1
|
Göttig L, Schreiner S. E4orf1: The triple agent of adenovirus - Unraveling its roles in oncogenesis, infectious obesity and immune responses in virus replication and vector therapy. Tumour Virus Res 2024; 17:200277. [PMID: 38428735 PMCID: PMC10937242 DOI: 10.1016/j.tvr.2024.200277] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2024] [Revised: 02/20/2024] [Accepted: 02/20/2024] [Indexed: 03/03/2024] Open
Abstract
Human Adenoviruses (HAdV) are nearly ubiquitous pathogens comprising numerous sub-types that infect various tissues and organs. Among many encoded proteins that facilitate viral replication and subversion of host cellular processes, the viral E4orf1 protein has emerged as an intriguing yet under-investigated player in the complex interplay between the virus and its host. E4orf1 has gained attention as a metabolism activator and oncogenic agent, while recent research is showing that E4orf1 may play a more important role in modulating cellular pathways such as PI3K-Akt-mTOR, Ras, the immune response and further HAdV replication stages than previously anticipated. In this review, we aim to explore the structure, molecular mechanisms, and biological functions of E4orf1, shedding light on its potentially multifaceted roles during HAdV infection, including metabolic diseases and oncogenesis. Furthermore, we discuss the role of functional E4orf1 in biotechnological applications such as Adenovirus (AdV) vaccine vectors and oncolytic AdV. By dissecting the intricate relationships between HAdV types and E4orf1 proteins, this review provides valuable insights into viral pathogenesis and points to promising areas of future research.
Collapse
Affiliation(s)
- Lilian Göttig
- Institute of Virology, School of Medicine, Technical University of Munich, Germany
| | - Sabrina Schreiner
- Institute of Virology, School of Medicine, Technical University of Munich, Germany; Institute of Virology, Hannover Medical School, Hannover, Germany; Cluster of Excellence RESIST (Resolving Infection Susceptibility; EXC 2155), Hannover, Germany; Institute of Virology, Medical Center - University of Freiburg, Freiburg, Germany.
| |
Collapse
|
2
|
Göttig L, Jummer S, Staehler L, Groitl P, Karimi M, Blanchette P, Kosulin K, Branton PE, Schreiner S. The human adenovirus PI3K-Akt activator E4orf1 is targeted by the tumor suppressor p53. J Virol 2024; 98:e0170123. [PMID: 38451084 PMCID: PMC11019960 DOI: 10.1128/jvi.01701-23] [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: 11/20/2023] [Accepted: 01/13/2024] [Indexed: 03/08/2024] Open
Abstract
Human adenoviruses (HAdV) are classified as DNA tumor viruses due to their potential to mediate oncogenic transformation in non-permissive mammalian cells and certain human stem cells. To achieve transformation, the viral early proteins of the E1 and E4 regions must block apoptosis and activate proliferation: the former predominantly through modulating the cellular tumor suppressor p53 and the latter by activating cellular pro-survival and pro-metabolism protein cascades, such as the phosphoinositide 3-kinase (PI3K-Akt) pathway, which is activated by HAdV E4orf1. Focusing on HAdV-C5, we show that E4orf1 is necessary and sufficient to stimulate Akt activation through phosphorylation in H1299 cells, which is not only hindered but repressed during HAdV-C5 infection with a loss of E4orf1 function in p53-positive A549 cells. Contrary to other research, E4orf1 localized not only in the common, cytoplasmic PI3K-Akt-containing compartment, but also in distinct nuclear aggregates. We identified a novel inhibitory mechanism, where p53 selectively targeted E4orf1 to destabilize it, also stalling E4orf1-dependent Akt phosphorylation. Co-IP and immunofluorescence studies showed that p53 and E4orf1 interact, and since p53 is bound by the HAdV-C5 E3 ubiquitin ligase complex, we also identified E4orf1 as a novel factor interacting with E1B-55K and E4orf6 during infection; overexpression of E4orf1 led to less-efficient E3 ubiquitin ligase-mediated proteasomal degradation of p53. We hypothesize that p53 specifically subverts the pro-survival function of E4orf1-mediated PI3K-Akt activation to protect the cell from metabolic hyper-activation or even transformation.IMPORTANCEHuman adenoviruses (HAdV) are nearly ubiquitous pathogens comprising numerous subtypes that infect various tissues and organs. Among many encoded proteins that facilitate viral replication and subversion of host cellular processes, the viral E4orf1 protein has emerged as an intriguing yet under-investigated player in the complex interplay between the virus and its host. Nonetheless, E4orf1 has gained attention as a metabolism activator and oncogenic agent, while recent research is showing that E4orf1 may play a more important role in modulating the cellular pathways such as phosphoinositide 3-kinase-Akt-mTOR. Our study reveals a novel and general impact of E4orf1 on host mechanisms, providing a novel basis for innovative antiviral strategies in future therapeutic settings. Ongoing investigations of the cellular pathways modulated by HAdV are of great interest, particularly since adenovirus-based vectors actually serve as vaccine or gene vectors. HAdV constitute an ideal model system to analyze the underlying molecular principles of virus-induced tumorigenesis.
Collapse
Affiliation(s)
- Lilian Göttig
- Institute of Virology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Simone Jummer
- Institute of Virology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Luisa Staehler
- Institute of Virology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Peter Groitl
- Institute of Virology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Maryam Karimi
- Institute of Virology, School of Medicine, Technical University of Munich, Munich, Germany
| | - Paola Blanchette
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
- Goodman Cancer Research Center, McGill University, Montreal, Quebec, Canada
| | - Karin Kosulin
- Molecular Microbiology, Children’s Cancer Research Institute, Vienna, Austria
| | - Philip E. Branton
- Department of Biochemistry, McGill University, Montreal, Quebec, Canada
- Goodman Cancer Research Center, McGill University, Montreal, Quebec, Canada
| | - Sabrina Schreiner
- Institute of Virology, School of Medicine, Technical University of Munich, Munich, Germany
- Institute of Virology, Hannover Medical School, Hannover, Germany
- Cluster of Excellence RESIST (Resolving Infection Susceptibility; EXC 2155), Freiburg, Germany
- Institute of Virology, Medical Center—University of Freiburg, Freiburg, Germany
| |
Collapse
|
3
|
Javorsky A, Humbert PO, Kvansakul M. Viral manipulation of cell polarity signalling. BIOCHIMICA ET BIOPHYSICA ACTA. MOLECULAR CELL RESEARCH 2023; 1870:119536. [PMID: 37437846 DOI: 10.1016/j.bbamcr.2023.119536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/08/2023] [Revised: 06/24/2023] [Accepted: 07/04/2023] [Indexed: 07/14/2023]
Abstract
Cell polarity refers to the asymmetric distribution of biomacromolecules that enable the correct orientation of a cell in a particular direction. It is thus an essential component for appropriate tissue development and function. Viral infections can lead to dysregulation of polarity. This is associated with a poor prognosis due to viral interference with core cell polarity regulatory scaffolding proteins that often feature PDZ (PSD-95, DLG, and ZO-1) domains including Scrib, Dlg, Pals1, PatJ, Par3 and Par6. PDZ domains are also promiscuous, binding to several different partners through their C-terminal region which contain PDZ-binding motifs (PBM). Numerous viruses encode viral effector proteins that target cell polarity regulators for their benefit and include papillomaviruses, flaviviruses and coronaviruses. A better understanding of the mechanisms of action utilised by viral effector proteins to subvert host cell polarity sigalling will provide avenues for future therapeutic intervention, while at the same time enhance our understanding of cell polarity regulation and its role tissue homeostasis.
Collapse
Affiliation(s)
- Airah Javorsky
- Department of Biochemistry & Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Patrick O Humbert
- Department of Biochemistry & Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia; Research Centre for Molecular Cancer Prevention, La Trobe University, Melbourne, Victoria 3086, Australia; Department of Biochemistry & Pharmacology, University of Melbourne, Melbourne, Victoria 3010, Australia; Department of Clinical Pathology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Marc Kvansakul
- Department of Biochemistry & Chemistry, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia; Research Centre for Molecular Cancer Prevention, La Trobe University, Melbourne, Victoria 3086, Australia.
| |
Collapse
|
4
|
Brown JS. Comparison of Oncogenes, Tumor Suppressors, and MicroRNAs Between Schizophrenia and Glioma: The Balance of Power. Neurosci Biobehav Rev 2023; 151:105206. [PMID: 37178944 DOI: 10.1016/j.neubiorev.2023.105206] [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: 11/29/2022] [Revised: 04/25/2023] [Accepted: 04/30/2023] [Indexed: 05/15/2023]
Abstract
The risk of cancer in schizophrenia has been controversial. Confounders of the issue are cigarette smoking in schizophrenia, and antiproliferative effects of antipsychotic medications. The author has previously suggested comparison of a specific cancer like glioma to schizophrenia might help determine a more accurate relationship between cancer and schizophrenia. To accomplish this goal, the author performed three comparisons of data; the first a comparison of conventional tumor suppressors and oncogenes between schizophrenia and cancer including glioma. This comparison determined schizophrenia has both tumor-suppressive and tumor-promoting characteristics. A second, larger comparison between brain-expressed microRNAs in schizophrenia with their expression in glioma was then performed. This identified a core carcinogenic group of miRNAs in schizophrenia offset by a larger group of tumor-suppressive miRNAs. This proposed "balance of power" between oncogenes and tumor suppressors could cause neuroinflammation. This was assessed by a third comparison between schizophrenia, glioma and inflammation in asbestos-related lung cancer and mesothelioma (ALRCM). This revealed that schizophrenia shares more oncogenic similarity to ALRCM than glioma.
Collapse
|
5
|
Bahouth SW, Nooh MM, Mancarella S. Involvement of SAP97 anchored multiprotein complexes in regulating cardiorenal signaling and trafficking networks. Biochem Pharmacol 2023; 208:115406. [PMID: 36596415 DOI: 10.1016/j.bcp.2022.115406] [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: 10/26/2022] [Revised: 12/26/2022] [Accepted: 12/28/2022] [Indexed: 01/02/2023]
Abstract
SAP97 is a member of the MAGUK family of proteins, but unlike other MAGUK proteins that are selectively expressed in the CNS, SAP97 is also expressed in peripheral organs, like the heart and kidneys. SAP97 has several protein binding cassettes, and this review will describe their involvement in creating SAP97-anchored multiprotein networks. SAP97-anchored networks localized at the inner leaflet of the cell membrane play a major role in trafficking and targeting of membrane G protein-coupled receptors (GPCR), channels, and structural proteins. SAP97 plays a major role in compartmentalizing voltage gated sodium and potassium channels to specific cellular compartments of heart cells. SAP97 undergoes extensive alternative splicing. These splice variants give rise to different SAP97 isoforms that alter its cellular localization, networking, signaling and trafficking effects. Regarding GPCR, SAP97 binds to the β1-adrenergic receptor and recruits AKAP5/PKA and PDE4D8 to create a multiprotein complex that regulates trafficking and signaling of cardiac β1-AR. In the kidneys, SAP97 anchored networks played a role in trafficking of aquaporin-2 water channels. Cardiac specific ablation of SAP97 (SAP97-cKO) resulted in cardiac hypertrophy and failure in aging mice. Similarly, instituting transverse aortic constriction (TAC) in young SAP97 c-KO mice exacerbated TAC-induced cardiac remodeling and dysfunction. These findings highlight a critical role for SAP97 in the pathophysiology of a number of cardiac and renal diseases, suggesting that SAP97 is a relevant target for drug discovery.
Collapse
Affiliation(s)
- Suleiman W Bahouth
- Department of Pharmacology, Addiction Science and Toxicology, The University of Tennessee-Health Sciences Center, Memphis, TN, United States.
| | - Mohammed M Nooh
- Department of Biochemistry, Faculty of Pharmacy Cairo University, Cairo, Egypt and Biochemistry Department, Faculty of Pharmacy, October 6 University, Giza, Egypt
| | - Salvatore Mancarella
- Department of Physiology, The University of Tennessee-Health Sciences Center, Memphis, TN, United States
| |
Collapse
|
6
|
Thomas M, Banks L. The biology of papillomavirus PDZ associations: what do they offer papillomaviruses? Curr Opin Virol 2021; 51:119-126. [PMID: 34655911 DOI: 10.1016/j.coviro.2021.09.011] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2021] [Revised: 09/10/2021] [Accepted: 09/21/2021] [Indexed: 01/05/2023]
Abstract
The high-risk α-type papillomaviruses have a C-terminal PDZ-binding motif (PBM) on one of the two major oncoproteins E6 or E7; the vast majority on E6. The PBM is essential for the high-risk HPV life cycle, for episomal maintenance of the virus genome, and for maintaining the mitotic stability of the infected cell. The question is why only these viruses have PBMs - are there specific constraints imposed by the mucosal epithelium in which these viruses replicate? However the low-risk α-HPVs, such as HPV-6 and HPV-11 replicate extremely efficiently without a PBM, while viruses of the alpha8 group, such as HPV-40, replicate well with a very primitive PBM. So what does PDZ-binding capacity contribute to the fitness of the virus?
Collapse
Affiliation(s)
- Miranda Thomas
- ICGEB, AREA Science Park, Padriciano 99, 34149, Trieste, Italy.
| | - Lawrence Banks
- ICGEB, AREA Science Park, Padriciano 99, 34149, Trieste, Italy
| |
Collapse
|
7
|
Tessier TM, Dodge MJ, MacNeil KM, Evans AM, Prusinkiewicz MA, Mymryk JS. Almost famous: Human adenoviruses (and what they have taught us about cancer). Tumour Virus Res 2021; 12:200225. [PMID: 34500123 PMCID: PMC8449131 DOI: 10.1016/j.tvr.2021.200225] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2021] [Revised: 08/25/2021] [Accepted: 09/03/2021] [Indexed: 12/11/2022] Open
Abstract
Papillomaviruses, polyomaviruses and adenoviruses are collectively categorized as the small DNA tumour viruses. Notably, human adenoviruses were the first human viruses demonstrated to be able to cause cancer, albeit in non-human animal models. Despite their long history, no human adenovirus is a known causative agent of human cancers, unlike a subset of their more famous cousins, including human papillomaviruses and human Merkel cell polyomavirus. Nevertheless, seminal research using human adenoviruses has been highly informative in understanding the basics of cell cycle control, gene expression, apoptosis and cell differentiation. This review highlights the contributions of human adenovirus research in advancing our knowledge of the molecular basis of cancer.
Collapse
Affiliation(s)
- Tanner M Tessier
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada
| | - Mackenzie J Dodge
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada
| | - Katelyn M MacNeil
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada
| | - Andris M Evans
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada
| | - Martin A Prusinkiewicz
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada
| | - Joe S Mymryk
- Department of Microbiology and Immunology, The University of Western Ontario, London, ON, Canada; Department of Otolaryngology, Head & Neck Surgery, The University of Western Ontario, London, ON, Canada; Department of Oncology, The University of Western Ontario, London, ON, Canada; London Regional Cancer Program, Lawson Health Research Institute, London, ON, Canada.
| |
Collapse
|
8
|
Zhang S, Li X, Liu W, Zhang X, Huang L, Li S, Yang M, Zhao P, Yang J, Fei P, Zhu X, Yang Z. Whole-Exome Sequencing Identified DLG1 as a Candidate Gene for Familial Exudative Vitreoretinopathy. Genet Test Mol Biomarkers 2021; 25:309-316. [PMID: 33945310 DOI: 10.1089/gtmb.2021.0013] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
Purpose: Familial exudative vitreoretinopathy (FEVR) is a blinding retinal vascular disease. Clinically, FEVR is characterized by incomplete vascularization of the peripheral retina and pathological neovascularization. Only about 50% of FEVR cases can be explained by known FEVR disease gene variations. This study aimed to identify novel genes associated with the FEVR phenotype and explore their pathogenic mechanisms. Materials and Methods: Exome sequencing analyses were conducted on one Chinese family with FEVR whose affected members did not exhibit pathogenic variants in the known FEVR genes (verified using Sanger sequencing analysis). Functions of the affected proteins were evaluated using reporter assays. Western blot analysis was used to detect mutant protein expression and the genes' pathogenic mechanisms. Results: A rare novel heterozygous variant in DLG1 (c.1792A>G; p.S598G) was identified. The amino acid residues surrounding the identified variant are highly conserved among vertebrates. A luciferase reporter assay revealed that the mutant DLG1 protein DLG1-S598G lost its ability to activate Wnt signaling. Moreover, a knockdown (KD) of DLG1 in human primary retinal endothelial cells impaired tube formation. Mechanistically, DLG1 KD led to a reduction in phosphorylated VEGFR2, an essential receptor for the angiogenic potency that signals the vascular endothelial growth factor molecule. Conclusions: The data reported here demonstrate that DLG1 is a novel candidate gene for FEVR.
Collapse
Affiliation(s)
- Shanshan Zhang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Xiao Li
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Wenjing Liu
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Xiang Zhang
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Lulin Huang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Shujin Li
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China.,Chengdu Institute of Biology, Sichuan Translational Medicine Research Hospital, Chinese Academy of Sciences, Chengdu, China
| | - Mu Yang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China.,Chengdu Institute of Biology, Sichuan Translational Medicine Research Hospital, Chinese Academy of Sciences, Chengdu, China
| | - Peiquan Zhao
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Jiyun Yang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China
| | - Ping Fei
- Department of Ophthalmology, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Xianjun Zhu
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China.,Chengdu Institute of Biology, Sichuan Translational Medicine Research Hospital, Chinese Academy of Sciences, Chengdu, China
| | - Zhenglin Yang
- The Sichuan Provincial Key Laboratory for Human Disease Gene Study, Prenatal Diagnosis Center, Sichuan Provincial People's Hospital, University of Electronic Science and Technology of China, Chengdu, China.,Research Unit for Blindness Prevention of Chinese Academy of Medical Sciences (2019RU026), Sichuan Academy of Medical Sciences and Sichuan Provincial People's Hospital, Chengdu, China.,Chengdu Institute of Biology, Sichuan Translational Medicine Research Hospital, Chinese Academy of Sciences, Chengdu, China
| |
Collapse
|
9
|
Polarity scaffolds signaling in epithelial cell permeability. Inflamm Res 2021; 70:525-538. [PMID: 33721031 DOI: 10.1007/s00011-021-01454-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/30/2020] [Revised: 01/20/2021] [Accepted: 03/06/2021] [Indexed: 01/14/2023] Open
Abstract
As an integral part of the innate immune system, the epithelial membrane is exposed to an array of insults that may trigger an immune response. One of the immune system's main functions is to regulate the level of communications between the mucosa and the lumen of various tissues. While it is clear that inhaled or ingested substances, or microorganisms may induce changes that affect the epithelial barrier in various ways, the proteins involved in the signaling cascades and physiological events leading to the regulation and maintenance of the barrier are not always well characterized. We review here some of the signaling components involved in regulating the barrier's paracellular permeability, and their potential effects on the activation of an immune response. While an effective immune response must be launched against pathogenic insults, tolerance must also be maintained for non-pathogenic antigens such as those in the commensal flora or for endogenous metabolites. Along with other members of the innate and adaptive immunity, the endocannabinoid system also plays an instrumental role in maintaining the balance between inflammation and tolerance. We discuss the potential effects of endo- and phytocannabinoids on epithelial permeability and how the dysregulation of this system could be involved in diseases and targeted for therapy.
Collapse
|
10
|
Christensen NR, Čalyševa J, Fernandes EFA, Lüchow S, Clemmensen LS, Haugaard‐Kedström LM, Strømgaard K. PDZ Domains as Drug Targets. ADVANCED THERAPEUTICS 2019; 2:1800143. [PMID: 32313833 PMCID: PMC7161847 DOI: 10.1002/adtp.201800143] [Citation(s) in RCA: 59] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/13/2018] [Revised: 03/25/2019] [Indexed: 12/14/2022]
Abstract
Protein-protein interactions within protein networks shape the human interactome, which often is promoted by specialized protein interaction modules, such as the postsynaptic density-95 (PSD-95), discs-large, zona occludens 1 (ZO-1) (PDZ) domains. PDZ domains play a role in several cellular functions, from cell-cell communication and polarization, to regulation of protein transport and protein metabolism. PDZ domain proteins are also crucial in the formation and stability of protein complexes, establishing an important bridge between extracellular stimuli detected by transmembrane receptors and intracellular responses. PDZ domains have been suggested as promising drug targets in several diseases, ranging from neurological and oncological disorders to viral infections. In this review, the authors describe structural and genetic aspects of PDZ-containing proteins and discuss the current status of the development of small-molecule and peptide modulators of PDZ domains. An overview of potential new therapeutic interventions in PDZ-mediated protein networks is also provided.
Collapse
Affiliation(s)
- Nikolaj R. Christensen
- Center for BiopharmaceuticalsDepartment of Drug Design and PharmacologyUniversity of CopenhagenUniversitetsparken 22100CopenhagenDenmark
| | - Jelena Čalyševa
- European Molecular Biology Laboratory (EMBL)Structural and Computational Biology UnitMeyerhofstraße 169117HeidelbergGermany
- EMBL International PhD ProgrammeFaculty of BiosciencesEMBL–Heidelberg UniversityGermany
| | - Eduardo F. A. Fernandes
- Center for BiopharmaceuticalsDepartment of Drug Design and PharmacologyUniversity of CopenhagenUniversitetsparken 22100CopenhagenDenmark
| | - Susanne Lüchow
- Department of Chemistry – BMCUppsala UniversityBox 576SE75123UppsalaSweden
| | - Louise S. Clemmensen
- Center for BiopharmaceuticalsDepartment of Drug Design and PharmacologyUniversity of CopenhagenUniversitetsparken 22100CopenhagenDenmark
| | - Linda M. Haugaard‐Kedström
- Center for BiopharmaceuticalsDepartment of Drug Design and PharmacologyUniversity of CopenhagenUniversitetsparken 22100CopenhagenDenmark
| | - Kristian Strømgaard
- Center for BiopharmaceuticalsDepartment of Drug Design and PharmacologyUniversity of CopenhagenUniversitetsparken 22100CopenhagenDenmark
| |
Collapse
|
11
|
Thomas M, Banks L. Upsetting the Balance: When Viruses Manipulate Cell Polarity Control. J Mol Biol 2018; 430:3481-3503. [PMID: 29680664 PMCID: PMC7094317 DOI: 10.1016/j.jmb.2018.04.016] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Revised: 04/12/2018] [Accepted: 04/14/2018] [Indexed: 12/20/2022]
Abstract
The central importance of cell polarity control is emphasized by the frequency with which it is targeted by many diverse viruses. It is clear that in targeting key polarity control proteins, viruses affect not only host cell polarity, but also influence many cellular processes, including transcription, replication, and innate and acquired immunity. Examination of the interactions of different virus proteins with the cell and its polarity controls during the virus life cycles, and in virally-induced cell transformation shows ever more clearly how intimately all cellular processes are linked to the control of cell polarity.
Collapse
|
12
|
Stephens R, Lim K, Portela M, Kvansakul M, Humbert PO, Richardson HE. The Scribble Cell Polarity Module in the Regulation of Cell Signaling in Tissue Development and Tumorigenesis. J Mol Biol 2018; 430:3585-3612. [PMID: 29409995 DOI: 10.1016/j.jmb.2018.01.011] [Citation(s) in RCA: 91] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2017] [Revised: 01/19/2018] [Accepted: 01/19/2018] [Indexed: 01/22/2023]
Abstract
The Scribble cell polarity module, comprising Scribbled (Scrib), Discs-large (Dlg) and Lethal-2-giant larvae (Lgl), has a tumor suppressive role in mammalian epithelial cancers. The Scribble module proteins play key functions in the establishment and maintenance of different modes of cell polarity, as well as in the control of tissue growth, differentiation and directed cell migration, and therefore are major regulators of tissue development and homeostasis. Whilst molecular details are known regarding the roles of Scribble module proteins in cell polarity regulation, their precise mode of action in the regulation of other key cellular processes remains enigmatic. An accumulating body of evidence indicates that Scribble module proteins play scaffolding roles in the control of various signaling pathways, which are linked to the control of tissue growth, differentiation and cell migration. Multiple Scrib, Dlg and Lgl interacting proteins have been discovered, which are involved in diverse processes, however many function in the regulation of cellular signaling. Herein, we review the components of the Scrib, Dlg and Lgl protein interactomes, and focus on the mechanism by which they regulate cellular signaling pathways in metazoans, and how their disruption leads to cancer.
Collapse
Affiliation(s)
- Rebecca Stephens
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Krystle Lim
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Marta Portela
- Department of Molecular, Cellular and Developmental Neurobiology, Cajal Institute (CSIC), Avenida Doctor Arce, 37, Madrid 28002, Spain
| | - Marc Kvansakul
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia
| | - Patrick O Humbert
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia; Department of Biochemistry & Molecular Biology, University of Melbourne, Melbourne, Victoria 3010, Australia; Department of Pathology, University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Helena E Richardson
- Department of Biochemistry and Genetics, La Trobe Institute of Molecular Science, La Trobe University, Melbourne, Victoria, Australia; Department of Biochemistry & Molecular Biology, University of Melbourne, Melbourne, Victoria 3010, Australia; Department of Anatomy & Neurobiology, University of Melbourne, Melbourne, Victoria 3010, Australia.
| |
Collapse
|
13
|
Milgrom-Hoffman M, Humbert PO. Regulation of cellular and PCP signalling by the Scribble polarity module. Semin Cell Dev Biol 2017; 81:33-45. [PMID: 29154823 DOI: 10.1016/j.semcdb.2017.11.021] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2017] [Revised: 11/11/2017] [Accepted: 11/13/2017] [Indexed: 10/18/2022]
Abstract
Since the first identification of the Scribble polarity module proteins as a new class of tumour suppressors that regulate both cell polarity and proliferation, an increasing amount of evidence has uncovered a broader role for Scribble, Dlg and Lgl in the control of fundamental cellular functions and their signalling pathways. Here, we review these findings as well as discuss more specifically the role of the Scribble module in PCP signalling.
Collapse
Affiliation(s)
- Michal Milgrom-Hoffman
- Department of Biochemistry & Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia
| | - Patrick O Humbert
- Department of Biochemistry & Genetics, La Trobe Institute for Molecular Science, La Trobe University, Melbourne, Victoria 3086, Australia; Department of Biochemistry & Molecular Biology, University of Melbourne, Melbourne, Victoria 3010, Australia; Department of Pathology, University of Melbourne, Melbourne, Victoria 3010, Australia.
| |
Collapse
|
14
|
Marziali F, Bugnon Valdano M, Brunet Avalos C, Moriena L, Cavatorta AL, Gardiol D. Interference of HTLV-1 Tax Protein with Cell Polarity Regulators: Defining the Subcellular Localization of the Tax-DLG1 Interaction. Viruses 2017; 9:E355. [PMID: 29168728 PMCID: PMC5744130 DOI: 10.3390/v9120355] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2017] [Revised: 11/15/2017] [Accepted: 11/21/2017] [Indexed: 12/17/2022] Open
Abstract
Human T cell leukemia virus (HTLV)-1 Tax (Tax) protein is very important in viral replication and cell transformation. Tax localizes in the nucleus and cytoplasm in association with organelles. Some activities of Tax depend on interactions with PDZ (PSD-95/Discs Large/Z0-1) domain-containing proteins such as Discs large protein 1 (DLG1) which is involved in cell polarity and proliferation. The DLG1 interaction results in a cytoplasmic co-localization pattern resembling vesicular aggregates, the nature of which is still unknown. To further explore the role of PDZ proteins in HTLV-1 cell transformation, we deeply investigated the Tax-DLG1 association. By fluorescence resonance energy transfer (FRET), we detected, for the first time, the direct binding of Tax to DLG1 within the cell. We showed that the interaction specifically affects the cellular distribution of not only DLG1, but also Tax. After studying different cell structures, we demonstrated that the aggregates distribute into the Golgi apparatus in spatial association with the microtubule-organizing center (MTOC). This study contributes to understand the biological significance of Tax-PDZ interactions.
Collapse
Affiliation(s)
- Federico Marziali
- Instituto de Biología Molecular y Celular de Rosario-CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina.
| | - Marina Bugnon Valdano
- Instituto de Biología Molecular y Celular de Rosario-CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina.
| | - Clarisse Brunet Avalos
- Instituto de Biología Molecular y Celular de Rosario-CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina.
| | - Lucía Moriena
- Instituto de Biología Molecular y Celular de Rosario-CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina.
| | - Ana Laura Cavatorta
- Instituto de Biología Molecular y Celular de Rosario-CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina.
| | - Daniela Gardiol
- Instituto de Biología Molecular y Celular de Rosario-CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, 2000 Rosario, Argentina.
| |
Collapse
|
15
|
Chaudhary N, Gonzalez E, Chang SH, Geng F, Rafii S, Altorki NK, McGraw TE. Adenovirus Protein E4-ORF1 Activation of PI3 Kinase Reveals Differential Regulation of Downstream Effector Pathways in Adipocytes. Cell Rep 2017; 17:3305-3318. [PMID: 28009298 DOI: 10.1016/j.celrep.2016.11.082] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/20/2016] [Revised: 10/05/2016] [Accepted: 11/28/2016] [Indexed: 12/13/2022] Open
Abstract
Insulin activation of phosphatidylinositol 3-kinase (PI3K) regulates metabolism, including the translocation of the Glut4 glucose transporter to the plasma membrane and inactivation of the FoxO1 transcription factor. Adenoviral protein E4-ORF1 stimulates cellular glucose metabolism by mimicking growth-factor activation of PI3K. We have used E4-ORF1 as a tool to dissect PI3K-mediated signaling in adipocytes. E4-ORF1 activation of PI3K in adipocytes recapitulates insulin regulation of FoxO1 but not regulation of Glut4. This uncoupling of PI3K effects occurs despite E4-ORF1 activating PI3K and downstream signaling to levels achieved by insulin. Although E4-ORF1 does not fully recapitulate insulin's effects on Glut4, it enhances insulin-stimulated insertion of Glut4-containing vesicles to the plasma membrane independent of Rab10, a key regulator of Glut4 trafficking. E4-ORF1 also stimulates plasma membrane translocation of ubiquitously expressed Glut1 glucose transporter, an effect that is likely essential for E4-ORF1 to promote an anabolic metabolism in a broad range of cell types.
Collapse
Affiliation(s)
- Natasha Chaudhary
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
| | - Eva Gonzalez
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA
| | - Sung-Hee Chang
- Department of Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Fuqiang Geng
- Department of Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Shahin Rafii
- Department of Medicine, Weill Cornell Medicine, New York, NY 10065, USA
| | - Nasser K Altorki
- Department of Cardiothoracic Surgery, Weill Cornell Medicine, New York, NY 10065, USA; Lung Cancer Program, Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA
| | - Timothy E McGraw
- Department of Biochemistry, Weill Cornell Medicine, New York, NY 10065, USA; Department of Cardiothoracic Surgery, Weill Cornell Medicine, New York, NY 10065, USA; Lung Cancer Program, Meyer Cancer Center, Weill Cornell Medicine, New York, NY 10065, USA.
| |
Collapse
|
16
|
Dianatpour A, Ghafouri-Fard S. Long Non Coding RNA Expression Intersecting Cancer and Spermatogenesis: A Systematic Review. Asian Pac J Cancer Prev 2017; 18:2601-2610. [PMID: 29072050 PMCID: PMC5747377 DOI: 10.22034/apjcp.2017.18.10.2601] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
Background: Numerous similarities have been noted between gametogenic and tumorigenic programs in features
such as global hypomethylation, immune evasion, immortalization, meiosis induction, and migration. In addition, aberrant
expression of testis specific genes has been detected in various cancers which has led to categorization of these genes
as “cancer-testis genes”. Most of the examples identified in this category are protein encoding. However, recent studies
have revealed that non-coding RNAs, including long non coding RNAs (lncRNAs), may have essential regulatory
roles in telomere biology, chromatin dynamics, modulation of gene expression and genome structural organization.
All of these functions are implicated in both gametogenic and tumorigenic programs. Methods: In the present study,
we conducted a computerized search of the MEDLINE/PUBMED and Embase databases with the key words lncRNA,
gametogenesis, testis and cancer. Results: We found a number of lncRNAs with essential roles and notable expression
in both gametogenic and cancer tissues. Conclusions: Comparison between cancer tissues and gametogenic tissues
has shown that numerous lncRNAs are expressed in both, playing similar roles in processes modulated by signaling
pathways such as Wnt/β-catenin and PI3K/AKT/mTOR. Evaluation of expression patterns and functions of these
genes should pave the way to discovery of biomarkers for early detection, prognostic assessment and evaluation of
therapeutic responses in cancers.
Collapse
Affiliation(s)
- Ali Dianatpour
- Department of Medical Genetics, Faculty of Medicine, Shahid Beheshti University of Medical sciences, Tehran, Iran.
| | | |
Collapse
|
17
|
Kozakai T, Takahashi M, Higuchi M, Hara T, Saito K, Tanaka Y, Masuko M, Takizawa J, Sone H, Fujii M. MAGI-1 expression is decreased in several types of human T-cell leukemia cell lines, including adult T-cell leukemia. Int J Hematol 2017; 107:337-344. [DOI: 10.1007/s12185-017-2359-1] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2017] [Revised: 10/03/2017] [Accepted: 10/10/2017] [Indexed: 01/31/2023]
|
18
|
Cavatorta AL, Di Gregorio A, Bugnon Valdano M, Marziali F, Cabral M, Bottai H, Cittadini J, Nocito AL, Gardiol D. DLG1 polarity protein expression associates with the disease progress of low-grade cervical intraepithelial lesions. Exp Mol Pathol 2016; 102:65-69. [PMID: 28040505 DOI: 10.1016/j.yexmp.2016.12.008] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2016] [Revised: 11/22/2016] [Accepted: 12/19/2016] [Indexed: 12/31/2022]
Abstract
Human Discs large tumour suppressor (DLG1) participates in regulating cell polarity and proliferation, suggesting an important connection between epithelial organization and cellular growth control. However, it was demonstrated that DLG1 could acquire oncogenic attributes in some specific contexts. In this work, we evaluated the expression of DLG1 and its contribution to the progress of cervical lesions in order to investigate a potential role of this polarity protein in human oncogenic processes. We analyzed cervical biopsies from women with low-grade squamous intraepithelial lesion (LSIL) diagnosis (n=30), for DLG1 expression by immunohistochemistry. These results were correlated with the clinical monitoring of the patients during a 24-month follow-up period. Our data indicate that while all LSIL patients with a DLG1 staining pattern similar to normal tissues are significantly more likely to regress (n=23, Pattern I), all LSIL biopsy specimens showing a diffuse and intense DLG1 staining likely progress to high-grade lesions (n=4, Pattern II). Finally, all persistent LSIL analyzed showed an undetermined DLG1 staining, with a diffuse distribution without a strong intensity (n=3, Pattern III). We found a significant association between the expression pattern of DLG1 and the evolution of the lesion (p<0.00001). This work contributes to the knowledge of DLG1 biological functions, suggesting that its expression may have an important role in the progression of early dysplastic cervical lesions, giving prognostic information.
Collapse
Affiliation(s)
- Ana Laura Cavatorta
- Instituto de Biología Molecular y Celular de Rosario-CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Argentina
| | | | - Marina Bugnon Valdano
- Instituto de Biología Molecular y Celular de Rosario-CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Argentina
| | - Federico Marziali
- Instituto de Biología Molecular y Celular de Rosario-CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Argentina
| | - Mariela Cabral
- Servicio de Ginecología, Hospital Provincial del Centenario, Rosario, Argentina
| | - Hebe Bottai
- Área Estadística y Procesamiento de Datos, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Argentina
| | - Jorge Cittadini
- Servicio de Ginecología, Hospital Provincial del Centenario, Rosario, Argentina
| | - Ana Lia Nocito
- Cátedra de Anatomía y Fisiología Patológicas, Facultad de Ciencias Médicas, Universidad Nacional de Rosario, Rosario, Argentina
| | - Daniela Gardiol
- Instituto de Biología Molecular y Celular de Rosario-CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Argentina.
| |
Collapse
|
19
|
Le Sage V, Cinti A, Amorim R, Mouland AJ. Adapting the Stress Response: Viral Subversion of the mTOR Signaling Pathway. Viruses 2016; 8:v8060152. [PMID: 27231932 PMCID: PMC4926172 DOI: 10.3390/v8060152] [Citation(s) in RCA: 80] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 05/16/2016] [Accepted: 05/19/2016] [Indexed: 02/06/2023] Open
Abstract
The mammalian target of rapamycin (mTOR) is a central regulator of gene expression, translation and various metabolic processes. Multiple extracellular (growth factors) and intracellular (energy status) molecular signals as well as a variety of stressors are integrated into the mTOR pathway. Viral infection is a significant stress that can activate, reduce or even suppress the mTOR signaling pathway. Consequently, viruses have evolved a plethora of different mechanisms to attack and co-opt the mTOR pathway in order to make the host cell a hospitable environment for replication. A more comprehensive knowledge of different viral interactions may provide fruitful targets for new antiviral drugs.
Collapse
Affiliation(s)
- Valerie Le Sage
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
| | - Alessandro Cinti
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
- Department of Medicine, McGill University, Montréal, QC H3A 0G4, Canada.
| | - Raquel Amorim
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
- Department of Medicine, McGill University, Montréal, QC H3A 0G4, Canada.
| | - Andrew J Mouland
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, QC H3T 1E2, Canada.
- Department of Medicine, McGill University, Montréal, QC H3A 0G4, Canada.
| |
Collapse
|
20
|
Valdano MB, Cavatorta AL, Morale MG, Marziali F, de Souza Lino V, Steenbergen RDM, Boccardo E, Gardiol D. Disc large 1 expression is altered by human papillomavirus E6/E7 proteins in organotypic cultures of human keratinocytes. J Gen Virol 2016; 97:453-462. [DOI: 10.1099/jgv.0.000364] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023] Open
Affiliation(s)
- M. Bugnon Valdano
- Instituto de Biología Molecular y Celular de Rosario – CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Argentina
| | - A. L. Cavatorta
- Instituto de Biología Molecular y Celular de Rosario – CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Argentina
| | - M. G. Morale
- Deparment of Biochemistry, Institute of Chemistry, University of Sao Paulo, Sao Paulo, Brazil
| | - F. Marziali
- Instituto de Biología Molecular y Celular de Rosario – CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Argentina
| | - V. de Souza Lino
- Department of Microbiology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - R. D. M. Steenbergen
- Department of Pathology, VU University Medical Center, Amsterdam, The Netherlands
| | - E. Boccardo
- Department of Microbiology, Institute of Biomedical Sciences, University of Sao Paulo, Sao Paulo, Brazil
| | - D. Gardiol
- Instituto de Biología Molecular y Celular de Rosario – CONICET, Facultad de Ciencias Bioquímicas y Farmacéuticas, Universidad Nacional de Rosario, Suipacha 531, Rosario, Argentina
| |
Collapse
|
21
|
James CD, Roberts S. Viral Interactions with PDZ Domain-Containing Proteins-An Oncogenic Trait? Pathogens 2016; 5:pathogens5010008. [PMID: 26797638 PMCID: PMC4810129 DOI: 10.3390/pathogens5010008] [Citation(s) in RCA: 43] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 01/14/2016] [Accepted: 01/15/2016] [Indexed: 02/06/2023] Open
Abstract
Many of the human viruses with oncogenic capabilities, either in their natural host or in experimental systems (hepatitis B and C, human T cell leukaemia virus type 1, Kaposi sarcoma herpesvirus, human immunodeficiency virus, high-risk human papillomaviruses and adenovirus type 9), encode in their limited genome the ability to target cellular proteins containing PSD95/ DLG/ZO-1 (PDZ) interaction modules. In many cases (but not always), the viruses have evolved to bind the PDZ domains using the same short linear peptide motifs found in host protein-PDZ interactions, and in some cases regulate the interactions in a similar fashion by phosphorylation. What is striking is that the diverse viruses target a common subset of PDZ proteins that are intimately involved in controlling cell polarity and the structure and function of intercellular junctions, including tight junctions. Cell polarity is fundamental to the control of cell proliferation and cell survival and disruption of polarity and the signal transduction pathways involved is a key event in tumourigenesis. This review focuses on the oncogenic viruses and the role of targeting PDZ proteins in the virus life cycle and the contribution of virus-PDZ protein interactions to virus-mediated oncogenesis. We highlight how many of the viral associations with PDZ proteins lead to deregulation of PI3K/AKT signalling, benefitting virus replication but as a consequence also contributing to oncogenesis.
Collapse
Affiliation(s)
- Claire D James
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK.
- Present address; Virginia Commonwealth University, School of Dentistry, W. Baxter Perkinson Jr. Building, 521 North 11th Street, P.O. Box 980566, Richmond, VA 23298-0566, USA.
| | - Sally Roberts
- Institute of Cancer and Genomic Sciences, College of Medical and Dental Sciences, University of Birmingham, Vincent Drive, Birmingham B15 2TT, UK.
| |
Collapse
|
22
|
Adenovirus E4-ORF1 Dysregulates Epidermal Growth Factor and Insulin/Insulin-Like Growth Factor Receptors To Mediate Constitutive Myc Expression. J Virol 2015; 89:10774-85. [PMID: 26269183 DOI: 10.1128/jvi.01463-15] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Accepted: 08/05/2015] [Indexed: 01/02/2023] Open
Abstract
UNLABELLED The E4-ORF1 protein encoded by human adenovirus stimulates viral replication in human epithelial cells by binding and activating cellular phosphatidylinositol 3-kinase (PI3K) at the plasma membrane and cellular Myc in the nucleus. In this study, we showed that E4-ORF1 hijacks the tyrosine kinase activities of cellular epidermal growth factor receptor (EGFR) and insulin receptor (InsR)/insulin-like growth factor receptor 1 (IGF1R), as well as the lipid kinase activity of PI3K, to mediate constitutive Myc protein expression. We additionally demonstrated that EGFR contributes to constitutive Myc expression through the capacity of E4-ORF1 to induce ligand-independent EGFR activation and stimulation of the Ras/Mek/Erk pathway, the latter activity of which was conserved by human adenoviruses. Results further suggested that EGFR normally forms a complex with the cellular PDZ protein Discs Large 1 (Dlg1), a component of the Dlg1:E4-ORF1:PI3K ternary complex that mediates E4-ORF1-induced PI3K activation, and that E4-ORF1 binds the Dlg1:EGFR complex and promotes the association of EGFR with InsR and IGF1R. In addition to its role in constitutive Myc expression, InsR/IGF1R also negatively regulates EGFR autophosphorylation and EGFR-mediated Ras/Mek/Erk signaling, and data suggested that E4-ORF1 binding to Dlg1 antagonizes these activities. Collectively, our findings suggest that in human epithelial cells, E4-ORF1 targets EGFR, InsR/IGF1R, and PI3K at the plasma membrane to activate cytosolic signaling pathways that sustain Myc protein levels in the nucleus. We postulate that E4-ORF1-induced constitutive Myc expression functions to ensure the formation of nuclear E4-ORF1:Myc complexes, which have been shown to activate Myc and to enhance adenovirus replication. IMPORTANCE While human adenoviruses primarily produce self-limited acute infections in humans, these agents are associated with life-threatening diseases in immunocompromised patients and in otherwise healthy individuals infected with certain virulent serotypes. The adenovirus E4-ORF1 protein enhances viral replication by activating the cellular lipid kinase PI3K and the cellular transcription factor Myc. Here we report that E4-ORF1 usurps the functions of the cellular tyrosine kinase receptors EGFR and InsR /: IGF1R, as well as PI3K, to sustain Myc protein expression in cells. Furthermore, sustained Myc expression depended on E4-ORF1-induced ligand-independent EGFR activation that stimulated Ras/Mek/Erk signaling, a function found to be conserved by human adenoviruses. Given the established roles of PI3K, the Ras/Mek/Erk pathway, and Myc in the adenovirus life cycle, our findings may aid in the development of safer, more effective therapeutic strategies to treat severe adenovirus infections as well as improved adenovirus vectors for use in vaccination and gene and cancer therapy.
Collapse
|
23
|
Marziali F, Cavatorta AL, Valdano MB, Facciuto F, Gardiol D. Transcriptional and translational mechanisms contribute to regulate the expression of Discs Large 1 protein during different biological processes. Biol Chem 2015; 396:893-902. [DOI: 10.1515/hsz-2014-0286] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 02/02/2015] [Indexed: 11/15/2022]
Abstract
Abstract
Human discs large (DLG1) has been demonstrated to be involved in cell polarity and maintenance of tissue architecture. However, the mechanisms controlling DLG1 expression are not fully understood. This is relevant as DLG1 is lost during the later stages of malignant progression. We initiated a series of studies to analyse the mechanisms regulating DLG1 expression. We have previously reported the identification of an alternative splicing event in the 5′ untranslated region (5′-UTR) of DLG1 mRNA that generates transcripts with two different 5′-UTR (short and large 5′-UTR variants). In this study, we further examined the impact of the DLG1 transcription and the role of the differential expression of the alternative 5′-UTRs on DLG1 protein levels. We analysed these mechanisms during cell processes like differentiation, cell cycle progression and cell-cell contact formation, where the importance of DLG1 activities was previously established. The data presented in this report suggest that the transcriptional regulation of DLG1 strongly contributes to DLG1 abundance and that differential expression of alternative 5′-UTRs with different translational properties, also cooperates, depending on the cell type and cell situation. This study provides new evidence for understanding the transcriptional regulation of DLG1 and the changes in DLG1 expression during different biological processes.
Collapse
|
24
|
Ganti K, Broniarczyk J, Manoubi W, Massimi P, Mittal S, Pim D, Szalmas A, Thatte J, Thomas M, Tomaić V, Banks L. The Human Papillomavirus E6 PDZ Binding Motif: From Life Cycle to Malignancy. Viruses 2015; 7:3530-51. [PMID: 26147797 PMCID: PMC4517114 DOI: 10.3390/v7072785] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/06/2015] [Revised: 06/24/2015] [Accepted: 06/25/2015] [Indexed: 01/01/2023] Open
Abstract
Cancer-causing HPV E6 oncoproteins are characterized by the presence of a PDZ binding motif (PBM) at their extreme carboxy terminus. It was long thought that this region of E6 had a sole function to confer interaction with a defined set of cellular substrates. However, more recent studies have shown that the E6 PBM has a complex pattern of regulation, whereby phosphorylation within the PBM can regulate interaction with two classes of cellular proteins: those containing PDZ domains and the members of the 14-3-3 family of proteins. In this review, we explore the roles that the PBM and its ligands play in the virus life cycle, and subsequently how these can inadvertently contribute towards the development of malignancy. We also explore how subtle alterations in cellular signal transduction pathways might result in aberrant E6 phosphorylation, which in turn might contribute towards disease progression.
Collapse
Affiliation(s)
- Ketaki Ganti
- International Center for Genetic Engineering and Biotechnology, Area Science Park, Padriciano 99, Trieste 34149, Italy.
| | - Justyna Broniarczyk
- International Center for Genetic Engineering and Biotechnology, Area Science Park, Padriciano 99, Trieste 34149, Italy.
| | - Wiem Manoubi
- International Center for Genetic Engineering and Biotechnology, Area Science Park, Padriciano 99, Trieste 34149, Italy.
| | - Paola Massimi
- International Center for Genetic Engineering and Biotechnology, Area Science Park, Padriciano 99, Trieste 34149, Italy.
| | - Suruchi Mittal
- International Center for Genetic Engineering and Biotechnology, Area Science Park, Padriciano 99, Trieste 34149, Italy.
| | - David Pim
- International Center for Genetic Engineering and Biotechnology, Area Science Park, Padriciano 99, Trieste 34149, Italy.
| | - Anita Szalmas
- International Center for Genetic Engineering and Biotechnology, Area Science Park, Padriciano 99, Trieste 34149, Italy.
| | - Jayashree Thatte
- International Center for Genetic Engineering and Biotechnology, Area Science Park, Padriciano 99, Trieste 34149, Italy.
| | - Miranda Thomas
- International Center for Genetic Engineering and Biotechnology, Area Science Park, Padriciano 99, Trieste 34149, Italy.
| | - Vjekoslav Tomaić
- International Center for Genetic Engineering and Biotechnology, Area Science Park, Padriciano 99, Trieste 34149, Italy.
| | - Lawrence Banks
- International Center for Genetic Engineering and Biotechnology, Area Science Park, Padriciano 99, Trieste 34149, Italy.
| |
Collapse
|
25
|
Hijacking Dlg1 for oncogenic phosphatidylinositol 3-kinase activation in human epithelial cells is a conserved mechanism of human adenovirus E4-ORF1 proteins. J Virol 2014; 88:14268-77. [PMID: 25253337 DOI: 10.1128/jvi.02324-14] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023] Open
Abstract
UNLABELLED The E4-ORF1 gene of human adenoviruses encodes a 14-kDa protein that promotes viral replication as well as cellular metabolic reprogramming, survival, and transformation by constitutively activating cellular phosphatidylinositol 3-kinase (PI3K). We recently reported that the E4-ORF1 protein from subgroup D human adenovirus type 9 upregulates and oncogenically activates PI3K by a novel mechanism involving separate interactions of E4-ORF1 with cellular discs large 1 (Dlg1) and PI3K to form a ternary complex that translocates to the plasma membrane (K. Kong, M. Kumar, M. Taruishi, and R. T. Javier, PLoS Pathog. 10:e1004102, 2014, doi:10.1371/journal.ppat.1004102). The current study was carried out to investigate whether other human adenovirus E4-ORF1 proteins share this mechanism of action. The results showed that in human MCF10A epithelial cells, stable expression of E4-ORF1 proteins encoded by representative human adenovirus serotypes from subgroups A to D induce ternary complex formation, Dlg1-dependent PI3K activation, PI3K protein elevation, Dlg1 and PI3K membrane recruitment, and PI3K-dependent cellular transformation. The first three of these E4-ORF1 activities were also observed in MCF10A cells infected with each wild-type human adenovirus from subgroups A to D. Our findings indicate that most, if not all, human adenovirus E4-ORF1 proteins share a conserved molecular mechanism of PI3K activation, which confers a common capacity to promote oncogenic transformation in human epithelial cells. IMPORTANCE PI3K activation by the adenovirus E4-ORF1 protein mediates oncogenic cellular transformation by human adenovirus type 9, augments viral protein expression and replication by human adenovirus type 5, and dysregulates cellular glucose and lipid metabolism by human adenovirus type 36. For the first time, we report that E4-ORF1 proteins from human adenoviruses in subgroups A to D evolved a conserved molecular mechanism to mediate constitutive PI3K activation that can provoke oncogenic transformation in human epithelial cells. The results raise potential safety concerns about the use of vectors encoding the E4-ORF1 gene in human gene therapy and vaccination. Our findings further suggest that the conserved mechanism revealed here may be targeted for development of therapeutic drugs to treat and prevent adenovirus-associated human diseases.
Collapse
|
26
|
The human adenovirus E4-ORF1 protein subverts discs large 1 to mediate membrane recruitment and dysregulation of phosphatidylinositol 3-kinase. PLoS Pathog 2014; 10:e1004102. [PMID: 24788832 PMCID: PMC4006922 DOI: 10.1371/journal.ppat.1004102] [Citation(s) in RCA: 28] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/16/2013] [Accepted: 03/18/2014] [Indexed: 12/19/2022] Open
Abstract
Adenoviruses infect epithelial cells lining mucous membranes to cause acute diseases in people. They are also utilized as vectors for vaccination and for gene and cancer therapy, as well as tools to discover mechanisms of cancer due to their tumorigenic potential in experimental animals. The adenovirus E4-ORF1 gene encodes an oncoprotein that promotes viral replication, cell survival, and transformation by activating phosphatidylinositol 3-kinase (PI3K). While the mechanism of activation is not understood, this function depends on a complex formed between E4-ORF1 and the membrane-associated cellular PDZ protein Discs Large 1 (Dlg1), a common viral target having both tumor suppressor and oncogenic functions. Here, we report that in human epithelial cells, E4-ORF1 interacts with the regulatory and catalytic subunits of PI3K and elevates their levels. Like PI3K activation, PI3K protein elevation by E4-ORF1 requires Dlg1. We further show that Dlg1, E4-ORF1, and PI3K form a ternary complex at the plasma membrane. At this site, Dlg1 also co-localizes with the activated PI3K effector protein Akt, indicating that the ternary complex mediates PI3K signaling. Signifying the functional importance of the ternary complex, the capacity of E4-ORF1 to induce soft agar growth and focus formation in cells is ablated either by a mutation that prevents E4-ORF1 binding to Dlg1 or by a PI3K inhibitor drug. These results demonstrate that E4-ORF1 interacts with Dlg1 and PI3K to assemble a ternary complex where E4-ORF1 hijacks the Dlg1 oncogenic function to relocate cytoplasmic PI3K to the membrane for constitutive activation. This novel mechanism of Dlg1 subversion by adenovirus to dysregulate PI3K could be used by other pathogenic viruses, such as human papillomavirus, human T-cell leukemia virus type 1, and influenza A virus, which also target Dlg1 and activate PI3K in cells. Adenoviruses cause acute illnesses in people, and are additionally utilized both as vehicles to cure genetic diseases, fight cancer, and deliver vaccines, and as tools to discover how cancers develop due to a capacity to generate tumors in experimental animals. The adenovirus E4-ORF1 protein reprograms cell metabolism to enhance virus production in infected cells and promotes cell survival and tumors by activating the important cellular protein phosphatidylinositol 3-kinase (PI3K). How E4-ORF1 activates PI3K is not known, though this function depends on E4-ORF1 binding to the membrane-associated cellular protein Discs Large 1 (Dlg1), which many different viruses evolved to target. In this study, we identify PI3K as a new direct target of E4-ORF1. Results further show that E4-ORF1 binds to PI3K in the cytoplasm and delivers it to Dlg1 at the membrane where the three proteins form a complex that activates PI3K and induces oncogenic growth in cells. This novel molecular mechanism in which adenovirus subverts Dlg1 to dysregulate PI3K may serve as a paradigm to understand PI3K activation mediated by other important pathogenic viruses, such as human papillomavirus, human T-cell leukemia virus type 1, and influenza A virus, which also target Dlg1 in infected cells.
Collapse
|
27
|
Jones G, Srivastava A. Understanding Lunasin’s biology and potential as a cancer therapeutic by utilizing Drosophila genetics. Exp Biol Med (Maywood) 2014; 239:519-28. [DOI: 10.1177/1535370214522180] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Soy contains many bioactive molecules known to elicit anticancer effects. One such peptide, Lunasin, has been shown to selectively act on newly transformed cells while having no cytotoxic effect on non-tumorigenic or established cancer cell lines. While this effect on in vitro systems is promising, Lunasin’s efficacy in an in vivo system is yet to be assessed. In this review, we discuss the state of knowledge with respect to Lunasin and then review some of the powerful genetic tools available in Drosophila. The availability of a sophisticated genetic tool box makes Drosophila an excellent genetic model well suited to studying the biology of Lunasin and its effect on tumor progression in an in vivo model organism.
Collapse
Affiliation(s)
- Gillian Jones
- Department of Biology and Biotechnology Center, Western Kentucky University, KY 42101, USA
| | - Ajay Srivastava
- Department of Biology and Biotechnology Center, Western Kentucky University, KY 42101, USA
| |
Collapse
|
28
|
Ma H, Cai H, Zhang Y, Wu J, Liu X, Zuo J, Jiang W, Ji G, Zhang Y, Liu C, Zhu W, Yu L. Membrane palmitoylated protein 3 promotes hepatocellular carcinoma cell migration and invasion via up-regulating matrix metalloproteinase 1. Cancer Lett 2014; 344:74-81. [PMID: 24513266 DOI: 10.1016/j.canlet.2013.10.017] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2013] [Revised: 09/29/2013] [Accepted: 10/18/2013] [Indexed: 12/31/2022]
|
29
|
Ahn SY, Kim Y, Kim ST, Swat W, Miner JH. Scaffolding proteins DLG1 and CASK cooperate to maintain the nephron progenitor population during kidney development. J Am Soc Nephrol 2013; 24:1127-38. [PMID: 23661808 DOI: 10.1681/asn.2012111074] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
DLG1 (discs-large homolog 1) and CASK (calcium/calmodulin-dependent serine protein kinase) interact at membrane-cytoskeleton interfaces and function as scaffolding proteins that link signaling molecules, receptors, and other scaffolding proteins at intercellular and synaptic junctions. Dlg1-null mice exhibit hydronephrosis, hydroureter, and occasionally hypoplastic kidneys, whereas Cask-null mice do not. To investigate whether DLG1 and CASK cooperate in the developing urogenital system, we generated mice deficient in both DLG1 and CASK either 1) globally, 2) in metanephric mesenchyme, or 3) in nephron progenitors. With each approach, Dlg1;Cask double-knockout (DKO) kidneys were severely hypoplastic and dysplastic and demonstrated rapid, premature depletion of nephron progenitors/stem cells. Several cellular and molecular defects were observed in the DKO kidneys, including reduced proliferation and increased apoptosis of cells in the nephrogenic zone and a progressive decrease in the number of cells expressing SIX2, a transcription factor essential for maintaining nephron progenitors. Fgf8 expression was reduced in early-stage DKO metanephric mesenchyme, accompanied by reduced levels of components of the Ras pathway, which is activated by fibroblast growth factor (FGF) signaling. Moreover, Dlg1(+/-);Cask(-/-) (het/null) kidneys were moderately hypoplastic and demonstrated impaired aggregation of SIX2-positive cells around the ureteric bud tips. Nephron progenitor-specific het/null mice survived with small kidneys but developed glomerulocystic kidney disease and renal failure. Taken together, these results suggest that DLG1 and CASK play critical cooperative roles in maintaining the nephron progenitor population, potentially via a mechanism involving effects on FGF signaling.
Collapse
Affiliation(s)
- Sun-Young Ahn
- Department of Pediatrics, Washington University School of Medicine, 8126 660 S. Euclid Avenue, St. Louis, MO 63110, USA
| | | | | | | | | |
Collapse
|
30
|
Li Y, Zhou B, Dai J, Liu R, Han ZG. Aberrant upregulation of LRRC1 contributes to human hepatocellular carcinoma. Mol Biol Rep 2013; 40:4543-51. [PMID: 23645086 DOI: 10.1007/s11033-013-2549-8] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2012] [Accepted: 04/29/2013] [Indexed: 10/26/2022]
Abstract
Loss of apico-basal polarity often results in a malignant phenotype in epithelial tissues. Aberrant expression of polarity mediator proteins is closely associated with this process. LRRC1/LANO, a putative cell polarity regulator, was previously screened from our gene expression profiling in which its expression was significantly upregulated in hepatocellular carcinoma (HCC). In the present study, we provide evidences that LRRC1 plays a potential oncogenic function in HCC. Consistent with the microarray data, quantitative real-time PCR results showed LRRC1 was aberrantly upregulated in 37/56 (66.1 %, more than twofolds) of HCC specimens compared with adjacent non-cancerous livers. Furthermore, the cellular expression of LRRC1 in all HCC cell lines examined exhibited much higher level than that in normal adult liver tissue. Functional analyses revealed that overexpression of LRRC1 promoted, while knockdown of LRRC1 by RNA interference inhibited the growth and colony formation of HCC cells. Importantly, enhanced expression of LRRC1 conferred NIH3T3 cells the ability of cell transformation. In a xenograft tumor model, we found LRRC1 overexpression increased the tumorigenicity of HCC cells. Thus, our collective findings suggest that LRRC1 contributes to HCC development, and may be a potential target for therapeutic intervention in this disease.
Collapse
Affiliation(s)
- Yandong Li
- Key Laboratory of Systems Biomedicine (Ministry of Education) of Rui-Jin Hospital, Shanghai Jiaotong University School of Medicine, 197 Rui-Jin II Road, Shanghai, 200025, China
| | | | | | | | | |
Collapse
|
31
|
Krishnapuram R, Dhurandhar EJ, Dubuisson O, Hegde V, Dhurandhar NV. Doxycycline-regulated 3T3-L1 preadipocyte cell line with inducible, stable expression of adenoviral E4orf1 gene: a cell model to study insulin-independent glucose disposal. PLoS One 2013; 8:e60651. [PMID: 23544159 PMCID: PMC3609787 DOI: 10.1371/journal.pone.0060651] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2013] [Accepted: 03/01/2013] [Indexed: 01/12/2023] Open
Abstract
Impaired glycemic control and excessive adiposity are major risk factors for Type 2 Diabetes mellitus. In rodent models, Ad36, a human adenovirus, improves glycemic control, independent of dietary fat intake or adiposity. It is impractical to use Ad36 for therapeutic action. Instead, we identified that E4orf1 protein of Ad36, mediates its anti-hyperglycemic action independent of insulin signaling. To further evaluate the therapeutic potential of E4orf1 to improve glycemic control, we established a stable 3T3-L1 cell system in which E4orf1 expression can be regulated. The development and characterization of this cell line is described here. Full-length adenoviral-36 E4orf1 cDNA obtained by PCR was cloned into a tetracycline responsive element containing vector (pTRE-Tight-E4orf1). Upon screening dozens of pTRE-Tight-E4orf1 clones, we identified the one with the highest expression of E4orf1 in response to doxycycline treatment. Furthermore, using this inducible system we characterized the ability of E4orf1 to improve glucose disposal in a time dependent manner. This stable cell line offers a valuable resource to carefully study the novel signaling pathways E4orf1 uses to enhance cellular glucose disposal independent of insulin.
Collapse
Affiliation(s)
- Rashmi Krishnapuram
- Infections and Obesity Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America
| | - Emily J. Dhurandhar
- Infections and Obesity Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America
| | - Olga Dubuisson
- Infections and Obesity Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America
| | - Vijay Hegde
- Infections and Obesity Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America
| | - Nikhil V. Dhurandhar
- Infections and Obesity Laboratory, Pennington Biomedical Research Center, Baton Rouge, Louisiana, United States of America
| |
Collapse
|
32
|
Dhurandhar NV. Insulin sparing action of adenovirus 36 and its E4orf1 protein. J Diabetes Complications 2013; 27:191-9. [PMID: 23246247 DOI: 10.1016/j.jdiacomp.2012.09.006] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 09/12/2012] [Accepted: 09/13/2012] [Indexed: 02/06/2023]
Abstract
Additional drugs are required to effectively manage diabetes and its complications. Recent studies have revealed protective effects of Ad36, a human adenovirus, and its E4orf1 protein on glucose disposal, which may be creatively harnessed to develop novel anti-diabetic agents. Experimental Ad36 infection improves hyperglycemia in animal models and natural Ad36 infection in humans is associated with better glycemic control. Available data indicate distinctive advantages for a drug that may mimic the action of Ad36/E4orf1. The key features of such a potential drug include the ability to increase glucose uptake by adipose tissue and skeletal muscle, to reduce hepatic glucose output independent of proximal insulin signaling, and to up-regulate adiponectin and its hepatic action. The effect of Ad36/E4orf1 on hepatocyte metabolism suggests a role for treating hepatic steatosis. Despite these potential advantages, considerable research is required before such a drug is developed. The in vivo efficacy and safety of E4orf1 in improving hyperglycemia remain unknown, and an appropriate drug delivery system is required. Nonetheless, Ad36 E4orf1 offers a research opportunity to develop a new anti-diabetic agent with multiple potential advantages and conceptually advances the use of a rather unconventional source, microbial proteins, for anti-diabetic drug development.
Collapse
Affiliation(s)
- Nikhil V Dhurandhar
- Infections and Obesity laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, LA 70808, USA.
| |
Collapse
|
33
|
Synergistic effect of the PDZ and p85β-binding domains of the NS1 protein on virulence of an avian H5N1 influenza A virus. J Virol 2013; 87:4861-71. [PMID: 23408626 DOI: 10.1128/jvi.02608-12] [Citation(s) in RCA: 47] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/13/2023] Open
Abstract
The influenza A virus NS1 protein affects virulence through several mechanisms, including the host's innate immune response and various signaling pathways. Highly pathogenic avian influenza (HPAI) viruses of the H5N1 subtype continue to evolve through reassortment and mutations. Our recent phylogenetic analysis identified a group of HPAI H5N1 viruses with two characteristic mutations in NS1: the avian virus-type PDZ domain-binding motif ESEV (which affects virulence) was replaced with ESKV, and NS1-138F (which is highly conserved among all influenza A viruses and may affect the activation of the phosphatidylinositol 3-kinase [PI3K]/Akt signaling pathway) was replaced with NS1-138Y. Here, we show that an HPAI H5N1 virus (A/duck/Hunan/69/2004) encoding NS1-ESKV and NS1-138Y was confined to the respiratory tract of infected mice, whereas a mutant encoding NS1-ESEV and NS1-138F caused systemic infection and killed mice more efficiently. Mutation of either one of these sites had small effects on virulence. In addition, we found that the amino acid at NS1-138 affected not only the induction of the PI3K/Akt pathway but also the interaction of NS1 with cellular PDZ domain proteins. Similarly, the mutation in the PDZ domain-binding motif of NS1 altered its binding to cellular PDZ domain proteins and affected Akt phosphorylation. These findings suggest a functional interplay between the mutations at NS1-138 and NS1-229 that results in a synergistic effect on influenza virulence.
Collapse
|
34
|
Requirement for Dlgh-1 in planar cell polarity and skeletogenesis during vertebrate development. PLoS One 2013; 8:e54410. [PMID: 23349879 PMCID: PMC3551758 DOI: 10.1371/journal.pone.0054410] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2012] [Accepted: 12/13/2012] [Indexed: 01/20/2023] Open
Abstract
The development of specialized organs is tightly linked to the regulation of cell growth, orientation, migration and adhesion during embryogenesis. In addition, the directed movements of cells and their orientation within the plane of a tissue, termed planar cell polarity (PCP), appear to be crucial for the proper formation of the body plan. In Drosophila embryogenesis, Discs large (dlg) plays a critical role in apical-basal cell polarity, cell adhesion and cell proliferation. Craniofacial defects in mice carrying an insertional mutation in Dlgh-1 suggest that Dlgh-1 is required for vertebrate development. To determine what roles Dlgh-1 plays in vertebrate development, we generated mice carrying a null mutation in Dlgh-1. We found that deletion of Dlgh-1 caused open eyelids, open neural tube, and misorientation of cochlear hair cell stereociliary bundles, indicative of defects in planar cell polarity (PCP). Deletion of Dlgh-1 also caused skeletal defects throughout the embryo. These findings identify novel roles for Dlgh-1 in vertebrates that differ from its well-characterized roles in invertebrates and suggest that the Dlgh-1 null mouse may be a useful animal model to study certain human congenital birth defects.
Collapse
|
35
|
The Scribble-Dlg-Lgl polarity module in development and cancer: from flies to man. Essays Biochem 2012; 53:141-68. [PMID: 22928514 DOI: 10.1042/bse0530141] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The Scribble, Par and Crumbs modules were originally identified in the vinegar (fruit) fly, Drosophila melanogaster, as being critical regulators of apico-basal cell polarity. In the present chapter we focus on the Scribble polarity module, composed of Scribble, discs large and lethal giant larvae. Since the discovery of the role of the Scribble polarity module in apico-basal cell polarity, these proteins have also been recognized as having important roles in other forms of polarity, as well as regulation of the actin cytoskeleton, cell signalling and vesicular trafficking. In addition to these physiological roles, an important role for polarity proteins in cancer progression has also been uncovered, with loss of polarity and tissue architecture being strongly correlated with metastatic disease.
Collapse
|
36
|
Abstract
The role of cell polarity regulators in the development of cancer has long been an enigma. Despite displaying characteristics of tumour suppressors, the core regulators of polarity are rarely mutated in tumours and there are few data from animal models to suggest that they directly contribute to cancer susceptibility, thus questioning their relevance to human carcinogenesis. However, a body of data from human tumour viruses is now providing compelling evidence of a central role for the perturbation of cell polarity in the development of cancer.
Collapse
Affiliation(s)
- Lawrence Banks
- The International Centre for Genetic Engineering and Biotechnology, Padriciano 99, I-34149 Trieste, Italy.
| | | | | |
Collapse
|
37
|
Roberts S, Delury C, Marsh E. The PDZ protein discs-large (DLG): the 'Jekyll and Hyde' of the epithelial polarity proteins. FEBS J 2012; 279:3549-3558. [PMID: 22846345 DOI: 10.1111/j.1742-4658.2012.08729.x] [Citation(s) in RCA: 76] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2012] [Revised: 07/16/2012] [Accepted: 07/26/2012] [Indexed: 12/25/2022]
Abstract
Discs-large (DLG) is a multi-PDZ domain-containing protein that belongs to the family of molecular scaffolding proteins known as membrane guanylate kinases or MAGUKs. DLG is a component of the Scribble polarity complex and genetic analyses of DLG in Drosophila have identified a role for the protein in several key biological processes including the regulation of apico-basal polarity of epithelial cells, as well as other polarity processes such as asymmetric cell division and cell invasion. Disturbance of DLG function leads to uncontrolled epithelial cell proliferation and neoplastic transformation, thereby defining DLG as a potential tumour suppressor. However, whether mammalian homologues of DLG (DLG1, DLG2, DLG3 and DLG4) also possess tumour suppressor functions is not known. In this minireview, we focus on the biological functions of DLG1 in human epithelial cells and on how the function of this MAGUK relates to its intracellular location. We examine some of the evidence that implies that DLG has both tumour suppressor and, paradoxically, oncogenic functions depending upon the precise cellular context.
Collapse
Affiliation(s)
- Sally Roberts
- School of Cancer Sciences, University of Birmingham, UK
| | - Craig Delury
- School of Cancer Sciences, University of Birmingham, UK
| | | |
Collapse
|
38
|
Liu W, Chen E, Zhao XW, Wan ZP, Gao YR, Davey A, Huang E, Zhang L, Crocetti J, Sandoval G, Joyce MG, Miceli C, Lukszo J, Aravind L, Swat W, Brzostowski J, Pierce SK. The scaffolding protein synapse-associated protein 97 is required for enhanced signaling through isotype-switched IgG memory B cell receptors. Sci Signal 2012; 5:ra54. [PMID: 22855505 PMCID: PMC3413325 DOI: 10.1126/scisignal.2002820] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
After their first encounter with a foreign antigen, naïve B cells that have immunoglobulin M (IgM) B cell receptors (BCRs) trigger the primary antibody response and the generation of memory B cells with IgG BCRs. When these memory B cells reencounter the same antigen, the cell surface IgG BCRs stimulate their rapid differentiation into plasma cells that release large amounts of IgG antibodies. We showed that the conserved cytoplasmic tail of the IgG BCR, which contains a putative PDZ (postsynaptic density 95/disc large/zona occludens 1)-binding motif, associated with synapse-associated protein 97 (SAP97), a PDZ domain-containing scaffolding molecule that is involved in controlling receptor density and signal strength at neuronal synapses. SAP97 accumulated and bound to IgG BCRs in the immunological synapses that formed in response to B cell engagement with antigen. Knocking down SAP97 in IgG⁺ B cells or mutating the putative PDZ-binding motif in the BCR tail impaired formation of the immunological synapse, initiation of IgG BCR signaling, and downstream activation of the mitogen-activated protein kinase p38. Thus, heightened B cell memory responses are encoded, in part, by a mechanism that involves SAP97 serving as a scaffolding protein in the IgG BCR immunological synapse.
Collapse
Affiliation(s)
- Wanli Liu
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA
- School of Life Sciences, Tsinghua University, Beijing, China, 100084
| | - Elizabeth Chen
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA
| | - Xing Wang Zhao
- School of Life Sciences, Tsinghua University, Beijing, China, 100084
| | - Zheng Peng Wan
- School of Life Sciences, Tsinghua University, Beijing, China, 100084
| | - Yi Ren Gao
- School of Life Sciences, Tsinghua University, Beijing, China, 100084
| | - Angel Davey
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA
| | - Eric Huang
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA
| | - Lijia Zhang
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA
| | - Jillian Crocetti
- Microbiology, Immunology and Molecular Genetics, UCLA School of Medicine and College of Letters and Sciences, 277B Biomedical Sciences Research Building, 615 Charles E. Young Dr. S., Los Angeles, CA 90095, USA
| | - Gabriel Sandoval
- Department of Pathology and Immunology, Washington University School of Medicine, 660 S Euclid Avenue, St Louis, MO 63110, USA
| | - M. Gordon Joyce
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA
| | - Carrie Miceli
- Microbiology, Immunology and Molecular Genetics, UCLA School of Medicine and College of Letters and Sciences, 277B Biomedical Sciences Research Building, 615 Charles E. Young Dr. S., Los Angeles, CA 90095, USA
| | - Jan Lukszo
- Peptide Synthesis and Analysis Laboratory, RTB, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA
| | - L. Aravind
- National Center for Biotechnology Information, National Library of Medicine, National Institutes of Health, Bethesda, MD 20894, USA
| | - Wojciech Swat
- Department of Pathology and Immunology, Washington University School of Medicine, 660 S Euclid Avenue, St Louis, MO 63110, USA
| | - Joseph Brzostowski
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA
| | - Susan K. Pierce
- Laboratory of Immunogenetics, National Institute of Allergy and Infectious Diseases, NIH, Rockville, MD 20852, USA
| |
Collapse
|
39
|
Massimi P, Zori P, Roberts S, Banks L. Differential regulation of cell-cell contact, invasion and anoikis by hScrib and hDlg in keratinocytes. PLoS One 2012; 7:e40279. [PMID: 22792261 PMCID: PMC3391271 DOI: 10.1371/journal.pone.0040279] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Accepted: 06/04/2012] [Indexed: 01/31/2023] Open
Abstract
The components of the Scrib/Dlg tumour suppressor complex have complementary roles in Drosophila and loss of both proteins is a common event in many different human tumours. However no studies have directly addressed the respective contributions of loss of hScrib and hDlg in the same human cell background to cellular phenotypes associated with cell transformation. In human HaCaT keratinocytes we show that removal of hScrib greatly reduces cell-cell contact and cell-matrix interactions, and promotes an invasive phenotype. Conversely, in cells lacking hDlg1 cell-cell contacts are maintained and there are decreases in both cell growth and invasion. However, hDlg-depleted cells show increased resistance to a specialized form of apoptosis known as anoikis, to which cells lacking hScrib are highly susceptible. Thus whilst it has been widely assumed that hScrib and hDlg have complementary roles, these studies in fact demonstrate that hScrib and hDlg1 have distinct and opposing functions in human keratinocytes.
Collapse
Affiliation(s)
- Paola Massimi
- International Centre For Genetic Engineering and Biotechnology Padriciano 99, Trieste, Italy
| | - Patrizia Zori
- International Centre For Genetic Engineering and Biotechnology Padriciano 99, Trieste, Italy
| | - Sally Roberts
- Department of Cancer Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
| | - Lawrence Banks
- International Centre For Genetic Engineering and Biotechnology Padriciano 99, Trieste, Italy
- * E-mail:
| |
Collapse
|
40
|
Krishna Subbaiah V, Massimi P, Boon SS, Myers MP, Sharek L, Garcia-Mata R, Banks L. The invasive capacity of HPV transformed cells requires the hDlg-dependent enhancement of SGEF/RhoG activity. PLoS Pathog 2012; 8:e1002543. [PMID: 22383878 PMCID: PMC3285591 DOI: 10.1371/journal.ppat.1002543] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Accepted: 01/06/2012] [Indexed: 11/19/2022] Open
Abstract
A major target of the HPV E6 oncoprotein is the human Discs Large (hDlg) tumour suppressor, although how this interaction contributes to HPV-induced malignancy is still unclear. Using a proteomic approach we show that a strong interacting partner of hDlg is the RhoG-specific guanine nucleotide exchange factor SGEF. The interaction between hDlg1 and SGEF involves both PDZ and SH3 domain recognition, and directly contributes to the regulation of SGEF's cellular localization and activity. Consistent with this, hDlg is a strong enhancer of RhoG activity, which occurs in an SGEF-dependent manner. We also show that HPV-18 E6 can interact indirectly with SGEF in a manner that is dependent upon the presence of hDlg and PDZ binding capacity. In HPV transformed cells, E6 maintains a high level of RhoG activity, and this is dependent upon the presence of hDlg and SGEF, which are found in complex with E6. Furthermore, we show that E6, hDlg and SGEF each directly contributes to the invasive capacity of HPV-16 and HPV-18 transformed tumour cells. These studies demonstrate that hDlg has a distinct oncogenic function in the context of HPV induced malignancy, one of the outcomes of which is increased RhoG activity and increased invasive capacity.
Collapse
Affiliation(s)
| | - Paola Massimi
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Siaw Shi Boon
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Michael P. Myers
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
| | - Lisa Sharek
- Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Rafael Garcia-Mata
- Department of Cell and Developmental Biology, University of North Carolina, Chapel Hill, North Carolina, United States of America
| | - Lawrence Banks
- International Centre for Genetic Engineering and Biotechnology, Trieste, Italy
- * E-mail:
| |
Collapse
|
41
|
Abstract
Over 250 PDZ (PSD95/Dlg/ZO-1) domain-containing proteins have been described in the human proteome. As many of these possess multiple PDZ domains, the potential combinations of associations with proteins that possess PBMs (PDZ-binding motifs) are vast. However, PDZ domain recognition is a highly specific process, and much less promiscuous than originally thought. Furthermore, a large number of PDZ domain-containing proteins have been linked directly to the control of processes whose loss, or inappropriate activation, contribute to the development of human malignancies. These regulate processes as diverse as cytoskeletal organization, cell polarity, cell proliferation and many signal transduction pathways. In the present review, we discuss how PBM–PDZ recognition and imbalances therein can perturb cellular homoeostasis and ultimately contribute to malignant progression.
Collapse
|
42
|
Dhurandhar EJ, Dubuisson O, Mashtalir N, Krishnapuram R, Hegde V, Dhurandhar NV. E4orf1: a novel ligand that improves glucose disposal in cell culture. PLoS One 2011; 6:e23394. [PMID: 21886789 PMCID: PMC3160302 DOI: 10.1371/journal.pone.0023394] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2011] [Accepted: 07/14/2011] [Indexed: 12/31/2022] Open
Abstract
Reducing dietary fat intake and excess adiposity, the cornerstones of behavioral treatment of insulin resistance (IR), are marginally successful over the long term. Ad36, a human adenovirus, offers a template to improve IR, independent of dietary fat intake or adiposity. Ad36 increases cellular glucose uptake via a Ras-mediated activation of phosphatidyl inositol 3-kinase(PI3K), and improves hyperglycemia in mice, despite a high-fat diet and without reducing adiposity. Ex-vivo studies suggest that Ad36 improves hyperglycemia in mice by increasing glucose uptake by adipose tissue and skeletal muscle, and by reducing hepatic glucose output. It is impractical to use Ad36 for therapeutic action. Instead, we investigated if the E4orf1 protein of Ad36, mediates its anti-hyperglycemic action. Such a candidate protein may offer an attractive template for therapeutic development. Experiment-1 determined that Ad36 'requires' E4orf1 protein to up-regulate cellular glucose uptake. Ad36 significantly increased glucose uptake in 3T3-L1 preadipocytes, which was abrogated by knocking down E4orf1 with siRNA. Experiment-2 identified E4orf1 as 'sufficient' to up-regulate glucose uptake. 3T3-L1 cells that inducibly express E4orf1, increased glucose uptake in an induction-dependent manner, compared to null vector control cells. E4orf1 up-regulated PI3K pathway and increased abundance of Ras--the obligatory molecule in Ad36-induced glucose uptake. Experiment-3: Signaling studies of cells transiently transfected with E4orf1 or a null vector, revealed that E4orf1 may activate Ras/PI3K pathway by binding to Drosophila discs-large (Dlg1) protein. E4orf1 activated total Ras and, particularly the H-Ras isoform. By mutating the PDZ domain binding motif (PBM) of E4orf1, Experiment-4 showed that E4orf1 requires its PBM to increase Ras activation or glucose uptake. Experiment-5: In-vitro, a transient transfection by E4orf1 significantly increased glucose uptake in preadipocytes, adipocytes, or myoblasts, and reduced glucose output by hepatocytes. Thus, the highly attractive anti-hyperglycemic effect of Ad36 is mirrored by E4orf1 protein, which may offer a novel ligand to develop anti-hyperglycemic drugs.
Collapse
Affiliation(s)
- Emily J. Dhurandhar
- Infections and Obesity Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, United States of America
| | - Olga Dubuisson
- Infections and Obesity Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, United States of America
| | - Nazar Mashtalir
- Infections and Obesity Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, United States of America
| | - Rashmi Krishnapuram
- Infections and Obesity Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, United States of America
| | - Vijay Hegde
- Infections and Obesity Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, United States of America
| | - Nikhil V. Dhurandhar
- Infections and Obesity Laboratory, Pennington Biomedical Research Center, Louisiana State University System, Baton Rouge, Louisiana, United States of America
| |
Collapse
|
43
|
The avian influenza virus NS1 ESEV PDZ binding motif associates with Dlg1 and Scribble to disrupt cellular tight junctions. J Virol 2011; 85:10639-48. [PMID: 21849460 DOI: 10.1128/jvi.05070-11] [Citation(s) in RCA: 96] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
The influenza A virus NS1 protein contains a conserved 4-amino-acid-residue PDZ-ligand binding motif (PBM) at the carboxyl terminus that can function as a virulence determinant by targeting cellular PDZ proteins. The NS1 proteins from avian and human viral isolates have consensus PBM sequences ESEV and RSKV, respectively. Currently circulating highly pathogenic H5N1 viruses contain the ESEV PBM which specifically associates with the PDZ proteins Scribble, Dlg1, MAGI-1, MAGI-2, and MAGI-3. In this study, we found NS1 proteins from viral isolates that contain the PBM sequence RSKV, KSEV, or EPEV are unable to associate with these PDZ proteins. Other results showed that the ESEV PBM mediates an indirect association with PDZ protein, Lin7C, via an interaction with Dlg1. Infection with a virus that expresses a NS1 protein with the ESEV PBM results in colocalization of NS1, Scribble, and Dlg1 within perinuclear puncta and mislocalization of plasma membrane-associated Lin7C to the cytoplasm. Infection of polarized MDCK cells with the ESEV virus additionally results in functional disruption of the tight junction (TJ) as measured by altered localization of TJ markers ZO-1 and Occludin, decreased transepithelial electrical resistance, and increased fluorescein isothiocyanate (FITC)-inulin diffusion across the polarized cell monolayer. A similar effect on the TJ was observed in MDCK cells depleted for either Scribble or Dlg1 by small interfering RNA (siRNA). These findings indicate that ESEV PBM-mediated binding of NS1 to Scribble and Dlg1 functions to disrupt the cellular TJ and that this effect likely contributes to the severe disease associated with highly pathogenic H5N1 influenza A viruses.
Collapse
|
44
|
Abstract
More than a decade ago, three viral oncoproteins, adenovirus type 9 E4-ORF1, human T-lymphotropic virus type 1 Tax, and high-risk human papillomavirus E6, were found to encode a related carboxyl-terminal PDZ domain-binding motif (PBM) that mediates interactions with a select group of cellular PDZ proteins. Recent studies have shown that many other viruses also encode PBM-containing proteins that bind to cellular PDZ proteins. Interestingly, these recently recognized viruses include not only some with oncogenic potential (hepatitis B virus, rhesus papillomavirus, cottontail rabbit papillomavirus) but also many without this potential (influenza virus, Dengue virus, tick-borne encephalitis virus, rabies virus, severe acute respiratory syndrome coronavirus, human immunodeficiency virus). Examination of the cellular PDZ proteins that are targets of viral PBMs reveals that the viral proteins often interact with the same or similar types of PDZ proteins, most notably Dlg1 and other members of the membrane-associated guanylate kinase protein family, as well as Scribble. In addition, cellular PDZ protein targets of viral PBMs commonly control tight junction formation, cell polarity establishment, and apoptosis. These findings reveal a new theme in virology wherein many different virus families encode proteins that bind and perturb the function of cellular PDZ proteins. The inhibition or perturbation of the function of cellular PDZ proteins appears to be a widely used strategy for viruses to enhance their replication, disseminate in the host, and transmit to new hosts.
Collapse
|
45
|
Yang X, Xie X, Chen L, Zhou H, Wang Z, Zhao W, Tian R, Zhang R, Tian C, Long J, Shen Y. Structural basis for tandem L27 domain‐mediated polymerization. FASEB J 2010. [DOI: 10.1096/fj.10.163857] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Affiliation(s)
- Xue Yang
- Tianjin Key Laboratory of Protein Science, College of Life Science, Nankai University Tianjin China
| | - Xingqiao Xie
- Tianjin Key Laboratory of Protein Science, College of Life Science, Nankai University Tianjin China
| | - Liu Chen
- School of Life Science, University of Science and Technology China Anhui China
| | - Hao Zhou
- Tianjin Key Laboratory of Protein Science, College of Life Science, Nankai University Tianjin China
| | - Zheng Wang
- Tianjin Key Laboratory of Protein Science, College of Life Science, Nankai University Tianjin China
| | - Weijing Zhao
- Tianjin Key Laboratory of Protein Science, College of Life Science, Nankai University Tianjin China
| | - Ran Tian
- Tianjin Key Laboratory of Protein Science, College of Life Science, Nankai University Tianjin China
| | - Rongguang Zhang
- Institute of BiophysicsChinese Academy of Science Beijing China
| | - Changlin Tian
- School of Life Science, University of Science and Technology China Anhui China
| | - Jiafu Long
- Tianjin Key Laboratory of Protein Science, College of Life Science, Nankai University Tianjin China
| | - Yuequan Shen
- Tianjin Key Laboratory of Protein Science, College of Life Science, Nankai University Tianjin China
| |
Collapse
|
46
|
The ESEV PDZ-binding motif of the avian influenza A virus NS1 protein protects infected cells from apoptosis by directly targeting Scribble. J Virol 2010; 84:11164-74. [PMID: 20702615 DOI: 10.1128/jvi.01278-10] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The NS1 protein from influenza A viruses contains a four-amino-acid sequence at its carboxyl terminus that is termed the PDZ-binding motif (PBM). The NS1 PBM is predicted to bind to cellular PDZ proteins and functions as a virulence determinant in infected mice. ESEV is the consensus PBM sequence of avian influenza viruses, while RSKV is the consensus sequence of human viruses. Currently circulating highly pathogenic H5N1 influenza viruses encode an NS1 protein with the ESEV PBM. We identified cellular targets of the avian ESEV PBM and identified molecular mechanisms involved in its function. Using glutathione S-transferase (GST) pull-down assays, we found that the ESEV PBM enables NS1 to associate with the PDZ proteins Scribble, Dlg1, MAGI-1, MAGI-2, and MAGI-3. Because Scribble possesses a proapoptotic activity, we investigated the interaction between NS1 and Scribble. The association between NS1 and Scribble is direct and requires the ESEV PBM and two Scribble PDZ domains. We constructed recombinant H3N2 viruses that encode an H6N6 avian virus NS1 protein with either an ESEV or mutant ESEA PBM, allowing an analysis of the ESEV PBM in infections in mammalian cells. The ESEV PBM enhanced viral replication up to 4-fold. In infected cells, NS1 with the ESEV PBM relocalized Scribble into cytoplasmic puncta concentrated in perinuclear regions and also protected cells from apoptosis. In addition, the latter effect was eliminated by small interfering RNA (siRNA)-mediated Scribble depletion. This study shows that one function of the avian ESEV PBM is to reduce apoptosis during infection through disruption of Scribble's proapoptotic function.
Collapse
|
47
|
Yang X, Xie X, Chen L, Zhou H, Wang Z, Zhao W, Tian R, Zhang R, Tian C, Long J, Shen Y. Structural basis for tandem L27 domain-mediated polymerization. FASEB J 2010; 24:4806-15. [PMID: 20702775 DOI: 10.1096/fj.10-163857] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
The establishment of epithelial cell polarity requires the assembly of multiprotein complexes and is crucial during epithelial morphogenesis. Three scaffolding proteins, Dlg1, MPP7, and Mals3, can be assembled to form a complex that functions in the establishment and maintenance of apicobasal polarity in epithelial tissues through their L27 domains. Here we report the crystal structure of a 4-L27-domain complex derived from the human tripartite complex Dlg1-MPP7-Mals3 in combination with paramagnetic relaxation enhancement measurements. The heterotrimer consists of 2 pairs of heterodimeric L27 domains. These 2 dimers are asymmetric due to the large difference between the N- and C-terminal tandem L27 domain of MPP7. Structural analysis combined with biochemical experiments further reveals that the loop αA-αB and helix αB of the C-terminal L27 domain of MPP7 play a critical role in assembling the entire tripartite complex, suggesting a synergistic tandem L27-mediated assembling event.
Collapse
Affiliation(s)
- Xue Yang
- Tianjin Key Laboratory of Protein Science, College of Life Science, Nankai University, Tianjin, China
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
48
|
Iñesta-Vaquera FA, Campbell DG, Arthur JSC, Cuenda A. ERK5 pathway regulates the phosphorylation of tumour suppressor hDlg during mitosis. Biochem Biophys Res Commun 2010; 399:84-90. [PMID: 20643107 DOI: 10.1016/j.bbrc.2010.07.046] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2010] [Accepted: 07/14/2010] [Indexed: 10/19/2022]
Abstract
Human disc-large (hDlg) is a scaffold protein critical for the maintenance of cell polarity and adhesion. hDlg is thought to be a tumour suppressor that regulates the cell cycle and proliferation. However, the mechanism and pathways involved in hDlg regulation during these processes is still unclear. Here we report that hDlg is phosphorylated during mitosis, and we establish the identity of at least three residues phosphorylated in hDlg; some are previously unreported. Phosphorylation affects hDlg localisation excluding it from the contact point between the two daughter cells. Our results reveal a previously unreported pathway for hDlg phosphorylation in mitosis and show that ERK5 pathway mediates hDlg cell cycle dependent phosphorylation. This is likely to have important implications in the correct timely mitotic entry and mitosis progression.
Collapse
Affiliation(s)
- Francisco A Iñesta-Vaquera
- Departamento de Inmunología y Oncología, Centro Nacional de Biotecnología-CSIC, Campus de Cantoblanco-UAM, Madrid, Spain
| | | | | | | |
Collapse
|
49
|
Liu H, Herrmann CH, Chiang K, Sung TL, Moon SH, Donehower LA, Rice AP. 55K isoform of CDK9 associates with Ku70 and is involved in DNA repair. Biochem Biophys Res Commun 2010; 397:245-50. [PMID: 20493174 DOI: 10.1016/j.bbrc.2010.05.092] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2010] [Accepted: 05/16/2010] [Indexed: 10/19/2022]
Abstract
Positive elongation factor b (P-TEFb) is a cellular protein kinase that is required for RNA polymerase II (RNAP II) transcriptional elongation of protein coding genes. P-TEFb is a set of different molecular complexes, each containing CDK9 as the catalytic subunit. There are two isoforms of the CDK9 protein - the major 42KDa CDK9 isoform and the minor 55KDa isoform that is translated from an in-frame mRNA that arises from an upstream transcriptional start site. We found that shRNA depletion of the 55K CDK9 protein in HeLa cells induces apoptosis and double-strand DNA breaks (DSBs). The levels of apoptosis and DSBs induced by the depletion were reduced by expression of a 55K CDK9 protein variant resistant to the shRNA, indicating that these phenotypes are the consequence of depletion of the 55K protein and not off-target effects. We also found that the 55K CDK9 protein, but not the 42K CDK9 protein, specifically associates with Ku70, a protein involved in DSB repair. Our findings suggest that the 55K CDK9 protein may function in repair of DNA through an association with Ku70.
Collapse
Affiliation(s)
- Hongbing Liu
- Department of Molecular Virology and Microbiology, Baylor College of Medicine, Houston, TX 77030, USA
| | | | | | | | | | | | | |
Collapse
|
50
|
Distinct functions of HTLV-1 Tax1 from HTLV-2 Tax2 contribute key roles to viral pathogenesis. Retrovirology 2009; 6:117. [PMID: 20017952 PMCID: PMC2806368 DOI: 10.1186/1742-4690-6-117] [Citation(s) in RCA: 77] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2009] [Accepted: 12/17/2009] [Indexed: 12/17/2022] Open
Abstract
While the human T-cell leukemia virus type 1 (HTLV-1) is the etiologic agent of adult T-cell leukemia/lymphoma (ATL), to date, its close relative HTLV-2 is not associated with ATL or other types of malignancies. Accumulating evidence shows that HTLV-1 Tax1 and HTLV-2 Tax2 have many shared activities, but the two proteins have a limited number of significantly distinct activities, and these distinctions appear to play key roles in HTLV-1 specific pathogenesis. In this review, we summarize the functions of Tax1 associated with cell survival, cell proliferation, persistent infection as well as pathogenesis. We emphasize special attention to distinctions between Tax1 and Tax2.
Collapse
|