Black Centre, BHF Centre of Research Excellence, 125 Coldharbour Lane, King's College London, London SE5 9NU, UK
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22
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Kschonsak YT, Hoffmann I. Activated Ezrin controls MISP levels to ensure correct NuMA polarization and spindle orientation. J Cell Sci 2018; 131:jcs.214544. [DOI: 10.1242/jcs.214544] [Citation(s) in RCA: 20] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2017] [Accepted: 04/11/2018] [Indexed: 12/11/2022] Open
Abstract
Correct spindle orientation is achieved through signaling pathways that provide a molecular link between the cell cortex and spindle microtubules in an F-actin dependent manner. A conserved cortical protein complex, composed of LGN, NuMA, dynein-dynactin, plays a key role in establishing proper spindle orientation. It has also been shown that the actin-binding protein MISP and the ERM family, that are activated by LOK/SLK in mitosis, regulate spindle orientation. Here, we report that MISP functions between the ERM family member Ezrin and NuMA to allow optimal spindle positioning. We show that MISP directly interacts with Ezrin and that SLK/LOK-activated Ezrin ensures appropriate cortical MISP levels in mitosis by competing with MISP for actin-binding sites at the cell cortex. Furthermore, we found that regulation of proper cortical MISP levels by preventing its excessive accumulation is essential for crescent-like polarized NuMA localization at the cortex and as a consequence for highly dynamic astral microtubules. Our results uncover how appropriate MISP levels at the cortex are required for proper NuMA polarization and therefore an optimal placement of the mitotic spindle within the cell.
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Affiliation(s)
- Yvonne T. Kschonsak
- Cell Cycle Control and Carcinogenesis, F045, German Cancer Research Center, DKFZ, 69120 Heidelberg, Germany
- University of Heidelberg, F045, German Cancer Research Center, DKFZ, 69120 Heidelberg, Germany
| | - Ingrid Hoffmann
- Cell Cycle Control and Carcinogenesis, F045, German Cancer Research Center, DKFZ, 69120 Heidelberg, Germany
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23
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Muallem S, Chung WY, Jha A, Ahuja M. Lipids at membrane contact sites: cell signaling and ion transport. EMBO Rep 2017; 18:1893-1904. [PMID: 29030479 DOI: 10.15252/embr.201744331] [Citation(s) in RCA: 62] [Impact Index Per Article: 8.9] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 06/10/2017] [Accepted: 09/21/2017] [Indexed: 12/14/2022] Open
Abstract
Communication between organelles is essential to coordinate cellular functions and the cell's response to physiological and pathological stimuli. Organellar communication occurs at membrane contact sites (MCSs), where the endoplasmic reticulum (ER) membrane is tethered to cellular organelle membranes by specific tether proteins and where lipid transfer proteins and cell signaling proteins are located. MCSs have many cellular functions and are the sites of lipid and ion transfer between organelles and generation of second messengers. This review discusses several aspects of MCSs in the context of lipid transfer, formation of lipid domains, generation of Ca2+ and cAMP second messengers, and regulation of ion transporters by lipids.
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Affiliation(s)
- Shmuel Muallem
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Woo Young Chung
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Archana Jha
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
| | - Malini Ahuja
- Epithelial Signaling and Transport Section, National Institute of Dental and Craniofacial Research, Bethesda, MD, USA
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24
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Li W, Jin WW, Tsuji K, Chen Y, Nomura N, Su L, Yui N, Arthur J, Cotecchia S, Paunescu TG, Brown D, Lu HAJ. Ezrin directly interacts with AQP2 and promotes its endocytosis. J Cell Sci 2017; 130:2914-2925. [PMID: 28754689 DOI: 10.1242/jcs.204842] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2017] [Accepted: 07/21/2017] [Indexed: 11/20/2022] Open
Abstract
The water channel aquaporin-2 (AQP2) is a major regulator of water homeostasis in response to vasopressin (VP). Dynamic trafficking of AQP2 relies on its close interaction with trafficking machinery proteins and the actin cytoskeleton. Here, we report the identification of ezrin, an actin-binding protein from the ezrin/radixin/moesin (ERM) family as an AQP2-interacting protein. Ezrin was first detected in a co-immunoprecipitation (co-IP) complex using an anti-AQP2 antibody in a proteomic analysis. Immunofluorescence staining revealed the co-expression of ezrin and AQP2 in collecting duct principal cells, and VP treatment caused redistribution of both proteins to the apical membrane. The ezrin-AQP2 interaction was confirmed by co-IP experiments with an anti-ezrin antibody, and by pulldown assays using purified full-length and FERM domain-containing recombinant ezrin. By using purified recombinant proteins, we showed that ezrin directly interacts with AQP2 C-terminus through its N-terminal FERM domain. Knocking down ezrin expression with shRNA resulted in increased membrane accumulation of AQP2 and reduced AQP2 endocytosis. Therefore, through direct interaction with AQP2, ezrin facilitates AQP2 endocytosis, thus linking the dynamic actin cytoskeleton network with AQP2 trafficking.
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Affiliation(s)
- Wei Li
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital, and Harvard Medical School, Boston, MA 02114, USA
| | - William W Jin
- Washington University in St. Louis, College of Arts and Sciences, St Louis, MO 63130, USA
| | - Kenji Tsuji
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital, and Harvard Medical School, Boston, MA 02114, USA
| | - Ying Chen
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital, and Harvard Medical School, Boston, MA 02114, USA
| | - Naohiro Nomura
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital, and Harvard Medical School, Boston, MA 02114, USA
| | - Limin Su
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital, and Harvard Medical School, Boston, MA 02114, USA.,Department of Pharmacology, School of Basic Medical Sciences, Peking University, Beijing 100191, China
| | - Naofumi Yui
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital, and Harvard Medical School, Boston, MA 02114, USA
| | - Julian Arthur
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital, and Harvard Medical School, Boston, MA 02114, USA
| | - Susanna Cotecchia
- Department of Pharmacology and Toxicology, University of Lausanne, Lausanne 1005, Switzerland
| | - Teodor G Paunescu
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital, and Harvard Medical School, Boston, MA 02114, USA
| | - Dennis Brown
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital, and Harvard Medical School, Boston, MA 02114, USA
| | - Hua A J Lu
- Center for Systems Biology, Program in Membrane Biology and Division of Nephrology, Massachusetts General Hospital, and Harvard Medical School, Boston, MA 02114, USA
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25
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Kawaguchi K, Yoshida S, Hatano R, Asano S. Pathophysiological Roles of Ezrin/Radixin/Moesin Proteins. Biol Pharm Bull 2017; 40:381-390. [PMID: 28381792 DOI: 10.1248/bpb.b16-01011] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Ezrin/radixin/moesin (ERM) proteins function as general cross-linkers between plasma membrane proteins and the actin cytoskeleton and are involved in the functional expression of membrane proteins on the cell surface. They also integrate Rho guanosine 5'-triphosphatase (GTPase) signaling to regulate cytoskeletal organization by sequestering Rho-related proteins. They act as protein kinase A (PKA)-anchoring proteins and sequester PKA close to its target proteins for their effective phosphorylation and functional regulation. Therefore, ERM proteins seem to play important roles in the membrane transport of electrolytes by ion channels and transporters. In this review, we focus on the pathophysiological roles of ERM proteins in in vivo studies and introduce the phenotypes of their knockout and knockdown mice.
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Affiliation(s)
- Kotoku Kawaguchi
- Department of Molecular Physiology, College of Pharmaceutical Sciences, Ritsumeikan University
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26
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The lipid 5-phoshatase SHIP2 controls renal brush border ultrastructure and function by regulating the activation of ERM proteins. Kidney Int 2017; 92:125-139. [DOI: 10.1016/j.kint.2017.01.008] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2016] [Revised: 01/01/2017] [Accepted: 01/06/2017] [Indexed: 02/02/2023]
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27
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Shabardina V, Kramer C, Gerdes B, Braunger J, Cordes A, Schäfer J, Mey I, Grill D, Gerke V, Steinem C. Mode of Ezrin-Membrane Interaction as a Function of PIP2 Binding and Pseudophosphorylation. Biophys J 2017; 110:2710-2719. [PMID: 27332129 DOI: 10.1016/j.bpj.2016.05.009] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2015] [Revised: 04/14/2016] [Accepted: 05/05/2016] [Indexed: 12/28/2022] Open
Abstract
Ezrin, a protein of the ezrin, radixin, moesin (ERM) family, provides a regulated linkage between the plasma membrane and the cytoskeleton. The hallmark of this linkage is the activation of ezrin by phosphatidylinositol-4,5-bisphosphate (PIP2) binding and a threonine phosphorylation at position 567. To analyze the influence of these activating factors on the organization of ezrin on lipid membranes and the proposed concomitant oligomer-monomer transition, we made use of supported lipid bilayers in conjunction with atomic force microscopy and fluorescence microscopy. Bilayers doped with either PIP2 as the natural receptor lipid of ezrin or a Ni-nitrilotriacetic acid-equipped lipid to bind the proteins via their His6-tags to the lipid membrane were used to bind two different ezrin variants: ezrin wild-type and ezrin T567D mimicking the phosphorylated state. Using a combination of reflectometric interference spectroscopy, atomic force microscopy, and Förster resonance energy transfer experiments, we show that only the ezrin T567D mutant, upon binding to PIP2-containing bilayers, undergoes a remarkable conformational change, which we attribute to an opening of the conformation resulting in monomeric protein on the lipid bilayer.
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Affiliation(s)
- Victoria Shabardina
- Institute of Medical Biochemistry and Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany
| | - Corinna Kramer
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany
| | - Benjamin Gerdes
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany
| | - Julia Braunger
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany
| | - Andrea Cordes
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany
| | - Jonas Schäfer
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany
| | - Ingo Mey
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany
| | - David Grill
- Institute of Medical Biochemistry and Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany
| | - Volker Gerke
- Institute of Medical Biochemistry and Center for Molecular Biology of Inflammation, University of Münster, Münster, Germany.
| | - Claudia Steinem
- Institute of Organic and Biomolecular Chemistry, University of Göttingen, Göttingen, Germany; Göttingen Center for Molecular Biosciences, Göttingen, Germany.
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28
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Abstract
Altered phosphorylation status of the C-terminal Thr residues of Ezrin/Radixin/Moesin (ERM) is often linked to cell shape change. To determine the role of phophorylated ERM, we modified phosphorylation status of ERM and investigated changes in cell adhesion and morphology. Treatment with Calyculin-A (Cal-A), a protein phosphatase inhibitor, dramatically augmented phosphorylated ERM (phospho-ERM). Cal-A-treatment or expression of phospho-mimetic Moesin mutant (Moesin-TD) induced cell rounding in adherent cells. Moreover, reattachment of detached cells to substrate was inhibited by either treatment. Phospho-ERM, Moesin-TD and actin cytoskeleton were observed at the plasma membrane of such round cells. Augmented cell surface rigidity was also observed in both cases. Meanwhile, non-adherent KG-1 cells were rather rich in phospho-ERM. Treatment with Staurosporine, a protein kinase inhibitor that dephosphorylates phospho-ERM, up-regulated the integrin-dependent adhesion of KG-1 cells to substrate. These findings strongly suggest the followings: (1) Phospho-ERM inhibit cell adhesion, and therefore, dephosphorylation of ERM proteins is essential for cell adhesion. (2) Phospho-ERM induce formation and/or maintenance of spherical cell shape. (3) ERM are constitutively both phosphorylated and dephosphorylated in cultured adherent and non-adherent cells.
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Affiliation(s)
- Kouichi Tachibana
- a Biomedical Research Institut; National Institute of Advanced Industrial Science and Technology (AIST) ; Tsukuba , Ibaraki , Japan
| | - Seyed Mohammad Ali Haghparast
- b Department of Mechanical Science and Bioengineering ; Graduate School of Engineering Science; Osaka University ; Toyonaka , Osaka , Japan
| | - Jun Miyake
- b Department of Mechanical Science and Bioengineering ; Graduate School of Engineering Science; Osaka University ; Toyonaka , Osaka , Japan
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29
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Structural characterization suggests models for monomeric and dimeric forms of full-length ezrin. Biochem J 2016; 473:2763-82. [DOI: 10.1042/bcj20160541] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 06/29/2016] [Indexed: 12/12/2022]
Abstract
Ezrin is a member of the ERM (ezrin–radixin–moesin) family of proteins that have been conserved through metazoan evolution. These proteins have dormant and active forms, where the latter links the actin cytoskeleton to membranes. ERM proteins have three domains: an N-terminal FERM [band Four-point-one (4.1) ERM] domain comprising three subdomains (F1, F2, and F3); a helical domain; and a C-terminal actin-binding domain. In the dormant form, FERM and C-terminal domains form a stable complex. We have determined crystal structures of the active FERM domain and the dormant FERM:C-terminal domain complex of human ezrin. We observe a bistable array of phenylalanine residues in the core of subdomain F3 that is mobile in the active form and locked in the dormant form. As subdomain F3 is pivotal in binding membrane proteins and phospholipids, these transitions may facilitate activation and signaling. Full-length ezrin forms stable monomers and dimers. We used small-angle X-ray scattering to determine the solution structures of these species. As expected, the monomer shows a globular domain with a protruding helical coiled coil. The dimer shows an elongated dumbbell structure that is twice as long as the monomer. By aligning ERM sequences spanning metazoan evolution, we show that the central helical region is conserved, preserving the heptad repeat. Using this, we have built a dimer model where each monomer forms half of an elongated antiparallel coiled coil with domain-swapped FERM:C-terminal domain complexes at each end. The model suggests that ERM dimers may bind to actin in a parallel fashion.
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30
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Xu W, Jin M, Hu R, Wang H, Zhang F, Yuan S, Cao Y. The Joubert Syndrome Protein Inpp5e Controls Ciliogenesis by Regulating Phosphoinositides at the Apical Membrane. J Am Soc Nephrol 2016; 28:118-129. [PMID: 27401686 DOI: 10.1681/asn.2015080906] [Citation(s) in RCA: 34] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2015] [Accepted: 05/30/2016] [Indexed: 12/23/2022] Open
Abstract
Phosphoinositides, a family of phosphorylated derivatives of phosphatidylinositol (PtdIns), are tightly regulated both temporally and spatially by PtdIns phosphatases and kinases. Mutations in inositol polyphosphate 5-phosphatase E (INPP5E) cause Joubert syndrome, a human disorder associated with numerous ciliopathic defects, including renal cyst formation, linking phosphoinositides to ciliopathies. However, the molecular mechanism by which INPP5E-mediated PtdIns signaling regulates ciliogenesis and cystogenesis is unclear. Here, we utilized an in vivo vertebrate model of renal cystogenesis to show that Inpp5e enzymatic activity at the apical membrane directs apical docking of basal bodies in renal epithelia. Knockdown or knockout of inpp5e led to ciliogenesis defects and cystic kidneys in zebrafish. Furthermore, knockdown of inpp5e in embryos led to defects in cell polarity, cortical organization of F-actin, and apical segregation of PtdIns(4,5)P2 and PtdIns(3,4,5)P3 Knockdown of the ezrin gene, which encodes an ezrin/radixin/moesin (ERM) protein that crosslinks PtdIns(4,5)P2 and F-actin, phenocopied inpp5e knockdowns. Notably, overexpression of the ezrin gene rescued inpp5e morphants. Finally, treatment with the PI 3-kinase inhibitor LY294002, which decreases PtdIns(3,4,5)P3 levels, rescued the cellular, phenotypic, and renal functional defects in inpp5e-knockdown embryos. Together, our data indicate that Inpp5e functions as a key regulator of cell polarity in the renal epithelia, by inhibiting PtdIns(3,4,5)P3 and subsequently stabilizing PtdIns(4,5)P2 and recruiting Ezrin, F-actin, and basal bodies to the apical membrane, and suggest a possible novel approach for treating human ciliopathies.
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Affiliation(s)
- Wenyan Xu
- Department of Molecular and Cell Biology, Tongji University School of Life Sciences and Technology, Shanghai, China
| | - Miaomiao Jin
- Department of Molecular and Cell Biology, Tongji University School of Life Sciences and Technology, Shanghai, China
| | - Ruikun Hu
- Department of Molecular and Cell Biology, Tongji University School of Life Sciences and Technology, Shanghai, China
| | - Hong Wang
- Department of Molecular and Cell Biology, Tongji University School of Life Sciences and Technology, Shanghai, China
| | - Fan Zhang
- Department of Molecular and Cell Biology, Tongji University School of Life Sciences and Technology, Shanghai, China
| | - Shiaulou Yuan
- Department of Pediatrics, Yale University School of Medicine, New Haven, Connecticut; and
| | - Ying Cao
- Department of Molecular and Cell Biology, Tongji University School of Life Sciences and Technology, Shanghai, China; .,Tongji University and Shanghai Changzheng Hospital Joint Research Center for Translational Medicine, Changzheng Hospital, Shanghai, China
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31
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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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32
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Interactions between Epac1 and ezrin in the control of endothelial barrier function. Biochem Soc Trans 2015; 42:274-8. [PMID: 24646230 DOI: 10.1042/bst20130271] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Loss of barrier function in the vasculature promotes inflammatory signalling which in turn contributes to the progression of cardiovascular disease. cAMP can protect against endothelial dysfunction through the effectors PKA (protein kinase A) and Epac (exchange protein directly activated by cAMP). The present review outlines the role of Epac1 signalling within the endothelium and, in particular, the role of Epac1 in cytoskeletal dynamics and the control of cell morphology. The actin/cytoskeleton linker ezrin will be described in terms of the growing body of evidence placing it downstream of cAMP signalling as a mediator of altered cellular morphology.
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33
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Babich V, Di Sole F. The Na+/H+ Exchanger-3 (NHE3) Activity Requires Ezrin Binding to Phosphoinositide and Its Phosphorylation. PLoS One 2015; 10:e0129306. [PMID: 26042733 PMCID: PMC4455992 DOI: 10.1371/journal.pone.0129306] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2015] [Accepted: 05/08/2015] [Indexed: 11/19/2022] Open
Abstract
Na+/H+ exchanger-3 (NHE3) plays an essential role in maintaining sodium and fluid homeostasis in the intestine and kidney epithelium. Thus, NHE3 is highly regulated and its function depends on binding to multiple regulatory proteins. Ezrin complexed with NHE3 affects its activity via not well-defined mechanisms. This study investigates mechanisms by which ezrin regulates NHE3 activity in epithelial Opossum Kidney cells. Ezrin is activated sequentially by phosphatidylinositol-4,5-bisphosphate (PIP2) binding and phosphorylation of threonine 567. Expression of ezrin lacking PIP2 binding sites inhibited NHE3 activity (-40%) indicating that ezrin binding to PIP2 is required for preserving NHE3 activity. Expression of a phosphomimetic ezrin mutated at the PIP2 binding region was sufficient not only to reverse NHE3 activity to control levels but also to increase its activity (+80%) similar to that of the expression of ezrin carrying the phosphomimetic mutation alone. Calcineurin Homologous Protein-1 (CHP1) is part, with ezrin, of the NHE3 regulatory complex. CHP1-mediated activation of NHE3 activity was blocked by expression of an ezrin variant that could not be phosphorylated but not by an ezrin variant unable to bind PIP2. Thus, for NHE3 activity under baseline conditions not only ezrin phosphorylation, but also ezrin spatial-temporal targeting on the plasma membrane via PIP2 binding is required; however, phosphorylation of ezrin appears to overcome the control of NHE3 transport. CHP1 action on NHE3 activity is not contingent on ezrin binding to PIP2 but rather on ezrin phosphorylation. These findings are important in understanding the interrelation and dynamics of a CHP1-ezrin-NHE3 regulatory complex.
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Affiliation(s)
- Victor Babich
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
| | - Francesca Di Sole
- Department of Medicine, University of Maryland School of Medicine, Baltimore, Maryland, United States of America
- Department of Internal Medicine, University of Texas Southwestern Medical Center, Dallas, Texas, United States of America
- Physiology and Pharmacology Department, Des Moines University, Iowa, United States of America
- * E-mail:
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34
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Abstract
Epithelial cells from diverse tissues, including the enterocytes that line the intestinal tract, remodel their apical surface during differentiation to form a brush border: an array of actin-supported membrane protrusions known as microvilli that increases the functional capacity of the tissue. Although our understanding of how epithelial cells assemble, stabilize, and organize apical microvilli is still developing, investigations of the biochemical and physical underpinnings of these processes suggest that cells coordinate cytoskeletal remodeling, membrane-cytoskeleton cross-linking, and extracellular adhesion to shape the apical brush border domain.
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Affiliation(s)
- Scott W Crawley
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232
| | - Mark S Mooseker
- Department of Molecular, Cellular and Developmental Biology, Department of Cell Biology, and Department of Pathology, Yale University, New Haven, CT 06520 Department of Molecular, Cellular and Developmental Biology, Department of Cell Biology, and Department of Pathology, Yale University, New Haven, CT 06520 Department of Molecular, Cellular and Developmental Biology, Department of Cell Biology, and Department of Pathology, Yale University, New Haven, CT 06520
| | - Matthew J Tyska
- Department of Cell and Developmental Biology, Vanderbilt University Medical Center, Nashville, TN 37232
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35
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Chen X, Khajeh JA, Ju JH, Gupta YK, Stanley CB, Do C, Heller WT, Aggarwal AK, Callaway DJE, Bu Z. Phosphatidylinositol 4,5-bisphosphate clusters the cell adhesion molecule CD44 and assembles a specific CD44-Ezrin heterocomplex, as revealed by small angle neutron scattering. J Biol Chem 2015; 290:6639-52. [PMID: 25572402 PMCID: PMC4358296 DOI: 10.1074/jbc.m114.589523] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2014] [Revised: 12/30/2014] [Indexed: 01/02/2023] Open
Abstract
The cell adhesion molecule CD44 regulates diverse cellular functions, including cell-cell and cell-matrix interaction, cell motility, migration, differentiation, and growth. In cells, CD44 co-localizes with the membrane-cytoskeleton adapter protein Ezrin that links the CD44 assembled receptor signaling complexes to the cytoskeletal actin network, which organizes the spatial and temporal localization of signaling events. Here we report that the cytoplasmic tail of CD44 (CD44ct) is largely disordered. Upon binding to the signaling lipid phosphatidylinositol 4,5-bisphosphate (PIP2), CD44ct clusters into aggregates. Further, contrary to the generally accepted model, CD44ct does not bind directly to the FERM domain of Ezrin or to the full-length Ezrin but only forms a complex with FERM or with the full-length Ezrin in the presence of PIP2. Using contrast variation small angle neutron scattering, we show that PIP2 mediates the assembly of a specific heterotetramer complex of CD44ct with Ezrin. This study reveals the role of PIP2 in clustering CD44 and in assembling multimeric CD44-Ezrin complexes. We hypothesize that polyvalent electrostatic interactions are responsible for the assembly of CD44 clusters and the multimeric PIP2-CD44-Ezrin complexes.
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Affiliation(s)
- Xiaodong Chen
- From the Department of Chemistry and Biochemistry, City College of New York, New York, New York 10031, the School of Pharmacy, Jiangxi University of Traditional Chinese Medicine, Nanchang, Jiangxi 330004, China
| | - Jahan Ali Khajeh
- From the Department of Chemistry and Biochemistry, City College of New York, New York, New York 10031
| | - Jeong Ho Ju
- From the Department of Chemistry and Biochemistry, City College of New York, New York, New York 10031
| | - Yogesh K Gupta
- the Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai, New York, New York 10029, and
| | - Christopher B Stanley
- the Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - Changwoo Do
- the Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - William T Heller
- the Biology and Soft Matter Division, Oak Ridge National Laboratory, Oak Ridge, Tennessee 37831
| | - Aneel K Aggarwal
- the Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai, New York, New York 10029, and
| | - David J E Callaway
- From the Department of Chemistry and Biochemistry, City College of New York, New York, New York 10031
| | - Zimei Bu
- From the Department of Chemistry and Biochemistry, City College of New York, New York, New York 10031,
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36
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Hammond GRV, Balla T. Polyphosphoinositide binding domains: Key to inositol lipid biology. Biochim Biophys Acta Mol Cell Biol Lipids 2015; 1851:746-58. [PMID: 25732852 DOI: 10.1016/j.bbalip.2015.02.013] [Citation(s) in RCA: 168] [Impact Index Per Article: 18.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2014] [Revised: 01/29/2015] [Accepted: 02/17/2015] [Indexed: 01/01/2023]
Abstract
Polyphosphoinositides (PPIn) are an important family of phospholipids located on the cytoplasmic leaflet of eukaryotic cell membranes. Collectively, they are critical for the regulation of many aspects of membrane homeostasis and signaling, with notable relevance to human physiology and disease. This regulation is achieved through the selective interaction of these lipids with hundreds of cellular proteins, and thus the capability to study these localized interactions is crucial to understanding their functions. In this review, we discuss current knowledge of the principle types of PPIn-protein interactions, focusing on specific lipid-binding domains. We then discuss how these domains have been re-tasked by biologists as molecular probes for these lipids in living cells. Finally, we describe how the knowledge gained with these probes, when combined with other techniques, has led to the current view of the lipids' localization and function in eukaryotes, focusing mainly on animal cells. This article is part of a Special Issue entitled Phosphoinositides.
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Affiliation(s)
- Gerald R V Hammond
- Department of Cell Biology, University of Pittsburgh School of Medicine, Pittsburgh, PA, USA.
| | - Tamas Balla
- Section on Molecular Signal Transduction, Eunice Shriver Kennedy National Institute for Child Health and Human Development, National Institutes of Health, Bethesda, MD, USA.
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Nammalwar RC, Heil A, Gerke V. Ezrin interacts with the scaffold protein IQGAP1 and affects its cortical localization. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:2086-94. [PMID: 25554515 DOI: 10.1016/j.bbamcr.2014.12.026] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/25/2014] [Revised: 12/18/2014] [Accepted: 12/19/2014] [Indexed: 10/24/2022]
Abstract
The cortical cytoskeleton constitutes an important subcellular structure that determines cell shape and regulates cell migration as well as membrane traffic to and from the plasma membrane. Many components of the cortical cytoskeleton have been identified including structural and scaffolding proteins, membrane-cytoskeleton linker proteins and signaling intermediates. We describe here an association of the membrane-F-actin linker protein ezrin with the scaffolding protein IQGAP1 that serves as a hub for concentrating different signaling complexes. Both, ezrin and IQGAP1 bind in a Ca²⁺-dependent manner to the EF hand protein S100P and complexes consisting of Ca²⁺-bound S100P, IQGAP1 and ezrin can be isolated by immunoprecipitation. Ezrin and IQGAP1 also interact in the absence of Ca²⁺, thus independent of S100P. Direct ezrin-IQGAP1 interaction can be shown with the purified proteins. It is mediated via the N-terminal FERM domain of ezrin and the IQ domain of IQGAP1, respectively. Ezrin and IQGAP1 colocalize in the submembraneous cytoskeleton and in cellular protrusions of human epithelial cells and knockdown of ezrin reduces the cortical localization of IQGAP1. Thus, ezrin appears to participate in recruiting IQGAP1 to the cell cortex thereby establishing a close connection between membrane-F-actin contacts and actin regulators that can be assembled by IQGAP1. This article is part of a Special Issue entitled: 13th European Symposium on Calcium.
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Affiliation(s)
- Rathangadhara Chakrapani Nammalwar
- Institute of Medical Biochemistry, Centre for Molecular Biology of Inflammation (ZMBE), Cells-in-Motion Cluster of Excellence (EXC 1003 - CiM), University of Münster, Von-Esmarch-Str. 56, 48149 Münster, Germany
| | - Annika Heil
- Institute of Medical Biochemistry, Centre for Molecular Biology of Inflammation (ZMBE), Cells-in-Motion Cluster of Excellence (EXC 1003 - CiM), University of Münster, Von-Esmarch-Str. 56, 48149 Münster, Germany
| | - Volker Gerke
- Institute of Medical Biochemistry, Centre for Molecular Biology of Inflammation (ZMBE), Cells-in-Motion Cluster of Excellence (EXC 1003 - CiM), University of Münster, Von-Esmarch-Str. 56, 48149 Münster, Germany.
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38
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Suetsugu S, Kurisu S, Takenawa T. Dynamic shaping of cellular membranes by phospholipids and membrane-deforming proteins. Physiol Rev 2014; 94:1219-48. [PMID: 25287863 DOI: 10.1152/physrev.00040.2013] [Citation(s) in RCA: 150] [Impact Index Per Article: 15.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
All cellular compartments are separated from the external environment by a membrane, which consists of a lipid bilayer. Subcellular structures, including clathrin-coated pits, caveolae, filopodia, lamellipodia, podosomes, and other intracellular membrane systems, are molded into their specific submicron-scale shapes through various mechanisms. Cells construct their micro-structures on plasma membrane and execute vital functions for life, such as cell migration, cell division, endocytosis, exocytosis, and cytoskeletal regulation. The plasma membrane, rich in anionic phospholipids, utilizes the electrostatic nature of the lipids, specifically the phosphoinositides, to form interactions with cytosolic proteins. These cytosolic proteins have three modes of interaction: 1) electrostatic interaction through unstructured polycationic regions, 2) through structured phosphoinositide-specific binding domains, and 3) through structured domains that bind the membrane without specificity for particular phospholipid. Among the structured domains, there are several that have membrane-deforming activity, which is essential for the formation of concave or convex membrane curvature. These domains include the amphipathic helix, which deforms the membrane by hemi-insertion of the helix with both hydrophobic and electrostatic interactions, and/or the BAR domain superfamily, known to use their positively charged, curved structural surface to deform membranes. Below the membrane, actin filaments support the micro-structures through interactions with several BAR proteins as well as other scaffold proteins, resulting in outward and inward membrane micro-structure formation. Here, we describe the characteristics of phospholipids, and the mechanisms utilized by phosphoinositides to regulate cellular events. We then summarize the precise mechanisms underlying the construction of membrane micro-structures and their involvements in physiological and pathological processes.
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Affiliation(s)
- Shiro Suetsugu
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan; Biosignal Research Center, Kobe University, Kobe, Hyogo, Japan; and Graduate School of Medicine, Kobe University, Kobe, Hyogo, Japan
| | - Shusaku Kurisu
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan; Biosignal Research Center, Kobe University, Kobe, Hyogo, Japan; and Graduate School of Medicine, Kobe University, Kobe, Hyogo, Japan
| | - Tadaomi Takenawa
- Graduate School of Biological Sciences, Nara Institute of Science and Technology, Ikoma, Nara, Japan; Biosignal Research Center, Kobe University, Kobe, Hyogo, Japan; and Graduate School of Medicine, Kobe University, Kobe, Hyogo, Japan
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39
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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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40
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Bosanquet DC, Ye L, Harding KG, Jiang WG. FERM family proteins and their importance in cellular movements and wound healing (review). Int J Mol Med 2014; 34:3-12. [PMID: 24820650 DOI: 10.3892/ijmm.2014.1775] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2014] [Accepted: 03/10/2014] [Indexed: 11/06/2022] Open
Abstract
Motility is a requirement for a number of biological processes, including embryonic development, neuronal development, immune responses, cancer progression and wound healing. Specific to wound healing is the migration of endothelial cells, fibroblasts and other key cellular players into the wound space. Aberrations in wound healing can result in either chronic wounds or abnormally healed wounds. The protein 4.1R, ezrin, radixin, moesin (FERM) superfamily consists of over 40 proteins all containing a three lobed N-terminal FERM domain which binds a variety of cell-membrane associated proteins and lipids. The C-terminal ends of these proteins typically contain an actin-binding domain (ABD). These proteins therefore mediate the linkage between the cell membrane and the actin cytoskeleton, and are involved in cellular movements and migration. Certain FERM proteins have been shown to promote cancer metastasis via this very mechanism. Herein we review the effects of a number of FERM proteins on wound healing and cancer. We show how these proteins typically aid wound healing through their effects on increasing cellular migration and movements, but also typically promote metastasis in cancer. We conclude that FERM proteins play important roles in cellular migration, with markedly different outcomes in the context of cancer and wound healing.
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Affiliation(s)
- David C Bosanquet
- Departments of Surgery and Wound Healing, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XW, UK
| | - Lin Ye
- Departments of Surgery and Wound Healing, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XW, UK
| | - Keith G Harding
- Departments of Surgery and Wound Healing, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XW, UK
| | - Wen G Jiang
- Departments of Surgery and Wound Healing, Cardiff University School of Medicine, Heath Park, Cardiff CF14 4XW, UK
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41
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Braunger JA, Brückner BR, Nehls S, Pietuch A, Gerke V, Mey I, Janshoff A, Steinem C. Phosphatidylinositol 4,5-bisphosphate alters the number of attachment sites between ezrin and actin filaments: a colloidal probe study. J Biol Chem 2014; 289:9833-43. [PMID: 24500715 DOI: 10.1074/jbc.m113.530659] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Direct linkage between the plasma membrane and the actin cytoskeleton is controlled by the protein ezrin, a member of the ezrin-radixin-moesin protein family. To function as a membrane-cytoskeleton linker, ezrin needs to be activated in a process that involves binding of ezrin to phosphatidylinositol 4,5-bisphosphate (PIP2) and phosphorylation of a conserved threonine residue. Here, we used colloidal probe microscopy to quantitatively analyze the interaction between ezrin and F-actin as a function of these activating factors. We show that the measured individual unbinding forces between ezrin and F-actin are independent of the activating parameters, in the range of approximately 50 piconewtons. However, the cumulative adhesion energy greatly increases in the presence of PIP2 demonstrating that a larger number of bonds between ezrin and F-actin has formed. In contrast, the phosphorylation state, represented by phosphor-mimetic mutants of ezrin, only plays a minor role in the activation process. These results are in line with in vivo experiments demonstrating that an increase in PIP2 concentration recruits more ezrin to the apical plasma membrane of polarized cells and significantly increases the membrane tension serving as a measure of the adhesion sites between the plasma membrane and the F-actin network.
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Affiliation(s)
- Julia A Braunger
- From the Institute of Organic and Biomolecular Chemistry, University of Göttingen, Tammannstrasse 2, 37077 Göttingen, Germany
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42
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Viswanatha R, Wayt J, Ohouo PY, Smolka MB, Bretscher A. Interactome analysis reveals ezrin can adopt multiple conformational states. J Biol Chem 2013; 288:35437-51. [PMID: 24151071 DOI: 10.1074/jbc.m113.505669] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022] Open
Abstract
Ezrin, a member of the ezrin-radixin-moesin family (ERM), is an essential regulator of the structure of microvilli on the apical aspect of epithelial cells. Ezrin provides a linkage between membrane-associated proteins and F-actin, oscillating between active/open and inactive/closed states, and is regulated in part by phosphorylation of a C-terminal threonine. In the open state, ezrin can bind a number of ligands, but in the closed state the ligand-binding sites are inaccessible. In vitro analysis has proposed that there may be a third hyperactivated form of ezrin. To gain a better understanding of ezrin, we conducted an unbiased proteomic analysis of ezrin-binding proteins in an epithelial cell line, Jeg-3. We refined our list of interactors by comparing the interactomes using quantitative mass spectrometry between wild-type ezrin, closed ezrin, open ezrin, and hyperactivated ezrin. The analysis reveals several novel interactors confirmed by their localization to microvilli, as well as a significant class of proteins that bind closed ezrin. Taken together, the data indicate that ezrin can exist in three different conformational states, and different ligands "perceive" ezrin conformational states differently.
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Affiliation(s)
- Raghuvir Viswanatha
- From the Department of Molecular Biology and Genetics and Weill Institute for Cell and Molecular Biology, Cornell University, Ithaca, New York 14853
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43
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Parameswaran N, Gupta N. Re-defining ERM function in lymphocyte activation and migration. Immunol Rev 2013; 256:63-79. [DOI: 10.1111/imr.12104] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/29/2023]
Affiliation(s)
- Neetha Parameswaran
- Department of Immunology; Lerner Research Institute; Cleveland Clinic; Cleveland OH USA
| | - Neetu Gupta
- Department of Immunology; Lerner Research Institute; Cleveland Clinic; Cleveland OH USA
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44
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Fatehullah A, Appleton PL, Näthke IS. Cell and tissue polarity in the intestinal tract during tumourigenesis: cells still know the right way up, but tissue organization is lost. Philos Trans R Soc Lond B Biol Sci 2013; 368:20130014. [PMID: 24062584 PMCID: PMC3785964 DOI: 10.1098/rstb.2013.0014] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Cell and tissue polarity are tightly coupled and are vital for normal tissue homeostasis. Changes in cellular and tissue organization are common to even early stages of disease, particularly cancer. The digestive tract is the site of the second most common cause of cancer deaths in the developed world. Tumours in this tissue arise in an epithelium that has a number of axes of cell and tissue polarity. Changes in cell and tissue polarity in response to genetic changes that are known to underpin disease progression provide clues about the link between molecular-, cellular- and tissue-based mechanisms that accompany cancer. Mutations in adenomatous polyposis coli (APC) are common to most colorectal cancers in humans and are sufficient to cause tumours in mouse intestine. Tissue organoids mimic many features of whole tissue and permit identifying changes at different times after inactivation of APC. Using gut organoids, we show that tissue polarity is lost very early during cancer progression, whereas cell polarity, at least apical-basal polarity, is maintained and changes only at later stages. These observations reflect the situation in tumours and validate tissue organoids as a useful system to investigate the relationship between cell polarity and tissue organization.
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Affiliation(s)
- Aliya Fatehullah
- Cell and Developmental Biology, University of Dundee, , Dundee DD1 5EH, UK
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45
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Jiang L, Phang JM, Yu J, Harrop SJ, Sokolova AV, Duff AP, Wilk KE, Alkhamici H, Breit SN, Valenzuela SM, Brown LJ, Curmi PMG. CLIC proteins, ezrin, radixin, moesin and the coupling of membranes to the actin cytoskeleton: a smoking gun? BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2013; 1838:643-57. [PMID: 23732235 DOI: 10.1016/j.bbamem.2013.05.025] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/04/2013] [Revised: 05/20/2013] [Accepted: 05/21/2013] [Indexed: 12/20/2022]
Abstract
The CLIC proteins are a highly conserved family of metazoan proteins with the unusual ability to adopt both soluble and integral membrane forms. The physiological functions of CLIC proteins may include enzymatic activity in the soluble form and anion channel activity in the integral membrane form. CLIC proteins are associated with the ERM proteins: ezrin, radixin and moesin. ERM proteins act as cross-linkers between membranes and the cortical actin cytoskeleton. Both CLIC and ERM proteins are controlled by Rho family small GTPases. CLIC proteins, ERM and Rho GTPases act in a concerted manner to control active membrane processes including the maintenance of microvillar structures, phagocytosis and vesicle trafficking. All of these processes involve the interaction of membranes with the underlying cortical actin cytoskeleton. The relationships between Rho GTPases, CLIC proteins, ERM proteins and the membrane:actin cytoskeleton interface are reviewed. Speculative models are proposed involving the formation of localised multi-protein complexes on the membrane surface that assemble via multiple weak interactions. This article is part of a Special Issue entitled: Reciprocal influences between cell cytoskeleton and membrane channels, receptors and transporters. Guest Editor: Jean Claude Hervé.
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Affiliation(s)
- Lele Jiang
- St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, NSW 2010, Australia
| | - Juanita M Phang
- School of Physics, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Jiang Yu
- School of Physics, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Stephen J Harrop
- School of Physics, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Anna V Sokolova
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, Australia
| | - Anthony P Duff
- Australian Nuclear Science and Technology Organisation, Lucas Heights, NSW, Australia
| | - Krystyna E Wilk
- School of Physics, The University of New South Wales, Sydney, NSW 2052, Australia
| | - Heba Alkhamici
- School of Medical and Molecular Biosciences, The University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Samuel N Breit
- St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, NSW 2010, Australia
| | - Stella M Valenzuela
- School of Medical and Molecular Biosciences, The University of Technology Sydney, Sydney, NSW 2007, Australia
| | - Louise J Brown
- Department of Chemistry and Biomolecular Sciences, Macquarie University, Sydney, NSW 2109, Australia
| | - Paul M G Curmi
- St Vincent's Centre for Applied Medical Research, St Vincent's Hospital, Sydney, NSW 2010, Australia; School of Physics, The University of New South Wales, Sydney, NSW 2052, Australia.
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46
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Maniti O, Carvalho K, Picart C. Model membranes to shed light on the biochemical and physical properties of ezrin/radixin/moesin. Biochimie 2013; 95:3-11. [PMID: 23041444 PMCID: PMC4112940 DOI: 10.1016/j.biochi.2012.09.033] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/17/2012] [Accepted: 09/28/2012] [Indexed: 10/27/2022]
Abstract
Ezrin, radixin and moesin (ERM) proteins are now more and more recognized to play a key role in a large number of important physiological processes such as morphogenesis, cancer metastasis and virus infection. Several recent reviews extensively discuss their biological functions [1 -4 ]. In this review, we will first remind the main features of this family of proteins, which are now known as linkers and regulators of the plasma membrane/cytoskeleton linkage. We will then briefly review their implication in pathological processes such as cancer and viral infection. In a second part, we will focus on biochemical and biophysical approaches to study ERM interaction with lipid membranes and conformational change in well-defined environments. In vitro studies using biomimetic lipid membranes, especially large unilamellar vesicles (LUVs), giant unilamellar vesicles (GUVs) and supported lipid bilayers (SLBs) and recombinant proteins help to understand the molecular mechanism of conformational activation of ERM proteins. These tools are aimed to decorticate the different steps of the interaction, to simplify the experiments performed in vivo in much more complex biological environments.
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Affiliation(s)
- Ofélia Maniti
- CNRS UMR 5628 (LMGP), Grenoble Institute of Technology and CNRS, 3 parvis Louis Néel, F-38016 Grenoble Cedex, France
- Institut de Chimie et de Biochimie Moléculaires et Supramoléculaires, UMR 5246, CNRS, Université de Lyon, Université Lyon 1, INSA-Lyon, CPE-Lyon, 43 Bd du 11 Novembre 1918, F-69622 Villeurbanne, France
| | - Kevin Carvalho
- Institut Curie, centre de recherche and CNRS UMR 168, 11 rue Pierre et Marie Curie, Paris, F-75248 cedex 5
| | - Catherine Picart
- CNRS UMR 5628 (LMGP), Grenoble Institute of Technology and CNRS, 3 parvis Louis Néel, F-38016 Grenoble Cedex, France
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47
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Hansen MDH, Kwiatkowski AV. Control of actin dynamics by allosteric regulation of actin binding proteins. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2013; 303:1-25. [PMID: 23445807 DOI: 10.1016/b978-0-12-407697-6.00001-5] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
The regulated assembly and organization of actin filaments allows the cell to construct a large diversity of actin-based structures specifically suited to a range of cellular processes. A vast array of actin regulatory proteins must work in concert to form specific actin networks within cells, and spatial and temporal requirements for actin assembly necessitate rapid regulation of protein activity. This chapter explores a common mechanism of controlling the activity of actin binding proteins: allosteric autoinhibition by interdomain head-tail interactions. Intramolecular interactions maintain these proteins in a closed conformation that masks protein domains needed to regulate actin dynamics. Autoinhibition is typically relieved by two or more ligand binding and/or posttranslational modification events that expose key protein domains. Regulation through multiple inputs permits precise temporal and spatial control of protein activity to guide actin network formation.
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Affiliation(s)
- Marc D H Hansen
- Department of Physiology and Developmental Biology, Brigham Young University, Provo, UT, USA.
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48
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Zhu X, Morales FC, Agarwal NK, Dogruluk T, Gagea M, Georgescu MM. Moesin is a glioma progression marker that induces proliferation and Wnt/β-catenin pathway activation via interaction with CD44. Cancer Res 2012; 73:1142-55. [PMID: 23221384 DOI: 10.1158/0008-5472.can-12-1040] [Citation(s) in RCA: 57] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Moesin is an ERM family protein that connects the actin cytoskeleton to transmembrane receptors. With the identification of the ERM family protein NF2 as a tumor suppressor in glioblastoma, we investigated roles for other ERM proteins in this malignancy. Here, we report that overexpression of moesin occurs generally in high-grade glioblastoma in a pattern correlated with the stem cell marker CD44. Unlike NF2, moesin acts as an oncogene by increasing cell proliferation and stem cell neurosphere formation, with its ectopic overexpression sufficient to shorten survival in an orthotopic mouse model of glioblastoma. Moesin was the major ERM member activated by phosphorylation in glioblastoma cells, where it interacted and colocalized with CD44 in membrane protrusions. Increasing the levels of moesin competitively displaced NF2 from CD44, increasing CD44 expression in a positive feedback loop driven by the Wnt/β-catenin signaling pathway. Therapeutic targeting of the moesin-CD44 interaction with the small-molecule inhibitor 7-cyanoquinocarcinol (DX-52-1) or with a CD44-mimetic peptide specifically reduced the proliferation of glioblastoma cells overexpressing moesin, where the Wnt/β-catenin pathway was activated. Our findings establish moesin and CD44 as progression markers and drugable targets in glioblastoma, relating their oncogenic effects to activation of the Wnt/β-catenin pathway.
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Affiliation(s)
- Xiaoping Zhu
- Department of Neuro-Oncology and Veterinary Medicine, University of Texas MD Anderson Cancer Center, Houston, TX 75390, USA
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Characterization of cytoskeletal protein 4.1R interaction with NHE1 (Na(+)/H(+) exchanger isoform 1). Biochem J 2012; 446:427-35. [PMID: 22731252 DOI: 10.1042/bj20120535] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023]
Abstract
NHE1 (Na(+)/H(+) exchanger isoform 1) has been reported to be hyperactive in 4.1R-null erythrocytes [Rivera, De Franceschi, Peters, Gascard, Mohandas and Brugnara (2006) Am. J. Physiol. Cell Physiol. 291, C880-C886], supporting a functional interaction between NHE1 and 4.1R. In the present paper we demonstrate that 4.1R binds directly to the NHE1cd (cytoplasmic domain of NHE1) through the interaction of an EED motif in the 4.1R FERM (4.1/ezrin/radixin/moesin) domain with two clusters of basic amino acids in the NHE1cd, K(519)R and R(556)FNKKYVKK, previously shown to mediate PIP(2) (phosphatidylinositol 4,5-bisphosphate) binding [Aharonovitz, Zaun, Balla, York, Orlowski and Grinstein (2000) J. Cell. Biol. 150, 213-224]. The affinity of this interaction (K(d) = 100-200 nM) is reduced in hypertonic and acidic conditions, demonstrating that this interaction is of an electrostatic nature. The binding affinity is also reduced upon binding of Ca(2+)/CaM (Ca(2+)-saturated calmodulin) to the 4.1R FERM domain. We propose that 4.1R regulates NHE1 activity through a direct protein-protein interaction that can be modulated by intracellular pH and Na(+) and Ca(2+) concentrations.
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50
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Roubinet C, Tran PT, Piel M. Common mechanisms regulating cell cortex properties during cell division and cell migration. Cytoskeleton (Hoboken) 2012; 69:957-72. [PMID: 23125194 DOI: 10.1002/cm.21086] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2012] [Revised: 09/28/2012] [Accepted: 10/02/2012] [Indexed: 12/14/2022]
Abstract
Single cell morphogenesis results from a balance of forces involving internal pressure (also called turgor pressure in plants and fungi) and the plastic and dynamic outer shell of the cell. Dominated by the cell wall in plants and fungi, mechanical properties of the outer shell of animal cells arise from the cell cortex, which is mostly composed of the plasma membrane (and membrane proteins) and the underlying meshwork of actin filaments and myosin motors (and associated proteins). In this review, following Bray and White [1988; Science 239:883-889], we draw a parallel between the regulation of the cell cortex during cell division and cell migration in animal cells. Starting from the similarities in shape changes and underlying mechanical properties, we further propose that the analogy between cell division and cell migration might run deeper, down to the basic molecular mechanisms driving cell cortex remodeling. We focus our attention on how an heterogeneous and dynamic cortex can be generated to allow cell shape changes while preserving cell integrity.
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Affiliation(s)
- Chantal Roubinet
- Université de Toulouse, UPS, Centre de Biologie du Développement, Bâtiment 4R3, 118 route de Narbonne, F-31062 Toulouse, France.
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