1
|
Czowski BJ, White KA. Intracellular pH regulates β-catenin with low pHi increasing adhesion and signaling functions. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2024.03.22.586349. [PMID: 38585883 PMCID: PMC10996556 DOI: 10.1101/2024.03.22.586349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/09/2024]
Abstract
Intracellular pH (pHi) dynamics are linked to cell processes including proliferation, migration, and differentiation. The adherens junction (AJ) and signaling protein β-catenin has decreased abundance at high pHi due to increased proteasomal-mediated degradation. However, the effects of low pHi on β-catenin abundance and functions have not been characterized. Here, we show that low pHi stabilizes β-catenin in epithelial cells using population-level and single-cell assays. β-catenin abundance is increased at low pHi and decreased at high pHi. We also assay single-cell protein degradation rates to show that β-catenin half-life is longer at low compared to high pHi. Importantly, we show that AJs are not disrupted by β-catenin loss at high pHi due to rescue by plakoglobin. Finally, we show that low pHi increases β-catenin transcriptional activity in single cells and is indistinguishable from a Wnt-on state. This work characterizes pHi as a rheostat regulating β-catenin abundance, stability, and function and implicates β-catenin as a molecular mediator of pHi-dependent cell processes.
Collapse
Affiliation(s)
- Brandon J Czowski
- Department of Chemistry and Biochemistry, University of Notre Dame
- Harper Cancer Research Institute, University of Notre Dame
| | - Katharine A White
- Department of Chemistry and Biochemistry, University of Notre Dame
- Harper Cancer Research Institute, University of Notre Dame
| |
Collapse
|
2
|
Moeinafshar A, Tehrani Fateh S, Sadeghi H, Karimzadeh P, Mirfakhraie R, Hashemi-Gorji F, Larki P, Miryounesi M, Ghasemi MR. Alopecia areata-like pattern of baldness: the most recent update and the expansion of novel phenotype and genotype in the CTNNB1 gene. Neurol Sci 2023; 44:4041-4048. [PMID: 37369877 DOI: 10.1007/s10072-023-06922-6] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/14/2023] [Accepted: 06/19/2023] [Indexed: 06/29/2023]
Abstract
Neurodevelopmental disorder with spastic diplegia and visual defects (NEDSDV) is a rare autosomal dominant genetic disorder caused by genetic alterations in the CTNNB1 gene. CTNNB1 is a gene that encodes β-catenin, an effector protein in the canonical Wnt pathway involved in stem cell differentiation and proliferation, synaptogenesis, and a wide range of essential cellular mechanisms. Mutations in this gene are also found in specific malignancies as well as exudative vitreoretinopathy. To date, only a limited number of cases of this disease have been reported, and though they share some phenotypic manifestations such as intellectual disability, developmental delay, microcephaly, behavioral abnormalities, and dystonia, the variety of phenotypic traits of these patients shows extreme heterogeneity. In this study, two cases of NEDSDV with de novo CTNNB1 mutations: c.1420C>T(p.R474X) and c.1377_1378Del(p.Ala460Serfs*29), found with whole exome sequencing (WES) have been reported and the clinical and paraclinical characteristics of these patients have been described. Due to such a wide range of clinical characteristics, the identification of new patients and novel variants is of great importance in order to establish a more complete phenotypic spectrum, as well as to conclude the genotype-phenotype correlations in these cases.
Collapse
Affiliation(s)
- Aysan Moeinafshar
- School of Medicine, Tehran University of Medical Sciences (TUMS), Tehran, Iran
| | | | - Hossein Sadeghi
- Genomic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Parvaneh Karimzadeh
- Pediatric Neurology Department, Mofid children's Hospital, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Reza Mirfakhraie
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Farzad Hashemi-Gorji
- Genomic Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Pegah Larki
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Mohammad Miryounesi
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| | - Mohammad-Reza Ghasemi
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
- Center for Comprehensive Genetic Services, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
| |
Collapse
|
3
|
Schäfer J, Wenck N, Janik K, Linnert J, Stingl K, Kohl S, Nagel-Wolfrum K, Wolfrum U. The Usher syndrome 1C protein harmonin regulates canonical Wnt signaling. Front Cell Dev Biol 2023; 11:1130058. [PMID: 36846582 PMCID: PMC9944737 DOI: 10.3389/fcell.2023.1130058] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2022] [Accepted: 01/23/2023] [Indexed: 02/11/2023] Open
Abstract
Human Usher syndrome (USH) is the most common form of hereditary combined deaf-blindness. USH is a complex genetic disorder, and the pathomechanisms underlying the disease are far from being understood, especially in the eye and retina. The USH1C gene encodes the scaffold protein harmonin which organizes protein networks due to binary interactions with other proteins, such as all USH proteins. Interestingly, only the retina and inner ear show a disease-related phenotype, although USH1C/harmonin is almost ubiquitously expressed in the human body and upregulated in colorectal cancer. We show that harmonin binds to β-catenin, the key effector of the canonical Wnt (cWnt) signaling pathway. We also demonstrate the interaction of the scaffold protein USH1C/harmonin with the stabilized acetylated β-catenin, especially in nuclei. In HEK293T cells, overexpression of USH1C/harmonin significantly reduced cWnt signaling, but a USH1C-R31* mutated form did not. Concordantly, we observed an increase in cWnt signaling in dermal fibroblasts derived from an USH1C R31*/R80Pfs*69 patient compared with healthy donor cells. RNAseq analysis reveals that both the expression of genes related to the cWnt signaling pathway and cWnt target genes were significantly altered in USH1C patient-derived fibroblasts compared to healthy donor cells. Finally, we show that the altered cWnt signaling was reverted in USH1C patient fibroblast cells by the application of Ataluren, a small molecule suitable to induce translational read-through of nonsense mutations, hereby restoring some USH1C expression. Our results demonstrate a cWnt signaling phenotype in USH establishing USH1C/harmonin as a suppressor of the cWnt/β-catenin pathway.
Collapse
Affiliation(s)
- Jessica Schäfer
- Institute of Molecular Physiology, Molecular Cell Biology and Photoreceptor Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Nicole Wenck
- Institute of Molecular Physiology, Molecular Cell Biology and Photoreceptor Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Katharina Janik
- Institute of Molecular Physiology, Molecular Cell Biology and Photoreceptor Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Joshua Linnert
- Institute of Molecular Physiology, Molecular Cell Biology and Photoreceptor Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Katarina Stingl
- Centre for Ophthalmology, University Eye Hospital, University of Tübingen, Tübingen, Germany
| | - Susanne Kohl
- Centre for Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
| | - Kerstin Nagel-Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology and Photoreceptor Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany,Institute of Developmental Biology and Neurobiology, Johannes Gutenberg University Mainz, Mainz, Germany
| | - Uwe Wolfrum
- Institute of Molecular Physiology, Molecular Cell Biology and Photoreceptor Cell Biology, Johannes Gutenberg University Mainz, Mainz, Germany,*Correspondence: Uwe Wolfrum,
| |
Collapse
|
4
|
Liu DX, Hao SL, Yang WX. Crosstalk Between β-CATENIN-Mediated Cell Adhesion and the WNT Signaling Pathway. DNA Cell Biol 2023; 42:1-13. [PMID: 36399409 DOI: 10.1089/dna.2022.0424] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
Cell adhesion and stable signaling regulation are fundamental ways of maintaining homeostasis. Among them, the Wnt/β-CATENIN signaling plays a key role in embryonic development and maintenance of body dynamic homeostasis. At the same time, the key signaling molecule β-CATENIN in the Wnt signaling can also function as a cytoskeletal linker protein to regulate tissue barriers, cell migration, and morphogenesis. Dysregulation of the balance between Wnt signaling and adherens junctions can lead to disease. How β-CATENIN maintains the independence of these two functions, or mediates the interaction and balance of these two functions, has been explored and debated for a long time. In this study, we will focus on five aspects of β-CATENIN chaperone molecules, phosphorylation of β-CATENIN and related proteins, epithelial mesenchymal transition, β-CATENIN homolog protein γ-CATENIN and disease, thus deepening the understanding of the Wnt/β-CATENIN signaling and the homeostasis between cell adhesion and further addressing related disease problems.
Collapse
Affiliation(s)
- Ding-Xi Liu
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Shuang-Li Hao
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou, China
| | - Wan-Xi Yang
- The Sperm Laboratory, College of Life Sciences, Zhejiang University, Hangzhou, China
| |
Collapse
|
5
|
Hale C, Moulton JK, Otis Y, Ganter G. ARMADILLO REGULATES NOCICEPTIVE SENSITIVITY IN THE ABSENCE OF INJURY. Mol Pain 2022; 18:17448069221111155. [PMID: 35712882 PMCID: PMC9500252 DOI: 10.1177/17448069221111155] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
Abnormal pain has recently been estimated to affect ∼50 million adults each year within the United States. With many treatment options for abnormal pain, such as opioid analgesics, carrying numerous deleterious side effects, research into safer and more effective treatment options is crucial. To help elucidate the mechanisms controlling nociceptive sensitivity, the Drosophila melanogaster larval nociception model has been used to characterize well-conserved pathways through the use of genetic modification and/or injury to alter the sensitivity of experimental animals. Mammalian models have provided evidence of β-catenin signaling involvement in neuropathic pain development. By capitalizing on the conserved nature of β-catenin functions in the fruit fly, here we describe a role for Armadillo, the fly homolog to mammalian β-catenin, in regulating baseline sensitivity in the primary nociceptor of the fly, in the absence of injury, using under- and over-expression of Armadillo in a cell-specific manner. Underexpression of Armadillo resulted in hyposensitivity, while overexpression of wild-type Armadillo or expression of a degradation-resistant Armadillo resulted in hypersensitivity. Neither underexpression nor overexpression of Armadillo resulted in observed dendritic morphological changes that could contribute to behavioral phenotypes observed. These results showed that focused manipulation of Armadillo expression within the nociceptors is sufficient to modulate baseline response in the nociceptors to a noxious stimulus and that these changes are not shown to be associated with a morphogenetic effect.
Collapse
Affiliation(s)
- Christine Hale
- Graduate School of Biomedical Science and Engineering6251University of Maine System
| | | | - Yvonne Otis
- School of Biological Sciences172741University of New England College of Arts and Sciences
| | | |
Collapse
|
6
|
Yang M, Li S, Huang L, Zhao R, Dai E, Jiang X, He Y, Lu J, Peng L, Liu W, Zhang Z, Jiang D, Zhang Y, Jiang Z, Yang Y, Zhao P, Zhu X, Ding X, Yang Z. CTNND1 variants cause familial exudative vitreoretinopathy through Wnt/Cadherin axis. JCI Insight 2022; 7:158428. [PMID: 35700046 PMCID: PMC9431724 DOI: 10.1172/jci.insight.158428] [Citation(s) in RCA: 9] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2022] [Accepted: 06/10/2022] [Indexed: 11/17/2022] Open
Abstract
Familial exudative vitreoretinopathy (FEVR) is a hereditary disorder that can cause vision loss. The CTNND1 gene encodes a cellular adhesion protein p120-catenin (p120), which is essential for vascularization, yet the function of p120 in postnatal physiological angiogenesis remains unclear. Here, we applied whole-exome sequencing (WES) on 140 probands of FEVR families and identified three candidate variants in the human CTNND1 gene. We performed inducible deletion of Ctnnd1 in the postnatal mouse endothelial cells (ECs) and observed typical phenotypes of FEVR. Immunofluorescence of retina flat mounts also revealed immune responses, including reactive astrogliosis and microgliosis accompanied by abnormal Vegfa expression. Using an unbiased proteomics analysis in combination with in vivo or in vitro approaches, we propose that p120 is critical for the integrity of cadherin/catenin complex, and that p120 activates Wnt signaling activity by protecting β-catenin from Gsk3β-ubiquitin-guided degradation. Treatment of CTNND1-depleted HRECs with Gsk3β inhibitors LiCl or CHIR-99021 successfully enhanced cell proliferation by preventing β-catenin from degradation. Moreover, LiCl treatment increased vessel density in Ctnnd1-deficient mouse retinas. Functional analysis also revealed that variants in CTNND1 cause FEVR by compromising the expression of adherens junctions (AJs) and Wnt signaling activity. Additionally, genetic interactions between p120 and β-catenin or α-catenin revealed by double heterozygous deletion in mice further confirmed that p120 regulates vascular development through the Wnt/Cadherin axis. Together, we propose that CTNND1 is a novel candidate gene associated with FEVR, and that variants in CTNND1 can cause FEVR through the Wnt/Cadherin axis.
Collapse
Affiliation(s)
- Mu Yang
- Prenatal Diagnosis Center, University of Electronic Science and Technology of China, Chengdu, China
| | - Shujin Li
- Prenatal Diagnosis Center, University of Electronic Science and Technology of China, Chengdu, China
| | - Li Huang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Rulian Zhao
- Prenatal Diagnosis Center, Sichuan Provincial Key Laboratory for Human Disease Gene Study, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| | - Erkuan Dai
- Department of Ophthalmology, Shanghai Jiaotong University School of Medicine Xinhua Hospital, Chengdu, China
| | - Xiaoyan Jiang
- Center for Human Molecular Genetics, University of Electronic Science and Technology of China, Chengdu, China
| | - Yunqi He
- Center for Human Molecular Genetics, University of Electronic Science and Technology of China, Chengdu, China
| | - Jinglin Lu
- Prenatal Diagnosis Center, Sun Yat-sen University, Guangzhou, China
| | - Li Peng
- Center for Human Molecular Genetics, Sun Yat-sen University, Chengdu, China
| | - Wenjing Liu
- Center for Human Molecular Genetics, Sun Yat-sen University, Chengdu, China
| | - Zhaotian Zhang
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Dan Jiang
- The Key Laboratory for Human Disease Gene Study of Sichuan Province, Sichua, Chengdu, China
| | - Yi Zhang
- Center for Human Molecular Genetics, University of Electronic Science and Technology of China, Chengdu, China
| | - Zhilin Jiang
- Center for Human Molecular Genetics, University of Electronic Science and Technology of China, Chengdu, China
| | - Yeming Yang
- Center for Human Molecular Genetics, University of Electronic Science and Technology of China, Chengdu, China
| | - Peiquan Zhao
- Department of Ophthalmology, Shanghai Jiaotong University School of Medicine Xinhua Hospital, Chengdu, China
| | - Xianjun Zhu
- Center for Human Molecular Genetics, University of Electronic Science and Technology of China, Chengdu, China
| | - Xiaoyan Ding
- State Key Laboratory of Ophthalmology, Zhongshan Ophthalmic Center, Sun Yat-sen University, Guangzhou, China
| | - Zhenglin Yang
- Department of Medical Genetics, Sichuan Provincial Key Laboratory for Human Disease Gene Study, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China
| |
Collapse
|
7
|
Identification of a novel de novo mutation in the CTNNB1 gene in an Iranian patient with intellectual disability. Neurol Sci 2022; 43:2859-2863. [PMID: 35099645 DOI: 10.1007/s10072-022-05904-4] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2021] [Accepted: 01/14/2022] [Indexed: 12/11/2022]
Abstract
CTNNB1 encodes for the β-catenin protein, a component of the cadherin adhesion complex, which regulates cell-cell adhesion and gene expression in the canonical Wnt signaling pathway. Mutations in CTNNB1 have been reported to be associated with cancer and mental disorders. Recently, loss-of-function mutations in CTNNB1 have been observed in patients with intellectual disability and some other clinical manifestations including motor and language delays, microcephaly, and mild visual defects. We report an 8-year-old Iranian girl with intellectual disability, hypotonia, impaired vision such as vitreomacular adhesion, motor delay, and speech delay. A novel, de novo nonsense mutation (c.1014G > A; p.Trp338Ter) in exon 7 of the CTNNB1 (NM_001904) gene was detected and confirmed by whole-exome sequencing and Sanger sequencing, respectively. This study helps to expand the growing list of loss-of-function mutations known in the CTNNB1 gene.
Collapse
|
8
|
Targeting β-catenin in acute myeloid leukaemia: past, present, and future perspectives. Biosci Rep 2022; 42:231097. [PMID: 35352805 PMCID: PMC9069440 DOI: 10.1042/bsr20211841] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2022] [Revised: 03/14/2022] [Accepted: 03/30/2022] [Indexed: 11/24/2022] Open
Abstract
Acute myeloid leukaemia (AML) is an aggressive disease of the bone marrow with a poor prognosis. Evidence suggests long established chemotherapeutic regimens used to treat AML are reaching the limits of their efficacy, necessitating the urgent development of novel targeted therapies. Canonical Wnt signalling is an evolutionary conserved cascade heavily implicated in normal developmental and disease processes in humans. For over 15 years its been known that the central mediator of this pathway, β-catenin, is dysregulated in AML promoting the emergence, maintenance, and drug resistance of leukaemia stem cells. Yet, despite this knowledge, and subsequent studies demonstrating the therapeutic potential of targeting Wnt activity in haematological cancers, β-catenin inhibitors have not yet reached the clinic. The aim of this review is to summarise the current understanding regarding the role and mechanistic dysregulation of β-catenin in AML, and assess the therapeutic merit of pharmacologically targeting this molecule, drawing on lessons from other disease contexts.
Collapse
|
9
|
Zhu X, Yang M, Zhao P, Li S, Zhang L, Huang L, Huang Y, Fei P, Yang Y, Zhang S, Xu H, Yuan Y, Zhang X, Zhu X, Ma S, Hao F, Sundaresan P, Zhu W, Yang Z. Catenin α 1 mutations cause familial exudative vitreoretinopathy by overactivating Norrin/β-catenin signaling. J Clin Invest 2021; 131:139869. [PMID: 33497368 DOI: 10.1172/jci139869] [Citation(s) in RCA: 29] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 01/22/2021] [Indexed: 12/19/2022] Open
Abstract
Familial exudative vitreoretinopathy (FEVR) is a severe retinal vascular disease that causes blindness. FEVR has been linked to mutations in several genes associated with inactivation of the Norrin/β-catenin signaling pathway, but these account for only approximately 50% of cases. We report that mutations in α-catenin (CTNNA1) cause FEVR by overactivating the β-catenin pathway and disrupting cell adherens junctions. We identified 3 heterozygous mutations in CTNNA1 (p.F72S, p.R376Cfs*27, and p.P893L) by exome sequencing and further demonstrated that FEVR-associated mutations led to overactivation of Norrin/β-catenin signaling as a result of impaired protein interactions within the cadherin-catenin complex. The clinical features of FEVR were reproduced in mice lacking Ctnna1 in vascular endothelial cells (ECs) or with overactivated β-catenin signaling by an EC-specific gain-of-function allele of Ctnnb1. In isolated mouse lung ECs, both CTNNA1-P893L and F72S mutants failed to rescue either the disrupted F-actin arrangement or the VE-cadherin and CTNNB1 distribution. Moreover, we discovered that compound heterozygous Ctnna1 F72S and a deletion allele could cause a similar phenotype. Furthermore, in a FEVR family, we identified a mutation of LRP5, which activates Norrin/β-catenin signaling, and the corresponding knockin mice exhibited a partial FEVR-like phenotype. Our study demonstrates that the precise regulation of β-catenin activation is critical for retinal vascular development and provides new insights into the pathogenesis of FEVR.
Collapse
Affiliation(s)
- Xianjun Zhu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
| | - Mu Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
| | - Peiquan Zhao
- Department of Ophthalmology, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Shujin Li
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan, China
| | - Lin Zhang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Lulin Huang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Yi Huang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Ping Fei
- Department of Ophthalmology, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Yeming Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Shanshan Zhang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Huijuan Xu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Ye Yuan
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Xiang Zhang
- Department of Ophthalmology, Xinhua Hospital, School of Medicine, Shanghai Jiaotong University, Shanghai, China
| | - Xiong Zhu
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Shi Ma
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Fang Hao
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China
| | - Periasamy Sundaresan
- Department of Genetics, Aravind Medical Research Foundation, Aravind Eye Hospital, Madurai, Tamil Nadu, India
| | - Weiquan Zhu
- Department of Molecular Medicine, School of Medicine, University of Utah, Salt Lake City, Utah, USA
| | - Zhenglin Yang
- Sichuan Provincial Key Laboratory for Human Disease Gene Study, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, Sichuan, China.,Research Unit for Blindness Prevention of the Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, Sichuan, China.,Chinese Academy of Sciences Sichuan Translational Medicine Research Hospital, Chengdu, China
| |
Collapse
|
10
|
Deciphering the Role of Wnt and Rho Signaling Pathway in iPSC-Derived ARVC Cardiomyocytes by In Silico Mathematical Modeling. Int J Mol Sci 2021; 22:ijms22042004. [PMID: 33670616 PMCID: PMC7923182 DOI: 10.3390/ijms22042004] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2020] [Revised: 01/29/2021] [Accepted: 02/16/2021] [Indexed: 02/07/2023] Open
Abstract
Arrhythmogenic Right Ventricular cardiomyopathy (ARVC) is an inherited cardiac muscle disease linked to genetic deficiency in components of the desmosomes. The disease is characterized by progressive fibro-fatty replacement of the right ventricle, which acts as a substrate for arrhythmias and sudden cardiac death. The molecular mechanisms underpinning ARVC are largely unknown. Here we propose a mathematical model for investigating the molecular dynamics underlying heart remodeling and the loss of cardiac myocytes identity during ARVC. Our methodology is based on three computational models: firstly, in the context of the Wnt pathway, we examined two different competition mechanisms between β-catenin and Plakoglobin (PG) and their role in the expression of adipogenic program. Secondly, we investigated the role of RhoA-ROCK pathway in ARVC pathogenesis, and thirdly we analyzed the interplay between Wnt and RhoA-ROCK pathways in the context of the ARVC phenotype. We conclude with the following remark: both Wnt/β-catenin and RhoA-ROCK pathways must be inactive for a significant increase of PPARγ expression, suggesting that a crosstalk mechanism might be responsible for mediating ARVC pathogenesis.
Collapse
|
11
|
Panda PP, Bohot M, Chaturvedi MM, Purohit JS. Purification and partial characterization of vinculin from chicken liver nuclear extract. Biologia (Bratisl) 2021. [DOI: 10.1007/s11756-021-00691-3] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
|
12
|
The Barrier Molecules Junction Plakoglobin, Filaggrin, and Dystonin Play Roles in Melanoma Growth and Angiogenesis. Ann Surg 2020; 270:712-722. [PMID: 31425296 DOI: 10.1097/sla.0000000000003522] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
OBJECTIVE To understand role of barrier molecules in melanomas. BACKGROUND We have reported poor patient survival and low immune infiltration of melanomas that overexpress a set of genes that include filaggrin (FLG), dystonin (DST), junction plakoglobin (JUP), and plakophilin-3 (PKP3), and are involved in cell-cell adhesions. We hypothesized that these associations are causal, either by interfering with immune cell infiltration or by enhancing melanoma cell growth. METHODS FLG and DST were knocked out by CRISPR/Cas9 in human DM93 and murine B16-F1 melanoma cells. PKP3 and JUP were overexpressed in murine B16-AAD and human VMM39 melanoma cells by lentiviral transduction. These cell lines were evaluated in vitro for cell proliferation and in vivo for tumor burden, immune composition, cytokine expression, and vascularity. RESULTS Immune infiltrates were not altered by these genes. FLG/DST knockout reduced proliferation of human DM93 melanoma in vitro, and decreased B16-F1 tumor burden in vivo. Overexpression of JUP, but not PKP3, in B16-AAD significantly increased tumor burden, increased VEGF-A, reduced IL-33, and enhanced vascularity. CONCLUSIONS FLG and DST support melanoma cell growth in vitro and in vivo. Growth effects of JUP were only evident in vivo, and may be mediated, in part, by enhancing angiogenesis. In addition, growth-promoting effects of FLG and DST in vitro suggest that these genes may also support melanoma cell proliferation through angiogenesis-independent pathways. These findings identify FLG, DST, and JUP as novel therapeutic targets whose down-regulation may provide clinical benefit to patients with melanoma.
Collapse
|
13
|
DYNLRB1 is essential for dynein mediated transport and neuronal survival. Neurobiol Dis 2020; 140:104816. [PMID: 32088381 PMCID: PMC7273200 DOI: 10.1016/j.nbd.2020.104816] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2019] [Revised: 02/08/2020] [Accepted: 02/18/2020] [Indexed: 12/19/2022] Open
Abstract
The cytoplasmic dynein motor complex transports essential signals and organelles from the cell periphery to the perinuclear region, hence is critical for the survival and function of highly polarized cells such as neurons. Dynein Light Chain Roadblock-Type 1 (DYNLRB1) is thought to be an accessory subunit required for specific cargos, but here we show that it is essential for general dynein-mediated transport and sensory neuron survival. Homozygous Dynlrb1 null mice are not viable and die during early embryonic development. Furthermore, heterozygous or adult knockdown animals display reduced neuronal growth, and selective depletion of Dynlrb1 in proprioceptive neurons compromises their survival. Conditional depletion of Dynlrb1 in sensory neurons causes deficits in several signaling pathways, including β-catenin subcellular localization, and a severe impairment in the axonal transport of both lysosomes and retrograde signaling endosomes. Hence, DYNLRB1 is an essential component of the dynein complex, and given dynein's critical functions in neuronal physiology, DYNLRB1 could have a prominent role in the etiology of human neurodegenerative diseases.
Collapse
|
14
|
Silva MJ, Holguin N. Aging aggravates intervertebral disc degeneration by regulating transcription factors toward chondrogenesis. FASEB J 2019; 34:1970-1982. [PMID: 31909538 DOI: 10.1096/fj.201902109r] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2019] [Revised: 10/08/2019] [Accepted: 10/15/2019] [Indexed: 12/17/2022]
Abstract
Osterix is a critical transcription factor of mesenchymal stem cell fate, where its loss or loss of Wnt signaling diverts differentiation to a chondrocytic lineage. Intervertebral disc (IVD) degeneration activates the differentiation of prehypertrophic chondrocyte-like cells and inactivates Wnt signaling, but its interactive role with osterix is unclear. First, compared to young-adult (5 mo), mechanical compression of old (18 mo) IVD induced greater IVD degeneration. Aging (5 vs 12 mo) and/or compression reduced the transcription of osterix and notochordal marker T by 40-75%. Compression elevated the transcription of hypertrophic chondrocyte marker MMP13 and pre-osterix transcription factor RUNX2, but less so in 12 mo IVD. Next, using an Ai9/td reporter and immunohistochemical staining, annulus fibrosus and nucleus pulposus cells of young-adult IVD expressed osterix, but aging and compression reduced its expression. Lastly, in vivo LRP5-deficiency in osterix-expressing cells inactivated Wnt signaling in the nucleus pulposus by 95%, degenerated the IVD to levels similar to aging and compression, reduced the biomechanical properties by 45-70%, and reduced the transcription of osterix, notochordal markers and chondrocytic markers by 60-80%. Overall, these data indicate that age-related inactivation of Wnt signaling in osterix-expressing cells may limit regeneration by depleting the progenitors and attenuating the expansion of chondrocyte-like cells.
Collapse
Affiliation(s)
- Matthew J Silva
- Department of Biomedical Engineering, Orthopaedic Surgery, Musculoskeletal Research Center, Washington University, St. Louis, MO, USA
| | - Nilsson Holguin
- Department of Mechanical and Energy Engineering, Indiana Center for Musculoskeletal Health, IUPUI, Indianapolis, IN, USA.,Department of Anatomy and Cell Biology, Indiana Center for Musculoskeletal Health, IUPUI, Indianapolis, IN, USA
| |
Collapse
|
15
|
Wickham RJ, Alexander JM, Eden LW, Valencia-Yang M, Llamas J, Aubrey JR, Jacob MH. Learning impairments and molecular changes in the brain caused by β-catenin loss. Hum Mol Genet 2019; 28:2965-2975. [PMID: 31131404 PMCID: PMC6736100 DOI: 10.1093/hmg/ddz115] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2019] [Revised: 05/20/2019] [Accepted: 05/22/2019] [Indexed: 12/31/2022] Open
Abstract
Intellectual disability (ID), defined as IQ<70, occurs in 2.5% of individuals. Elucidating the underlying molecular mechanisms is essential for developing therapeutic strategies. Several of the identified genes that link to ID in humans are predicted to cause malfunction of β-catenin pathways, including mutations in CTNNB1 (β-catenin) itself. To identify pathological changes caused by β-catenin loss in the brain, we have generated a new β-catenin conditional knockout mouse (β-cat cKO) with targeted depletion of β-catenin in forebrain neurons during the period of major synaptogenesis, a critical window for brain development and function. Compared with control littermates, β-cat cKO mice display severe cognitive impairments. We tested for changes in two β-catenin pathways essential for normal brain function, cadherin-based synaptic adhesion complexes and canonical Wnt (Wingless-related integration site) signal transduction. Relative to control littermates, β-cat cKOs exhibit reduced levels of key synaptic adhesion and scaffold binding partners of β-catenin, including N-cadherin, α-N-catenin, p120ctn and S-SCAM/Magi2. Unexpectedly, the expression levels of several canonical Wnt target genes were not altered in β-cat cKOs. This lack of change led us to find that β-catenin loss leads to upregulation of γ-catenin (plakoglobin), a partial functional homolog, whose neural-specific role is poorly defined. We show that γ-catenin interacts with several β-catenin binding partners in neurons but is not able to fully substitute for β-catenin loss, likely due to differences in the N-and C-termini between the catenins. Our findings identify severe learning impairments, upregulation of γ-catenin and reductions in synaptic adhesion and scaffold proteins as major consequences of β-catenin loss.
Collapse
Affiliation(s)
- Robert J Wickham
- Department of Neuroscience, Sackler Biomedical Graduate School, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Jonathan M Alexander
- Department of Neuroscience, Sackler Biomedical Graduate School, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Lillian W Eden
- Department of Neuroscience, Sackler Biomedical Graduate School, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Mabel Valencia-Yang
- Department of Neuroscience, Sackler Biomedical Graduate School, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Josué Llamas
- Department of Neuroscience, Sackler Biomedical Graduate School, Tufts University School of Medicine, Boston, MA 02111, USA
| | - John R Aubrey
- Department of Neuroscience, Sackler Biomedical Graduate School, Tufts University School of Medicine, Boston, MA 02111, USA
| | - Michele H Jacob
- Department of Neuroscience, Sackler Biomedical Graduate School, Tufts University School of Medicine, Boston, MA 02111, USA
| |
Collapse
|
16
|
Morgan RG, Ridsdale J, Payne M, Heesom KJ, Wilson MC, Davidson A, Greenhough A, Davies S, Williams AC, Blair A, Waterman ML, Tonks A, Darley RL. LEF-1 drives aberrant β-catenin nuclear localization in myeloid leukemia cells. Haematologica 2019; 104:1365-1377. [PMID: 30630973 PMCID: PMC6601079 DOI: 10.3324/haematol.2018.202846] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/26/2018] [Accepted: 01/03/2019] [Indexed: 12/24/2022] Open
Abstract
Canonical Wnt/β-catenin signaling is frequently dysregulated in myeloid leukemias and is implicated in leukemogenesis. Nuclear-localized β-catenin is indicative of active Wnt signaling and is frequently observed in acute myeloid leukemia (AML) patients; however, some patients exhibit little or no nuclear β-catenin even where cytosolic β-catenin is abundant. Control of the subcellular localization of β-catenin therefore represents an additional mechanism regulating Wnt signaling in hematopoietic cells. To investigate the factors mediating the nuclear-localization of β-catenin, we carried out the first nuclear/cytoplasmic proteomic analysis of the β-catenin interactome in myeloid leukemia cells and identified putative novel β-catenin interactors. Comparison of interacting factors between Wnt-responsive cells (high nuclear β-catenin) versus Wnt-unresponsive cells (low nuclear β-catenin) suggested the transcriptional partner, LEF-1, could direct the nuclear-localization of β-catenin. The relative levels of nuclear LEF-1 and β-catenin were tightly correlated in both cell lines and in primary AML blasts. Furthermore, LEF-1 knockdown perturbed β-catenin nuclear-localization and transcriptional activation in Wnt-responsive cells. Conversely, LEF-1 overexpression was able to promote both nuclear-localization and β-catenin-dependent transcriptional responses in previously Wnt-unresponsive cells. This is the first β-catenin interactome study in hematopoietic cells and reveals LEF-1 as a mediator of nuclear β- catenin level in human myeloid leukemia.
Collapse
Affiliation(s)
- Rhys G Morgan
- School of Life Sciences, University of Sussex, Brighton, UK .,School of Cellular and Molecular Medicine, University of Bristol, UK
| | - Jenna Ridsdale
- Department of Haematology, Division of Cancer and Genetics, School of Medicine, Cardiff University, UK
| | - Megan Payne
- School of Life Sciences, University of Sussex, Brighton, UK
| | | | | | | | | | - Sara Davies
- Department of Haematology, Division of Cancer and Genetics, School of Medicine, Cardiff University, UK
| | - Ann C Williams
- School of Life Sciences, University of Sussex, Brighton, UK
| | - Allison Blair
- School of Life Sciences, University of Sussex, Brighton, UK
| | - Marian L Waterman
- Department of Microbiology and Molecular Genetics, University of California, Irvine, CA, USA
| | - Alex Tonks
- Department of Haematology, Division of Cancer and Genetics, School of Medicine, Cardiff University, UK
| | - Richard L Darley
- Department of Haematology, Division of Cancer and Genetics, School of Medicine, Cardiff University, UK
| |
Collapse
|
17
|
Wu Q, Mathers C, Wang EW, Sheng S, Wenkert D, Huang JH. TGF-β Initiates β-Catenin-Mediated CTGF Secretory Pathway in Old Bovine Nucleus Pulposus Cells: A Potential Mechanism for Intervertebral Disc Degeneration. JBMR Plus 2018; 3:e10069. [PMID: 30828686 PMCID: PMC6383704 DOI: 10.1002/jbm4.10069] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/26/2018] [Revised: 05/07/2018] [Accepted: 06/12/2018] [Indexed: 01/17/2023] Open
Abstract
We have recently demonstrated that overexpression of Smurf2 under the control of type II collagen alpha 1 (Col2a1) promoter induces an intervertebral disc degeneration phenotype in Col2a1‐Smurf2 transgenic mice. The chondrocyte‐like cells that express type II collagen and Smurf2 in the transgenic mouse discs are prone to degenerate. However, how the chondrocyte‐like cells contribute to disc degeneration is not known. Here, we utilized primary old bovine nucleus pulposus (NP) cells as substitutes for the chondrocyte‐like cells in Col2a1‐Smurf2 transgenic mouse discs to identify mechanism. We found that 35% of the cells were senescent; TGF‐β treatment of the cells induced a rapid moderate accumulation of β‐catenin, which interacted with connective tissue growth factor (CTGF/CCN2) in the cytoplasm and recruited it to the membrane for secretion. The TGF‐β‐initiated β‐catenin‐mediated CTGF secretory cascade did not occur in primary young bovine NP cells; however, when Smurf2 was overexpressed in young bovine NP cells, the cells became senescent and allowed this cascade to occur. These results suggest that Smurf2‐induced disc degeneration in Col2a1‐Smurf2 transgenic mice occurs through activation of CTGF secretory pathway in senescent disc cells. © 2018 The Authors JBMR Plus published by Wiley Periodicals, Inc. on behalf of American Society for Bone and Mineral Research.
Collapse
Affiliation(s)
- Qiuqian Wu
- Department of Neurosurgery Institute for Translational Medicine Baylor Scott & White Health Temple TX USA
| | - Chun Mathers
- Department of Neurosurgery Institute for Translational Medicine Baylor Scott & White Health Temple TX USA
| | - Ernest W Wang
- Department of Neurosurgery Institute for Translational Medicine Baylor Scott & White Health Temple TX USA
| | - Sen Sheng
- Department of Neurosurgery Institute for Translational Medicine Baylor Scott & White Health Temple TX USA
| | - David Wenkert
- Division of Endocrinology Baylor Scott & White Health Temple TX USA
| | - Jason H Huang
- Department of Neurosurgery Baylor Scott & White Health Temple TX USA
| |
Collapse
|
18
|
Alaee M, Nool K, Pasdar M. Plakoglobin restores tumor suppressor activity of p53 R175H mutant by sequestering the oncogenic potential of β-catenin. Cancer Sci 2018; 109:1876-1888. [PMID: 29660231 PMCID: PMC5989865 DOI: 10.1111/cas.13612] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2018] [Revised: 04/03/2018] [Accepted: 04/06/2018] [Indexed: 12/16/2022] Open
Abstract
Tumor suppressor/transcription factor p53 is mutated in over 50% of all cancers. Some mutant p53 proteins have not only lost tumor suppressor activities but they also gain oncogenic functions (GOF). One of the most frequently expressed GOF p53 mutants is Arg175His (p53R175H ) with well-documented roles in cancer development and progression. Plakoglobin is a cell adhesion and signaling protein and a paralog of β-catenin. Unlike β-catenin that has oncogenic function through its role in the Wnt pathway, plakoglobin generally acts as a tumor/metastasis suppressor. We have shown that plakoglobin interacted with wild type and a number of p53 mutants in various carcinoma cell lines. Plakoglobin and mutant p53 interacted with the promoter and regulated the expression of several p53 target genes. Furthermore, plakoglobin interactions with p53 mutants restored their tumor suppressor/metastasis activities in vitro. GOF p53 mutants induce accumulation and oncogenic activation of β-catenin. Previously, we showed that one mechanism by which plakoglobin may suppress tumorigenesis is by sequestering β-catenin's oncogenic activity. Here, we examined the effects of p53R175H expression on β-catenin accumulation and transcriptional activation and their modifications by plakoglobin coexpression. We showed that p53R175H expression in plakoglobin null cells increased total and nuclear levels of β-catenin and its transcriptional activity. Coexpression of plakoglobin in these cells promoted β-catenin's proteasomal degradation, and decreased its nuclear levels and transactivation. Wnt/β-catenin targets, c-MYC and S100A4 were upregulated in p53R175H cells and were downregulated when plakoglobin was coexpressed. Plakoglobin-p53R175H cells also showed significant reduction in their migration and invasion in vitro.
Collapse
Affiliation(s)
- Mahsa Alaee
- Department of OncologyUniversity of AlbertaEdmontonCanada
| | - Kristina Nool
- Department of OncologyUniversity of AlbertaEdmontonCanada
| | - Manijeh Pasdar
- Department of OncologyUniversity of AlbertaEdmontonCanada
| |
Collapse
|
19
|
Aktary Z, Alaee M, Pasdar M. Beyond cell-cell adhesion: Plakoglobin and the regulation of tumorigenesis and metastasis. Oncotarget 2018; 8:32270-32291. [PMID: 28416759 PMCID: PMC5458283 DOI: 10.18632/oncotarget.15650] [Citation(s) in RCA: 53] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2016] [Accepted: 12/16/2016] [Indexed: 12/13/2022] Open
Abstract
Plakoglobin (also known as? -catenin) is a member of the Armadillo family of proteins and a paralog of β -catenin. Plakoglobin is a component of both the adherens junctions and desmosomes, and therefore plays a vital role in the regulation of cell-cell adhesion. Similar to β -catenin, plakoglobin is capable of participating in cell signaling in addition to its role in cell-cell adhesion. In this context, β -catenin has a well-documented oncogenic potential as a component of the Wnt signaling pathway. In contrast, while some studies have suggested a tumor promoting activity of plakoglobin in a cell/malignancy specific context, it generally acts as a tumor/metastasis suppressor. How plakoglobin acts as a growth/metastasis inhibitory protein has remained, until recently, unclear. Recent evidence suggests that plakoglobin may suppress tumorigenesis and metastasis by multiple mechanisms, including the suppression of oncogenic signaling, interactions with various proteins involved in tumorigenesis and metastasis, and the regulation of the expression of genes involved in these processes. This review is primarily focused on various mechanisms by which plakoglobin may inhibit tumorigenesis and metastasis.
Collapse
Affiliation(s)
- Zackie Aktary
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada.,Institut Curie, Orsay, France
| | - Mahsa Alaee
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| | - Manijeh Pasdar
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
| |
Collapse
|
20
|
Su H, Sureda-Gomez M, Rabaneda-Lombarte N, Gelabert M, Xie J, Wu W, Adell T. A C-terminally truncated form of β-catenin acts as a novel regulator of Wnt/β-catenin signaling in planarians. PLoS Genet 2017; 13:e1007030. [PMID: 28976975 PMCID: PMC5643146 DOI: 10.1371/journal.pgen.1007030] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2017] [Revised: 10/16/2017] [Accepted: 09/17/2017] [Indexed: 12/12/2022] Open
Abstract
β-Catenin, the core element of the Wnt/β-catenin pathway, is a multifunctional and evolutionarily conserved protein which performs essential roles in a variety of developmental and homeostatic processes. Despite its crucial roles, the mechanisms that control its context-specific functions in time and space remain largely unknown. The Wnt/β-catenin pathway has been extensively studied in planarians, flatworms with the ability to regenerate and remodel the whole body, providing a ‘whole animal’ developmental framework to approach this question. Here we identify a C-terminally truncated β-catenin (β-catenin4), generated by gene duplication, that is required for planarian photoreceptor cell specification. Our results indicate that the role of β-catenin4 is to modulate the activity of β-catenin1, the planarian β-catenin involved in Wnt signal transduction in the nucleus, mediated by the transcription factor TCF-2. This inhibitory form of β-catenin, expressed in specific cell types, would provide a novel mechanism to modulate nuclear β-catenin signaling levels. Genomic searches and in vitro analysis suggest that the existence of a C-terminally truncated form of β-catenin could be an evolutionarily conserved mechanism to achieve a fine-tuned regulation of Wnt/β-catenin signaling in specific cellular contexts. The Wnt signaling pathway is essential for proper intercellular communication in every developmental process since it controls basic cellular events as cell fate or proliferation. The key element of the Wnt signaling is β-catenin, which controls the transcription of multiple genes in the Wnt receiving cell. A main level of regulation of the Wnt/β-catenin signaling occurs in the cytoplasm, where β-catenin protein levels depend on the activity of the β-catenin destruction complex. However, once it reaches the nucleus, β-catenin transcriptional activity requires a fine-tuned regulation to enable the multiple context-specific responses that it performs. These nuclear mechanisms that regulate the Wnt/β-catenin signaling remain poorly understood. Here we report the existence of C-terminal truncated forms of β-catenin in planarians (β-cat3 and 4), which, in vitro, do not show transactivation activity and compete with the canonical planarian β-catenin (β-cat1), thus acting as competitor inhibitors. Functional analyses in planarians indicate that β-cat4 acts as a negative regulator of β-cat1 during planarian eye photoreceptor specification. We provide evidence to suggest that this novel mechanism for the regulation of nuclear β-catenin activity could be conserved across animal evolution.
Collapse
Affiliation(s)
- Hanxia Su
- MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing, China
| | - Miquel Sureda-Gomez
- Departament de Genètica, Microbiologia i Estadística,Facultat de Biologia, Universitat de Barcelona and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Barcelona, Catalunya, Spain
| | - Neus Rabaneda-Lombarte
- Departament de Genètica, Microbiologia i Estadística,Facultat de Biologia, Universitat de Barcelona and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Barcelona, Catalunya, Spain
| | - Maria Gelabert
- Departament de Genètica, Microbiologia i Estadística,Facultat de Biologia, Universitat de Barcelona and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Barcelona, Catalunya, Spain
| | - Jianlei Xie
- MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing, China
| | - Wei Wu
- MOE Key Laboratory of Protein Science, School of Life Sciences, Tsinghua University, Beijing, China
| | - Teresa Adell
- Departament de Genètica, Microbiologia i Estadística,Facultat de Biologia, Universitat de Barcelona and Institut de Biomedicina de la Universitat de Barcelona (IBUB), Universitat de Barcelona, Barcelona, Catalunya, Spain
- * E-mail:
| |
Collapse
|
21
|
Nagel JM, Lahm H, Ofner A, Göke B, Kolligs FT. γ-Catenin acts as a tumor suppressor through context-dependent mechanisms in colorectal cancer. Int J Colorectal Dis 2017; 32:1243-1251. [PMID: 28681073 DOI: 10.1007/s00384-017-2846-0] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 06/20/2017] [Indexed: 02/04/2023]
Abstract
PURPOSE γ-Catenin is a protein closely related to β-catenin. While the overexpression of β-catenin has been linked with impaired prognosis and survival in various malignancies, both oncogenic and tumor suppressor functions have been described for γ-catenin. Thus, its role in cancer remains controversial. In this study, we examined the impact of γ-catenin expression on the malignant potential of colorectal cancer cells. METHODS γ-Catenin was knocked down by short interfering RNA in the γ-catenin-proficient DLD-1 cell line and stably overexpressed in the γ-catenin-deficient cell line RKO. The effects of these molecular manipulations on the malignant potential of the cell lines were tested in vitro and in vivo in a xenograft tumor model. RESULTS γ-Catenin contributed to Wnt signaling independent of the cellular context. Unlike its sister molecule β-catenin, γ-catenin inhibited cellular invasion and anoikis in cells endogenously expressing γ-catenin. In line with this tumor suppressor function, its de novo expression in RKO cells inhibited proliferation via cell cycle arrest. In a xenograft tumor model, overexpression of γ-catenin starkly reduced tumor growth in vivo. CONCLUSIONS This is the first report demonstrating a tumor-suppressive effect of γ-catenin in colorectal cancer both in vitro and in vivo. Detailed in vitro analysis revealed that effects of γ-catenin differ in γ-catenin proficient and deficient cells, indicating that its function in colorectal cancer is dependent on the cellular context. This finding adds to our understanding of γ-catenin and may have implications for future studies of catenin/Wnt targeted cancer therapies.
Collapse
Affiliation(s)
- Jutta Maria Nagel
- Department of Medicine II, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany.
| | - Harald Lahm
- Institute of Molecular Animal Breeding and Biotechnology, Gene Center, Ludwig-Maximilian University of Munich (LMU), Feodor-Lynen-Strasse 25, 81377, Munich, Germany
- Department of Cardiovascular Surgery, Division of Experimental Surgery, German Heart Center Munich, Technical University (TU), Munich Heart Alliance, Lazarettstraße 36, 80636, Munich, Germany
| | - Andrea Ofner
- Department of Medicine II, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
| | - Burkhard Göke
- Department of Medicine II, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
- University Hospital Hamburg-Eppendorf (UKE), Martinistraße 52, 20246, Hamburg, Germany
| | - Frank Thomas Kolligs
- Department of Medicine II, University Hospital, LMU Munich, Marchioninistr. 15, 81377, Munich, Germany
- Department of Internal Medicine and Gastroenterology, HELIOS Klinikum Berlin-Buch, Schwanebecker Chaussee 50, 13125, Berlin, Germany
| |
Collapse
|
22
|
Jazi MS, Najafi SMA. Beta-catenin Forms Protein Aggregation at High Concentrations in HEK293TCells. IRANIAN JOURNAL OF MEDICAL SCIENCES 2017; 42:66-72. [PMID: 28293052 PMCID: PMC5337767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Abstract
BACKGROUND The canonical Wnt signal transduction (or the Wnt/β-catenin pathway) plays a crucial role in the development of animals and in carcinogenesis. Beta-catenin is the central component of this signaling pathway. The activation of Wnt/β-catenin signaling results in the cytoplasmic and nuclear accumulation of β-catenin. In the nucleus, β-catenin interacts with the TCF/LEF transcription factors and, therefore, participates in the upregulation or downregulation of some important genes involved in diverse cellular activities. In addition, β-catenin is a critical component of the cadherin-mediated cell adherens junction. We had previously noticed that very high cellular concentrations of β-catenin had a negative effect on the transcriptional activity of this protein and, therefore, the aim of this study was to find a mechanism for this negative interaction. METHODS Cell fractionation, western blotting, and immunofluorescence microscopy experiments were performed to measure β-catenin protein levels and β-catenin cellular localization in HEK293Tcells transfected with various amounts of a β-catenin-encoding plasmid. Also, total RNA was extracted from the cells and used for reverse transcriptase-PCR experiments to measure the expression of the β-catenin target genes. SPSS, version 16, was used to analyze the results statistically. RESULTS We demonstrated that overexpression of β-catenin led to the formation of rod-shaped protein aggregates. The aggregate structures were mainly formed in the cell nucleus and were heavy enough to be isolated by centrifugation. Beta-catenin aggregate formation was accompanied by a decrease in the expression of the β-catenin target genes used in this study. CONCLUSION Since deregulation of β-catenin function occurs in several human diseases, including cancer and neurological disorders, the results of this paper further support the possible biological and clinical significance of β-catenin aggregate formation.
Collapse
Affiliation(s)
- Marie Saghaeian Jazi
- Department of Molecular Medicine, Golestan University of Medial Sciences, Gorgan, Iran
| | - Seyed Mahmoud Arab Najafi
- Department of Cell and Molecular Biology, School of Biology, Tehran University, Tehran, Iran,Correspondence: Seyed Mahmoud Arab Najafi, PhD; Department of Cell and Molecular Biology, School of Biology, Tehran University, P.O. Box: 14155-6455, Tehran, Iran Tel: +98 21 61113648 Fax: +98 21 66492992
| |
Collapse
|
23
|
Aktary Z, Bertrand JU, Larue L. The WNT-less wonder: WNT-independent β-catenin signaling. Pigment Cell Melanoma Res 2016; 29:524-40. [PMID: 27311806 DOI: 10.1111/pcmr.12501] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 06/14/2016] [Indexed: 12/18/2022]
Abstract
β-catenin is known as an Armadillo protein that regulates gene expression following WNT pathway activation. However, WNT-independent pathways also activate β-catenin. During the establishment of the melanocyte lineage, β-catenin plays an important role. In the context of physiopathology, β-catenin is activated genetically or transiently in various cancers, including melanoma, where it can be found in the nucleus of tumors. In this review, we discuss alternative pathways that activate β-catenin independent of WNTs and highlight what is known regarding these pathways in melanoma. We also discuss the role of β-catenin as a transcriptional regulator in various cell types, with emphasis on the different transcription factors it associates with independent of WNT induction. Finally, the role of WNT-independent β-catenin in melanocyte development and melanomagenesis is also discussed.
Collapse
Affiliation(s)
- Zackie Aktary
- Normal and Pathological Development of Melanocytes, INSERM U1021, Institut Curie, PSL Research University, Orsay, France.,CNRS UMR 3347, Univ Paris-Sud, Univ Paris-Saclay, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Orsay, France
| | - Juliette U Bertrand
- Normal and Pathological Development of Melanocytes, INSERM U1021, Institut Curie, PSL Research University, Orsay, France.,CNRS UMR 3347, Univ Paris-Sud, Univ Paris-Saclay, Orsay, France.,Equipe Labellisée Ligue Contre le Cancer, Orsay, France
| | - Lionel Larue
- Normal and Pathological Development of Melanocytes, INSERM U1021, Institut Curie, PSL Research University, Orsay, France. .,CNRS UMR 3347, Univ Paris-Sud, Univ Paris-Saclay, Orsay, France. .,Equipe Labellisée Ligue Contre le Cancer, Orsay, France.
| |
Collapse
|
24
|
Abstract
β-catenin is widely regarded as the primary transducer of canonical WNT signals to the nucleus. In most vertebrates, there are eight additional catenins that are structurally related to β-catenin, and three α-catenin genes encoding actin-binding proteins that are structurally related to vinculin. Although these catenins were initially identified in association with cadherins at cell-cell junctions, more recent evidence suggests that the majority of catenins also localize to the nucleus and regulate gene expression. Moreover, the number of catenins reported to be responsive to canonical WNT signals is increasing. Here, we posit that multiple catenins form a functional network in the nucleus, possibly engaging in conserved protein-protein interactions that are currently better characterized in the context of actin-based cell junctions.
Collapse
|
25
|
Maturana JL, Niechi I, Silva E, Huerta H, Cataldo R, Härtel S, Barros LF, Galindo M, Tapia JC. Transactivation activity and nucleocytoplasmic transport of β-catenin are independently regulated by its C-terminal end. Gene 2015; 573:115-22. [PMID: 26187068 DOI: 10.1016/j.gene.2015.07.039] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2015] [Accepted: 07/11/2015] [Indexed: 11/20/2022]
Abstract
The key protein in the canonical Wnt pathway is β-catenin, which is phosphorylated both in absence and presence of Wnt signals by different kinases. Upon activation in the cytoplasm, β-catenin can enter into the nucleus to transactivate target gene expression, many of which are cancer-related genes. The mechanism governing β-catenin's nucleocytoplasmic transport has been recently unvealed, although phosphorylation at its C-terminal end and its functional consequences are not completely understood. Serine 646 of β-catenin is a putative CK2 phosphorylation site and lies in a region which has been proposed to be important for its nucleocytoplasmic transport and transactivation activity. This residue was mutated to aspartic acid mimicking CK2-phosphorylation and its effects on β-catenin activity as well as localization were explored. β-Catenin S6464D did not show significant differences in both transcriptional activity and nuclear localization compared to the wild-type form, but displayed a characteristic granular nuclear pattern. Three-dimensional models of nuclei were constructed which showed differences in number and volume of granules, being those from β-catenin S646D more and smaller than the wild-type form. FRAP microscopy was used to compare nuclear export of both proteins which showed a slightly higher but not significant retention of β-catenin S646D. Altogether, these results show that C-terminal phosphorylation of β-catenin seems to be related with its nucleocytoplasmic transport but not transactivation activity.
Collapse
Affiliation(s)
- J L Maturana
- Program of Cellular and Molecular Biology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
| | - I Niechi
- Program of Cellular and Molecular Biology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
| | - E Silva
- Program of Cellular and Molecular Biology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
| | - H Huerta
- Program of Cellular and Molecular Biology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
| | - R Cataldo
- Program of Cellular and Molecular Biology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
| | - S Härtel
- Laboratory for Scientific Image Analysis (SCIAN-Lab), ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
| | - L F Barros
- Centro de Estudios Cientificos, Valdivia, Chile
| | - M Galindo
- Program of Cellular and Molecular Biology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile
| | - J C Tapia
- Program of Cellular and Molecular Biology, ICBM, Faculty of Medicine, University of Chile, Santiago, Chile.
| |
Collapse
|
26
|
Que D, Yang P, Song X, Liu L. Traditional vs. genetic pathogenesis of arrhythmogenic right ventricular cardiomyopathy. Europace 2015; 17:1770-6. [DOI: 10.1093/europace/euv042] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2014] [Accepted: 02/08/2015] [Indexed: 12/22/2022] Open
|
27
|
Hickman GJ, Rees RC, Boocock DJ, Pockley AG, Perry CC. Controlling the dynamics of cell transition in heterogeneous cultures using surface chemistry. Adv Healthc Mater 2015; 4:593-601. [PMID: 25393206 DOI: 10.1002/adhm.201400525] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2014] [Revised: 10/08/2014] [Indexed: 11/09/2022]
Abstract
Developing materials that can preferentially select defined cancer cell populations for biological characterization will greatly enhance our understanding of cancer cell growth, differentiation, and invasion. The transitional events between epithelial and mesenchymal phenotypes are particularly crucial, as primary tumors and secondary metastasis are generally epithelial in nature, whereas circulating mesenchymal cells derived from primary epithelial cells appear to facilitate the spread of disease and its resistance to therapy. This study describes an amino-functionalized material, which promotes the enrichment of an epithelial phenotype from a single cell line containing both epithelial and mesenchymal subpopulations of cancer cells. The isolation and transitional control of such subpopulations using functional materials will advance understanding of the disease process, have a significant impact on the downstream development of new targeted cancer therapeutics, and also be applicable to tissue engineering and regenerative medicine.
Collapse
Affiliation(s)
- Graham J. Hickman
- The John van Geest Cancer Research Centre; Nottingham Trent University; Nottingham NG11 8NS UK
- Biomolecular & Materials Interface Research Group; Nottingham Trent University; Nottingham NG11 8NS UK
| | - Robert C. Rees
- The John van Geest Cancer Research Centre; Nottingham Trent University; Nottingham NG11 8NS UK
| | - David J. Boocock
- The John van Geest Cancer Research Centre; Nottingham Trent University; Nottingham NG11 8NS UK
| | - A. Graham Pockley
- The John van Geest Cancer Research Centre; Nottingham Trent University; Nottingham NG11 8NS UK
| | - Carole C. Perry
- Biomolecular & Materials Interface Research Group; Nottingham Trent University; Nottingham NG11 8NS UK
| |
Collapse
|
28
|
Abstract
The arrival of multicellularity in evolution facilitated cell-cell signaling in conjunction with adhesion. As the ectodomains of cadherins interact with each other directly in trans (as well as in cis), spanning the plasma membrane and associating with multiple other entities, cadherins enable the transduction of "outside-in" or "inside-out" signals. We focus this review on signals that originate from the larger family of cadherins that are inwardly directed to the nucleus, and thus have roles in gene control or nuclear structure-function. The nature of cadherin complexes varies considerably depending on the type of cadherin and its context, and we will address some of these variables for classical cadherins versus other family members. Substantial but still fragmentary progress has been made in understanding the signaling mediators used by varied cadherin complexes to coordinate the state of cell-cell adhesion with gene expression. Evidence that cadherin intracellular binding partners also localize to the nucleus is a major point of interest. In some models, catenins show reduced binding to cadherin cytoplasmic tails favoring their engagement in gene control. When bound, cadherins may serve as stoichiometric competitors of nuclear signals. Cadherins also directly or indirectly affect numerous signaling pathways (e.g., Wnt, receptor tyrosine kinase, Hippo, NFκB, and JAK/STAT), enabling cell-cell contacts to touch upon multiple biological outcomes in embryonic development and tissue homeostasis.
Collapse
Affiliation(s)
- Pierre D McCrea
- Department of Genetics, University of Texas MD Anderson Cancer Center; Program in Genes & Development, Graduate School in Biomedical Sciences, Houston, Texas, USA.
| | - Meghan T Maher
- Department of Biology, Washington University in St. Louis, St. Louis, Missouri, USA
| | - Cara J Gottardi
- Cellular and Molecular Biology, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA; Medicine, Northwestern University Feinberg School of Medicine, Chicago, Illinois, USA.
| |
Collapse
|
29
|
Zhou Y, Wu J, Fu X, Du W, Zhou L, Meng X, Yu H, Lin J, Ye W, Liu J, Peng H, Liu RY, Pan C, Huang W. OTUB1 promotes metastasis and serves as a marker of poor prognosis in colorectal cancer. Mol Cancer 2014; 13:258. [PMID: 25431208 PMCID: PMC4351937 DOI: 10.1186/1476-4598-13-258] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/27/2014] [Accepted: 11/03/2014] [Indexed: 02/06/2023] Open
Abstract
Background OTUB1 (OTU deubiquitinase, ubiquitin aldehyde binding 1) is a deubiquitinating enzyme (DUB) that belongs to the OTU (ovarian tumor) superfamily. The aim of this study was to clarify the role of OTUB1 in colorectal cancer (CRC) and to identify the mechanism underlying its function. Methods Two hundred and sixty CRC samples were subjected to association analysis of OTUB1 expression and clinicopathological variables using immunohistochemical (IHC) staining. Overexpression of OTUB1 was achieved in SW480 and DLD-1 cells, and downregulation of OTUB1 was employed in SW620 cells. Then, migration and invasion assays were performed, and markers of the epithelial-mesenchymal transition (EMT) were analyzed. In addition, hepatic metastasis models in mice were used to validate the function of OTUB1 in vivo. Results OTUB1 was overexpressed in CRC tissues, and the expression level of OTUB1 was associated with metastasis. A high expression level of OTUB1 was also associated with poor survival, and OTUB1 served as an independent prognostic factor in multivariate analysis. OTUB1 also promoted the metastasis of CRC cell lines in vitro and in vivo by regulating EMT. Conclusions OTUB1 promotes CRC metastasis by facilitating EMT and acts as a potential distant metastasis marker and prognostic factor in CRC. Targeting OTUB1 may be helpful for the treatment of CRC. Electronic supplementary material The online version of this article (doi:10.1186/1476-4598-13-258) contains supplementary material, which is available to authorized users.
Collapse
Affiliation(s)
| | | | | | | | | | | | | | | | | | | | | | | | - Changchuan Pan
- State Key Laboratory of Oncology in Southern China, Sun Yat-sen University Cancer Center;Collaborative Innovation Center for Cancer Medicine, No, 651 Dongfeng East Road, Guangzhou 510060, China.
| | | |
Collapse
|
30
|
Janus-faces of NME-oncoprotein interactions. Naunyn Schmiedebergs Arch Pharmacol 2014; 388:175-87. [PMID: 25366701 DOI: 10.1007/s00210-014-1062-5] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Accepted: 10/15/2014] [Indexed: 12/26/2022]
Abstract
Since the identification of Nm23 (NME1, NME/NM23 nucleoside diphosphate kinase 1) as the first non-metastatic protein, a great deal of research on members of the NME family of proteins has focused on roles in processes implicated in carcinogenesis and particularly their regulation of cellular motility and the process of metastatic spread. To date, there are ten identified members of this family of genes, and these can be dichotomized into groups both taxonomically and by the presence or absence of their nucleoside diphosphate kinase activity with NMEs 1-4 encoding nucleoside diphosphate kinases (NDPKs) and NMEs 5-9 plus RP2 displaying little if any NDPK activity. NMEs are relatively small proteins that can form hetero-oligomers (typically hexamers), and given the apparent genetic redundancy of some NMEs and the number of different isoforms, it is perhaps not surprising that there remains a great deal of uncertainty regarding their function and even more regarding cellular mechanisms of action. Since residues that contribute to NDPK activity span much of the protein, it seems likely that the consequences of NME expression must be mediated through their NDPK activity, through interactions with other structures in cells including protein-protein interactions or through combinations of these. Our goal in this review is to focus on some of the protein-protein interactions that have been identified and to highlight some of the challenges that face this area of research.
Collapse
|
31
|
|
32
|
Morgan RG, Ridsdale J, Tonks A, Darley RL. Factors Affecting the Nuclear Localization of β-Catenin in Normal and Malignant Tissue. J Cell Biochem 2014; 115:1351-61. [DOI: 10.1002/jcb.24803] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2014] [Accepted: 03/04/2014] [Indexed: 01/01/2023]
Affiliation(s)
- Rhys G. Morgan
- School of Cellular and Molecular Medicine; University of Bristol; University Walk; Clifton Bristol BS8 1TD UK
| | - Jenna Ridsdale
- Department of Haematology; Institute of Cancer & Genetics; School of Medicine; Cardiff University; S Wales CF14 4XN UK
| | - Alex Tonks
- Department of Haematology; Institute of Cancer & Genetics; School of Medicine; Cardiff University; S Wales CF14 4XN UK
| | - Richard L. Darley
- Department of Haematology; Institute of Cancer & Genetics; School of Medicine; Cardiff University; S Wales CF14 4XN UK
| |
Collapse
|
33
|
Patel DM, Green KJ. Desmosomes in the Heart: A Review of Clinical and Mechanistic Analyses. ACTA ACUST UNITED AC 2014; 21:109-28. [DOI: 10.3109/15419061.2014.906533] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
|
34
|
Abstract
α-Catenin (α-cat) is an actin-binding protein required for cell-cell cohesion. Although this adhesive function for α-cat is well appreciated, cells contain a substantial amount of nonjunctional α-cat that may be used for other functions. We show that α-cat is a nuclear protein that can interact with β-catenin (β-cat) and T-cell factor (TCF) and that the nuclear accumulation of α-cat depends on β-cat. Using overexpression, knockdown, and chromatin immunoprecipitation approaches, we show that α-cat attenuates Wnt/β-cat-responsive genes in a manner that is downstream of β-cat/TCF loading on promoters. Both β-cat- and actin-binding domains of α-cat are required to inhibit Wnt signaling. A nuclear-targeted form of α-cat induces the formation of nuclear filamentous actin, whereas cells lacking α-cat show altered nuclear actin properties. Formation of nuclear actin filaments correlates with reduced RNA synthesis and altered chromatin organization. Conversely, nuclear extracts made from cells lacking α-cat show enhanced general transcription in vitro, an activity that can be partially rescued by restoring the C-terminal actin-binding region of α-cat. These data demonstrate that α-cat may limit gene expression by affecting nuclear actin organization.
Collapse
|
35
|
Kulpa DA, Brehm JH, Fromentin R, Cooper A, Cooper C, Ahlers J, Chomont N, Sékaly RP. The immunological synapse: the gateway to the HIV reservoir. Immunol Rev 2014; 254:305-25. [PMID: 23772628 PMCID: PMC3707302 DOI: 10.1111/imr.12080] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Abstract
A major challenge in the development of a cure for human immunodeficiency virus (HIV) has been the incomplete understanding of the basic mechanisms underlying HIV persistence during antiretroviral therapy. It is now realized that the establishment of a latently infected reservoir refractory to immune system recognition has thus far hindered eradication efforts. Recent investigation into the innate immune response has shed light on signaling pathways downstream of the immunological synapse critical for T-cell activation and establishment of T-cell memory. This has led to the understanding that the cell-to-cell contacts observed in an immunological synapse that involve the CD4+ T cell and antigen-presenting cell or T-cell–T-cell interactions enhance efficient viral spread and facilitate the induction and maintenance of latency in HIV-infected memory T cells. This review focuses on recent work characterizing the immunological synapse and the signaling pathways involved in T-cell activation and gene regulation in the context of HIV persistence.
Collapse
Affiliation(s)
- Deanna A Kulpa
- Division of Infectious Diseases, Vaccine and Gene Therapy Institute-Florida (VGTI-FL), Port Saint Lucie, FL 34987, USA
| | | | | | | | | | | | | | | |
Collapse
|
36
|
|
37
|
Plakoglobin but not desmoplakin regulates keratinocyte cohesion via modulation of p38MAPK signaling. J Invest Dermatol 2014; 134:1655-1664. [PMID: 24441103 DOI: 10.1038/jid.2014.21] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2013] [Revised: 11/25/2013] [Accepted: 12/10/2013] [Indexed: 12/16/2022]
Abstract
Plakoglobin (Pg) and desmoplakin (DP) are adapter proteins within the desmosome, providing a mechanical link between desmosomal cadherins as transmembrane adhesion molecules and the intermediate filament cytoskeleton. As in the severe skin blistering disease pemphigus, autoantibodies against desmosomal adhesion molecules induce loss of keratinocyte cohesion at least in part via p38 mitogen-activated protein kinase (p38MAPK) activation and depletion of desmosomal components, we evaluated the roles of Pg and DP in the p38MAPK-dependent loss of cell adhesion. Silencing of either Pg or DP reduced cohesion of cultured human keratinocytes in dissociation assays. However, Pg but not DP silencing caused activation of p38MAPK-dependent keratin filament collapse and cell dissociation. Interestingly, extranuclear but not nuclear Pg rescued loss of cell adhesion and keratin retraction. In line with this, Pg regulated the levels of the desmosomal adhesion molecule desmoglein 3 and tethered p38MAPK to desmosomal complexes. Our data demonstrate a role of extranuclear Pg in controlling cell adhesion via p38MAPK-dependent regulation of keratin filament organization.
Collapse
|
38
|
Aktary Z, Pasdar M. Plakoglobin represses SATB1 expression and decreases in vitro proliferation, migration and invasion. PLoS One 2013; 8:e78388. [PMID: 24260116 PMCID: PMC3832639 DOI: 10.1371/journal.pone.0078388] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2013] [Accepted: 09/18/2013] [Indexed: 01/16/2023] Open
Abstract
Plakoglobin (γ-catenin) is a homolog of β-catenin with dual adhesive and signaling functions. Plakoglobin participates in cell-cell adhesion as a component of the adherens junction and desmosomes whereas its signaling function is mediated by its interactions with various intracellular protein partners. To determine the role of plakoglobin during tumorigenesis and metastasis, we expressed plakoglobin in the human tongue squamous cell carcinoma (SCC9) cells and compared the mRNA profiles of parental SCC9 cells and their plakoglobin-expressing transfectants (SCC9-PG). We observed that the mRNA levels of SATB1, the oncogenic chromatin remodeling factor, were decreased approximately 3-fold in SCC9-PG cells compared to parental SCC9 cells. Here, we showed that plakoglobin decreased levels of SATB1 mRNA and protein in SCC9-PG cells and that plakoglobin and p53 associated with the SATB1 promoter. Plakoglobin expression also resulted in decreased SATB1 promoter activity. These results were confirmed following plakoglobin expression in the very low plakoglobin expressing and invasive mammary carcinoma cell line MDA-MB-231 cells (MDA-231-PG). In addition, knockdown of endogenous plakoglobin in the non-invasive mammary carcinoma MCF-7 cells (MCF-7-shPG) resulted in increased SATB1 mRNA and protein. Plakoglobin expression also resulted in increased mRNA and protein levels of the metastasis suppressor Nm23-H1, a SATB1 target gene. Furthermore, the levels of various SATB1 target genes involved in tumorigenesis and metastasis were altered in MCF-7-shPG cells relative to parental MCF-7 cells. Finally, plakoglobin expression resulted in decreased in vitro proliferation, migration and invasion in different carcinoma cell lines. Together with the results of our previous studies, the data suggests that plakoglobin suppresses tumorigenesis and metastasis through the regulation of genes involved in these processes.
Collapse
Affiliation(s)
- Zackie Aktary
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
| | - Manijeh Pasdar
- Department of Oncology, University of Alberta, Edmonton, Alberta, Canada
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
| |
Collapse
|
39
|
Abstract
Desmosomes anchor intermediate filaments at sites of cell contact established by the interaction of cadherins extending from opposing cells. The incorporation of cadherins, catenin adaptors, and cytoskeletal elements resembles the closely related adherens junction. However, the recruitment of intermediate filaments distinguishes desmosomes and imparts a unique function. By linking the load-bearing intermediate filaments of neighboring cells, desmosomes create mechanically contiguous cell sheets and, in so doing, confer structural integrity to the tissues they populate. This trait and a well-established role in human disease have long captured the attention of cell biologists, as evidenced by a publication record dating back to the mid-1860s. Likewise, emerging data implicating the desmosome in signaling events pertinent to organismal development, carcinogenesis, and genetic disorders will secure a prominent role for desmosomes in future biological and biomedical investigations.
Collapse
Affiliation(s)
- Robert M Harmon
- Department of Pathology, Northwestern University Feinberg, School of Medicine , Chicago, IL , USA
| | | |
Collapse
|
40
|
γ-Catenin at adherens junctions: mechanism and biologic implications in hepatocellular cancer after β-catenin knockdown. Neoplasia 2013; 15:421-34. [PMID: 23555187 DOI: 10.1593/neo.122098] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2012] [Revised: 01/29/2013] [Accepted: 01/30/2013] [Indexed: 12/22/2022] Open
Abstract
β-Catenin is important in liver homeostasis as a part of Wnt signaling and adherens junctions (AJs), while its aberrant activation is observed in hepatocellular carcinoma (HCC). We have reported hepatocyte-specific β-catenin knockout (KO) mice to lack adhesive defects as γ-catenin compensated at AJ. Because γ-catenin is a desmosomal protein, we asked if its increase in KO might deregulate desmosomes. No changes in desmosomal proteins or ultrastructure other than increased plakophilin-3 were observed. To further elucidate the role and regulation of γ-catenin, we contemplate an in vitro model and show γ-catenin increase in HCC cells upon β-catenin knockdown (KD). Here, γ-catenin is unable to rescue β-catenin/T cell factor (TCF) reporter activity; however, it sufficiently compensates at AJs as assessed by scratch wound assay, centrifugal assay for cell adhesion (CAFCA), and hanging drop assays. γ-Catenin increase is observed only after β-catenin protein decrease and not after blockade of its transactivation. γ-Catenin increase is associated with enhanced serine/threonine phosphorylation and abrogated by protein kinase A (PKA) inhibition. In fact, several PKA-binding sites were detected in γ-catenin by in silico analysis. Intriguingly γ-catenin KD led to increased β-catenin levels and transactivation. Thus, γ-catenin compensates for β-catenin loss at AJ without affecting desmosomes but is unable to fulfill functions in Wnt signaling. γ-Catenin stabilization after β-catenin loss is brought about by PKA. Catenin-sensing mechanism may depend on absolute β-catenin levels and not its activity. Anti-β-catenin therapies for HCC affecting total β-catenin may target aberrant Wnt signaling without negatively impacting intercellular adhesion, provided mechanisms leading to γ-catenin stabilization are spared.
Collapse
|
41
|
Chen YJ, Lee LY, Chao YK, Chang JT, Lu YC, Li HF, Chiu CC, Li YC, Li YL, Chiou JF, Cheng AJ. DSG3 facilitates cancer cell growth and invasion through the DSG3-plakoglobin-TCF/LEF-Myc/cyclin D1/MMP signaling pathway. PLoS One 2013; 8:e64088. [PMID: 23737966 PMCID: PMC3667790 DOI: 10.1371/journal.pone.0064088] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2012] [Accepted: 04/10/2013] [Indexed: 02/04/2023] Open
Abstract
Desmoglein 3 (DSG3) is a component of the desmosome, which confers strong cell-cell adhesion. Previously, an oncogenic function of DSG3 has been found in head neck cancer (HNC). Here, we investigated how this molecule contributes to the malignant phenotype. Because DSG3 is associated with plakoglobin, we examined whether these phenotypic alterations were mediated through the plakoglobin molecule. Immunoprecipitation and immunofluorescence staining revealed that DSG3 silencing disrupted its interaction with plakoglobin and induced plakoglobin translocation from the cytoplasm to the nucleus. Knockdown of DSG3 significantly increased the interaction of plakoglobin with the transcriptional factor TCF and suppressed the TCF/LEF transcriptional activity. These effects further conferred to reduced expression of the TCF/LEF downstream target genes, including c-myc, cyclin D1, and MMP-7. Functional analyses showed that DSG3 silencing reduced cell growth and arrested cells at G0/G1 phase. Besides, cell migration and invasion abilities were also decreased. These cellular results were confirmed using tumor xenografts in mice, as DSG3 silencing led to the suppressed tumor growth, plakoglobin translocation and reduced expression of TCF/LEF target genes in tumors. Therefore, our study shows that the desmosomal protein DSG3 additionally functions to regulate malignant phenotypes via nuclear signaling. In conclusion, we found that DSG3 functions as an oncogene and facilitates cancer growth and invasion in HNC cells through the DSG3-plakoglobin-TCF/LEF pathway.
Collapse
Affiliation(s)
- Yin-Ju Chen
- Department of Radiation Oncology, Taipei Medical University Hospital, Taipei, Taiwan
- Translational Research Laboratory, Taipei Medical University Hospital, Taipei, Taiwan
- Department of Medical Biotechnology, Chang Gung University, Taoyuan, Taiwan
| | - Li-Yu Lee
- Department of Pathology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Yin-Ka Chao
- Department of Thoracic Surgery, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Joseph T. Chang
- Department of Radiation Oncology, Chang Gung Memorial Hospital, Taoyuan, Taiwan
| | - Ya-Ching Lu
- Department of Medical Biotechnology, Chang Gung University, Taoyuan, Taiwan
| | - Hsiao-Fang Li
- Department of Medical Biotechnology, Chang Gung University, Taoyuan, Taiwan
| | - Ching-Chi Chiu
- Department of Medical Biotechnology, Chang Gung University, Taoyuan, Taiwan
| | - Yi-Chen Li
- Department of Medical Biotechnology, Chang Gung University, Taoyuan, Taiwan
| | - Yan-Liang Li
- Department of Medical Biotechnology, Chang Gung University, Taoyuan, Taiwan
| | - Jeng-Fong Chiou
- Department of Radiation Oncology, Taipei Medical University Hospital, Taipei, Taiwan
- Translational Research Laboratory, Taipei Medical University Hospital, Taipei, Taiwan
- Department of Radiology, School of Medicine, College of Medicine, Taipei Medical University, Taipei, Taiwan
- Cancer Center, Taipei Medical University Hospital, Taipei, Taiwan
| | - Ann-Joy Cheng
- Department of Medical Biotechnology, Chang Gung University, Taoyuan, Taiwan
- * E-mail:
| |
Collapse
|
42
|
Aktary Z, Kulak S, Mackey J, Jahroudi N, Pasdar M. Plakoglobin interacts with the transcription factor p53 and regulates the expression of 14-3-3σ. J Cell Sci 2013; 126:3031-42. [PMID: 23687381 DOI: 10.1242/jcs.120642] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Plakoglobin (γ-catenin), a constituent of the adherens junction and desmosomes, has signaling capabilities typically associated with tumor/metastasis suppression through mechanisms that remain undefined. To determine the role of plakoglobin during tumorigenesis and metastasis, we expressed plakoglobin in human tongue squamous cell carcinoma (SCC9) cells and compared the mRNA profiles of parental SCC9 cells and their plakoglobin-expressing transfectants (SCC9-PG). We detected several p53-target genes whose levels were altered upon plakoglobin expression. In this study, we identified the p53 regulated tumor suppressor 14-3-3σ as a direct plakoglobin-p53 target gene. Coimmunoprecipitation experiments revealed that plakoglobin and p53 interact, and chromatin immunoprecipitation and electrophoretic mobility shift assays revealed that plakoglobin and p53 associate with the 14-3-3σ promoter. Furthermore, luciferase reporter assays showed that p53 transcriptional activity is increased in the presence of plakoglobin. Finally, knockdown of plakoglobin in MCF-7 cells followed by luciferase assays confirmed that p53 transcriptional activity is enhanced in the presence of plakoglobin. Our data suggest that plakoglobin regulates gene expression in conjunction with p53 and that plakoglobin may regulate p53 transcriptional activity, which may account, in part, for the tumor/metastasis suppressor activity of plakoglobin.
Collapse
Affiliation(s)
- Zackie Aktary
- Department of Cell Biology, University of Alberta, Edmonton, AB T6G 2H7, Canada
| | | | | | | | | |
Collapse
|
43
|
Plakoglobin as a regulator of desmocollin gene expression. J Invest Dermatol 2013; 133:2732-2740. [PMID: 23652796 PMCID: PMC3760975 DOI: 10.1038/jid.2013.220] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2013] [Revised: 04/10/2013] [Accepted: 04/12/2013] [Indexed: 11/08/2022]
Abstract
Desmosomes are cell adhesion junctions required for the normal development and maintenance of mammalian tissues and organs such as the skin, skin appendages and the heart. The goal of the present study was to investigate how desmocollins (DSC), transmembrane components of desmosomes, are regulated at the transcriptional level. We hypothesized that differential expression of the Dsc2 and Dsc3 genes is a prerequisite for normal development of skin appendages. We demonstrate that plakoglobin (Pg) in conjunction with Lef-1 differentially regulates the proximal promoters of these two genes. Specifically, we found that Lef-1 acts as a switch activating Dsc2 and repressing Dsc3 in the presence of Pg. Interestingly, we also determined that NFκB pathway components, down-stream effectors of the Eda/EDAR signaling cascade, can activate Dsc2 expression. We hypothesize that Lef-1 and Eda/EDAR/NFκB signaling contribute to a shift in Dsc isoform expression from Dsc3 to Dsc2 in placode keratinocytes. It is tempting to speculate that this shift is required for invasive growth of placode keratinocytes into the dermis, a crucial step in skin appendage formation.
Collapse
|
44
|
Morgan RG, Liddiard K, Pearn L, Pumford SL, Burnett AK, Darley RL, Tonks A. γ-Catenin is expressed throughout normal human hematopoietic development and is required for normal PU.1-dependent monocyte differentiation. Leukemia 2013; 27:2096-100. [PMID: 23545990 DOI: 10.1038/leu.2013.96] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Affiliation(s)
- R G Morgan
- Department of Hematology, Institute of Cancer & Genetics, School of Medicine, Cardiff University, Wales, UK
| | | | | | | | | | | | | |
Collapse
|
45
|
Recurrent somatic mutation of FAT1 in multiple human cancers leads to aberrant Wnt activation. Nat Genet 2013; 45:253-61. [PMID: 23354438 PMCID: PMC3729040 DOI: 10.1038/ng.2538] [Citation(s) in RCA: 256] [Impact Index Per Article: 23.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2012] [Accepted: 01/02/2013] [Indexed: 12/11/2022]
Abstract
Aberrant Wnt signaling can drive cancer development. In many cancer types, the genetic basis of Wnt pathway activation remains incompletely understood. Here, we report recurrent somatic mutations of the Drosophila melanogaster tumor suppressor-related gene FAT1 in glioblastoma (20.5%), colorectal cancer (7.7%), and head and neck cancer (6.7%). FAT1 encodes a cadherin-like protein, which we found is able to potently suppress cancer cell growth in vitro and in vivo by binding β-catenin and antagonizing its nuclear localization. Inactivation of FAT1 via mutation therefore promotes Wnt signaling and tumorigenesis and affects patient survival. Taken together, these data strongly point to FAT1 as a tumor suppressor gene driving loss of chromosome 4q35, a prevalent region of deletion in cancer. Loss of FAT1 function is a frequent event during oncogenesis. These findings address two outstanding issues in cancer biology: the basis of Wnt activation in non-colorectal tumors and the identity of a 4q35 tumor suppressor.
Collapse
|
46
|
Arrhythmogenic right ventricular cardiomyopathy: Reassessing the link with the desmosome. Pathology 2012; 44:596-604. [DOI: 10.1097/pat.0b013e32835a0163] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
|
47
|
Abstract
Desmosomes are intercellular adhesive junctions that are particularly prominent in tissues experiencing mechanical stress, such as the heart and epidermis. Whereas the related adherens junction links actin to calcium-dependent adhesion molecules known as classical cadherins, desmosomes link intermediate filaments (IF) to the related subfamily of desmosomal cadherins. By tethering these stress-bearing cytoskeletal filaments to the plasma membrane, desmosomes serve as integrators of the IF cytoskeleton throughout a tissue. Recent evidence suggests that IF attachment in turn strengthens desmosomal adhesion. This collaborative arrangement results in formation of a supracellular network, which is critical for imparting mechanical integrity to tissues. Diseases and animal models targeting desmosomal components highlight the importance of desmosomes in development and tissue integrity, while the downregulation of individual protein components in cancer metastasis and wound healing suggests their importance in cell homeostasis. This chapter will provide an update on desmosome composition, function, and regulation, and will also discuss recent work which raises the possibility that desmosome proteins do more than play a structural role in tissues where they reside.
Collapse
|
48
|
Swope D, Li J, Radice GL. Beyond cell adhesion: the role of armadillo proteins in the heart. Cell Signal 2012; 25:93-100. [PMID: 23022961 DOI: 10.1016/j.cellsig.2012.09.025] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2012] [Accepted: 09/24/2012] [Indexed: 10/27/2022]
Abstract
Plakoglobin (PG, γ-Catenin, JUP), a member of the armadillo protein family and close homolog of β-catenin, functions to link cell surface cadherin molecules with the cytoskeleton. PG is the only junctional component found in both desmosomes and adherens junctions and thus plays a critical role in the regulation of cell-cell adhesion. Similar to β-catenin, PG is able to interact with components of the Wnt signaling pathway and directly affect gene expression by binding with LEF/TCF transcription factors. In addition, it has been proposed that PG functions primarily as a competitive inhibitor of β-catenin transcriptional activity by sequestering LEF/TCF. Compared to β-catenin, the contribution of PG as a transcriptional regulator in either physiological or pathological conditions is poorly understood. There is increasing clinical interest in PG as both a structural protein as well as a signaling molecule as mutations have been identified in the human PG gene that cause Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) and cutaneous syndromes. This review will discuss the connection between altered cell adhesion and gene expression and its contribution to disease pathogenesis.
Collapse
Affiliation(s)
- David Swope
- Center for Translational Medicine, Department of Medicine, Jefferson Medical College, Philadelphia, PA 19107, USA
| | | | | |
Collapse
|
49
|
γ-Catenin is overexpressed in acute myeloid leukemia and promotes the stabilization and nuclear localization of β-catenin. Leukemia 2012; 27:336-43. [PMID: 22858986 PMCID: PMC3613703 DOI: 10.1038/leu.2012.221] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023]
Abstract
Canonical Wnt signaling regulates the transcription of T-cell factor (TCF)-responsive genes through the stabilization and nuclear translocation of the transcriptional co-activator, β-catenin. Overexpression of β-catenin features prominently in acute myeloid leukemia (AML) and has previously been associated with poor clinical outcome. Overexpression of γ-catenin mRNA (a close homologue of β-catenin) has also been reported in AML and has been linked to the pathogenesis of this disease, however, the relative roles of these catenins in leukemia remains unclear. Here we report that overexpression and aberrant nuclear localization of γ-catenin is frequent in AML. Significantly, γ-catenin expression was associated with β-catenin stabilization and nuclear localization. Consistent with this, we found that ectopic γ-catenin expression promoted the stabilization and nuclear translocation of β-catenin in leukemia cells. β-Catenin knockdown demonstrated that both γ- and β-catenin contribute to TCF-dependent transcription in leukemia cells. These data indicate that γ-catenin expression is a significant factor in the stabilization of β-catenin in AML. We also show that although normal cells exclude nuclear translocation of both γ- and β-catenin, this level of regulation is lost in the majority of AML patients and cell lines, which allow nuclear accumulation of these catenins and inappropriate TCF-dependent transcription.
Collapse
|
50
|
Kang MA, So EY, Ouchi T. Deregulation of DNA damage response pathway by intercellular contact. J Biol Chem 2012; 287:16246-55. [PMID: 22431734 PMCID: PMC3351312 DOI: 10.1074/jbc.m111.337212] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2011] [Revised: 03/02/2012] [Indexed: 11/06/2022] Open
Abstract
Deregulation of the DNA damage response (DDR) pathway could compromise genomic integrity in normal cells and reduce cancer cell sensitivity to anticancer treatments. We found that intercellular contact stabilizes histone H2AX and γH2AX (H2AX phosphorylated on Ser-139) by up-regulating N/E-cadherin and γ-catenin. γ-catenin and its DNA-binding partner LEF-1 indirectly increase levels of H2AX by suppressing the promoter of the RNF8 ubiquitin ligase, which decreases levels of H2AX protein under conditions of low intercellular contact. Hyperphosphorylation of DDR proteins is induced by up-regulated H2AX. Constitutive apoptosis is caused in confluent cells but is not further induced by DNA damage. This is conceivably due to insufficient p53 activation because ChIP assay shows that its DNA binding ability is not induced in those cells. Together, our results illustrate a novel mechanism of the regulation of DDR proteins by the cadherin-catenin pathway.
Collapse
Affiliation(s)
- Meyke Ausman Kang
- From the Department of Molecular Biosciences, Interdepartmental Biological Sciences Program, Northwestern University, Evanston, Illinois 60201
- the Department of Medicine, Systems Biology Program, National University of Health Sciences, University of Chicago, Evanston, Illinois 60201, and
| | - Eui-Young So
- the Department of Medicine, Systems Biology Program, National University of Health Sciences, University of Chicago, Evanston, Illinois 60201, and
- the Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, New York 14263
| | - Toru Ouchi
- From the Department of Molecular Biosciences, Interdepartmental Biological Sciences Program, Northwestern University, Evanston, Illinois 60201
- the Department of Medicine, Systems Biology Program, National University of Health Sciences, University of Chicago, Evanston, Illinois 60201, and
- the Department of Cancer Genetics, Roswell Park Cancer Institute, Buffalo, New York 14263
| |
Collapse
|