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Wang Y, Xing J, Liang Y, Liang H, Liang N, Li J, Yin G, Li X, Zhang K. The structure and function of multifunctional protein ErbB3 binding protein 1 (Ebp1) and its role in diseases. Cell Biol Int 2024; 48:1069-1079. [PMID: 38884348 DOI: 10.1002/cbin.12196] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Revised: 05/20/2024] [Accepted: 05/27/2024] [Indexed: 06/18/2024]
Abstract
ErbB3-binding protein 1(Ebp1) has two isoforms, p42 Ebp1 and p48 Ebp1, both of which can regulate cell growth and differentiation. But these isoforms often have opposite effects, including contradictory roles in regulation of cell growth in different tissues and cells. P48 Ebp1 belongs to the full-length sequence, while conformational changes in the crystal structure of p42 Ebp1 reveals a lack of an α helix at the amino terminus. Due to the differences in the structures of these two isoforms, they have different binding partners and protein modifications. Ebp1 can function as both an oncogene and a tumor suppressor factor. However, the underlying mechanisms by which these two isoforms exert opposite functions are still not fully understood. In this review, we summarize the genes and the structures of protein of these two isoforms, protein modifications, binding partners and the association of different isoforms with diseases.
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Affiliation(s)
- Ying Wang
- ShanXi Key Laboratory of Stem Cells for Immunological Dermatosis, State Key Breeding Laboratory of Stem Cells for Immunological Dermatosis, Institute of Dermatology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, China
| | - Jianxiao Xing
- ShanXi Key Laboratory of Stem Cells for Immunological Dermatosis, State Key Breeding Laboratory of Stem Cells for Immunological Dermatosis, Institute of Dermatology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, China
| | - Yanyang Liang
- ShanXi Key Laboratory of Stem Cells for Immunological Dermatosis, State Key Breeding Laboratory of Stem Cells for Immunological Dermatosis, Institute of Dermatology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, China
| | - Huifang Liang
- ShanXi Key Laboratory of Stem Cells for Immunological Dermatosis, State Key Breeding Laboratory of Stem Cells for Immunological Dermatosis, Institute of Dermatology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, China
| | - Nannan Liang
- ShanXi Key Laboratory of Stem Cells for Immunological Dermatosis, State Key Breeding Laboratory of Stem Cells for Immunological Dermatosis, Institute of Dermatology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, China
| | - Junqin Li
- ShanXi Key Laboratory of Stem Cells for Immunological Dermatosis, State Key Breeding Laboratory of Stem Cells for Immunological Dermatosis, Institute of Dermatology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, China
| | - Guohua Yin
- ShanXi Key Laboratory of Stem Cells for Immunological Dermatosis, State Key Breeding Laboratory of Stem Cells for Immunological Dermatosis, Institute of Dermatology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, China
| | - Xinhua Li
- ShanXi Key Laboratory of Stem Cells for Immunological Dermatosis, State Key Breeding Laboratory of Stem Cells for Immunological Dermatosis, Institute of Dermatology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, China
| | - Kaiming Zhang
- ShanXi Key Laboratory of Stem Cells for Immunological Dermatosis, State Key Breeding Laboratory of Stem Cells for Immunological Dermatosis, Institute of Dermatology, Taiyuan Central Hospital of Shanxi Medical University, Taiyuan, China
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Meng H, Cao S, Tian S, Huo J, Li X, Xu D, Liu L. EBP1 promotes the malignant biological behaviors of kidney renal clear cell carcinoma through activation of p38/HIF-1α signaling pathway. Cancer Cell Int 2024; 24:261. [PMID: 39049021 PMCID: PMC11267812 DOI: 10.1186/s12935-024-03442-x] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2024] [Accepted: 07/08/2024] [Indexed: 07/27/2024] Open
Abstract
BACKGROUND Kidney Renal Clear Cell Carcinoma (KIRC) is a common malignant tumor of the urinary system, and its incidence is increasing. ERBB3 binding protein (EBP1) is upregulated in various cancers. However, the connection between EBP1 and KIRC has not been reported. METHODS The expression of EBP1 in normal kidney tissue and KIRC tissue was analyzed through database and tissue microarray. EBP1 was knocked down in KIRC cell lines, and its impact on KIRC proliferation was assessed through CCK-8, soft agar assay, and flow cytometry. Scratch and transwell assays were used to evaluate the influence of EBP1 on KIRC invasion and migration. Nude mice tumor experiment were conducted to examine the effect of EBP1 on tumor tissue. Database analysis explored potential pathways involving EBP1, and validation was performed through Western blot experiments and p38 inhibitor. RESULTS EBP1 is upregulated in KIRC and significantly correlates with clinical staging, pathological grading, and lymph node metastasis in patients. The mechanism research showed that knocking down EBP1 inhibited KIRC proliferation, invasion, and migration and inhibited p38 phosphorylation and the expression of hypoxia-inducible factor-1α (HIF-1α) in KIRC. p-38 inhibitor (SB203580) inhibits p38 phosphorylation and HIF-1α expression and suppresses cell viability in a concentration-dependent manner, but has no effect on EBP1 expression. HEK 293T cells overexpressing EBP1 showed increased expression of phosphorylated p38 and HIF-1α and enhanced cell viability, however, SB203580 inhibited this effect of EBP1. CONCLUSION EBP1 may promote the occurrence and development of KIRC by regulating the expression of p38/HIF-1α signaling pathway.
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Affiliation(s)
- Huan Meng
- Center of Morphological Experiment, Yanbian University, Yanji, 133002, Jilin, China
| | - Shuxia Cao
- Key Laboratory of Cellular Function and Pharmacology of Jilin Province, Yanbian University, Yanji, 133002, Jilin, China
| | - Shengri Tian
- Center of Morphological Experiment, Yanbian University, Yanji, 133002, Jilin, China
| | - Jiaqi Huo
- Key Laboratory of Cellular Function and Pharmacology of Jilin Province, Yanbian University, Yanji, 133002, Jilin, China
| | - Xiangdan Li
- Center of Morphological Experiment, Yanbian University, Yanji, 133002, Jilin, China
| | - Dongyuan Xu
- Key Laboratory of Cellular Function and Pharmacology of Jilin Province, Yanbian University, Yanji, 133002, Jilin, China.
| | - Lan Liu
- Department of Pathology, Yanbian University Hospital, Yanji, 133000, Jilin, China.
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Shaw S, Chourasia M, Nayak R, Kumeria T, Ghosh MP, Santoshi S, Bose S. Molecular interaction of quercetin and its derivatives against nucleolin in breast cancer: in-silico and in-vitro study. J Biomol Struct Dyn 2024:1-12. [PMID: 38468538 DOI: 10.1080/07391102.2024.2326668] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2023] [Accepted: 02/28/2024] [Indexed: 03/13/2024]
Abstract
Nucleolin, a multifaceted RNA binding domain protein is overexpressed in various cancers leading to dysfunction of several cellular signaling pathways. Quercetin, a distinctive bioactive molecule, along with its derivatives have shown exclusive physio-chemical properties which makes them appealing choices for drug development, yet their role in targeted cancer therapy is limited. Here, the RBD domain structure of Nucleolin was modeled and stabilized by MD simulations for a period of 1000 ns. Molecular docking was performed to determine the binding capability of ligands with the target. To determine the stability of the ligand inside the binding pocket of the protein, MD simulation was performed for a period of 250 ns each for Quercetin-4'-o'-Glucoside, Quercetin_9 and Quercetin complexes. Further, in-vitro studies including cytotoxicity and RT-PCR assays were performed to validate quercetin against Nucleolin. Molecular docking and MD Simulation studies suggested a potential mechanism of interaction of Quercetin-4'-o'-Glucoside, Querectin_9 and Quercetin with Nucleolin with the binding free energy of -63.653, -58.86 and -46.9 kcal/mol, respectively. Moreover, Lys 348 and Glu379 were identified as important amino acids in ligand interaction located at the RRM2 motif of Nucleolin. In-vitro studies showed significant downregulation in Nucleolin expression by 15.18 and 2.51-fold at 48h and 72h respectively in MCF-7 cells with Quercetin (IC50 = 160 µM). Our findings suggested the potential role of specific RRM motifs in interaction with natural compounds targeting Nucleolin. This could be an effective strategy in the identification of potential molecules in targeting Nucleolin which can be further explored for developing targeted therapies for breast cancer.Communicated by Ramaswamy H. Sarma.
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Affiliation(s)
- Siuli Shaw
- Centre for Medical Biotechnology, Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh, India
| | - Mukesh Chourasia
- Center for Computational Biology and Bioinformatics, Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh, India
| | - Ranu Nayak
- Amity Institute of Nanotechnology, Amity University, Noida, Uttar Pradesh
| | - Tushar Kumeria
- School of Materials Science and Engineering, The University of New South Wales, Sydney, NSW, Australia
| | - Madhumita P Ghosh
- Centre for Medical Biotechnology, Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh, India
| | - Seneha Santoshi
- Center for Computational Biology and Bioinformatics, Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh, India
| | - Sudeep Bose
- Centre for Medical Biotechnology, Amity Institute of Biotechnology, Amity University, Noida, Uttar Pradesh, India
- Amity Institute of Molecular Medicine and Stem Cell Research, Amity University, Noida, Uttar Pradesh
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Sun L, Xing G, Wang W, Ma X, Bu X. Proliferation-associated 2G4 P48 is stabilized by malignant T-cell amplified sequence 1 and promotes the proliferation of head and neck squamous cell carcinoma. J Dent Sci 2023; 18:1588-1597. [PMID: 37799877 PMCID: PMC10548002 DOI: 10.1016/j.jds.2023.02.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Revised: 02/19/2023] [Indexed: 03/09/2023] Open
Abstract
Background/purpose Proliferation-associated protein 2G4 (PA2G4) has alternative transcriptional and translational initiation. One dominant transcript ENST00000303305 could be translated into two protein isoforms (PA2G4-P42 and PA2G4-P48). In this study, we aimed to explore the effects of PA2G4-P42 and PA2G4-P48 on the proliferation of head and neck squamous cell carcinoma (HNSCC) and the mechanisms regulating PA2G4-P48 stability. Materials and methods HNSCC cell lines HSC2 and SCC25 with relatively low PA2G4 expression were used for in-vitro cell studies. PA2G4-P42 and PA2G4-P48 overexpression lentiviruses were generated. In vitro cell proliferation was assessed by CCK-8 and colony formation. In vivo tumor cell proliferation was assessed by HSC2 cell-derived xenograft tumors. Liquid chromatography-mass spectrometry (LC-MS)/MS and co-immunoprecipitation (co-IP) assays were applied to check PA2G4-P48 interacting partners. Cycloheximide (CHX) chase and ubiquitin-based co-IP assays were also performed. Results PA2G4-P48 was the dominant isoform, with substantially higher expression than PA2G4-P42 in HNSCC. PA2G4-P48 overexpression enhanced HNSCC cell proliferation, but PA2G4-P42 overexpression slowed the proliferation. MCTS1 interacted with PA2G4-P48, but not PA2G4-P42. PA2G4 protein but not its mRNA expression was decreased in cells with MCTS1 knockdown. MG132 treatment abrogated this alteration. MCTS1 overexpression significantly elevated the half-life of PA2G4-P48, while its knockdown drastically reduced the half-life compared with the control cells. In addition, MCTS1 overexpression significantly decreased the polyubiquitination of exogenous flag-tagged PA2G4-P48. MCTS1 overexpression-induced cell proliferation was hampered by knocking down of PA2G4-P48. Conclusion PA2G4-P42 and PA2G4-P48 exert growth-suppressive and growth-promoting effects in HNSCC, respectively. MCTS1 can interact with PA2G4-P48 and prolong its half-life by reducing its poly-ubiquitination.
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Affiliation(s)
- Legang Sun
- Department of Oral and Maxillofacial Surgery, Binzhou Medical University Hospital, Binzhou, Shandong, China
| | - Guoyi Xing
- Department of Oral and Maxillofacial Surgery, Binzhou Medical University Hospital, Binzhou, Shandong, China
| | - Wenlong Wang
- Department of Oral and Maxillofacial Surgery, Binzhou Medical University Hospital, Binzhou, Shandong, China
| | - Xiangrui Ma
- Department of Oral and Maxillofacial Surgery, Binzhou Medical University Hospital, Binzhou, Shandong, China
| | - Xiangbin Bu
- Department of Oral and Maxillofacial Surgery, Binzhou Medical University Hospital, Binzhou, Shandong, China
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LINC00987 knockdown inhibits the progression of acute myeloid leukemia by suppressing IGF2BP2-mediated PA2G4 expression. Anticancer Drugs 2021; 33:e207-e217. [PMID: 34407052 DOI: 10.1097/cad.0000000000001188] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
This study aimed to investigate the role and potential mechanisms of LINC00987 in acute myeloid leukemia (AML) progression. The expression of LINC00987 in bone marrow specimens of AML patients and cell lines was measured by quantitative reverse transcription PCR (RT-qPCR). Small interfering RNA targeting LINC00987 (si-LINC00987) was transfected into AML cell lines HL-60 and KG-1, and the proliferation, invasion and apoptosis were detected with Cell Counting Kit-8 (CCK-8), Transwell and flow cytometry, respectively. Moreover, the binding between LINC00987 and insulin like growth factor 2 mRNA binding protein 2 (IGF2BP2) was validated with an RNA pull-down assay. Co-immunoprecipitation assay was used to verify the binding between IGF2BP2 and proliferation-associated 2G4 (PA2G4). Then rescue experiments were performed to explore the effects of LINC00987/IGF2BP2/PA2G4 axis on HL-60 and KG-1 cell functions. Additionally, HL-60 cells transfected with si-LINC00987 were injected into mice, followed by the evaluation of xenograft tumor growth. LINC00987 was upregulated in AML patient specimens and cell lines. LINC00987 knockdown inhibited proliferation and invasion and promoted apoptosis in AML cells. LINC00987 could bind with IGF2BP2 and promote its expression, and IGF2BP2 overexpression reversed the effects of LINC00987 knockdown on the proliferation, invasion and apoptosis in AML cells. Besides, IGF2BP2 could bind with PA2G4. IGF2BP2 knockdown inhibited proliferation and invasion, and promoted apoptosis in AML cells, whereas PA2G4 overexpression reversed these effects. Additionally, the LINC00987 knockdown inhibited the xenograft tumor growth of AML in vivo. Knockdown of LINC00987 inhibits AML cell proliferation and invasion, and promotes apoptosis in vitro and reduces tumor growth in vivo by suppressing IGF2BP2-mediated PA2G4 expression.
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Stevenson BW, Gorman MA, Koach J, Cheung BB, Marshall GM, Parker MW, Holien JK. A structural view of PA2G4 isoforms with opposing functions in cancer. J Biol Chem 2020; 295:16100-16112. [PMID: 32952126 DOI: 10.1074/jbc.rev120.014293] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2020] [Revised: 09/17/2020] [Indexed: 01/04/2023] Open
Abstract
The role of proliferation-associated protein 2G4 (PA2G4), alternatively known as ErbB3-binding protein 1 (EBP1), in cancer has become apparent over the past 20 years. PA2G4 expression levels are correlated with prognosis in a range of human cancers, including neuroblastoma, cervical, brain, breast, prostate, pancreatic, hepatocellular, and other tumors. There are two PA2G4 isoforms, PA2G4-p42 and PA2G4-p48, and although both isoforms of PA2G4 regulate cellular growth and differentiation, these isoforms often have opposing roles depending on the context. Therefore, PA2G4 can function either as a contextual tumor suppressor or as an oncogene, depending on the tissue being studied. However, it is unclear how distinct structural features of the two PA2G4 isoforms translate into different functional outcomes. In this review, we examine published structures to identify important structural and functional components of PA2G4 and consider how they may explain its crucial role in the malignant phenotype. We will highlight the lysine-rich regions, protein-protein interaction sites, and post-translational modifications of the two PA2G4 isoforms and relate these to the functional cellular role of PA2G4. These data will enable a better understanding of the function and structure relationship of the two PA2G4 isoforms and highlight the care that will need to be undertaken for those who wish to conduct isoform-specific structure-based drug design campaigns.
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Affiliation(s)
| | - Michael A Gorman
- Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Jessica Koach
- Department of Pediatrics, Helen Diller Family Comprehensive Cancer Center, University of California, San Francisco, California, USA; Children's Cancer Institute Australia for Medical Research, Lowy Cancer Research Centre, University of New South Wales, Sydney, New South Wales, Australia
| | - Belamy B Cheung
- Children's Cancer Institute Australia for Medical Research, Lowy Cancer Research Centre, University of New South Wales, Sydney, New South Wales, Australia; School of Women's and Children's Health, University of New South Wales, Randwick, New South Wales, Australia
| | - Glenn M Marshall
- School of Women's and Children's Health, University of New South Wales, Randwick, New South Wales, Australia; Kids Cancer Centre, Sydney Children's Hospital, Randwick, New South Wales, Australia
| | - Michael W Parker
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia; Bio21 Molecular Science and Biotechnology Institute, University of Melbourne, Parkville, Victoria, Australia
| | - Jessica K Holien
- St. Vincent's Institute of Medical Research, Fitzroy, Victoria, Australia; Department of Surgery, University of Melbourne, Parkville, Victoria, Australia; School of Science, College of Science, Engineering, and Health, RMIT University, Melbourne, Victoria, Australia.
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The roles of multifunctional protein ErbB3 binding protein 1 (EBP1) isoforms from development to disease. Exp Mol Med 2020; 52:1039-1047. [PMID: 32719408 PMCID: PMC8080562 DOI: 10.1038/s12276-020-0476-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2020] [Accepted: 06/01/2020] [Indexed: 12/13/2022] Open
Abstract
The roles of the two isoforms of ErbB3-binding protein 1 (Ebp1) in cellular function and its regulation in disease and development is a stimulating area in current fields of biology, such as neuroscience, cancer biology, and structural biology. Over the last two decades, a growing body of studies suggests have suggested different functions for the EBP1 isoforms in various cancers, along with their specific binding partners in the ubiquitin-proteasome system. Owing to the specific cellular context or spatial/temporal expression of the EBP1 isoforms, either transcriptional repression or the activation function of EBP1 has been proposed, and epigenetic regulation by p48 EBP1 has also been observed during in the embryo development, including in brain development and neurologic disorders, such as schizophrenia, in using an Ebp1 knockout mouse model. Here, we review recent findings that have shaped our current understanding of the emerging function of EBP1 isoforms in cellular events and gene expression, from development to disease. A pair of proteins that originate from a common gene exert strikingly different effects on embryonic development as well as tumor growth and progression. RNA transcripts generated from the PA2G4 gene can undergo enzymatic processing to yield two different protein products, p42 EB1 and p48 EB1. These proteins differ by the presence or absence of 54 amino acids at one end, and Jee-Yin Ahn at the Sungkyunkwan University School of Medicine, Suwon, South Korea, and colleagues have reviewed current insights into the functional consequences of this difference. The two proteins bind to distinct sets of molecular partners. The p48 form appears to regulate a host of genes involved in brain development, but also appears to drive cancerous growth in various tumors. In contrast, p42 is scarcer during development, and appears to inhibit tumor formation.
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Lokdarshi A, Papdi C, Pettkó-Szandtner A, Dorokhov S, Scheres B, Magyar Z, von Arnim AG, Bögre L, Horváth BM. ErbB-3 BINDING PROTEIN 1 Regulates Translation and Counteracts RETINOBLASTOMA RELATED to Maintain the Root Meristem. PLANT PHYSIOLOGY 2020; 182:919-932. [PMID: 31818906 PMCID: PMC6997692 DOI: 10.1104/pp.19.00805] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Accepted: 11/22/2019] [Indexed: 05/09/2023]
Abstract
The ErbB-3 BINDING PROTEIN 1 (EBP1) drives growth, but the mechanism of how it acts in plants is little understood. Here, we show that EBP1 expression and protein abundance in Arabidopsis (Arabidopsis thaliana) are predominantly confined to meristematic cells and are induced by sucrose and partially dependent on TARGET OF RAPAMYCIN (TOR) kinase activity. Consistent with being downstream of TOR, silencing of EBP1 restrains, while overexpression promotes, root growth, mostly under sucrose-limiting conditions. Inducible overexpression of RETINOBLASTOMA RELATED (RBR), a sugar-dependent transcriptional repressor of cell proliferation, depletes meristematic activity and causes precocious differentiation, which is attenuated by EBP1. To understand the molecular mechanism, we searched for EBP1- and RBR-interacting proteins by affinity purification and mass spectrometry. In line with the double-stranded RNA-binding activity of EBP1 in human (Homo sapiens) cells, the overwhelming majority of EBP1 interactors are part of ribonucleoprotein complexes regulating many aspects of protein synthesis, including ribosome biogenesis and mRNA translation. We confirmed that EBP1 associates with ribosomes and that EBP1 silencing hinders ribosomal RNA processing. We revealed that RBR also interacts with a set of EBP1-associated nucleolar proteins as well as factors that function in protein translation. This suggests EBP1 and RBR act antagonistically on common processes that determine the capacity for translation to tune meristematic activity in relation to available resources.
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Affiliation(s)
- Ansul Lokdarshi
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996
| | - Csaba Papdi
- Department of Biological Sciences, Centre for Systems and Synthetic Biology, Royal Holloway, University of London, Egham Hill, Egham TW20 0EX, United Kingdom
| | - Aladár Pettkó-Szandtner
- Laboratory of Proteomics Research, Biological Research Centre, POB 521, H-6701 Szeged, Hungary
| | - Stefan Dorokhov
- Department of Biological Sciences, Centre for Systems and Synthetic Biology, Royal Holloway, University of London, Egham Hill, Egham TW20 0EX, United Kingdom
| | - Ben Scheres
- Department of Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
| | - Zoltán Magyar
- Institute of Plant Biology, Biological Research Centre, POB 521, H-6701 Szeged, Hungary
| | - Albrecht G von Arnim
- Department of Biochemistry & Cellular and Molecular Biology, University of Tennessee, Knoxville, Tennessee 37996
- UT-ORNL Graduate School of Genome Science and Technology, Knoxville, Tennessee 37996
| | - László Bögre
- Department of Biological Sciences, Centre for Systems and Synthetic Biology, Royal Holloway, University of London, Egham Hill, Egham TW20 0EX, United Kingdom
| | - Beatrix M Horváth
- Department of Biological Sciences, Centre for Systems and Synthetic Biology, Royal Holloway, University of London, Egham Hill, Egham TW20 0EX, United Kingdom
- Department of Biology, Utrecht University, 3584 CH Utrecht, The Netherlands
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Nguyen DQ, Hoang DH, Nguyen Vo TT, Huynh V, Ghoda L, Marcucci G, Nguyen LXT. The role of ErbB3 binding protein 1 in cancer: Friend or foe? J Cell Physiol 2018; 233:9110-9120. [PMID: 30076717 DOI: 10.1002/jcp.26951] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2017] [Accepted: 06/12/2018] [Indexed: 12/20/2022]
Abstract
ErbB3, a member of the epidermal growth factor receptor family, reportedly plays an essential role in the regulation of cancer progression and therapeutic resistance. Numerous studies have indicated that ErbB3 binding protein 1 (Ebp1), a binding partner for ErbB3, plays an important regulatory role in the expression and function of ErbB3, but there is no agreement as to whether Ebp1 also has an ErbB3-independent function in cancer and how it might contribute to tumorigenesis. In this review, we will discuss the different functions of the two Ebp1 isoforms, p48 and p42, that may be responsible for the potentially dual role of Ebp1 in cancer growth.
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Affiliation(s)
- Dang Quan Nguyen
- Department of Medical Biotechnology, Biotechnology Center of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Dinh Hoa Hoang
- Gehr Family Center for Leukemia Research, Hematology Malignancies and Stem Cell Transplantation Institute, City of Hope Medical Center, Duarte, California
| | - Thanh Thao Nguyen Vo
- Department of Medical Biotechnology, Biotechnology Center of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Vu Huynh
- Department of Medical Biotechnology, Biotechnology Center of Ho Chi Minh City, Ho Chi Minh City, Vietnam
| | - Lucy Ghoda
- Gehr Family Center for Leukemia Research, Hematology Malignancies and Stem Cell Transplantation Institute, City of Hope Medical Center, Duarte, California
| | - Guido Marcucci
- Gehr Family Center for Leukemia Research, Hematology Malignancies and Stem Cell Transplantation Institute, City of Hope Medical Center, Duarte, California
| | - Le Xuan Truong Nguyen
- Department of Medical Biotechnology, Biotechnology Center of Ho Chi Minh City, Ho Chi Minh City, Vietnam.,Gehr Family Center for Leukemia Research, Hematology Malignancies and Stem Cell Transplantation Institute, City of Hope Medical Center, Duarte, California
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Saha M, Mitsuhashi S, Jones MD, Manko K, Reddy HM, Bruels CC, Cho KA, Pacak CA, Draper I, Kang PB. Consequences of MEGF10 deficiency on myoblast function and Notch1 interactions. Hum Mol Genet 2018; 26:2984-3000. [PMID: 28498977 DOI: 10.1093/hmg/ddx189] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2017] [Accepted: 05/08/2017] [Indexed: 01/22/2023] Open
Abstract
Mutations in MEGF10 cause early onset myopathy, areflexia, respiratory distress, and dysphagia (EMARDD), a rare congenital muscle disease, but the pathogenic mechanisms remain largely unknown. We demonstrate that short hairpin RNA (shRNA)-mediated knockdown of Megf10, as well as overexpression of the pathogenic human p.C774R mutation, leads to impaired proliferation and migration of C2C12 cells. Myoblasts from Megf10-/- mice and Megf10-/-/mdx double knockout (dko) mice also show impaired proliferation and migration compared to myoblasts from wild type and mdx mice, whereas the dko mice show histological abnormalities that are not observed in either single mutant mouse. Cell proliferation and migration are known to be regulated by the Notch receptor, which plays an essential role in myogenesis. Reciprocal co-immunoprecipitation studies show that Megf10 and Notch1 interact via their respective intracellular domains. These interactions are impaired by the pathogenic p.C774R mutation. Megf10 regulation of myoblast function appears to be mediated at least in part via interactions with key components of the Notch signaling pathway, and defects in these interactions may contribute to the pathogenesis of EMARDD.
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Affiliation(s)
- Madhurima Saha
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Satomi Mitsuhashi
- Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Michael D Jones
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Kelsey Manko
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Hemakumar M Reddy
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Christine C Bruels
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Kyung-Ah Cho
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA
| | - Christina A Pacak
- Child Health Research Institute, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA
| | - Isabelle Draper
- Molecular Cardiology Research Institute, Department of Medicine, Tufts Medical Center, Boston, MA 02111, USA
| | - Peter B Kang
- Division of Pediatric Neurology, Department of Pediatrics, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Department of Neurology, Boston Children's Hospital and Harvard Medical School, Boston, MA 02115, USA.,Department of Neurology and Department of Molecular Genetics and Microbiology, University of Florida College of Medicine, Gainesville, FL 32610, USA.,Genetics Institute and Myology Institute, University of Florida, Gainesville, FL 32610, USA
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Chakraborty A, Mukherjee S, Saha S, De S, Sengupta Bandyopadhyay S. Phorbol-12-myristate-13-acetate-mediated stabilization of leukemia inhibitory factor ( lif) mRNA: involvement of Nucleolin and PCBP1. Biochem J 2017; 474:2349-2363. [PMID: 28512205 DOI: 10.1042/bcj20170051] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 05/06/2017] [Accepted: 05/15/2017] [Indexed: 01/09/2023]
Abstract
Leukemia inhibitory factor (LIF) is a potent pleiotropic cytokine involved in diverse biological activities, thereby requiring precise spatial and temporal control of its expression. The present study reveals that enhanced expression of LIF in response to PMA (phorbol-12-myristate-13-acetate) in human histiocytic lymphoma cell line U937 largely happens through stabilization of its mRNA. Functional characterization of the long 3'-untranslated region of human lif mRNA revealed several conserved sequences with conventional cis-acting elements. A 216 nucleotide containing proximal cis-element with two AUUUA pentamers and four poly-rC sequences demonstrated significant mRNA destabilizing potential, which, on treatment with PMA, showed stabilizing activity. Affinity chromatography followed by western blot and RNA co-immunoprecipitation of PMA-treated U937 extract identified Nucleolin and PCBP1 as two protein trans-factors interacting with lif mRNA, specifically to the proximal non-conventional AU-rich region. PMA induced nucleo-cytoplasmic translocation of both Nucleolin and PCBP1. RNA-dependent in vivo co-association of both these proteins with lif mRNA was demonstrated by decreased co-precipitation in the presence of RNase. Ectopic overexpression of Nucleolin showed stabilization of both intrinsic lif mRNA and gfp reporter, whereas knockdown of Nucleolin and PCBP1 demonstrated a significant decrease in both lif mRNA and protein levels. Collectively, this report establishes the stabilization of lif mRNA by PMA, mediated by the interactions of two RNA-binding proteins, Nucleolin and PCBP1 with a proximal cis-element.
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Affiliation(s)
- Alina Chakraborty
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata, India
| | - Srimoyee Mukherjee
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata, India
| | - Sucharita Saha
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata, India
| | - Soumasree De
- Department of Biophysics, Molecular Biology and Bioinformatics, University of Calcutta, Kolkata, India
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12
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Ko HR, Hwang I, Ahn SY, Chang YS, Park WS, Ahn JY. Neuron-specific expression of p48 Ebp1 during murine brain development and its contribution to CNS axon regeneration. BMB Rep 2017; 50:126-131. [PMID: 27916024 PMCID: PMC5422024 DOI: 10.5483/bmbrep.2017.50.3.190] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2016] [Indexed: 01/06/2023] Open
Abstract
P48 Ebp1 is expressed in rapidly proliferating cells such as cancer cells and accelerates cell growth and survival. However, its expression pattern and role in central nervous system development have not been studied. Here, we demonstrated the spatiotemporal expression pattern of p48 Ebp1 during embryonic development and the postnatal period. During embryonic development, p48 Ebp1 was highly expressed in the brain. Expression gradually decreased after birth but was still more abundant than p42 expression after birth. Strikingly, we found that p48 Ebp1 was expressed in a cell type specific manner in neurons but not astrocytes. Moreover, p48 Ebp1 physically interacted with beta tubulin but not alpha tubulin. This fits with its accumulation in distal microtubule growth cone regions. Furthermore, in injured hippocampal slices, p48 Ebp1 introduction promoted axon regeneration. Thus, we speculate that p48 Ebp1 might contribute to microtubule dynamics acting as an MAP and promotes CNS axon regeneration. [BMB Reports 2017; 50(3): 126-131].
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Affiliation(s)
- Hyo Rim Ko
- Department of Molecular Cell Biology, Center for Molecular Medicine, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 16419, Korea
| | - Inwoo Hwang
- Department of Molecular Cell Biology, Center for Molecular Medicine, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 16419, Korea
| | - So Yoon Ahn
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351; Stem Cell and Regenerative Medicine Institute, Samsung Medical Center, Seoul 06351, Korea
| | - Yun Sil Chang
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351; Stem Cell and Regenerative Medicine Institute, Samsung Medical Center, Seoul 06351; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351, Korea
| | - Won Soon Park
- Department of Pediatrics, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351; Stem Cell and Regenerative Medicine Institute, Samsung Medical Center, Seoul 06351; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351, Korea
| | - Jee-Yin Ahn
- Department of Molecular Cell Biology, Center for Molecular Medicine, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine, Suwon 16419; Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul 06351, Korea
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13
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Matsye P, Zheng L, Si Y, Kim S, Luo W, Crossman DK, Bratcher PE, King PH. HuR promotes the molecular signature and phenotype of activated microglia: Implications for amyotrophic lateral sclerosis and other neurodegenerative diseases. Glia 2017; 65:945-963. [PMID: 28300326 DOI: 10.1002/glia.23137] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Revised: 02/16/2017] [Accepted: 02/16/2017] [Indexed: 12/25/2022]
Abstract
In neurodegenerative diseases such as amyotrophic lateral sclerosis (ALS), chronic activation of microglia contributes to disease progression. Activated microglia produce cytokines, chemokines, and other factors that normally serve to clear infection or damaged tissue either directly or through the recruitment of other immune cells. The molecular program driving this phenotype is classically linked to the transcription factor NF-κB and characterized by the upregulation of proinflammatory factors such as IL-1β, TNF-α, and IL-6. Here, we investigated the role of HuR, an RNA-binding protein that regulates gene expression through posttranscriptional pathways, on the molecular and cellular phenotypes of activated microglia. We performed RNA sequencing of HuR-silenced microglia and found significant attenuation of lipopolysaccharide-induced IL-1β and TNF-α inflammatory pathways and other factors that promote microglial migration and invasion. RNA kinetics and luciferase reporter studies suggested that the attenuation was related to altered promoter activity rather than a change in RNA stability. HuR-silenced microglia showed reduced migration, invasion, and chemotactic properties but maintained viability. MMP-12, a target exquisitely sensitive to HuR knockdown, participates in the migration/invasion phenotype. HuR is abundantly detected in the cytoplasmic compartment of activated microglia from ALS spinal cords consistent with its increased activity. Microglia from ALS-associated mutant SOD1 mice demonstrated higher migration/invasion properties which can be blocked with HuR inhibition. These findings underscore an important role for HuR in sculpting the molecular signature and phenotype of activated microglia, and as a possible therapeutic target in ALS and other neurodegenerative diseases.
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Affiliation(s)
- Prachi Matsye
- Department of Neurology, University of Alabama, Birmingham, Alabama.,Birmingham Veterans Affairs Medical Center, Birmingham, Alabama
| | - Lei Zheng
- Department of Neurology, University of Alabama, Birmingham, Alabama.,Birmingham Veterans Affairs Medical Center, Birmingham, Alabama
| | - Ying Si
- Department of Neurology, University of Alabama, Birmingham, Alabama.,Birmingham Veterans Affairs Medical Center, Birmingham, Alabama
| | - Soojin Kim
- Department of Neurology, University of Alabama, Birmingham, Alabama
| | - Wenyi Luo
- Department of Pathology, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - David K Crossman
- Department of Genetics, University of Alabama, Birmingham, Alabama
| | - Preston E Bratcher
- Department of Pediatrics, Division of Pediatric Pulmonary Medicine, National Jewish Health, Denver, Colorado
| | - Peter H King
- Department of Neurology, University of Alabama, Birmingham, Alabama.,Department of Genetics, University of Alabama, Birmingham, Alabama.,Department of Pediatrics, Division of Pediatric Pulmonary Medicine, National Jewish Health, Denver, Colorado.,Department of Cell, Developmental and Integrative Biology, University of Alabama, Birmingham, Alabama
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14
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Bose S, Tholanikunnel TE, Reuben A, Tholanikunnel BG, Spicer EK. Regulation of nucleolin expression by miR-194, miR-206, and HuR. Mol Cell Biochem 2016; 417:141-53. [PMID: 27221739 DOI: 10.1007/s11010-016-2721-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2015] [Accepted: 05/13/2016] [Indexed: 11/29/2022]
Abstract
Nucleolin is a proliferation-associated protein that is overexpressed in multiple types of cancer. The mechanisms leading to overexpression of nucleolin in specific cancers are not fully understood. This study found that nucleolin is notably elevated in breast cancer cell lines MCF-7 and MDA-231 compared to nonmalignant breast epithelial MCF-10A cells. In silico analyses revealed the presence of putative binding sites for microRNAs miR-194 and miR-206 in the 3'-untranslated region (3'-UTR) of Ncl mRNA. Transfection of the three cell lines with pre-miR-194 or pre-miR-206 specifically decreased the Ncl mRNA and protein expression. Treatments of the cells with antagomiR-194 or antagomiR-206 upregulated nucleolin expression ~2- to 3-fold. Co-transfection of cells with a reporter vector containing the Ncl 3'-UTR downstream from the Renilla luciferase gene and pre-miR-194 or pre-miR-206 led to a ~3-fold decrease in Renilla/firefly luciferase activity. Cytoplasmic levels of the RNA-binding protein HuR were higher in MCF-7 and MDA-231 cells than those in MCF-10A cells. RNA immunoprecipitation assays demonstrated that HuR binds to Ncl mRNA in all the three cell types. ShRNA-mediated knock-down of HuR induced a decrease in nucleolin expression, while exogenous expression of HuR led to upregulation of nucleolin expression. Analysis of the polysome-monosome distribution of Ncl mRNA in HuR knock-down cells demonstrated that HuR enhances the translation efficiency of Ncl mRNA. These findings demonstrate that nucleolin expression is down-regulated by miR-194 and miR-206 and upregulated by HuR.
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Affiliation(s)
- Sudeep Bose
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, P. O. Box 250509, Charleston, SC, 29425, USA
- Amity Centre for Medical Biotechnology, Amity Institute of Biotechnology, Amity University, Gautam Buddha Nagar Sec-125, Noida, 201301, India
| | - Tracy E Tholanikunnel
- College of Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Adrian Reuben
- Division of Gastroenterology and Hepatology, Department of Medicine, Medical University of South Carolina, Charleston, SC, 29425, USA
| | - Baby G Tholanikunnel
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, P. O. Box 250509, Charleston, SC, 29425, USA.
| | - Eleanor K Spicer
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, P. O. Box 250509, Charleston, SC, 29425, USA
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15
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Ko HR, Chang YS, Park WS, Ahn JY. Opposing roles of the two isoforms of ErbB3 binding protein 1 in human cancer cells. Int J Cancer 2016; 139:1202-8. [DOI: 10.1002/ijc.30165] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2016] [Accepted: 04/25/2016] [Indexed: 11/06/2022]
Affiliation(s)
- Hyo Rim Ko
- Department of Molecular Cell Biology; Center for Molecular Medicine, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine; Suwon Korea
| | - Yun Sil Chang
- Department of Pediatrics; Samsung Medical Center, Sungkyunkwan University School of Medicine; Seoul Korea
| | - Won Soon Park
- Department of Pediatrics; Samsung Medical Center, Sungkyunkwan University School of Medicine; Seoul Korea
| | - Jee-Yin Ahn
- Department of Molecular Cell Biology; Center for Molecular Medicine, Samsung Biomedical Research Institute, Sungkyunkwan University School of Medicine; Suwon Korea
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16
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High expression of ErbB3 binding protein 1 (EBP1) predicts poor prognosis of pancreatic ductal adenocarcinoma (PDAC). Tumour Biol 2015; 36:9189-99. [PMID: 26088450 DOI: 10.1007/s13277-015-3625-6] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2015] [Accepted: 05/27/2015] [Indexed: 02/04/2023] Open
Abstract
Recent studies have identified that ErbB3 binding protein 1 (EBP1) is broadly expressed in various cancer tissues and critically involved in plenty of biological processes in this regard. However, the functional role of EBP1 in pancreatic ductal adenocarcinoma (PDAC) has never been elucidated. In this study, we found that EBP1 could serve as a prognostic biomarker of PDAC. Western blot analysis revealed that EBP1 was remarkably upregulated in PDAC tissues and cell lines. Using immunohistochemical analysis, we showed that the expression of EBP1 was correlated with tumor size (P = 0.004), histological differentiation (P = 0.041), and tumor node metastasis (TNM) stage (P = 0.000). Notably, Kaplan-Meier curve showed that high expression of EBP1 predicted significantly worsened prognosis of PDAC patients (P = 0.001). In addition, knockdown of EBP1 expression suppressed PDAC cell proliferation and retarded cell cycle progression. Furthermore, depletion of EBP1 induced the apoptosis of Panc-1 cells. Of great interest, we found that EBP1 interacted with anti-apoptotic protein, Bcl-xL, and promoted its accumulation. In summary, our results suggest that EBP1 is a novel prognostic indicator and potential therapeutic target of PDAC, shedding new insights into the important role of EBP1 in cancer development.
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17
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Pisapia L, Barba P, Cortese A, Cicatiello V, Morelli F, Del Pozzo G. EBP1 protein modulates the expression of human MHC class II molecules in non-hematopoietic cancer cells. Int J Oncol 2015; 47:481-9. [PMID: 26081906 PMCID: PMC4501648 DOI: 10.3892/ijo.2015.3051] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2015] [Accepted: 05/04/2015] [Indexed: 12/11/2022] Open
Abstract
Many solid tumours including melanoma, glioblastoma, and breast carcinomas express MHC class II molecules (MHC II). The surface expression of these molecules confers to non-hematopoietic tumour cells the role of non-professional antigen presenting cells and the ability to potentially stimulate tumour-specific CD4+ T cell response. We studied EBP1, an ErbB3 binding protein, and the effects of p48 and p42 isoforms on the MHC II expression in U87 glioblastoma, M14 melanoma and MCF7 mammary carcinoma cell lines. We found that overexpression of p48 increases MHC II transcription in U87 and M14, through upregulation of CIITA transactivator and STAT1 phosphorylation. In addition, p48 protein influences MHC II expression by increasing mRNA stability. In melanoma and glioblastoma cell lines, p48 isoform functions as oncogene promoting tumour growth, while p42 isoform, that does not affect MHC II expression, acts as a tumour suppressor by blocking cell growth and inducing apoptosis. In contrast, p48 seems to act as tumour suppressor in breast carcinoma inhibiting proliferation, favouring apoptosis, and inducing a slight increase of MHC II expression similar to p42. Our data highlight the tissue specificity function of EBP1 isoforms and demonstrate that only the oncogene p48 activates MHC II expression in human solid tumours, via STAT1 phosphorylation, in order to affect tumour progression by triggering specific immune response.
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Affiliation(s)
- Laura Pisapia
- Institute of Genetics and Biophysics 'Adriano Buzzati Traverso'-CNR, 80131 Naples, Italy
| | - Pasquale Barba
- Institute of Genetics and Biophysics 'Adriano Buzzati Traverso'-CNR, 80131 Naples, Italy
| | - Angela Cortese
- Institute of Genetics and Biophysics 'Adriano Buzzati Traverso'-CNR, 80131 Naples, Italy
| | - Valeria Cicatiello
- Institute of Genetics and Biophysics 'Adriano Buzzati Traverso'-CNR, 80131 Naples, Italy
| | - Franco Morelli
- Institute of Genetics and Biophysics 'Adriano Buzzati Traverso'-CNR, 80131 Naples, Italy
| | - Giovanna Del Pozzo
- Institute of Genetics and Biophysics 'Adriano Buzzati Traverso'-CNR, 80131 Naples, Italy
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18
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Awasthi S, Ezelle H, Hassel BA, Hamburger AW. The ErbB3-binding protein EBP1 modulates lapatinib sensitivity in prostate cancer cells. Mol Cell Biochem 2015; 405:177-86. [PMID: 25876877 DOI: 10.1007/s11010-015-2409-z] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 04/09/2015] [Indexed: 11/28/2022]
Abstract
Although ErbB receptors have been implicated in prostate cancer progression, ErbB-directed drugs have not proven effective for prostate cancer treatment. The ErbB3-binding protein EBP1 affects both ErbB2 and androgen receptor signaling, two components of the response to ErbB-targeted therapies. We therefore examined the effects of EBP1 expression on the response to the ErbB1/2 tyrosine kinase inhibitor lapatinib. We found a negative correlation between endogenous EBP1 levels and lapatinib sensitivity in prostate cancer cell lines. We then overexpressed or inhibited expression of EBP1. Silencing EBP1 expression increased lapatinib sensitivity and overexpression of EBP1 increased resistance in androgen-containing media. Androgen depletion resulted in an increased sensitivity of androgen-dependent EBP1 expressing cells to lapatinib, but did not affect the lapatinib sensitivity of hormone resistant cells. However, EBP1 silenced cells were still more sensitive to lapatinib than EBP1-expressing cells in the absence of androgens. The increase in sensitivity to lapatinib following EBP1 silencing was associated with increased ErbB2 levels. In addition, lapatinib treatment increased ErbB2 levels in sensitive cells that express low levels of EBP1, but decreased ErbB2 levels in resistant EBP1-expressing cells. In contrast, ErbB3 and phospho ErbB3 levels were not affected by either changes in EBP1 levels or lapatinib treatment. The production of the ErbB3/4 ligand heregulin was increased in EBP1-silenced cells. EBP1-induced changes in AR levels were not associated with changes in lapatinib sensitivity. These studies suggest that the ability of EBP1 to activate ErbB2 signaling pathways results in increased lapatinib sensitivity.
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Affiliation(s)
- Smita Awasthi
- Greenebaum Cancer Center, University of Maryland School of Medicine, BRB 9-029, 655 W. Baltimore Street, Baltimore, MD, 21201, USA
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19
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Díaz-Muñoz MD, Bell SE, Turner M. Deletion of AU-rich elements within the Bcl2 3'UTR reduces protein expression and B cell survival in vivo. PLoS One 2015; 10:e0116899. [PMID: 25680182 PMCID: PMC4332480 DOI: 10.1371/journal.pone.0116899] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2014] [Accepted: 12/16/2014] [Indexed: 11/18/2022] Open
Abstract
Post-transcriptional mRNA regulation by RNA binding proteins (RBPs) associated with AU-rich elements (AREs) present in the 3' untranslated region (3'UTR) of specific mRNAs modulates transcript stability and translation in eukaryotic cells. Here we have functionally characterised the importance of the AREs present within the Bcl2 3'UTR in order to maintain Bcl2 expression. Gene targeting deletion of 300 nucleotides of the Bcl2 3'UTR rich in AREs diminishes Bcl2 mRNA stability and protein levels in primary B cells, decreasing cell lifespan. Generation of chimeric mice indicates that Bcl2-ARE∆/∆ B cells have an intrinsic competitive disadvantage compared to wild type cells. Biochemical assays and predictions using a bioinformatics approach show that several RBPs bind to the Bcl2 AREs, including AUF1 and HuR proteins. Altogether, association of RBPs to Bcl2 AREs contributes to Bcl2 protein expression by stabilizing Bcl2 mRNA and promotes B cell maintenance.
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Affiliation(s)
- Manuel D. Díaz-Muñoz
- Lymphocyte Signalling and Development, The Babraham Institute, Cambridge, United Kingdom
| | - Sarah E. Bell
- Lymphocyte Signalling and Development, The Babraham Institute, Cambridge, United Kingdom
| | - Martin Turner
- Lymphocyte Signalling and Development, The Babraham Institute, Cambridge, United Kingdom
- * E-mail:
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20
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Regulation of cell cycle of hepatocellular carcinoma by NF90 through modulation of cyclin E1 mRNA stability. Oncogene 2014; 34:4460-70. [PMID: 25399696 DOI: 10.1038/onc.2014.373] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 10/04/2014] [Accepted: 10/06/2014] [Indexed: 12/14/2022]
Abstract
Activation of cyclin E1, a key regulator of the G1/S cell-cycle transition, has been implicated in many cancers including hepatocellular carcinoma (HCC). Although much is known about the regulation of cyclin E1 expression and stability, its post-transcriptional regulation mechanism remains incompletely understood. Here, we report that nuclear factor 90 (NF90), a double-stranded RNA (dsRNA) binding protein, regulates cyclin E1 in HCC. We demonstrate that NF90 is upregulated in HCC specimens and that suppression of NF90 decreases HCC cell growth and delays G1/S transition. We identified cyclin E1 as a new target of NF90 and found a significant correlation between NF90 and cyclin E1 expression in HCC. The mRNA and protein levels of cyclin E1 were downregulated upon NF90 knockdown. Suppression of NF90 caused a decrease in the half-life of cyclin E1 mRNA, which was rescued by ectopic expression of NF90. Furthermore, NF90 bound to the 3' untranslated regions (3'UTRs) of cyclin E1 mRNA in vitro and in vivo. Knockdown of NF90 also inhibited tumor growth of HCC cell lines in mouse xenograft model. Moreover, we showed that inhibition of NF90 sensitized HCC cells to the cyclin-dependent kinase 2 (CDK2) inhibitor, roscovitine. Taken together, downregulation of NF90 in HCC cell lines can delay cell-cycle progression, inhibit cell proliferation, and reduce tumorigenic capacity in vivo. These results suggest that NF90 has an important role in HCC pathogenesis and that it can serve as a novel therapeutic target for HCC.
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21
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Ko HR, Kim CK, Ahn JY. Phosphorylation of the N-terminal domain of p48 Ebp1 by CDK2 is required for tumorigenic function of p48. Mol Carcinog 2014; 54:1283-91. [DOI: 10.1002/mc.22203] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2014] [Revised: 06/07/2014] [Accepted: 06/11/2014] [Indexed: 01/08/2023]
Affiliation(s)
- Hyo Rim Ko
- Department of Molecular Cell Biology; Center for Molecular Medicine; Samsung Biomedical Research Institute; Sungkyunkwan University School of Medicine; Suwon Korea
| | - Chung Kwon Kim
- Department of Molecular Cell Biology; Center for Molecular Medicine; Samsung Biomedical Research Institute; Sungkyunkwan University School of Medicine; Suwon Korea
| | - Jee-Yin Ahn
- Department of Molecular Cell Biology; Center for Molecular Medicine; Samsung Biomedical Research Institute; Sungkyunkwan University School of Medicine; Suwon Korea
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Figeac N, Serralbo O, Marcelle C, Zammit PS. ErbB3 binding protein-1 (Ebp1) controls proliferation and myogenic differentiation of muscle stem cells. Dev Biol 2013; 386:135-51. [PMID: 24275324 DOI: 10.1016/j.ydbio.2013.11.017] [Citation(s) in RCA: 48] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2013] [Revised: 10/21/2013] [Accepted: 11/15/2013] [Indexed: 12/16/2022]
Abstract
Satellite cells are resident stem cells of skeletal muscle, supplying myoblasts for post-natal muscle growth, hypertrophy and repair. Many regulatory networks control satellite cell function, which includes EGF signalling via the ErbB family of receptors. Here we investigated the role of ErbB3 binding protein-1 (Ebp1) in regulation of myogenic stem cell proliferation and differentiation. Ebp1 is a well-conserved DNA/RNA binding protein that is implicated in cell growth, apoptosis and differentiation in many cell types. Of the two main Ebp1 isoforms, only p48 was expressed in satellite cells and C2C12 myoblasts. Although not present in quiescent satellite cells, p48 was strongly induced during activation, remaining at high levels during proliferation and differentiation. While retroviral-mediated over-expression of Ebp1 had only minor effects, siRNA-mediated Ebp1 knockdown inhibited both proliferation and differentiation of satellite cells and C2C12 myoblasts, with a clear failure of myotube formation. Ebp1-knockdown significantly reduced ErbB3 receptor levels, yet over-expression of ErbB3 in Ebp1 knockdown cells did not rescue differentiation. Ebp1 was also expressed by muscle cells during developmental myogenesis in mouse. Since Ebp1 is well-conserved between mouse and chick, we switched to chick to examine its role in muscle formation. In chick embryo, Ebp1 was expressed in the dermomyotome, and myogenic differentiation of muscle progenitors was inhibited by specific Ebp1 down-regulation using shRNA electroporation. These observations demonstrate a conserved function of Ebp1 in the regulation of embryonic muscle progenitors and adult muscle stem cells, which likely operates independently of ErbB3 signaling.
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Affiliation(s)
- Nicolas Figeac
- King's College London, Randall Division of Cell & Molecular Biophysics, New Hunt's House, Guy's Campus, London SE1 1UL, England, UK
| | - Olivier Serralbo
- EMBL Australia, Australian Regenerative Medicine Institute (ARMI), Monash University, Building 75, Clayton, Victoria 3800, Australia
| | - Christophe Marcelle
- EMBL Australia, Australian Regenerative Medicine Institute (ARMI), Monash University, Building 75, Clayton, Victoria 3800, Australia
| | - Peter S Zammit
- King's College London, Randall Division of Cell & Molecular Biophysics, New Hunt's House, Guy's Campus, London SE1 1UL, England, UK.
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23
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Tacheny A, Dieu M, Arnould T, Renard P. Mass spectrometry-based identification of proteins interacting with nucleic acids. J Proteomics 2013; 94:89-109. [PMID: 24060998 DOI: 10.1016/j.jprot.2013.09.011] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2013] [Revised: 08/19/2013] [Accepted: 09/13/2013] [Indexed: 01/02/2023]
Abstract
The identification of the regulatory proteins that control DNA transcription as well as RNA stability and translation represents a key step in the comprehension of gene expression regulation. Those proteins can be purified by DNA- or RNA-affinity chromatography, followed by identification by mass spectrometry. Although very simple in the concept, this represents a real technological challenge due to the low abundance of regulatory proteins compared to the highly abundant proteins binding to nucleic acids in a nonsequence-specific manner. Here we review the different strategies that have been set up to reach this purpose, discussing the key parameters that should be considered to increase the chances of success. Typically, two categories of biological questions can be distinguished: the identification of proteins that specifically interact with a precisely defined binding site, mostly addressed by quantitative mass spectrometry, and the identification in a non-comparative manner of the protein complexes recruited by a poorly characterized long regulatory region of nucleic acids. Finally, beside the numerous studies devoted to in vitro-assembled nucleic acid-protein complexes, the scarce data reported on proteomic analyses of in vivo-assembled complexes are described, with a special emphasis on the associated challenges.
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Affiliation(s)
- A Tacheny
- Laboratory of Biochemistry and Cell Biology (URBC), NAmur Research Institute for LIfe Sciences (NARILIS), University of Namur, 61 rue de Bruxelles, 5000 Namur, Belgium
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24
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Pisapia L, Cicatiello V, Barba P, Malanga D, Maffei A, Hamilton RS, Del Pozzo G. Co-regulated expression of alpha and beta mRNAs encoding HLA-DR surface heterodimers is mediated by the MHCII RNA operon. Nucleic Acids Res 2013; 41:3772-86. [PMID: 23393186 PMCID: PMC3616700 DOI: 10.1093/nar/gkt059] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Major histocompatibility complex class II (MHCII) molecules are heterodimeric surface proteins involved in the presentation of exogenous antigens during the adaptive immune response. We demonstrate the existence of a fine level of regulation, coupling the transcription and processing of mRNAs encoding α and β chains of MHCII molecules, mediated through binding of their Untraslated Regions (UTRs) to the same ribonucleoproteic complex (RNP). We propose a dynamic model, in the context of the 'MHCII RNA operon' in which the increasing levels of DRA and DRB mRNAs are docked by the RNP acting as a bridge between 5'- and 3'-UTR of the same messenger, building a loop structure and, at the same time, joining the two chains, thanks to shared common predicted secondary structure motifs. According to cell needs, as during immune surveillance, this RNP machinery guarantees a balanced synthesis of DRA and DRB mRNAs and a consequent balanced surface expression of the heterodimer.
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Affiliation(s)
- Laura Pisapia
- Institute of Genetics and Biophysics Adriano Buzzati Traverso-CNR, Naples, 80131, Italy
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Chaumet A, Castella S, Gasmi L, Fradin A, Clodic G, Bolbach G, Poulhe R, Denoulet P, Larcher JC. Proteomic analysis of interleukin enhancer binding factor 3 (Ilf3) and nuclear factor 90 (NF90) interactome. Biochimie 2013; 95:1146-57. [PMID: 23321469 DOI: 10.1016/j.biochi.2013.01.004] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2012] [Accepted: 01/04/2013] [Indexed: 11/17/2022]
Abstract
Interleukin enhancer binding factor 3 (Ilf3) and Nuclear Factor 90 (NF90) are two ubiquitous proteins generated by alternative splicing from the ILF3 gene that provides each protein with a long and identical N-terminal domain of 701 amino acids and a specific C-terminal domain of 210 and 15 amino acids, respectively. They exhibit a high polymorphism due to their posttranscriptional and posttranslational modifications. Ilf3 and NF90 functions remain unclear although they have been described as RNA binding proteins but have been implicated in a large scale of cellular phenomena depending on the nature of their interacting partners, the composition of their protein complexes and their subcellular localization. In order to better understand the functions of Ilf3 and NF90, we have investigated their protein partners by an affinity chromatography approach. In this report, we have identified six partners of Ilf3 and NF90 that interact with their double-stranded RNA binding motifs: hnRNP A/B, hnRNP A2/B1, hnRNP A3, hnRNP D, hnRNP Q and PSF. These hnRNP are known to be implicated in mRNA stabilization, transport and/or translation regulation whereas PSF is a splicing factor. Furthermore, Ilf3, NF90 and most of their identified partners have been shown to be present in large complexes. Altogether, these data suggest an implication of Ilf3 and NF90 in mRNA metabolism. This work allows to establish a link between Ilf3 and NF90 functions, as RNA binding proteins, and their interacting partners implicated in these functions.
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Affiliation(s)
- Alexandre Chaumet
- Laboratoire de Biologie du Développement, UMR 7622 CNRS, UPMC Univ Paris 06, 9 quai Saint Bernard, 75252 Paris Cedex 05, France
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Ghosh A, Awasthi S, Hamburger AW. ErbB3-binding protein EBP1 decreases ErbB2 levels via a transcriptional mechanism. Oncol Rep 2012; 29:1161-6. [PMID: 23242156 PMCID: PMC3597558 DOI: 10.3892/or.2012.2186] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2012] [Accepted: 10/09/2012] [Indexed: 01/19/2023] Open
Abstract
Ectopic expression of EBP1, an ErbB3-interacting protein, reduces the expression of the ErbB2 protein and mRNA. However, the mechanism of EBP1-induced decrease in ErbB2 mRNA levels has not yet been determined. Since EBP1 affects both transcriptional and post-transcriptional processes, we evaluated the ability of EBP1 to regulate ErbB2 transcription and RNA stability. We discovered that while wild-type EBP1 decreased the activity of a proximal ErbB2 promoter, EBP1 mutants unable to interact with the Sin3A transcriptional repressor inhibited activity to a lesser extent. EBP1 also decreased the activity of distal ErbB2 promoters. Chromatin immunoprecipitation analysis indicated that EBP1 bound both distal and proximal endogenous ErbB2 promoters in serum-starved conditions. The ErbB3 ligand heregulin (HRG) at growth-promoting concentrations reduced EBP1 binding to the ErbB2 promoter. Although endogenous EBP1 bound ErbB2 mRNA, EBP1 overexpression or ablation of EBP1 protein by shRNA failed to alter ErbB2 mRNA stability. These results suggest that the major effect of EBP1 on ErbB2 mRNA levels is at the transcriptional level.
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Affiliation(s)
- Arundhati Ghosh
- Greenebaum Cancer Center, University of Maryland, Baltimore, MD 21201, USA
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27
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Shamanna RA, Hoque M, Pe'ery T, Mathews MB. Induction of p53, p21 and apoptosis by silencing the NF90/NF45 complex in human papilloma virus-transformed cervical carcinoma cells. Oncogene 2012. [PMID: 23208500 PMCID: PMC4032571 DOI: 10.1038/onc.2012.533] [Citation(s) in RCA: 50] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The heterodimeric nuclear factor 90/nuclear factor 45 complex (NF90/NF45) binds nucleic acids and is a multifunctional regulator of gene expression. Here we report that depletion of NF90/NF45 restores the expression of the p53 and p21 proteins in cervical carcinoma cells infected with high-risk human papillomaviruses (HPV). Knockdown of either NF90 or NF45 by RNA interference led to greatly elevated levels of p53 and p21 proteins in HPV-derived HeLa and SiHa cells, but not in other cancerous or normal cell lines. In HeLa cells, p21 mRNA increased concomitantly but the level of p53 mRNA was unaffected. RNA interference directed against p53 prevented the induction of both proteins. These results indicated that the up-regulation of p21 is due to p53-dependent transcription, whereas p53 is regulated post-transcriptionally. Proteasome-mediated turnover of p53 is accelerated by the HPV E6 and cellular E6AP proteins. We therefore examined the hypothesis that this pathway is regulated by NF90/NF45. Indeed, depletion of NF90 attenuated the expression of E6 RNA and inhibited transcription from the HPV early promoter, revealing a new role for NF90/NF45 in HPV gene expression. The transcription inhibition was largely independent of the reduction of P-TEFb levels caused by NF90 depletion. Consistent with p53 derepression, NF90/NF45-depleted HeLa cells displayed elevated PARP cleavage and susceptibility to camptothecin-induced apoptosis. We conclude that high-risk strains of HPV utilize the cellular NF90/NF45 complex for viral E6 expression in infected cervical carcinoma cell lines. Interference with NF90/NF45 function could assist in controlling cervical carcinoma.
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Affiliation(s)
- R A Shamanna
- 1] Department of Biochemistry and Molecular Biology, New Jersey Medical School, UMDNJ, Newark, NJ, USA [2] Graduate School of Biomedical Sciences, UMDNJ, Newark, NJ, USA
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28
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Corso C, Pisapia L, Citro A, Cicatiello V, Barba P, Cigliano L, Abrescia P, Maffei A, Manco G, Del Pozzo G. EBP1 and DRBP76/NF90 binding proteins are included in the major histocompatibility complex class II RNA operon. Nucleic Acids Res 2011; 39:7263-75. [PMID: 21624892 PMCID: PMC3167597 DOI: 10.1093/nar/gkr278] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Abstract
Major histocompatibility complex class II mRNAs encode heterodimeric proteins involved in the presentation of exogenous antigens during an immune response. Their 3'UTRs bind a protein complex in which we identified two factors: EBP1, an ErbB3 receptor-binding protein and DRBP76, a double-stranded RNA binding nuclear protein, also known as nuclear factor 90 (NF90). Both are well-characterized regulatory factors of several mRNA molecules processing. Using either EBP1 or DRBP76/NF90-specific knockdown experiments, we established that the two proteins play a role in regulating the expression of HLA-DRA, HLA-DRB1 and HLA-DQA1 mRNAs levels. Our study represents the first indication of the existence of a functional unit that includes different transcripts involved in the adaptive immune response. We propose that the concept of 'RNA operon' may be suitable for our system in which MHCII mRNAs are modulated via interaction of their 3'UTR with same proteins.
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Affiliation(s)
- Carmela Corso
- Institute of Genetics and Biophysics ‘A. Buzzati Traverso’, CNR, Via Pietro Castellino 111, 80131, Naples, Department of Biological Science, University of Naples Federico II, Via Mezzocannone 8, 80134, Naples and Institute of Protein Biochemistry, CNR, Via Pietro Castellino 111, 80131, Naples, Italy
| | - Laura Pisapia
- Institute of Genetics and Biophysics ‘A. Buzzati Traverso’, CNR, Via Pietro Castellino 111, 80131, Naples, Department of Biological Science, University of Naples Federico II, Via Mezzocannone 8, 80134, Naples and Institute of Protein Biochemistry, CNR, Via Pietro Castellino 111, 80131, Naples, Italy
| | - Alessandra Citro
- Institute of Genetics and Biophysics ‘A. Buzzati Traverso’, CNR, Via Pietro Castellino 111, 80131, Naples, Department of Biological Science, University of Naples Federico II, Via Mezzocannone 8, 80134, Naples and Institute of Protein Biochemistry, CNR, Via Pietro Castellino 111, 80131, Naples, Italy
| | - Valeria Cicatiello
- Institute of Genetics and Biophysics ‘A. Buzzati Traverso’, CNR, Via Pietro Castellino 111, 80131, Naples, Department of Biological Science, University of Naples Federico II, Via Mezzocannone 8, 80134, Naples and Institute of Protein Biochemistry, CNR, Via Pietro Castellino 111, 80131, Naples, Italy
- *To whom correspondence should be addressed. Valeria Cicatiello. Tel: +390816132455; Fax: +390816132718;
| | - Pasquale Barba
- Institute of Genetics and Biophysics ‘A. Buzzati Traverso’, CNR, Via Pietro Castellino 111, 80131, Naples, Department of Biological Science, University of Naples Federico II, Via Mezzocannone 8, 80134, Naples and Institute of Protein Biochemistry, CNR, Via Pietro Castellino 111, 80131, Naples, Italy
| | - Luisa Cigliano
- Institute of Genetics and Biophysics ‘A. Buzzati Traverso’, CNR, Via Pietro Castellino 111, 80131, Naples, Department of Biological Science, University of Naples Federico II, Via Mezzocannone 8, 80134, Naples and Institute of Protein Biochemistry, CNR, Via Pietro Castellino 111, 80131, Naples, Italy
| | - Paolo Abrescia
- Institute of Genetics and Biophysics ‘A. Buzzati Traverso’, CNR, Via Pietro Castellino 111, 80131, Naples, Department of Biological Science, University of Naples Federico II, Via Mezzocannone 8, 80134, Naples and Institute of Protein Biochemistry, CNR, Via Pietro Castellino 111, 80131, Naples, Italy
| | - Antonella Maffei
- Institute of Genetics and Biophysics ‘A. Buzzati Traverso’, CNR, Via Pietro Castellino 111, 80131, Naples, Department of Biological Science, University of Naples Federico II, Via Mezzocannone 8, 80134, Naples and Institute of Protein Biochemistry, CNR, Via Pietro Castellino 111, 80131, Naples, Italy
| | - Giuseppe Manco
- Institute of Genetics and Biophysics ‘A. Buzzati Traverso’, CNR, Via Pietro Castellino 111, 80131, Naples, Department of Biological Science, University of Naples Federico II, Via Mezzocannone 8, 80134, Naples and Institute of Protein Biochemistry, CNR, Via Pietro Castellino 111, 80131, Naples, Italy
- *To whom correspondence should be addressed. Valeria Cicatiello. Tel: +390816132455; Fax: +390816132718;
| | - Giovanna Del Pozzo
- Institute of Genetics and Biophysics ‘A. Buzzati Traverso’, CNR, Via Pietro Castellino 111, 80131, Naples, Department of Biological Science, University of Naples Federico II, Via Mezzocannone 8, 80134, Naples and Institute of Protein Biochemistry, CNR, Via Pietro Castellino 111, 80131, Naples, Italy
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Mactier S, Henrich S, Che Y, Kohnke PL, Christopherson RI. Comprehensive Proteomic Analysis of the Effects of Purine Analogs on Human Raji B-Cell Lymphoma. J Proteome Res 2011; 10:1030-42. [DOI: 10.1021/pr100803b] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Affiliation(s)
- Swetlana Mactier
- School of Molecular Bioscience, University of Sydney, Sydney, NSW 2006, Australia
| | - Silke Henrich
- School of Molecular Bioscience, University of Sydney, Sydney, NSW 2006, Australia
| | - Yiping Che
- School of Molecular Bioscience, University of Sydney, Sydney, NSW 2006, Australia
| | - Philippa L. Kohnke
- School of Molecular Bioscience, University of Sydney, Sydney, NSW 2006, Australia
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30
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Kim CK, Nguyen TL, Joo KM, Nam DH, Park J, Lee KH, Cho SW, Ahn JY. Negative Regulation of p53 by the Long Isoform of ErbB3 Binding Protein Ebp1 in Brain Tumors. Cancer Res 2010; 70:9730-41. [DOI: 10.1158/0008-5472.can-10-1882] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
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31
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Ishimaru D, Zuraw L, Ramalingam S, Sengupta TK, Bandyopadhyay S, Reuben A, Fernandes DJ, Spicer EK. Mechanism of regulation of bcl-2 mRNA by nucleolin and A+U-rich element-binding factor 1 (AUF1). J Biol Chem 2010; 285:27182-27191. [PMID: 20571027 PMCID: PMC2930717 DOI: 10.1074/jbc.m109.098830] [Citation(s) in RCA: 87] [Impact Index Per Article: 6.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2009] [Revised: 05/28/2010] [Indexed: 11/06/2022] Open
Abstract
The antiapoptotic Bcl-2 protein is overexpressed in a variety of cancers, particularly leukemias. In some cell types this is the result of enhanced stability of bcl-2 mRNA, which is controlled by elements in its 3'-untranslated region. Nucleolin is one of the proteins that binds to bcl-2 mRNA, thereby increasing its half-life. Here, we examined the site on the bcl-2 3'-untranslated region that is bound by nucleolin as well as the protein binding domains important for bcl-2 mRNA recognition. RNase footprinting and RNA fragment binding assays demonstrated that nucleolin binds to a 40-nucleotide region at the 5' end of the 136-nucleotide bcl-2 AU-rich element (ARE(bcl-2)). The first two RNA binding domains of nucleolin were sufficient for high affinity binding to ARE(bcl-2). In RNA decay assays, ARE(bcl-2) transcripts were protected from exosomal decay by the addition of nucleolin. AUF1 has been shown to recruit the exosome to mRNAs. When MV-4-11 cell extracts were immunodepleted of AUF1, the rate of decay of ARE(bcl-2) transcripts was reduced, indicating that nucleolin and AUF1 have opposing roles in bcl-2 mRNA turnover. When the function of nucleolin in MV-4-11 cells was impaired by treatment with the nucleolin-targeting aptamer AS1411, association of AUF1 with bcl-2 mRNA was increased. This suggests that the degradation of bcl-2 mRNA induced by AS1411 results from both interference with nucleolin protection of bcl-2 mRNA and recruitment of the exosome by AUF1. Based on our findings, we propose a model that illustrates the opposing roles of nucleolin and AUF1 in regulating bcl-2 mRNA stability.
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Affiliation(s)
- Daniella Ishimaru
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Lisa Zuraw
- Department of Chemistry, The Citadel, Charleston, South Carolina 29409
| | - Sivakumar Ramalingam
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Tapas K Sengupta
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Sumita Bandyopadhyay
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Adrian Reuben
- Division of Gastroenterology and Hepatology, Department of Medicine, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Daniel J Fernandes
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina 29425
| | - Eleanor K Spicer
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, South Carolina 29425.
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32
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Lu Y, Zhou H, Chen W, Zhang Y, Hamburger AW. The ErbB3 binding protein EBP1 regulates ErbB2 protein levels and tamoxifen sensitivity in breast cancer cells. Breast Cancer Res Treat 2010; 126:27-36. [PMID: 20379846 DOI: 10.1007/s10549-010-0873-4] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Accepted: 03/24/2010] [Indexed: 01/13/2023]
Abstract
The ErbB2/3 heterodimer plays a critical role in breast cancer progression and in the development of endocrine resistance. EBP1, an ErbB3 binding protein, inhibits HRG-stimulated breast cancer growth, decreases ErbB2 protein levels and contributes to tamoxifen sensitivity. We report here that ectopic expression of EBP1 in Estrogen Receptor (ER) positive breast cancers that express ErbB2 at both high and low levels decreased ErbB2 protein levels. ErbB2 protein expression was also increased in mammary glands of Ebp1 knock out mice. To define the mechanism of ErbB2 down regulation, we examined the effects of EBP1 on ErbB2 mRNA levels, transcription of the ErbB2 gene and ErbB2 protein stability. We found that ectopic expression of EBP1 decreased steady state levels of endogenous ErbB2 mRNA in all cell lines tested. EBP1 overexpression decreased the activity of an ErbB2 promoter reporter in cells which overxpress ErbB2. However, reporter activity was unchanged or increased in cells which express low endogenous levels of ErbB2. We also found that ectopic expression of EBP1 accelerated ErbB2 protein degradation and enhanced ErbB2 ubiquitination in cells which express both low and high levels of ErbB2. Treatment with proteasome inhibitors prevented this decrease in ErbB2 protein levels. Ablation of EBP1 expression led to tamoxifen resistance that was abrogated by inhibition of ErbB2 activity. These results suggest that EBP1 inhibits expression of ErbB2 protein levels by multiple mechanisms and that EBP1's effects on tamoxifen sensitivity are mediated in part by its ability to modulate ErbB2 levels.
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Affiliation(s)
- Yan Lu
- Greenebaum Cancer Center, University of Maryland School of Medicine, Baltimore, MD 21201, USA
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Zhou H, Mazan-Mamczarz K, Martindale JL, Barker A, Liu Z, Gorospe M, Leedman PJ, Gartenhaus RB, Hamburger AW, Zhang Y. Post-transcriptional regulation of androgen receptor mRNA by an ErbB3 binding protein 1 in prostate cancer. Nucleic Acids Res 2010; 38:3619-31. [PMID: 20159994 PMCID: PMC2887957 DOI: 10.1093/nar/gkq084] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Androgen receptor (AR)-mediated pathways play a critical role in the development and progression of prostate cancer. However, little is known about the regulation of AR mRNA stability and translation, two central processes that control AR expression. The ErbB3 binding protein 1 (EBP1), an AR corepressor, negatively regulates crosstalk between ErbB3 ligand heregulin (HRG)-triggered signaling and the AR axis, affecting biological properties of prostate cancer cells. EBP1 protein expression is also decreased in clinical prostate cancer. We previously demonstrated that EBP1 overexpression results in decreased AR protein levels by affecting AR promoter activity. However, EBP1 has recently been demonstrated to be an RNA binding protein. We therefore examined the ability of EBP1 to regulate AR post-transcriptionally. Here we show that EBP1 promoted AR mRNA decay through physical interaction with a conserved UC-rich motif within the 3'-UTR of AR. The ability of EBP1 to accelerate AR mRNA decay was further enhanced by HRG treatment. EBP1 also bound to a CAG-formed stem-loop in the 5' coding region of AR mRNA and was able to inhibit AR translation. Thus, decreases of EBP1 in prostate cancer could be important for the post-transcriptional up-regulation of AR contributing to aberrant AR expression and disease progression.
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Affiliation(s)
- Hua Zhou
- Greenebaum Cancer Center, Department of Pathology, University of Maryland School of Medicine, Baltimore, Maryland 21201, USA
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Gopinath M, Raju S, Honda A, Shaila MS. Host factor Ebp1 inhibits rinderpest virus transcription in vivo. Arch Virol 2010; 155:455-62. [PMID: 20127373 DOI: 10.1007/s00705-010-0599-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2009] [Accepted: 11/06/2009] [Indexed: 11/26/2022]
Abstract
ErbB3 binding protein Ebp1 has been shown to downregulate ErbB3 receptor-mediated signaling to inhibit cell proliferation. Rinderpest virus belongs to the family Paramyxoviridae and is characterized by the presence of a non-segmented negative-sense RNA genome. In this work, we show that rinderpest virus infection of Vero cells leads to the down-regulation of the host factor Ebp1, at both the mRNA and protein levels. Ebp1 protein has been shown to co-localize with viral inclusion bodies in infected cells, and it is packaged into virions, presumably through its interaction with the N protein or the N-RNA itself. Overexpression of Ebp1 inhibits viral transcription and multiplication in infected cells, suggesting that a mutual antagonism operates between host factor Ebp1 and the virus.
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Affiliation(s)
- M Gopinath
- Department of Microbiology and Cell Biology, Indian Institute of Science, Bangalore 560012, India
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35
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Lapucci A, Lulli M, Amedei A, Papucci L, Witort E, Di Gesualdo F, Bertolini F, Brewer G, Nicolin A, Bevilacqua A, Schiavone N, Morello D, Donnini M, Capaccioli S. zeta-Crystallin is a bcl-2 mRNA binding protein involved in bcl-2 overexpression in T-cell acute lymphocytic leukemia. FASEB J 2010; 24:1852-65. [PMID: 20103721 DOI: 10.1096/fj.09-140459] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The human antiapoptotic bcl-2 gene has been discovered in t(14;18) B-cell leukemias/lymphomas because of its overexpression caused at a transcriptional control level by the bcl-2/IgH fusion gene. We were the first to disclose the post-transcriptional control of bcl-2 expression mediated by interactions of an adenine + uracil (AU)-rich element (ARE) in the 3'-UTR of bcl-2 mRNA with AU-binding proteins (AUBPs). Here, we identify and characterize zeta-crystallin as a new bcl-2 AUBP, whose silencing or overexpression has impact on bcl-2 mRNA stability. An increased Bcl-2 level observed in normal phytohemagglutinin (PHA)-activated T lymphocytes, acute lymphatic leukemia (ALL) T-cell lines, and T cells of patients with leukemia in comparison with normal non-PHA-activated T lymphocytes was concomitant with an increase in zeta-crystallin level. The specific association of zeta-crystallin with the bcl-2 ARE was significantly enhanced in T cells of patients with ALL, which accounts for the higher stability of bcl-2 mRNA and suggests a possible contribution of zeta-crystallin to bcl-2 overexpression occurring in this leukemia.
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Affiliation(s)
- Andrea Lapucci
- Department of Experimental Pathology and Oncology, University of Florence, Florence, Italy
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36
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Ishimaru D, Ramalingam S, Sengupta TK, Bandyopadhyay S, Dellis S, Tholanikunnel BG, Fernandes DJ, Spicer EK. Regulation of Bcl-2 expression by HuR in HL60 leukemia cells and A431 carcinoma cells. Mol Cancer Res 2009; 7:1354-66. [PMID: 19671677 DOI: 10.1158/1541-7786.mcr-08-0476] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Overexpression of the proto-oncogene bcl-2 promotes abnormal cell survival by inhibiting apoptosis. Expression of bcl-2 is determined, in part, by regulatory mechanisms that control the stability of bcl-2 mRNA. Elements in the 3'-untranslated region of bcl-2 mRNA have been shown to play a role in regulating the stability of the message. Previously, it was found that the RNA binding proteins nucleolin and Ebp1 have a role in stabilizing bcl-2 mRNA in HL60 cells. Here, we have identified HuR as a component of bcl-2 messenger ribonucleoprotein (mRNP) complexes. RNA coimmunoprecipitation assays showed that HuR binds to bcl-2 mRNA in vivo. We also observed an RNA-dependent coprecipitation of HuR and nucleolin, suggesting that the two proteins are present in common mRNP complexes. Moreover, nucleolin and HuR bind concurrently to bcl-2 AU-rich element (ARE) RNA in vitro, suggesting separate binding sites for these proteins on bcl-2 mRNA. Knockdown of HuR in A431 cells leads to down-regulation of bcl-2 mRNA and protein levels. Observation of a decreased ratio of bcl-2 mRNA to heterogeneous nuclear RNA in HuR knockdown cells confirmed a positive role for HuR in regulating bcl-2 stability. Recombinant HuR retards exosome-mediated decay of bcl-2 ARE RNA in extracts of HL60 cells. This supports a role for HuR in the regulation of bcl-2 mRNA stability in HL60 cells, as well as in A431 cells. Addition of nucleolin and HuR to HL60 cell extracts produced a synergistic protective effect on decay of bcl-2 ARE RNA. HuR knockdown also leads to redistribution of bcl-2 mRNA from polysomes to monosomes. Thus, HuR seems to play a positive role in both regulation of bcl-2 mRNA translation and mRNA stability.
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MESH Headings
- Antigens, Surface/metabolism
- Carcinoma, Squamous Cell/genetics
- Carcinoma, Squamous Cell/pathology
- Centrifugation, Density Gradient
- ELAV Proteins
- ELAV-Like Protein 1
- Gene Expression Regulation, Neoplastic
- Gene Knockdown Techniques
- HL-60 Cells
- Humans
- Immunoprecipitation
- Leukemia/genetics
- Leukemia/pathology
- Phosphoproteins/metabolism
- Polyribosomes/metabolism
- Protein Binding
- Proto-Oncogene Mas
- Proto-Oncogene Proteins c-bcl-2/genetics
- Proto-Oncogene Proteins c-bcl-2/metabolism
- RNA Stability
- RNA, Messenger/genetics
- RNA, Messenger/metabolism
- RNA, Neoplasm/metabolism
- RNA, Small Interfering/metabolism
- RNA-Binding Proteins/metabolism
- Recombinant Proteins/metabolism
- Regulatory Sequences, Ribonucleic Acid/genetics
- Nucleolin
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Affiliation(s)
- Daniella Ishimaru
- Department of Biochemistry and Molecular Biology, Medical University of South Carolina, Charleston, SC 29425, USA
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37
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Zhang Y, Lu Y, Zhou H, Lee M, Liu Z, Hassel BA, Hamburger AW. Alterations in cell growth and signaling in ErbB3 binding protein-1 (Ebp1) deficient mice. BMC Cell Biol 2008; 9:69. [PMID: 19094237 PMCID: PMC2648959 DOI: 10.1186/1471-2121-9-69] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2008] [Accepted: 12/18/2008] [Indexed: 11/29/2022] Open
Abstract
Background The ErbB3 binding protein-1 (Ebp1) belongs to a family of DNA/RNA binding proteins implicated in cell growth, apoptosis and differentiation. However, the physiological role of Ebp1 in the whole organism is not known. Therefore, we generated Ebp1-deficient mice carrying a gene trap insertion in intron 2 of the Ebp1 (pa2g4) gene. Results Ebp1-/- mice were on average 30% smaller than wild type and heterozygous sex matched littermates. Growth retardation was apparent from Day 10 until Day 30. IGF-1 production and IGBP-3 and 4 protein levels were reduced in both embryo fibroblasts and adult knock-out mice. The proliferation of fibroblasts derived from Day 12.5 knock out embryos was also decreased as compared to that of wild type cells. Microarray expression analysis revealed changes in genes important in cell growth including members of the MAPK signal transduction pathway. In addition, the expression or activation of proliferation related genes such as AKT and the androgen receptor, previously demonstrated to be affected by Ebp1 expression in vitro, was altered in adult tissues. Conclusion These results indicate that Ebp1 can affect growth in an animal model, but that the expression of proliferation related genes is cell and context specific. The Ebp1-/- mouse line represents a new in vivo model to investigate Ebp1 function in the whole organism.
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Affiliation(s)
- Yuexing Zhang
- Department of Pathology, University of Maryland School of Medicine, Baltimore, MD, USA.
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Unterberger A, Torrisani J, Szyf M. A method for purification, identification and validation of DNMT1 mRNA binding proteins. Biol Proced Online 2008; 10:47-57. [PMID: 19048127 PMCID: PMC2591025 DOI: 10.1251/bpo142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2007] [Revised: 01/28/2008] [Accepted: 01/31/2008] [Indexed: 11/30/2022] Open
Abstract
DNA methyltransferase 1 (DNMT1) is the enzyme responsible for the maintenance of DNA methylation patterns during cell division. DNMT1 expression is tightly regulated within the cell cycle. Our previous study showed that the binding of a protein with an apparent size of ~40 kDa on DNMT1 3’-UTR triggered the destabilization of DNMT1 mRNA transcript during Go/G1 phase. Using RNA affinity capture with the 3’-UTR of DNMT1 mRNA and matrix-assisted laser desorption-time of flight tandem mass spectrometry (MALDI-TOF-MS-MS) analysis, we isolated and identified AUF 1 (AU-rich element ARE:poly-(U)-binding/degradation factor) as the binding protein. We then validated the role of this protein in the destabilization of DNMT1 mRNA. In this report, we detail the different approaches used for the isolation, the identification of a RNA binding protein and the validation of its role.
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Liu Z, Oh SM, Okada M, Liu X, Cheng D, Peng J, Brat DJ, Sun SY, Zhou W, Gu W, Ye K. Human BRE1 is an E3 ubiquitin ligase for Ebp1 tumor suppressor. Mol Biol Cell 2008; 20:757-68. [PMID: 19037095 DOI: 10.1091/mbc.e08-09-0983] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Human Bre1, an E3 ligase for H2B monoubiquitination, binds p53 and enhances activator-dependent transcription. Ebp1, an ErbB3 receptor-binding protein, inhibits cell proliferation and acts as a tumor suppressor. Here, we show that hBre1 acts as an E3 ubiquitin ligase for Ebp1 tumor suppressor and promotes its polyubiquitination and degradation. Ebp1 is polyubiquitinated in cancer cells, which is regulated by its phosphorylation. We identified hBre1 acting as an E3 ligase for Ebp1 and increasing its polyubiquitination. Depletion of hBre1 blocks Ebp1's polyubiquitination and elevates its protein level, preventing cancer proliferation. hBre1 binds Ebp1 and suppresses its repressive effect on E2F-1. Moreover, Ebp1 protein level is substantially diminished in human cancers. It is robustly phosphorylated and localized in the nucleus of primary gliomas, correlating with hBre1 subcellular residency. Thus, hBre1 inhibits Ebp1's tumor suppressive activity through mediating its polyubiquitination and degradation.
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Affiliation(s)
- Zhixue Liu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, GA 30322, USA
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40
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Zhang Y, Linn D, Liu Z, Melamed J, Tavora F, Young CY, Burger AM, Hamburger AW. EBP1, an ErbB3-binding protein, is decreased in prostate cancer and implicated in hormone resistance. Mol Cancer Ther 2008; 7:3176-86. [PMID: 18852121 DOI: 10.1158/1535-7163.mct-08-0526] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Aberrant activation of the androgen receptor (AR) by the ErbB2/ErbB3 heterodimer contributes to the development of hormone resistance in prostate cancer. EBP1, an ErbB3-binding protein, acts as an AR corepressor. As EBP1 is decreased in preclinical models of hormone-refractory prostate cancer, we studied the expression of EBP1 in human prostate cancer. We found that the expression of the EBP1 gene was significantly decreased in prostate cancer tissues compared with benign prostate at both mRNA and protein levels. Restoration of EBP1 expression in the hormone-refractory LNCaP C81 cell line led to an amelioration of the androgen-independent phenotype based on established biological criteria and a reduction in the expression of a cohort of AR target genes. The ability of the ErbB3 ligand heregulin (HRG) to stimulate growth and AKT phosphorylation of hormone-refractory prostate cancer cells was abolished. Abrogation of EBP1 expression by short hairpin RNA in hormone-dependent LNCaP cells, which undergo apoptosis in response to HRG, resulted in HRG-stimulated cell growth. Restoration of EBP1 expression decreased the tumorigenicity of C81 xenografts in female mice, whereas elimination of EBP1 expression enhanced the ability of LNCaP cells to grow in female mice. Our data support a role for EBP1 in the development of hormone-refractory prostate cancer via inhibition of both AR- and HRG-stimulated growth and present a novel strategy for treating androgen-refractory prostate cancer.
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Affiliation(s)
- Yuexing Zhang
- Greenebaum Cancer Center, University of Maryland School of Medicine, 655 West Baltimore Street, Baltimore, MD 21201, USA
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41
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Tsaytler PA, C. O’Flaherty M, Sakharov DV, Krijgsveld J, Egmond MR. Immediate Protein Targets of Photodynamic Treatment in Carcinoma Cells. J Proteome Res 2008; 7:3868-78. [PMID: 18652502 DOI: 10.1021/pr800189q] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Pavel A. Tsaytler
- Department of Membrane Enzymology, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands, and Biomolecular Mass Spectrometry and Proteomics Group, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Sorbonnelaan 16, Utrecht 3584 CA, The Netherlands
| | - Martina C. O’Flaherty
- Department of Membrane Enzymology, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands, and Biomolecular Mass Spectrometry and Proteomics Group, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Sorbonnelaan 16, Utrecht 3584 CA, The Netherlands
| | - Dmitri V. Sakharov
- Department of Membrane Enzymology, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands, and Biomolecular Mass Spectrometry and Proteomics Group, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Sorbonnelaan 16, Utrecht 3584 CA, The Netherlands
| | - Jeroen Krijgsveld
- Department of Membrane Enzymology, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands, and Biomolecular Mass Spectrometry and Proteomics Group, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Sorbonnelaan 16, Utrecht 3584 CA, The Netherlands
| | - Maarten R. Egmond
- Department of Membrane Enzymology, Bijvoet Center for Biomolecular Research, Utrecht University, Padualaan 8, Utrecht 3584 CH, The Netherlands, and Biomolecular Mass Spectrometry and Proteomics Group, Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Sorbonnelaan 16, Utrecht 3584 CA, The Netherlands
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42
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Zhang Y, Akinmade D, Hamburger AW. Inhibition of heregulin mediated MCF-7 breast cancer cell growth by the ErbB3 binding protein EBP1. Cancer Lett 2008; 265:298-306. [PMID: 18355957 DOI: 10.1016/j.canlet.2008.02.024] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2007] [Revised: 02/12/2008] [Accepted: 02/14/2008] [Indexed: 12/18/2022]
Abstract
The ErbB2/3 heterodimer plays a critical role in breast cancer genesis and progression. EBP1, an ErbB3 binding protein, inhibits breast cancer growth but its effects on ErbB3 ligand mediated signal transduction or ErbB receptors is not known. We report here that ectopic expression of EBP1 in MCF-7 and AU565 breast cancer cell lines inhibited HRG-induced proliferation. ErbB2 protein levels were substantially decreased in EBP1 transfectants, while ErbB3 levels were unchanged. HRG-induced AKT activation was attenuated in EBP1 stable transfectants and transfection of a constitutively activated AKT partially restored the growth response to HRG. Down-regulation of EBP1 expression in MCF-7 cells by shRNA resulted in increased cell growth in response to HRG and increased cyclin D1 and ErbB2 expression. These results suggest that EBP1, by down-regulating ErbB signal transduction, attentuates HRG-mediated growth of breast cancer cells.
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Affiliation(s)
- Yuexing Zhang
- Department of Pathology, University of Maryland, Baltimore, MD, United States
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43
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Parrott AM, Mathews MB. Novel rapidly evolving hominid RNAs bind nuclear factor 90 and display tissue-restricted distribution. Nucleic Acids Res 2007; 35:6249-58. [PMID: 17855395 PMCID: PMC2094060 DOI: 10.1093/nar/gkm668] [Citation(s) in RCA: 60] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023] Open
Abstract
Nuclear factor 90 (NF90) is a double-stranded RNA-binding protein implicated in multiple cellular functions, but with few identified RNA partners. Using in vivo cross-linking followed by immunoprecipitation, we discovered a family of small NF90-associated RNAs (snaR). These highly structured non-coding RNAs of ∼117 nucleotides are expressed in immortalized human cell lines of diverse lineages. In human tissues, they are abundant in testis, with minor distribution in brain, placenta and some other organs. Two snaR subsets were isolated from human 293 cells, and additional species were found by bioinformatic analysis. Their genes often occur in multiple copies arranged in two inverted regions of tandem repeats on chromosome 19. snaR-A is transcribed by RNA polymerase III from an intragenic promoter, turns over rapidly, and shares sequence identity with Alu RNA and two potential piRNAs. It interacts with NF90's double-stranded RNA-binding motifs. snaR orthologs are present in chimpanzee but not other mammals, and include genes located in the promoter of two chorionic gonadotropin hormone genes. snaRs appear to have undergone accelerated evolution and differential expansion in the great apes.
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44
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Monie TP, Perrin AJ, Birtley JR, Sweeney TR, Karakasiliotis I, Chaudhry Y, Roberts LO, Matthews S, Goodfellow IG, Curry S. Structural insights into the transcriptional and translational roles of Ebp1. EMBO J 2007; 26:3936-44. [PMID: 17690690 PMCID: PMC1994118 DOI: 10.1038/sj.emboj.7601817] [Citation(s) in RCA: 82] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2007] [Accepted: 07/11/2007] [Indexed: 11/08/2022] Open
Abstract
The ErbB3-binding protein 1 (Ebp1) is an important regulator of transcription, affecting eukaryotic cell growth, proliferation, differentiation and survival. Ebp1 can also affect translation and cooperates with the polypyrimidine tract-binding protein (PTB) to stimulate the activity of the internal ribosome entry site (IRES) of foot-and-mouth disease virus (FMDV). We report here the crystal structure of murine Ebp1 (p48 isoform), providing the first glimpse of the architecture of this versatile regulator. The structure reveals a core domain that is homologous to methionine aminopeptidases, coupled to a C-terminal extension that contains important motifs for binding proteins and RNA. It sheds new light on the conformational differences between the p42 and p48 isoforms of Ebp1, the disposition of the key protein-interacting motif ((354)LKALL(358)) and the RNA-binding activity of Ebp1. We show that the primary RNA-binding site is formed by a Lys-rich motif in the C terminus and mediates the interaction with the FMDV IRES. We also demonstrate a specific functional requirement for Ebp1 in FMDV IRES-directed translation that is independent of a direct interaction with PTB.
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Affiliation(s)
- Tom P Monie
- Division of Cell and Molecular Biology, Imperial College, South Kensington Campus, London, UK
| | - Andrew J Perrin
- Division of Cell and Molecular Biology, Imperial College, South Kensington Campus, London, UK
| | - James R Birtley
- Division of Cell and Molecular Biology, Imperial College, South Kensington Campus, London, UK
| | - Trevor R Sweeney
- Division of Cell and Molecular Biology, Imperial College, South Kensington Campus, London, UK
| | | | - Yasmin Chaudhry
- Department of Virology, Faculty of Medicine, Imperial College London, London, UK
| | - Lisa O Roberts
- School of Biomedical and Molecular Sciences, University of Surrey, Guildford, Surrey, UK
| | | | - Ian G Goodfellow
- Department of Virology, Faculty of Medicine, Imperial College London, London, UK
| | - Stephen Curry
- Division of Cell and Molecular Biology, Imperial College, South Kensington Campus, London, UK
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45
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Kowalinski E, Bange G, Bradatsch B, Hurt E, Wild K, Sinning I. The crystal structure of Ebp1 reveals a methionine aminopeptidase fold as binding platform for multiple interactions. FEBS Lett 2007; 581:4450-4. [PMID: 17765895 DOI: 10.1016/j.febslet.2007.08.024] [Citation(s) in RCA: 48] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2007] [Revised: 08/13/2007] [Accepted: 08/13/2007] [Indexed: 11/21/2022]
Abstract
The ErbB-3 receptor binding protein (Ebp1) is a member of the proliferation-associated 2G4 (PA2G4) family implicated in regulation of cell growth and differentiation. Here, we report the crystal structure of the human Ebp1 at 1.6 A resolution. The protein has the conserved pita bread fold of methionine aminopeptidases, but without the characteristic enzymatic activity. Moreover, Ebp1 is known to interact with a number of proteins and RNAs involved in either transcription regulation or translation control. The structure provides insights in how Ebp1 discriminates between its different interaction partners.
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Affiliation(s)
- Eva Kowalinski
- Heidelberg University Biochemistry Center (BZH), INF 328, D-69120 Heidelberg, Germany
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46
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Kowalinski E, Bange G, Wild K, Sinning I. Expression, purification, crystallization and preliminary crystallographic analysis of the proliferation-associated protein Ebp1. Acta Crystallogr Sect F Struct Biol Cryst Commun 2007; 63:768-70. [PMID: 17768350 PMCID: PMC2376314 DOI: 10.1107/s1744309107038985] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2007] [Accepted: 08/07/2007] [Indexed: 11/10/2022]
Abstract
ErbB-3-binding protein 1 (Ebp1) is a member of the family of proliferation-associated 2G4 proteins (PA2G4s) and plays a role in cellular growth and differentiation. Ligand-induced activation of the transmembrane receptor ErbB3 leads to dissociation of Ebp1 from the receptor in a phosphorylation-dependent manner. The non-associated protein is involved in transcriptional and translational regulation in the cell. Here, the overexpression, purification, crystallization and preliminary crystallographic studies of Ebp1 from Homo sapiens are reported. Initially observed crystals were improved by serial seeding to single crystals suitable for data collection. The optimized crystals belong to the tetragonal space group P4(1)2(1)2 or P4(3)2(1)2 and diffracted to a resolution of 1.6 A.
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Affiliation(s)
- Eva Kowalinski
- Heidelberg University Biochemistry Center, INF 328, D-69120 Heidelberg, Germany
| | - Gert Bange
- Heidelberg University Biochemistry Center, INF 328, D-69120 Heidelberg, Germany
| | - Klemens Wild
- Heidelberg University Biochemistry Center, INF 328, D-69120 Heidelberg, Germany
| | - Irmgard Sinning
- Heidelberg University Biochemistry Center, INF 328, D-69120 Heidelberg, Germany
- Correspondence e-mail:
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47
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Parrott AM, Walsh MR, Mathews MB. Analysis of RNA:protein interactions in vivo: identification of RNA-binding partners of nuclear factor 90. Methods Enzymol 2007; 429:243-60. [PMID: 17913627 DOI: 10.1016/s0076-6879(07)29012-3] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Ribonucleoprotein complexes (RNPs) perform a multitude of functions in the cell. Elucidating the composition of such complexes and unraveling their many interactions are current challenges in molecular biology. To stabilize complexes formed in cells and to preclude reassortment of their components during isolation, we employ chemical crosslinking of the RNA and protein moieties. Here we describe the identification of cellular RNAs bound to nuclear factor 90 (NF90), the founder member of a family of ubiquitous double-stranded RNA-binding proteins. Crosslinked RNA-NF90 complexes were immunoprecipitated from stable cell lines containing epitope-tagged NF90 protein isoforms. The bound RNA was released and identified through RNase H digestion and by various gene amplification techniques. We appraise the methods used by altering crosslinking conditions, and the binding profiles of different NF90 protein isoforms in synchronized and asynchronous cells are compared. This study discovers two novel RNA species and establishes NF90 as a multiclass RNA-binding protein, capable of binding representatives of all three classes of RNA.
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Affiliation(s)
- Andrew M Parrott
- Department of Biochemistry and Molecular Biology, University of Medicine and Dentistry of New Jersey, New Jersey Medical School, Newark, New Jersey, USA
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48
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Liu Z, Liu X, Nakayama KI, Nakayama K, Ye K. Protein kinase C-δ phosphorylates Ebp1 and prevents its proteolytic degradation, enhancing cell survival. J Neurochem 2006; 100:1278-88. [PMID: 17316401 DOI: 10.1111/j.1471-4159.2006.04313.x] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
ErbB3-binding protein (Ebp1) promotes cell survival by preventing apoptotic DNA fragmentation through a complex with active nuclear Akt. Ebp1 phosphorylation by protein kinase C (PKC)-delta mediates its binding to nuclear Akt. In this study, we show that Ebp1 itself acts as a substrate of active caspase 3 during the programmed cell death. PKC-delta phosphorylation on Ebp1 protects it from apoptotic degradation initiated in cell-free apoptotic solution. Moreover, Ebp1 is evidently cleaved in PKC-delta-deficient cells but not in wild-type cells. Ebp1 translated from first ATG is resistant to apoptotic cleavage; by contrast, Ebp1 from second and third ATG demonstrates robust degradation, and PKC phosphorylation on S360 suppresses its cleavage by active caspase 3. Ebp1 can be digested at both D53 and D196 sites, but cleavage at D196 appears to be a prerequisite for its further degradation at D53 site. Compared with wild-type Ebp1, D196A mutant markedly protects cells from apoptosis. Thus, PKC-delta antagonizes apoptosis through phosphorylating Ebp1 and protects it from apoptotic degradation.
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Affiliation(s)
- Zhixue Liu
- Department of Pathology and Laboratory Medicine, Emory University School of Medicine, Atlanta, Georgia 30322, USA
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49
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Liu Z, Ahn JY, Liu X, Ye K. Ebp1 isoforms distinctively regulate cell survival and differentiation. Proc Natl Acad Sci U S A 2006; 103:10917-22. [PMID: 16832058 PMCID: PMC1544149 DOI: 10.1073/pnas.0602923103] [Citation(s) in RCA: 91] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Ebp1, an ErbB3 receptor-binding protein, inhibits the proliferation and induces the differentiation of human cancer cells. Ebp1 binds nuclear Akt and prevents DNA fragmentation by inhibiting caspase-activated DNase. Here, we show that Ebp1 possesses two different isoforms, p48 and p42, which differentially mediate PC12 cell survival and differentiation. The longer-form p48 localizes in both the cytoplasm and the nucleus and suppresses apoptosis, whereas the shorter-form p42 predominantly resides in the cytoplasm and promotes cell differentiation. EGF strongly stimulates p42 to bind ErbB3, and the association depends on PKC-mediated phosphorylation of Ebp1. By contrast, p48 does not bind to ErbB3 regardless of EGF treatment. Overexpression of p48 provokes cell proliferation, which is inhibited by p42. Moreover, nerve growth factor elicits extensive sprouting in p42 stably transfected PC12 cells, whereas p48 cells reveal modest neurite outgrowth. Although mitogen-activated protein kinase cascade remains similar in both cells, Akt is more active in p48 cells than in p42 cells. Thus, Ebp1 might regulate cell survival and differentiation through two distinctive p48 and p42 isoforms.
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Affiliation(s)
- Zhixue Liu
- *Department of Pathology and Laboratory Medicine, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322; and
| | - Jee-Yin Ahn
- Department of Molecular Cell Biology, Sungkyunkwan University School of Medicine, 300 Cheoncheon-dong, Jangan-gu, Suwon 440-746, Korea
| | - Xia Liu
- *Department of Pathology and Laboratory Medicine, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322; and
| | - Keqiang Ye
- *Department of Pathology and Laboratory Medicine, Emory University School of Medicine, 615 Michael Street, Atlanta, GA 30322; and
- To whom correspondence should be addressed. E-mail:
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50
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Squatrito M, Mancino M, Sala L, Draetta GF. Ebp1 is a dsRNA-binding protein associated with ribosomes that modulates eIF2alpha phosphorylation. Biochem Biophys Res Commun 2006; 344:859-68. [PMID: 16631606 DOI: 10.1016/j.bbrc.2006.03.205] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2006] [Accepted: 03/25/2006] [Indexed: 10/24/2022]
Abstract
dsRNA-binding domains (dsRBDs) characterize an expanding family of proteins involved in different cellular processes, ranging from RNA editing and processing to translational control. Here we present evidence that Ebp1, a cell growth regulating protein that is part of ribonucleoprotein (RNP) complexes, contains a dsRBD and that this domain mediates its interaction with dsRNA. Deletion of Ebp1's dsRBD impairs its localization to the nucleolus and its ability to form RNP complexes. We show that in the cytoplasm, Ebp1 is associated with mature ribosomes and that it is able to inhibit the phosphorylation of serine 51 in the eukaryotic initiation factor 2 alpha (eIF2alpha). In response to various cellular stress, eIF2alpha is phosphorylated by distinct protein kinases (PKR, PERK, GCN2, and HRI), and this event results in protein translation shut-down. Ebp1 overexpression in HeLa cells is able to protect eIF2alpha from phosphorylation at steady state and also in response to various treatments. We demonstrate that Ebp1 interacts with and is phosphorylated by the PKR protein kinase. Our results demonstrate that Ebp1 is a new dsRNA-binding protein that acts as a cellular inhibitor of eIF2alpha phosphorylation suggesting that it could be involved in protein translation control.
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Affiliation(s)
- Massimo Squatrito
- European Institute of Oncology, 435 Via Ripamonti, 20141 Milan, Italy.
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