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Ruhanya V, Jacobs GB, Paul RH, Joska JA, Seedat S, Nyandoro G, Glashoff RH, Engelbrecht S. HIV-1 Subtype C Vpr Amino Acid Residue 45Y and Specific Conserved Fragments Are Associated with Neurocognitive Impairment and Markers of Viral Load. AIDS Res Hum Retroviruses 2023; 39:166-175. [PMID: 36401355 DOI: 10.1089/aid.2022.0022] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
There is increasing evidence that HIV-1 viral protein R (Vpr) plays an important role in the pathogenesis of cognitive impairment. We investigated the relationship between HIV-1 subtype C Vpr sequence variation and HIV-associated neurocognitive impairment as measured by global deficit score (GDS) in treatment-naive individuals. We used different bioinformatic tools and statistical models to correlate vpr variation and cognitive function. We identified a tyrosine at position 45 (45Y) as a signature for neurocognitive impairment and histidine (45H) as a signature in the non-impaired individuals. The presence of signature 45Y was associated by 3.66 times higher GDS, 525 times higher plasma viral load, 15.84 times higher proviral load, and 60% lower absolute CD4-T cell count compared with those without the signature. Additionally, we identified four conserved Vpr fragment sequences, PEDQGPQREPYNEWTLE (5-21), LGQYIY (42-47), TYGDTW (49-54), and PEDQGPQREPYNEW (5-18), that were associated with higher plasma viral load and proviral load. The implication of these findings is that variation of Vpr leads to neurocognitive impairment in HIV infection and worsens the progression of disease in general by promoting the production of provirus, promoting HIV replication and depletion of CD4+ T cells in the periphery.
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Affiliation(s)
- Vurayai Ruhanya
- Division of Medical Virology, Department of Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa.,Department of Medical Microbiology, University of Zimbabwe, Harare, Zimbabwe
| | - Graeme Brendon Jacobs
- Division of Medical Virology, Department of Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
| | - Robert H Paul
- Department of Psychology and Behavioral Neuroscience, University of Missouri-St Louis, University Boulevard, St Louis, Missouri, USA
| | - John A Joska
- MRC Unit of Anxiety and Stress Disorders, Department of Psychiatry and Mental Health, University of Cape Town, Cape Town, South Africa
| | - Soraya Seedat
- MRC Unit of Anxiety and Stress Disorders, Department of Psychiatry, University of Stellenbosch, Cape Town, South Africa
| | - George Nyandoro
- Department of Medical Microbiology, University of Zimbabwe, Harare, Zimbabwe
| | - Richard Helmuth Glashoff
- Division of Medical Microbiology, Stellenbosch University, Cape Town, South Africa.,National Health Laboratory Service (NHLS), Tygerberg Business Unity, Cape Town, South Africa
| | - Susan Engelbrecht
- Division of Medical Virology, Department of Pathology, Faculty of Medicine and Health Sciences, Stellenbosch University, Cape Town, South Africa
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Agarwal N, Ramirez Bustamante CE, Wu H, Armamento‐Villareal R, Lake JE, Balasubramanyam A, Hartig S. Heightened levels of plasma growth differentiation factor 15 in men living with HIV. Physiol Rep 2022; 10:e15293. [PMID: 35510313 PMCID: PMC9069165 DOI: 10.14814/phy2.15293] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2022] [Revised: 04/14/2022] [Accepted: 04/17/2022] [Indexed: 01/13/2023] Open
Abstract
Plasma biomarkers that reflect energy balance disorders in people living with HIV (PLWH) remain limited. Growth differentiation factor 15 (GDF15) abundance in plasma of mice and humans induces negative energy balance but also becomes highly elevated in obesity and other metabolic diseases. We sought to compare plasma GDF15 levels in PLWH and HIV-negative persons and mouse models expressing the HIV accessory protein Vpr (that recapitulate HIV-associated metabolic disorders) and determine their relationship to metabolic parameters. We measured liver Gdf15 mRNA levels and plasma GDF15 levels in male Vpr mice and littermate controls. In parallel, we analyzed plasma GDF15 levels in 18 male PLWH on stable, long-term antiretroviral therapy and 13 HIV-negative men (6 healthy controls and 7 with metabolic syndrome). Plasma GDF15 levels were correlated with anthropometric and immune cell parameters in humans. Gene expression analysis of Vpr mouse liver demonstrated elevated Gdf15 mRNA. Plasma GDF15 levels were also higher in Vpr mouse models. Levels of plasma GDF15 in PLWH were greater than in both HIV-negative groups and correlated positively with the CD4/CD8 T cell ratio in PLWH. Plasma GDF15 levels correlated positively with age in the HIV-negative subjects but not in PLWH. Since GDF15 levels predict fatty liver disease and energy balance disorders, further studies are warranted to determine the effect of GDF15 in mediating the metabolic disturbances that occur in Vpr mice and PLWH.
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Affiliation(s)
- Neeti Agarwal
- Division of Diabetes, Endocrinology, and MetabolismBaylor College of MedicineHoustonTexasUSA
| | | | - Huaizhu Wu
- Atherosclerosis and Lipoprotein ResearchBaylor College of MedicineHoustonTexasUSA
| | - Reina Armamento‐Villareal
- Division of Diabetes, Endocrinology, and MetabolismBaylor College of MedicineHoustonTexasUSA
- Center for Translational Research on Inflammatory DiseasesMichael E DeBakey VA Medical CenterHoustonTexasUSA
| | - Jordan E. Lake
- Division of Infectious DiseasesDepartment of Internal MedicineMcGovern Medical SchoolUniversity of Texas Health Science CenterHoustonTexasUSA
| | - Ashok Balasubramanyam
- Division of Diabetes, Endocrinology, and MetabolismBaylor College of MedicineHoustonTexasUSA
| | - Sean M. Hartig
- Division of Diabetes, Endocrinology, and MetabolismBaylor College of MedicineHoustonTexasUSA
- Department of Molecular and Cellular BiologyBaylor College of MedicineHoustonTexasUSA
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3
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Liu CH, Huang SJ, Yu TY. Cholesterol Modulates the Interaction between HIV-1 Viral Protein R and Membrane. MEMBRANES 2021; 11:784. [PMID: 34677550 PMCID: PMC8539443 DOI: 10.3390/membranes11100784] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 09/04/2021] [Revised: 10/08/2021] [Accepted: 10/10/2021] [Indexed: 11/24/2022]
Abstract
Being a major metabolite for maintaining cellular homeostasis, as well as an important structural component in lipid membrane, cholesterol also plays critical roles in the life cycles of some viruses, including human immunodeficiency virus-1 (HIV-1). The involvement of cholesterol in HIV-1 infectivity, assembly and budding has made it an important research target. Viral protein R (Vpr) is an accessory protein of HIV-1, which is involved in many major events in the life cycle of HIV-1. In addition to its multi-functional roles in the HIV-1 life cycle, it is shown to interact with lipid membrane and form a cation-selective channel. In this work, we examined the effect of cholesterol on the interaction of Vpr and lipid membrane. Using calcein release assay, we found that the membrane permeability induced by the membrane binding of Vpr was significantly reduced in the presence of cholesterol in membrane. In addition, using solid-state NMR (ssNMR) spectroscopy, Vpr was shown to experience multiple chemical environments in lipid membrane, as indicated by the broad line shape of carbonyl 13C resonance of Cys-76 residue ranging from 165-178 ppm, which can be attributed to the existence of complex Vpr-membrane environments. We further showed that the presence of cholesterol in membrane will alter the distribution of Vpr in the complex membrane environments, which may explain the change of the Vpr induced membrane permeability in the presence of cholesterol.
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Affiliation(s)
- Chun-Hao Liu
- Chemical Biology and Molecular Biophysics, Taiwan International Graduate Program, Academia Sinica, Taipei 11529, Taiwan;
- Institute of Bioinformatics and Structural Biology, National Tsing Hua University, Hsin Chu 300044, Taiwan
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
| | - Shing-Jong Huang
- Instrumentation Center, National Taiwan University, Taipei 10617, Taiwan
| | - Tsyr-Yan Yu
- Institute of Atomic and Molecular Sciences, Academia Sinica, Taipei 10617, Taiwan
- International Graduate Program of Molecular Science and Technology, National Taiwan University, Taipei 10617, Taiwan
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4
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Agarwal N, Iyer D, Saha P, Cox AR, Xia Y, Utay NS, Somasundaram A, Schubert U, Lake JE, Hartig SM, Balasubramanyam A. HIV-1 Viral Protein R Couples Metabolic Inflexibility With White Adipose Tissue Thermogenesis. Diabetes 2021; 70:2014-2025. [PMID: 34233931 PMCID: PMC8576429 DOI: 10.2337/db20-0888] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Accepted: 06/29/2021] [Indexed: 11/13/2022]
Abstract
Persons living with HIV (PLWH) manifest chronic disorders of brown and white adipose tissues that lead to diabetes and metabolic syndrome. The mechanisms that link viral factors to defective adipose tissue function and abnormal energy balance in PLWH remain incompletely understood. Here, we explored how the HIV accessory protein viral protein R (Vpr) contributes to adaptive thermogenesis in two mouse models and human adipose tissues. Uncoupling protein 1 (UCP1) gene expression was strongly increased in subcutaneous white adipose tissue (WAT) biopsy specimens from PLWH and in subcutaneous WAT of the Vpr mice, with nearly equivalent mRNA copy number. Histology and functional studies confirmed beige transformation in subcutaneous but not visceral WAT in the Vpr mice. Measurements of energy balance indicated Vpr mice displayed metabolic inflexibility and could not shift efficiently from carbohydrate to fat metabolism during day-night cycles. Furthermore, Vpr mice showed a marked inability to defend body temperature when exposed to 4°C. Importantly, Vpr couples higher tissue catecholamine levels with UCP1 expression independent of β-adrenergic receptors. Our data reveal surprising deficits of adaptive thermogenesis that drive metabolic inefficiency in HIV-1 Vpr mouse models, providing an expanded role for viral factors in the pathogenesis of metabolic disorders in PLWH.
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Affiliation(s)
- Neeti Agarwal
- Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX
| | - Dinakar Iyer
- Department of Biology and Biochemistry, University of Houston, Houston, TX
| | - Pradip Saha
- Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX
| | - Aaron R Cox
- Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX
| | - Yan Xia
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX
| | - Netanya S Utay
- Division of Infectious Diseases, Department of Internal Medicine, McGovern Medical School at the University of Texas Health Science Center, Houston, TX
| | - Anoma Somasundaram
- Division of Infectious Diseases, Department of Internal Medicine, McGovern Medical School at the University of Texas Health Science Center, Houston, TX
| | | | - Jordan E Lake
- Division of Infectious Diseases, Department of Internal Medicine, McGovern Medical School at the University of Texas Health Science Center, Houston, TX
| | - Sean M Hartig
- Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX
| | - Ashok Balasubramanyam
- Division of Diabetes, Endocrinology, and Metabolism, Baylor College of Medicine, Houston, TX
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Eldin P, Péron S, Galashevskaya A, Denis-Lagache N, Cogné M, Slupphaug G, Briant L. Impact of HIV-1 Vpr manipulation of the DNA repair enzyme UNG2 on B lymphocyte class switch recombination. J Transl Med 2020; 18:310. [PMID: 32778120 PMCID: PMC7418440 DOI: 10.1186/s12967-020-02478-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2020] [Accepted: 08/02/2020] [Indexed: 02/06/2023] Open
Abstract
Background HIV-1 Vpr encodes a 14 kDa protein that has been implicated in viral pathogenesis through modulation of several host cell functions. In addition to pro-apoptotic and cytostatic properties, Vpr can redirect cellular E3 ubiquitin ligases (such as DCAF1-Cul4A E3 ligase complex) to target many host proteins and interfere with their functions. Among them, Vpr binds the uracil DNA glycosylase UNG2, which controls genome uracilation, and induces its specific degradation leading to loss of uracil removal activity in infected cells. Considering the essential role of UNG2 in antibody diversification in B-cells, we evaluated the impact of Vpr on UNG2 fate in B lymphocytes and examined the functional consequences of UNG2 modulations on class switch recombination (CSR). Methods The impact of Vpr-induced UNG2 deregulation on CSR proficiency was evaluated by using virus-like particles able to deliver Vpr protein to target cells including the murine model CSR B cell line CH12F3 and mouse primary B-cells. Co-culture experiments were used to re-examine the ability of Vpr to be released by HIV-1 infected cells and to effectively accumulate in bystander B-cells. Vpr-mediated UNG2 modulations were monitored by following UNG2 protein abundance and uracil removal enzymatic activity. Results In this study we report the ability of Vpr to reduce immunoglobulin class switch recombination (CSR) in immortalized and primary mouse B-cells through the degradation of UNG2. We also emphasize that Vpr is released by producing cells and penetrates bystander B lymphocytes. Conclusions This work therefore opens up new perspectives to study alterations of the B-cell response by using Vpr as a specific CSR blocking tool. Moreover, our results raise the question of whether extracellular HIV-1 Vpr detected in some patients may manipulate the antibody diversification process that engineers an adapted response against pathogenic intruders and thereby contribute to the intrinsic B-cell humoral defect reported in infected patients.
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Affiliation(s)
- Patrick Eldin
- Institut de Recherche en Infectiologie de Montpellier (IRIM), CNRS, UMR 9004, Université de Montpellier, 1919 Route de Mende, 34293, Montpellier Cedex 5, France.
| | - Sophie Péron
- Contrôle de la Réponse Immune B et des Lymphoproliférations (CBRIL), UMR CNRS 7276 INSERM 1262, Centre de Biologie et de Recherche en Santé (CBRS), Faculté de Limoges, 2 rue du Dr. Marcland, 87000, Limoges, France
| | - Anastasia Galashevskaya
- Proteomics and Modomics Experimental Core (PROMEC), Department of Cancer Research and Molecular Medicine, Laboratory Centre, Norwegian University of Science and Technology (NTNU), 5th Floor. Erling Skjalgssons gt. 1, 7491, Trondheim, Norway
| | - Nicolas Denis-Lagache
- Contrôle de la Réponse Immune B et des Lymphoproliférations (CBRIL), UMR CNRS 7276 INSERM 1262, Centre de Biologie et de Recherche en Santé (CBRS), Faculté de Limoges, 2 rue du Dr. Marcland, 87000, Limoges, France
| | - Michel Cogné
- Contrôle de la Réponse Immune B et des Lymphoproliférations (CBRIL), UMR CNRS 7276 INSERM 1262, Centre de Biologie et de Recherche en Santé (CBRS), Faculté de Limoges, 2 rue du Dr. Marcland, 87000, Limoges, France
| | - Geir Slupphaug
- Proteomics and Modomics Experimental Core (PROMEC), Department of Cancer Research and Molecular Medicine, Laboratory Centre, Norwegian University of Science and Technology (NTNU), 5th Floor. Erling Skjalgssons gt. 1, 7491, Trondheim, Norway
| | - Laurence Briant
- Institut de Recherche en Infectiologie de Montpellier (IRIM), CNRS, UMR 9004, Université de Montpellier, 1919 Route de Mende, 34293, Montpellier Cedex 5, France
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6
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Marquette A, Leborgne C, Schartner V, Salnikov E, Bechinger B, Kichler A. Peptides derived from the C-terminal domain of HIV-1 Viral Protein R in lipid bilayers: Structure, membrane positioning and gene delivery. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2020; 1862:183149. [PMID: 31816324 DOI: 10.1016/j.bbamem.2019.183149] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/10/2019] [Revised: 12/03/2019] [Accepted: 12/04/2019] [Indexed: 12/19/2022]
Abstract
Viral protein R (Vpr) is a small accessory protein of 96 amino acids that is present in Human and simian immunodeficiency viruses. Among the very different properties that Vpr possesses we can find cell penetrating capabilities. Based on this and on its capacity to interact with nucleic acids we previously investigated the DNA transfection properties of Vpr and subfragments thereof. We found that fragments of the C-terminal helical domain of Vpr are able to deliver efficiently plasmid DNA into different cell lines. As the amphipathic helix may play a role in the interactions with membranes, we investigated whether insertion of a proline residue in the α-helix modifies the transfection properties of Vpr. Unexpectedly, we found that the resulting Vpr55-82 Pro70 peptide was even more efficient than wild type Vpr55-82 in the gene delivery assays. Using circular dichroism, light scattering and solid-state NMR techniques, we characterized the secondary structure and interactions of Vpr and several mutants with model membranes. A model is proposed where the proline shifts the dissociation equilibrium of the peptide-cargo complex and thereby its endosomal release.
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Affiliation(s)
- Arnaud Marquette
- Université de Strasbourg, CNRS, UMR7177, IUF, Institut de Chimie, 4, Rue Blaise Pascal, 67070 Strasbourg, France
| | | | - Vanessa Schartner
- Laboratoire de Conception et Application de Molécules Bioactives UMR7199 CNRS - Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch, France
| | - Evgeniy Salnikov
- Université de Strasbourg, CNRS, UMR7177, IUF, Institut de Chimie, 4, Rue Blaise Pascal, 67070 Strasbourg, France
| | - Burkhard Bechinger
- Université de Strasbourg, CNRS, UMR7177, IUF, Institut de Chimie, 4, Rue Blaise Pascal, 67070 Strasbourg, France.
| | - Antoine Kichler
- Laboratoire de Conception et Application de Molécules Bioactives UMR7199 CNRS - Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch, France.
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7
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Vpr and Its Cellular Interaction Partners: R We There Yet? Cells 2019; 8:cells8111310. [PMID: 31652959 PMCID: PMC6912716 DOI: 10.3390/cells8111310] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2019] [Revised: 10/22/2019] [Accepted: 10/23/2019] [Indexed: 12/17/2022] Open
Abstract
Vpr is a lentiviral accessory protein that is expressed late during the infection cycle and is packaged in significant quantities into virus particles through a specific interaction with the P6 domain of the viral Gag precursor. Characterization of the physiologically relevant function(s) of Vpr has been hampered by the fact that in many cell lines, deletion of Vpr does not significantly affect viral fitness. However, Vpr is critical for virus replication in primary macrophages and for viral pathogenesis in vivo. It is generally accepted that Vpr does not have a specific enzymatic activity but functions as a molecular adapter to modulate viral or cellular processes for the benefit of the virus. Indeed, many Vpr interacting factors have been described by now, and the goal of this review is to summarize our current knowledge of cellular proteins targeted by Vpr.
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8
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Wanjalla CN, McDonnell WJ, Koethe JR. Adipose Tissue T Cells in HIV/SIV Infection. Front Immunol 2018; 9:2730. [PMID: 30559739 PMCID: PMC6286992 DOI: 10.3389/fimmu.2018.02730] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/10/2018] [Accepted: 11/05/2018] [Indexed: 12/12/2022] Open
Abstract
Adipose tissue comprises one of the largest organs in the body and performs diverse functions including energy storage and release, regulation of appetite and other neuroendocrine signaling, and modulation of immuity, among others. Adipocytes reside in a complex compartment where antigen, antigen presenting cells, innate immune cells, and adaptive immune cells interact locally and exert systemic effects on inflammation, circulating immune cell profiles, and metabolic homeostasis. T lymphocytes are a major component of the adipose tissue milieu which are altered in disease states such as obesity and human immunodeficiency virus (HIV) infection. While obesity, HIV infection, and simian immunodeficiency virus (SIV; a non-human primate virus similar to HIV) infection are accompanied by enrichment of CD8+ T cells in the adipose tissue, major phenotypic differences in CD4+ T cells and other immune cell populations distinguish HIV/SIV infection from obesity. Furthermore, DNA and RNA species of HIV and SIV can be detected in the stromal vascular fraction of visceral and subcutaneous adipose tissue, and replication-competent HIV resides in local CD4+ T cells. Here, we review studies of adipose tissue CD4+ and CD8+ T cell populations in HIV and SIV, and contrast the findings with those reported in obesity.
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Affiliation(s)
- Celestine N Wanjalla
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States.,Center for Translational Immunology and Infectious Disease, Vanderbilt University Medical Center, Nashville, TN, United States
| | - Wyatt J McDonnell
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States.,Center for Translational Immunology and Infectious Disease, Vanderbilt University Medical Center, Nashville, TN, United States.,Department of Pathology, Microbiology, and Immunology, Vanderbilt University, Nashville, TN, United States
| | - John R Koethe
- Division of Infectious Diseases, Department of Medicine, Vanderbilt University Medical Center, Nashville, TN, United States.,Center for Translational Immunology and Infectious Disease, Vanderbilt University Medical Center, Nashville, TN, United States
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Takashina T, Koyama T, Nohara S, Hasegawa M, Ishiguro A, Iijima K, Lu J, Shimura M, Okamura T, Sakuma T, Yamamoto T, Ishizaka Y. Identification of a cell-penetrating peptide applicable to a protein-based transcription activator-like effector expression system for cell engineering. Biomaterials 2018; 173:11-21. [PMID: 29734017 DOI: 10.1016/j.biomaterials.2018.04.040] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Accepted: 04/21/2018] [Indexed: 02/08/2023]
Abstract
Cellular reprogramming is a promising technology in regenerative medicine, but most studies have been performed by using expression vectors. For future clinical applications, it is necessary to establish a system in which cell engineering can be manipulated without any risk of damaging the genome. Here, we identified a cell-penetrating peptide composed of 10 amino acids (RIFIHFRIGC) with nuclear trafficking activity and found that it was significantly more potent than a Tat-derived peptide or polyarginine peptide (R11). We named the peptide "nuclear trafficking peptide" (NTP) and applied it to a protein-based artificial transcription factor (NTP-ATF), which was composed of a transcription activator-like effector and transcription domain (VP64). An NTP-ATF designed to the proximal promoter region of the microRNA-302/367 cluster efficiently induced endogenous RNA expression at an extremely low concentration (0.25 nM), and repetitive treatment of mouse embryonic fibroblasts with NTP-ATF generated induced pluripotent stem-like cells, which gave chimeric mice. Together with the observation that recombinant NTP-ATF protein did not induce any apparent cytotoxicity, we propose that NTP-ATF is a promising system for cellular reprogramming applicable to regenerative medicine.
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Affiliation(s)
- Tomoki Takashina
- Department of Intractable Diseases, National Center for Global Health and Medicine, Toyama 1-21-1, Shinjuku-ku, Tokyo 162-8655, Japan
| | - Takayoshi Koyama
- Department of Intractable Diseases, National Center for Global Health and Medicine, Toyama 1-21-1, Shinjuku-ku, Tokyo 162-8655, Japan
| | - Satoshi Nohara
- Nagoya Research Laboratory, Meito Sangyo Co., Ltd., 25-5 Kaechi, Nishibiwajima, Kiyosu, Aichi, 452-0067, Japan
| | - Masakatsu Hasegawa
- Nagoya Research Laboratory, Meito Sangyo Co., Ltd., 25-5 Kaechi, Nishibiwajima, Kiyosu, Aichi, 452-0067, Japan
| | - Akira Ishiguro
- Department of Intractable Diseases, National Center for Global Health and Medicine, Toyama 1-21-1, Shinjuku-ku, Tokyo 162-8655, Japan
| | - Kenta Iijima
- Department of Intractable Diseases, National Center for Global Health and Medicine, Toyama 1-21-1, Shinjuku-ku, Tokyo 162-8655, Japan
| | - Jun Lu
- Department of Intractable Diseases, National Center for Global Health and Medicine, Toyama 1-21-1, Shinjuku-ku, Tokyo 162-8655, Japan
| | - Mari Shimura
- Department of Intractable Diseases, National Center for Global Health and Medicine, Toyama 1-21-1, Shinjuku-ku, Tokyo 162-8655, Japan
| | - Tadashi Okamura
- Section of Animal Models, Department of Infectious Diseases, National Center for Global Health and Medicine, Toyama 1-21-1, Shinjuku-ku, Tokyo 162-8655, Japan
| | - Tetsushi Sakuma
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Takashi Yamamoto
- Department of Mathematical and Life Sciences, Graduate School of Science, Hiroshima University, 1-3-1 Kagamiyama, Higashi-Hiroshima, Hiroshima 739-8526, Japan
| | - Yukihito Ishizaka
- Department of Intractable Diseases, National Center for Global Health and Medicine, Toyama 1-21-1, Shinjuku-ku, Tokyo 162-8655, Japan.
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10
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HIV-1 viral protein R (Vpr) induces fatty liver in mice via LXRα and PPARα dysregulation: implications for HIV-specific pathogenesis of NAFLD. Sci Rep 2017; 7:13362. [PMID: 29042644 PMCID: PMC5645472 DOI: 10.1038/s41598-017-13835-w] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2017] [Accepted: 10/02/2017] [Indexed: 12/18/2022] Open
Abstract
HIV patients develop hepatic steatosis. We investigated hepatic steatosis in transgenic mice expressing the HIV-1 accessory protein Vpr (Vpr-Tg) in liver and adipose tissues, and WT mice infused with synthetic Vpr. Vpr-Tg mice developed increased liver triglyceride content and elevated ALT, bilirubin and alkaline phosphatase due to three hepatic defects: 1.6-fold accelerated de novo lipogenesis (DNL), 45% slower fatty acid ß-oxidation, and 40% decreased VLDL-triglyceride export. Accelerated hepatic DNL was due to coactivation by Vpr of liver X receptor-α (LXRα) with increased expression of its lipogenic targets Srebp1c, Chrebp, Lpk, Dgat, Fasn and Scd1, and intranuclear SREBP1c and ChREBP. Vpr enhanced association of LXRα with Lxrα and Srebp1c promoters, increased LXRE-LXRα binding, and broadly altered hepatic expression of LXRα-regulated lipid metabolic genes. Diminished hepatic fatty acid ß-oxidation was associated with decreased mRNA expression of Pparα and its targets Cpt1, Aox, Lcad, Ehhadh, Hsd10 and Acaa2, and blunted VLDL export with decreased expression of Mttp and its product microsomal triglyceride transfer protein. With our previous findings that Vpr circulates in HIV patients (including those with undetectable plasma HIV-1 RNA), co-regulates the glucocorticoid receptor and PPARγ and transduces hepatocytes, these data indicate a potential role for Vpr in HIV-associated fatty liver disease.
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11
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Abstract
HIV infection and antiretroviral therapy (ART) treatment exert diverse effects on adipocytes and stromal-vascular fraction cells, leading to changes in adipose tissue quantity, distribution, and energy storage. A HIV-associated lipodystrophic condition was recognized early in the epidemic, characterized by clinically apparent changes in subcutaneous, visceral, and dorsocervical adipose depots. Underlying these changes is altered adipose tissue morphology and expression of genes central to adipocyte maturation, regulation, metabolism, and cytokine signaling. HIV viral proteins persist in circulation and locally within adipose tissue despite suppression of plasma viremia on ART, and exposure to these proteins impairs preadipocyte maturation and reduces adipocyte expression of peroxisome proliferator-activated receptor gamma (PPAR-γ) and other genes involved in cell regulation. Several early nucleoside reverse transcriptase inhibitor and protease inhibitor antiretroviral drugs demonstrated substantial adipocyte toxicity, including reduced mitochondrial DNA content and respiratory chain enzymes, reduced PPAR-γ and other regulatory gene expression, and increased proinflammatory cytokine production. Newer-generation agents, such as integrase inhibitors, appear to have fewer adverse effects. HIV infection also alters the balance of CD4+ and CD8+ T cells in adipose tissue, with effects on macrophage activation and local inflammation, while the presence of latently infected CD4+ T cells in adipose tissue may constitute a protected viral reservoir. This review provides a synthesis of the literature on how HIV virus, ART treatment, and host characteristics interact to affect adipose tissue distribution, immunology, and contribution to metabolic health, and adipocyte maturation, cellular regulation, and energy storage. © 2017 American Physiological Society. Compr Physiol 7:1339-1357, 2017.
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Affiliation(s)
- John R Koethe
- Division of Infectious Diseases, Vanderbilt University School of Medicine, Nashville, Tennessee, USA
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12
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HIV-1 Vpr Inhibits Kaposi's Sarcoma-Associated Herpesvirus Lytic Replication by Inducing MicroRNA miR-942-5p and Activating NF-κB Signaling. J Virol 2016; 90:8739-53. [PMID: 27440900 DOI: 10.1128/jvi.00797-16] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/22/2016] [Accepted: 07/15/2016] [Indexed: 12/18/2022] Open
Abstract
UNLABELLED Kaposi's sarcoma-associated herpesvirus (KSHV) infection is required for the development of several AIDS-related malignancies, including Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL). The high incidence of AIDS-KS has been ascribed to the interaction of KSHV and HIV-1. We have previously shown that HIV-1-secreted proteins Tat and Nef regulate the KSHV life cycle and synergize with KSHV oncogenes to promote angiogenesis and tumorigenesis. Here, we examined the regulation of KSHV latency by HIV-1 viral protein R (Vpr). We found that soluble Vpr inhibits the expression of KSHV lytic transcripts and proteins, as well as viral particle production by activating NF-κB signaling following internalization into PEL cells. By analyzing the expression profiles of microRNAs combined with target search by bioinformatics and luciferase reporter analyses, we identified a Vpr-upregulated cellular microRNA (miRNA), miR-942-5p, that directly targeted IκBα. Suppression of miR-942-5p relieved the expression of IκBα and reduced Vpr inhibition of KSHV lytic replication, while overexpression of miR-942-5p enhanced Vpr inhibition of KSHV lytic replication. Our findings collectively illustrate that, by activating NF-κB signaling through upregulating a cellular miRNA to target IκBα, internalized HIV-1 Vpr inhibits KSHV lytic replication. These results have demonstrated an essential role of Vpr in the life cycle of KSHV. IMPORTANCE Coinfection by HIV-1 promotes the aggressive growth of Kaposi's sarcoma-associated herpesvirus (KSHV)-related malignancies, including Kaposi's sarcoma (KS) and primary effusion lymphoma (PEL). In this study, we have shown that soluble HIV-1 Vpr inhibits KSHV lytic replication by activating NF-κB signaling following internalization into PEL cells. Mechanistic studies revealed that a cellular microRNA upregulated by Vpr, miR-942-5p, directly targeted IκBα. Suppression of miR-942-5p relieved IκBα expression and reduced Vpr inhibition of KSHV replication, while overexpression of miR-942-5p enhanced Vpr inhibition of KSHV replication. These results indicate that by activating NF-κB signaling through upregulating a cellular miRNA to target IκBα, internalized Vpr inhibits KSHV lytic replication. This work illustrates a molecular mechanism by which HIV-1-secreted regulatory protein Vpr regulates KSHV latency and the pathogenesis of AIDS-related malignancies.
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Dampier W, Antell GC, Aiamkitsumrit B, Nonnemacher MR, Jacobson JM, Pirrone V, Zhong W, Kercher K, Passic S, Williams JW, James T, Devlin KN, Giovannetti T, Libon DJ, Szep Z, Ehrlich GD, Wigdahl B, Krebs FC. Specific amino acids in HIV-1 Vpr are significantly associated with differences in patient neurocognitive status. J Neurovirol 2016; 23:113-124. [PMID: 27400931 DOI: 10.1007/s13365-016-0462-3] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2016] [Revised: 06/05/2016] [Accepted: 06/09/2016] [Indexed: 11/26/2022]
Abstract
Even in the era of combination antiretroviral therapies used to combat human immunodeficiency virus type 1 (HIV-1) infection, up to 50 % of well-suppressed HIV-1-infected patients are still diagnosed with mild neurological deficits referred to as HIV-associated neurocognitive disorders (HAND). The multifactorial nature of HAND likely involves the HIV-1 accessory protein viral protein R (Vpr) as an agent of neuropathogenesis. To investigate the effect of naturally occurring variations in Vpr on HAND in well-suppressed HIV-1-infected patients, bioinformatic analyses were used to correlate peripheral blood-derived Vpr sequences with patient neurocognitive performance, as measured by comprehensive neuropsychological assessment and the resulting Global Deficit Score (GDS). Our studies revealed unique associations between GDS and the presence of specific amino acid changes in peripheral blood-derived Vpr sequences [neuropsychological impairment Vpr (niVpr) variants]. Amino acids N41 and A55 in the Vpr sequence were associated with more pronounced neurocognitive deficits (higher GDS). In contrast, amino acids I37 and S41 were connected to measurably lower GDS. All niVpr variants were also detected in DNA isolated from HIV-1-infected brain tissues. The implication of these results is that niVpr variants alter the genesis and/or progression of HAND through differences in Vpr-mediated effects in the peripheral blood and/or the brain.
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Affiliation(s)
- Will Dampier
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
- School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Gregory C Antell
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
- School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, PA, USA
| | - Benjamas Aiamkitsumrit
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Michael R Nonnemacher
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Jeffrey M Jacobson
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Department of Medicine, Division of Infectious Diseases and HIV Medicine, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Clinical and Translational Medicine, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
- Department of Medicine, Section of Infectious Disease, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, USA
| | - Vanessa Pirrone
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Wen Zhong
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Katherine Kercher
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Shendra Passic
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Jean W Williams
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Tony James
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Kathryn N Devlin
- Department of Psychology, Temple University, Philadelphia, PA, USA
| | | | - David J Libon
- Department of Geriatrics and Gerontology, New Jersey Institute for Successful Aging, School of Osteopathic Medicine, Rowan University, Stratford, NJ, USA
| | - Zsofia Szep
- Department of Medicine, Division of Infectious Diseases and HIV Medicine, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Garth D Ehrlich
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Genomic Sciences, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Advanced Microbial Processing, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
| | - Brian Wigdahl
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA
- Sidney Kimmel Cancer Center, Thomas Jefferson University, Philadelphia, PA, USA
| | - Fred C Krebs
- Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, PA, USA.
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, Philadelphia, PA, USA.
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14
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Soares R, Rocha G, Meliço-Silvestre A, Gonçalves T. HIV1-viral protein R (Vpr) mutations: associated phenotypes and relevance for clinical pathologies. Rev Med Virol 2016; 26:314-29. [DOI: 10.1002/rmv.1889] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/08/2015] [Revised: 04/11/2016] [Accepted: 04/13/2016] [Indexed: 11/08/2022]
Affiliation(s)
- Rui Soares
- FMUC-Faculdade de Medicina; Universidade de Coimbra; Coimbra Portugal
- CNC-Centro de Neurociências e Biologia Celular; Universidade de Coimbra; Coimbra Portugal
- IPO-Instituto Português de Oncologia Francisco Gentil; Coimbra Portugal
| | - Graça Rocha
- FMUC-Faculdade de Medicina; Universidade de Coimbra; Coimbra Portugal
- Departamento de Doenças Infeciosas Hospital Pediátrico de Coimbra; CHUC-Centro Hospitalar e Universitário de Coimbra; Coimbra Portugal
| | - António Meliço-Silvestre
- FMUC-Faculdade de Medicina; Universidade de Coimbra; Coimbra Portugal
- Departamento de Doenças Infeciosas; CHUC - Centro Hospitalar e Universitário de Coimbra; Coimbra Portugal
| | - Teresa Gonçalves
- FMUC-Faculdade de Medicina; Universidade de Coimbra; Coimbra Portugal
- CNC-Centro de Neurociências e Biologia Celular; Universidade de Coimbra; Coimbra Portugal
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Saxena M, Busca A, Holcik M, Kumar A. Bacterial DNA Protects Monocytic Cells against HIV-Vpr-Induced Mitochondrial Membrane Depolarization. THE JOURNAL OF IMMUNOLOGY 2016; 196:3754-67. [PMID: 26969755 DOI: 10.4049/jimmunol.1402379] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/19/2014] [Accepted: 02/19/2016] [Indexed: 12/26/2022]
Abstract
Monocytes and macrophages are important HIV reservoirs, as they exhibit marked resistance to apoptosis upon infection. However, the mechanism underlying resistance to apoptosis in these cells is poorly understood. Using HIV-viral protein R-52-96 aa peptide (Vpr), we show that primary monocytes and THP-1 cells treated with Vpr are highly susceptible to mitochondrial depolarization, but develop resistance following stimulation with bacterial DNA or CpG oligodeoxynucleotide. We have shown that Vpr-induced mitochondrial depolarization is mediated by TNFR-associated factor-1 (TRAF-1) and TRAF-2 degradation and subsequent activation of caspase-8, Bid, and Bax. To provide the mechanism governing such resistance to mitochondrial depolarization, our results show that prior stimulation with CpG oligodeoxynucleotide or Escherichia coli DNA prevented: 1) TRAF-1/2 downregulation; 2) activation of caspase-8, Bid, and Bax; and 3) subsequent mitochondrial depolarization and release of apoptosis-inducing factor and cytochrome c Furthermore, this protection was mediated by upregulation of antiapoptotic protein (c-IAP-2) through calmodulin-dependent kinase-II activation. Thus, c-IAP-2 may prevent Vpr-mediated mitochondrial depolarization through stabilizing TRAF-1/2 expression and sequential inhibition of caspase-8, Bid, and Bax.
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Affiliation(s)
- Mansi Saxena
- Department of Biochemistry, Microbiology and Immunology, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
| | - Aurelia Busca
- Department of Biochemistry, Microbiology and Immunology, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
| | - Martin Holcik
- Research Institute, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada; and
| | - Ashok Kumar
- Department of Biochemistry, Microbiology and Immunology, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada; Research Institute, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada; and Department of Pathology and Laboratory Medicine, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
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16
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Faust O, Bigman L, Friedler A. A role of disordered domains in regulating protein oligomerization and stability. Chem Commun (Camb) 2015; 50:10797-800. [PMID: 25054624 DOI: 10.1039/c4cc03863k] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Intrinsically disordered proteins (IDPs) or regions (IDRs) in proteins hold many functions but their biological roles are still not fully understood. Here we describe a new role of such regions. Using the HIV-1 Rev protein, we show that disordered domains have a role in maintaining the correct oligomeric state and the thermodynamic stability of proteins.
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Affiliation(s)
- Ofrah Faust
- Institute of Chemistry, The Hebrew University of Jerusalem, The Edmond J. Safra Campus, Givat Ram 91904, Jerusalem, Israel.
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17
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Richert L, Didier P, de Rocquigny H, Mély Y. Monitoring HIV-1 Protein Oligomerization by FLIM FRET Microscopy. SPRINGER SERIES IN CHEMICAL PHYSICS 2015. [DOI: 10.1007/978-3-319-14929-5_8] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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18
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Soares R, Rocha G, Nogueira C, Meliço-Silvestre A, Gonçalves T. R77Q and Q3R HIV1-VPR mutations in an otherwise asymptomatic 5-year-old child with repeated ear infections. JMM Case Rep 2014; 1:e002709. [PMID: 28663807 PMCID: PMC5415930 DOI: 10.1099/jmmcr.0.002709] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2014] [Accepted: 09/26/2014] [Indexed: 11/18/2022] Open
Abstract
INTRODUCTION Viral protein R (Vpr) of human immunodeficiency virus type 1 (HIV-1) has been described as being involved in the progression of AIDS, and specific mutations are associated with long-term non-progressor patients. CASE PRESENTATION We describe the case of a child with repeated ear infections who was otherwise healthy. The patient, a 5-year-old boy, was HIV-1 positive and the viral load at admission was 1 073 899 RNA copies ml-1 and 0 % CD4+ lymphocytes. A detailed study of the vpr gene sequence of the child revealed mutations leading to amino acid substitutions at positions 3 and 77. CONCLUSION The case reported provides clinical support of previous findings that show that the R77Q and Q3R HIV-1 Vpr variants are associated with patients with delayed disease progression.
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Affiliation(s)
- Rui Soares
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
| | - Graça Rocha
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Hospital Pediátrico de Coimbra, Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Célia Nogueira
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal
| | - António Meliço-Silvestre
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Centro Hospitalar e Universitário de Coimbra, Coimbra, Portugal
| | - Teresa Gonçalves
- Faculty of Medicine, University of Coimbra, Coimbra, Portugal.,Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
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19
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Choi SB, Choong YS, Saito A, Wahab HA, Najimudin N, Watanabe N, Osada H, Ong EBB. In Silico Investigation of a HIV-1 Vpr Inhibitor Binding Site: Potential for Virtual Screening and anti-HIV Drug Design. Mol Inform 2014; 33:742-8. [DOI: 10.1002/minf.201400080] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2014] [Accepted: 10/15/2014] [Indexed: 11/06/2022]
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20
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Mutation of the highly conserved Ser-40 of the HIV-1 p6 gag protein to Phe causes the formation of a hydrophobic patch, enhances membrane association, and polyubiquitination of Gag. Viruses 2014; 6:3738-65. [PMID: 25279819 PMCID: PMC4213559 DOI: 10.3390/v6103738] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/06/2014] [Revised: 09/19/2014] [Accepted: 09/26/2014] [Indexed: 01/04/2023] Open
Abstract
The HIV-1 p6 Gag protein contains two late assembly (l-) domains that recruit proteins of the endosomal sorting complex required for transport (ESCRT) pathway to mediate membrane fission between the nascent virion and the cell membrane. It was recently demonstrated that mutation of the highly conserved Ser-40 to Phe (S40F) disturbs CA-SP1 processing, virus morphogenesis, and infectivity. It also causes the formation of filopodia-like structures, while virus release remains unaffected. Here, we show that the mutation S40F, but not the conservative mutation to Asp (S40D) or Asn (S40N), augments membrane association, K48-linked polyubiquitination, entry into the 26S proteasome, and, consequently, enhances MHC-I antigen presentation of Gag derived epitopes. Nuclear magnetic resonance (NMR) structure analyses revealed that the newly introduced Phe-40, together with Tyr-36, causes the formation of a hydrophobic patch at the C-terminal α-helix of p6, providing a molecular rationale for the enhanced membrane association of Gag observed in vitro and in HIV-1 expressing cells. The extended exposure of the S40F mutant to unidentified membrane-resident ubiquitin E3-ligases might trigger the polyubiquitination of Gag. The cumulative data support a previous model of a so far undefined property of p6, which, in addition to MA, acts as membrane targeting domain of Gag.
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Agarwal N, Iyer D, Patel SG, Sekhar RV, Phillips TM, Schubert U, Oplt T, Buras ED, Samson SL, Couturier J, Lewis DE, Rodriguez-Barradas MC, Jahoor F, Kino T, Kopp JB, Balasubramanyam A. HIV-1 Vpr induces adipose dysfunction in vivo through reciprocal effects on PPAR/GR co-regulation. Sci Transl Med 2014; 5:213ra164. [PMID: 24285483 DOI: 10.1126/scitranslmed.3007148] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Viral infections, such as HIV, have been linked to obesity, but mechanistic evidence that they cause adipose dysfunction in vivo is lacking. We investigated a pathogenic role for the HIV-1 accessory protein viral protein R (Vpr), which can coactivate the glucocorticoid receptor (GR) and co-repress peroxisome proliferator-activated receptor γ (PPARγ) in vitro, in HIV-associated adipose dysfunction. Vpr circulated in the blood of most HIV-infected patients tested, including those on antiretroviral therapy (ART) with undetectable viral load. Vpr-mediated mechanisms were dissected in vivo using mouse models expressing the Vpr transgene in adipose tissues and liver (Vpr-Tg) or infused with synthetic Vpr. Both models demonstrated accelerated whole-body lipolysis, hyperglycemia and hypertriglyceridemia, and tissue-specific findings. Fat depots in these mice had diminished mass, macrophage infiltration, and blunted PPARγ target gene expression but increased GR target gene expression. In liver, we observed blunted PPARα target gene expression, steatosis with decreased adenosine monophosphate-activated protein kinase activity, and insulin resistance. Similar to human HIV-infected patients, Vpr circulated in the serum of Vpr-Tg mice. Vpr blocked differentiation in preadipocytes through cell cycle arrest, whereas in mature adipocytes, it increased lipolysis with reciprocally altered association of PPARγ and GR with their target promoters. These results delineate a distinct pathogenic sequence: Vpr, released from HIV-1 in tissue reservoirs after ART, can disrupt PPAR/GR co-regulation and cell cycle control to produce adipose dysfunction and hepatosteatosis. Confirmation of these mechanisms in HIV patients could lead to targeted treatment of the metabolic complications with Vpr inhibitors, GR antagonists, or PPARγ/PPARα agonists.
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Affiliation(s)
- Neeti Agarwal
- Translational Metabolism Unit, Diabetes Research Center, Division of Diabetes, Endocrinology and Metabolism, Baylor College of Medicine, Houston, TX 77030, USA
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22
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Xue B, Blocquel D, Habchi J, Uversky AV, Kurgan L, Uversky VN, Longhi S. Structural disorder in viral proteins. Chem Rev 2014; 114:6880-911. [PMID: 24823319 DOI: 10.1021/cr4005692] [Citation(s) in RCA: 140] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Affiliation(s)
- Bin Xue
- Department of Cell Biology, Microbiology and Molecular Biology, College of Fine Arts and Sciences, and ‡Department of Molecular Medicine and USF Health Byrd Alzheimer's Research Institute, Morsani College of Medicine, University of South Florida , Tampa, Florida 33620, United States
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23
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Shrivastav S, Zhang L, Okamoto K, Lee H, Lagranha C, Abe Y, Balasubramanyam A, Lopaschuk GD, Kino T, Kopp JB. HIV-1 Vpr enhances PPARβ/δ-mediated transcription, increases PDK4 expression, and reduces PDC activity. Mol Endocrinol 2013; 27:1564-76. [PMID: 23842279 DOI: 10.1210/me.2012-1370] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
HIV infection and its therapy are associated with disorders of lipid metabolism and bioenergetics. Previous work has suggested that viral protein R (Vpr) may contribute to the development of lipodystrophy and insulin resistance observed in HIV-1-infected patients. In adipocytes, Vpr suppresses mRNA expression of peroxisomal proliferator-activating receptor-γ (PPARγ)-responsive genes and inhibits differentiation. We investigated whether Vpr might interact with PPARβ/δ and influence its transcriptional activity. In the presence of PPARβ/δ, Vpr induced a 3.3-fold increase in PPAR response element-driven transcriptional activity, a 1.9-fold increase in pyruvate dehydrogenase kinase 4 (PDK4) protein expression, and a 1.6-fold increase in the phosphorylated pyruvate dehydrogenase subunit E1α leading to a 47% decrease in the activity of the pyruvate dehydrogenase complex in HepG2 cells. PPARβ/δ knockdown attenuated Vpr-induced enhancement of endogenous PPARβ/δ-responsive PDK4 mRNA expression. Vpr induced a 1.3-fold increase in mRNA expression of both carnitine palmitoyltransferase I (CPT1) and acetyl-coenzyme A acyltransferase 2 (ACAA2) and doubled the activity of β-hydroxylacyl coenzyme A dehydrogenase (HADH). Vpr physically interacted with the ligand-binding domain of PPARβ/δ in vitro and in vivo. Consistent with a role in energy expenditure, Vpr increased state-3 respiration in isolated mitochondria (1.16-fold) and basal oxygen consumption rate in intact HepG2 cells (1.2-fold) in an etomoxir-sensitive manner, indicating that the oxygen consumption rate increase is β-oxidation-dependent. The effects of Vpr on PPAR response element activation, pyruvate dehydrogenase complex activity, and β-oxidation were reversed by specific PPARβ/δ antagonists. These results support the hypothesis that Vpr contributes to impaired energy metabolism and increased energy expenditure in HIV patients.
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Affiliation(s)
- Shashi Shrivastav
- Kidney Disease Section, National Institute of Diabetes and Digestive andKidney Diseases, National Institutes of Health,Bethesda, Maryland 20892-1268, USA
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24
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Tomasicchio M, Avenant C, Du Toit A, Ray RM, Hapgood JP. The progestin-only contraceptive medroxyprogesterone acetate, but not norethisterone acetate, enhances HIV-1 Vpr-mediated apoptosis in human CD4+ T cells through the glucocorticoid receptor. PLoS One 2013; 8:e62895. [PMID: 23658782 PMCID: PMC3643923 DOI: 10.1371/journal.pone.0062895] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2012] [Accepted: 03/26/2013] [Indexed: 12/25/2022] Open
Abstract
The glucocorticoid receptor (GR) regulates several physiological functions, including immune function and apoptosis. The HIV-1 virus accessory protein, viral protein R (Vpr), can modulate the transcriptional response of the GR. Glucocorticoids (GCs) and Vpr have been reported to induce apoptosis in various cells, including T-cells. We have previously shown that the injectable contraceptive, medroxyprogesterone acetate (MPA) is a partial to full agonist for the GR, unlike norethisterone acetate (NET-A). We investigated the functional cross talk between the GR and Vpr in inducing apoptosis in CD4(+) T-cells, in the absence and presence of GCs and these progestins, as well as progesterone. By using flow cytometry, we show that, in contrast to NET-A and progesterone, the synthetic GR ligand dexamethasone (Dex), cortisol and MPA induce apoptosis in primary CD4(+) T-cells. Furthermore, the C-terminal part of the Vpr peptide, or HIV-1 pseudovirus, together with Dex or MPA further increased the apoptotic phenotype, unlike NET-A and progesterone. By a combination of Western blotting, PCR and the use of receptor- selective agonists, we provide evidence that the GR and the estrogen receptor are the only steroid receptors expressed in peripheral blood mononuclear cells. These results, together with the findings that RU486, a GR antagonist, prevents Dex-, MPA- and Vpr-mediated apoptosis, provide evidence for the first time that GR agonists or partial agonists increase apoptosis in primary CD4(+) T-cells via the GR. We show that apoptotic induction involves differential expression of key apoptotic genes by both Vpr and GCs/MPA. This work suggests that contraceptive doses of MPA but not NET-A or physiological doses of progesterone could potentially accelerate depletion of CD4(+) T-cells in a GR-dependent fashion in HIV-1 positive women, thereby contributing to immunodeficiency. The results imply that choice of progestin used in contraception may be critical to susceptibility and progression of diseases such as HIV-1.
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Affiliation(s)
- Michele Tomasicchio
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, Western Province, South Africa
| | - Chanel Avenant
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, Western Province, South Africa
| | - Andrea Du Toit
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, Western Province, South Africa
| | - Roslyn M. Ray
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, Western Province, South Africa
| | - Janet P. Hapgood
- Department of Molecular and Cell Biology, University of Cape Town, Cape Town, Western Province, South Africa
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25
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Solbak SMØ, Reksten TR, Hahn F, Wray V, Henklein P, Henklein P, Halskau Ø, Schubert U, Fossen T. HIV-1 p6 - a structured to flexible multifunctional membrane-interacting protein. BIOCHIMICA ET BIOPHYSICA ACTA-BIOMEMBRANES 2012; 1828:816-23. [PMID: 23174350 DOI: 10.1016/j.bbamem.2012.11.010] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/15/2012] [Revised: 10/30/2012] [Accepted: 11/06/2012] [Indexed: 02/02/2023]
Abstract
The human immunodeficiency virus type 1 (HIV-1) p6 protein has recently been recognized as a docking site for several cellular and viral binding partners and is important for the formation of infectious viruses. Most of its known functions are suggested to occur under hydrophobic conditions near the cytoplasmic membrane, where the protein is presumed to exist in its most structured state. Although p6 is involved in manifold specific interactions, the protein has previously been considered to possess a random structure in aqueous solution. We show that p6 exhibits a defined structure with N- and C-terminal helical domains, connected by a flexible hinge region in 100mM dodecylphosphocholine micelle solution at pH 7 devoid of any organic co-solvents, indicating that this is a genuine limiting structural feature of the molecule in a hydrophobic environment. Furthermore, we show that p6 directly interacts with a cytoplasmic model membrane through both N-terminal and C-terminal regions by use of surface plasmon resonance (SPR) spectroscopy. Phosphorylation of Ser-40 located in the center of the C-terminal α-helix does not alter the secondary structure of the protein but amplifies the interaction with membranes significantly, indicating that p6 binds to the polar head groups at the surface of the cytoplasmic membrane. The increased hydrophobic membrane interaction of p6(23-52) S40F correlated with the observed increased amount of the polyprotein Gag in the RIPA insoluble fraction when Ser40 of p6 was mutated with Phe indicating that p6 modulates the membrane interactions of HIV-1 Gag.
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Affiliation(s)
- Sara Marie Øie Solbak
- Department of Chemistry and Centre for Pharmacy, University of Bergen, N-5007 Bergen, Norway
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Sörgel S, Fraedrich K, Votteler J, Thomas M, Stamminger T, Schubert U. Perinuclear localization of the HIV-1 regulatory protein Vpr is important for induction of G2-arrest. Virology 2012; 432:444-51. [PMID: 22832123 DOI: 10.1016/j.virol.2012.06.027] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/22/2012] [Revised: 04/07/2012] [Accepted: 06/21/2012] [Indexed: 11/30/2022]
Abstract
The HIV-1 accessory protein Vpr induces G2 cell cycle arrest and apoptosis. Previous studies indicate that the induction of G2-arrest requires the localization of Vpr to the nuclear envelope. Here we show that treatment of Vpr-expressing HeLa cells with the caspase 3 inhibitor Z-DEVD-fmk induced accumulation of Vpr at the nuclear lamina, while other proteins or structures of the nuclear envelope were not influenced. Furthermore, Z-DEVD-fmk enhances the Vpr-mediated G2-arrest that even occurred in HIV-1(NL4-3)-infected T-cells. Mutation of Pro-35, which is important for the integrity of helix-α1 in Vpr, completely abrogated the Z-DEVD-fmk-mediated accumulation of Vpr at the nuclear lamina and the enhancement of G2-arrest. As expected, inhibition of caspase 3 reduced the induction of apoptosis by Vpr. Taken together, we could show that besides its role in Vpr-mediated apoptosis induction caspase 3 influences the localization of Vpr at the nuclear envelope and thereby augments the Vpr-induced G2-arrest.
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Affiliation(s)
- Stefan Sörgel
- Institute of Virology, University of Erlangen-Nuremberg, Erlangen 91054, Germany.
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27
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Xue B, Mizianty MJ, Kurgan L, Uversky VN. Protein intrinsic disorder as a flexible armor and a weapon of HIV-1. Cell Mol Life Sci 2012; 69:1211-59. [PMID: 22033837 PMCID: PMC11114566 DOI: 10.1007/s00018-011-0859-3] [Citation(s) in RCA: 84] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2011] [Revised: 09/28/2011] [Accepted: 10/03/2011] [Indexed: 01/19/2023]
Abstract
Many proteins and protein regions are disordered in their native, biologically active states. These proteins/regions are abundant in different organisms and carry out important biological functions that complement the functional repertoire of ordered proteins. Viruses, with their highly compact genomes, small proteomes, and high adaptability for fast change in their biological and physical environment utilize many of the advantages of intrinsic disorder. In fact, viral proteins are generally rich in intrinsic disorder, and intrinsically disordered regions are commonly used by viruses to invade the host organisms, to hijack various host systems, and to help viruses in accommodation to their hostile habitats and to manage their economic usage of genetic material. In this review, we focus on the structural peculiarities of HIV-1 proteins, on the abundance of intrinsic disorder in viral proteins, and on the role of intrinsic disorder in their functions.
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Affiliation(s)
- Bin Xue
- Department of Molecular Medicine, University of South Florida, College of Medicine, 12901 Bruce B. Downs Blvd, MDC07, Tampa, FL 33612 USA
| | - Marcin J. Mizianty
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 2V4 Canada
| | - Lukasz Kurgan
- Department of Electrical and Computer Engineering, University of Alberta, Edmonton, AB T6G 2V4 Canada
| | - Vladimir N. Uversky
- Department of Molecular Medicine, University of South Florida, College of Medicine, 12901 Bruce B. Downs Blvd, MDC07, Tampa, FL 33612 USA
- Institute for Biological Instrumentation, Russian Academy of Sciences, 142290 Pushchino, Moscow Region Russia
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28
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Busca A, Saxena M, Kumar A. Critical role for antiapoptotic Bcl-xL and Mcl-1 in human macrophage survival and cellular IAP1/2 (cIAP1/2) in resistance to HIV-Vpr-induced apoptosis. J Biol Chem 2012; 287:15118-33. [PMID: 22403404 DOI: 10.1074/jbc.m111.312660] [Citation(s) in RCA: 64] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
Macrophages are resistant to HIV cytopathic effects, which contributes to viral persistence and reservoir formation. HIV viral protein R (Vpr) is a potent apoptosis-inducing agent for primary monocytes. Because the biologically active Vpr is found in serum and cerebrospinal fluid of HIV-infected patients, we investigated the apoptotic effect of Vpr on monocyte-derived macrophages and phorbol 12-myristate 13-acetate-activated THP1 macrophages. Our results show that primary monocytes and THP1 cells develop resistance to Vpr-induced apoptosis following differentiation into macrophages. To determine the effect of Vpr on the expression of antiapoptotic proteins, we show that in contrast to the undifferentiated cells, Vpr did not down-regulate the expression of antiapoptotic inhibitors of apoptosis (IAPs) and Bcl2 family members in macrophages, suggesting their involvement in resistance to Vpr-induced apoptosis. However, knocking down Bcl-xL and Mcl-1 proteins induced spontaneous apoptosis with no impact on susceptibility to Vpr-induced apoptosis. In contrast, down-regulation of cellular IAP1 (cIAP1) and cIAP2 by using siRNAs and SMAC (second mitochondria-derived activator of caspases) mimetic sensitized macrophages to Vpr-induced apoptosis. Overall, our results suggest that resistance to Vpr-induced apoptosis is specifically mediated by cIAP1/2 genes independent of Bcl-xL and Mcl-1, which play a key role in maintaining cell viability. Moreover, IAP modulation may be a potential strategy to eliminate HIV persistence in macrophages.
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Affiliation(s)
- Aurelia Busca
- Department of Biochemistry, Microbiology and Immunology, Research Institute, Children's Hospital of Eastern Ontario, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
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Ferrucci A, Nonnemacher MR, Wigdahl B. Human immunodeficiency virus viral protein R as an extracellular protein in neuropathogenesis. Adv Virus Res 2012; 81:165-99. [PMID: 22094081 DOI: 10.1016/b978-0-12-385885-6.00010-9] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Numerous studies published in the past two decades have identified the viral protein R (Vpr) as one of the most versatile proteins in the life cycle of human immunodeficiency virus type 1 (HIV-1). In this regard, more than a thousand Vpr molecules are present in extracellular viral particles. Subsequent to viral entry, Vpr participates in early replicative events by assisting in viral genome nuclear import and, during the viral life cycle, by shuttling between the nucleus and the cytoplasm to accomplish its functions within the context of other replicative functions. Additionally, several studies have implicated Vpr as a proapoptotic protein because it promotes formation of permeability transition pores in mitochondria, which in turn affects transmembrane potential and adenosine triphosphate synthesis. Recent studies have identified Vpr as a virion-free protein in the serum and cerebrospinal fluid of patients infected with HIV-1 whose plasma viremia directly correlates with the extracellular concentration of Vpr. These observations pointed to a new role for Vpr as an additional weapon in the HIV-1 arsenal, involving the use of an extracellular protein to target and possibly inhibit HIV-1-uninfected bystander cells to enable them to escape immune surveillance. In addition, extracellular Vpr decreases adenosine triphosphate levels and affects the intracellular redox balance in neurons, ultimately causing their apoptosis. Herein, we review the role of Vpr as an extracellular protein and its downstream effects on cellular metabolism, functionality, and survival, with particular emphasis on how extracellular Vpr-induced oxidative stress might aggravate HIV-1-induced symptoms, thus affecting pathogenesis and disease progression.
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Affiliation(s)
- Adriano Ferrucci
- School of Biomedical Engineering, Science, and Health Systems, Drexel University, Philadelphia, Pennsylvania, USA
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30
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Solbak SMØ, Reksten TR, Röder R, Wray V, Horvli O, Raae AJ, Henklein P, Henklein P, Fossen T. HIV-1 p6-Another viral interaction partner to the host cellular protein cyclophilin A. BIOCHIMICA ET BIOPHYSICA ACTA-PROTEINS AND PROTEOMICS 2012; 1824:667-78. [PMID: 22342556 DOI: 10.1016/j.bbapap.2012.02.002] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/30/2011] [Revised: 01/12/2012] [Accepted: 02/01/2012] [Indexed: 11/30/2022]
Abstract
The 52-amino acid human immunodeficiency virus type 1 (HIV-1) p6 protein has previously been recognized as a docking site for several cellular and viral binding factors and is important for the formation of infectious viruses. A particular structural feature of p6 is the notably high relative content of proline residues, located at positions 5, 7, 10, 11, 24, 30, 37 and 49 in the sequence. Proline cis/trans isomerism was detected for all these proline residues to such an extent that more than 40% of all p6 molecules contain at least one proline in a cis conformation. 2D (1)H nuclear magnetic resonance analysis of full-length HIV-1 p6 and p6 peptides established that cyclophilin A (CypA) interacts as a peptidyl-prolyl cis/trans isomerase with all proline residues of p6. Only catalytic amounts of CypA were necessary for the interaction with p6 to occur, strongly suggesting that the observed interaction is highly relevant in vivo. In addition, surface plasmon resonance studies revealed binding of full-length p6 to CypA, and that this binding was significantly stronger than any of its N- or C-terminal peptides. This study demonstrates the first identification of an interaction between HIV-1 p6 and the host cellular protein CypA. The mode of interaction involves both transient enzyme-substrate interactions and a more stable binding. The binding motifs of p6 to Tsg-101, ALIX and Vpr coincide with binding regions and catalytic sites of p6 to CypA, suggesting a potential role of CypA in modulating functional interactions of HIV-1.
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Affiliation(s)
- Sara M Ø Solbak
- Department of Chemistry and Centre of Pharmacy, University of Bergen, Bergen, Norway
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31
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Solbak SMØ, Wray V, Horvli O, Raae AJ, Flydal MI, Henklein P, Henklein P, Nimtz M, Schubert U, Fossen T. The host-pathogen interaction of human cyclophilin A and HIV-1 Vpr requires specific N-terminal and novel C-terminal domains. BMC STRUCTURAL BIOLOGY 2011; 11:49. [PMID: 22185200 PMCID: PMC3269379 DOI: 10.1186/1472-6807-11-49] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/01/2011] [Accepted: 12/20/2011] [Indexed: 12/26/2022]
Abstract
BACKGROUND Cyclophilin A (CypA) represents a potential key molecule in future antiretroviral therapy since inhibition of CypA suppresses human immunodeficiency virus type 1 (HIV-1) replication. CypA interacts with the virus proteins Capsid (CA) and Vpr, however, the mechanism through which CypA influences HIV-1 infectivity still remains unclear. RESULTS Here the interaction of full-length HIV-1 Vpr with the host cellular factor CypA has been characterized and quantified by surface plasmon resonance spectroscopy. A C-terminal region of Vpr, comprising the 16 residues 75GCRHSRIGVTRQRRAR90, with high binding affinity for CypA has been identified. This region of Vpr does not contain any proline residues but binds much more strongly to CypA than the previously characterized N-terminal binding domain of Vpr, and is thus the first protein binding domain to CypA described involving no proline residues. The fact that the mutant peptide Vpr75-90 R80A binds more weakly to CypA than the wild-type peptide confirms that Arg-80 is a key residue in the C-terminal binding domain. The N- and C-terminal binding regions of full-length Vpr bind cooperatively to CypA and have allowed a model of the complex to be created. The dissociation constant of full-length Vpr to CypA was determined to be approximately 320 nM, indicating that the binding may be stronger than that of the well characterized interaction of HIV-1 CA with CypA. CONCLUSIONS For the first time the interaction of full-length Vpr and CypA has been characterized and quantified. A non-proline-containing 16-residue region of C-terminal Vpr which binds specifically to CypA with similar high affinity as full-length Vpr has been identified. The fact that this is the first non-proline containing binding motif of any protein found to bind to CypA, changes the view on how CypA is able to interact with other proteins. It is interesting to note that several previously reported key functions of HIV-1 Vpr are associated with the identified N- and C-terminal binding domains of the protein to CypA.
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Affiliation(s)
- Sara M Ø Solbak
- Centre of Pharmacy, University of Bergen, N-5007 Bergen Norway
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32
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Saxena M, Busca A, Pandey S, Kryworuchko M, Kumar A. CpG protects human monocytic cells against HIV-Vpr-induced apoptosis by cellular inhibitor of apoptosis-2 through the calcium-activated JNK pathway in a TLR9-independent manner. THE JOURNAL OF IMMUNOLOGY 2011; 187:5865-78. [PMID: 22068233 DOI: 10.4049/jimmunol.1100115] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Monocytic cells survive HIV replication and consequent cytopathic effects because of their decreased sensitivity to HIV-induced apoptosis. However, the mechanism underlying this resistance to apoptosis remains poorly understood. Lymphocytic cells are exposed to microbial products because of their translocation from the gut in persons with chronic HIV infections or following coinfections. We hypothesized that activation of monocytic cells by such microbial products through interaction with corresponding TLRs may confer antiapoptotic signals. Using HIV-viral protein R (Vpr)(52-96) peptide as a model apoptosis-inducing agent, we demonstrated that unlike monocyte-derived macrophages, undifferentiated primary human monocytes and promonocytic THP-1 cells are highly susceptible to Vpr(52-96)-induced apoptosis. Interestingly, monocytes and THP-1 cells stimulated with TLR9 agonist CpG induced almost complete resistance to Vpr(52-96)-induced apoptosis, albeit through a TLR9-independent signaling pathway. Moreover, CpG selectively induced the antiapoptotic cellular inhibitor of apoptosis (c-IAP)-2 protein and inhibition of the c-IAP-2 gene by either specific small interfering RNA or synthetic second mitochondrial activator of caspases mimetic reversed CpG-induced resistance against Vpr(52-96)-mediated apoptosis. We demonstrated that c-IAP-2 is regulated by the JNK and calcium signaling pathway, in particular calmodulin-dependent protein kinase-II. Furthermore, inhibition of JNK and the calcium signaling including the calmodulin-dependent protein kinase-II by either pharmacological inhibitors or their specific small interfering RNAs reversed CpG-induced protection against Vpr(52-96)-mediated apoptosis. We also show that CpG induced JNK phosphorylation through activation of the calcium signaling pathway. Taken together, our results suggest that CpG-induced protection may be mediated by c-IAP-2 through the calcium-activated JNK pathway via what appeared to be TLR9-independent signaling pathways.
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Affiliation(s)
- Mansi Saxena
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario K1H 8L1, Canada
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Mukerjee R, Chang JR, Del Valle L, Bagashev A, Gayed MM, Lyde RB, Hawkins BJ, Brailoiu E, Cohen E, Power C, Azizi SA, Gelman BB, Sawaya BE. Deregulation of microRNAs by HIV-1 Vpr protein leads to the development of neurocognitive disorders. J Biol Chem 2011; 286:34976-85. [PMID: 21816823 PMCID: PMC3186354 DOI: 10.1074/jbc.m111.241547] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2011] [Revised: 08/02/2011] [Indexed: 12/23/2022] Open
Abstract
Studies have shown that HIV-infected patients develop neurocognitive disorders characterized by neuronal dysfunction. The lack of productive infection of neurons by HIV suggests that viral and cellular proteins, with neurotoxic activities, released from HIV-1-infected target cells can cause this neuronal deregulation. The viral protein R (Vpr), a protein encoded by HIV-1, has been shown to alter the expression of various important cytokines and inflammatory proteins in infected and uninfected cells; however the mechanisms involved remain unclear. Using a human neuronal cell line, we found that Vpr can be taken up by neurons causing: (i) deregulation of calcium homeostasis, (ii) endoplasmic reticulum-calcium release, (iii) activation of the oxidative stress pathway, (iv) mitochondrial dysfunction and v- synaptic retraction. In search for the cellular factors involved, we performed microRNAs and gene array assays using human neurons (primary cultures or cell line, SH-SY5Y) that we treated with recombinant Vpr proteins. Interestingly, Vpr deregulates the levels of several microRNAs (e.g. miR-34a) and their target genes (e.g. CREB), which could lead to neuronal dysfunctions. Therefore, we conclude that Vpr plays a major role in neuronal dysfunction through deregulating microRNAs and their target genes, a phenomenon that could lead to the development of neurocognitive disorders.
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Affiliation(s)
| | | | - Luis Del Valle
- the Department of Medicine, Section of Hematology/Oncology, and Department of Pathology, Stanley S. Scott Cancer Center, Louisiana State University School of Medicine, New Orleans, Louisiana 70112
| | | | | | | | - Brian J. Hawkins
- Anesthesiology and Pain Medicine, Mitochondria and Metabolism Center, University of Washington, Seattle, Washington 98109
| | - Eugen Brailoiu
- Pharmacology, Molecular Studies of Neurodegenerative Diseases Laboratory, Temple University School of Medicine, Philadelphia, Pennsylvania 19140
| | - Eric Cohen
- the Institut de Recherches Cliniques de Montréal (IRCM) and Department of Microbiology and Immunology, Université de Montréal, Quebec, Canada
| | - Chris Power
- the Departments of Medicine (Neurology), Medical Microbiology & Immunology, and Psychiatry, University of Alberta, Edmonton, Alberta T6G 2S2, Canada, and
| | | | - Benjamin B. Gelman
- the Departments of Pathology and Neuroscience & Cell Biology, Texas NeuroAIDS Research Center, University of Texas Medical Branch, Galveston, Texas 77555-0609
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Greiner VJ, Shvadchak V, Fritz J, Arntz Y, Didier P, Frisch B, Boudier C, Mély Y, de Rocquigny H. Characterization of the mechanisms of HIV-1 Vpr(52–96) internalization in cells. Biochimie 2011; 93:1647-58. [DOI: 10.1016/j.biochi.2011.05.033] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2011] [Accepted: 05/31/2011] [Indexed: 02/08/2023]
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35
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Cellular phenotype impacts human immunodeficiency virus type 1 viral protein R subcellular localization. Virol J 2011; 8:397. [PMID: 21831263 PMCID: PMC3168423 DOI: 10.1186/1743-422x-8-397] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2011] [Accepted: 08/10/2011] [Indexed: 01/01/2023] Open
Abstract
Background Human immunodeficiency virus type 1 (HIV-1) viral protein R (Vpr) is a virion-associated regulatory protein that functions at several points within the viral life cycle and has been shown to accumulate primarily in the nucleus and at the nuclear envelope. However, most studies have investigated Vpr localization employing cell types irrelevant to HIV-1 pathogenesis. To gain a better understanding of how cellular phenotype might impact HIV-1 Vpr intracellular localization, Vpr localization was examined in several cell lines representing major cellular targets for HIV-1 infection within the peripheral blood, bone marrow, and central nervous system (CNS). Results Utilizing a green fluorescent protein-tagged Vpr, we detected Vpr mainly in foci inside the nucleus, at the nuclear envelope, and around the nucleoli, with dispersed accumulation in the cytoplasm of human endothelial kidney 293T cells. No differences were observed in Vpr localization pattern with respect to either the location of the tag (N- or C-terminus) or the presence of other viral proteins. Subsequently, the Vpr localization pattern was explored in two primary HIV-1 target cells within the peripheral blood: the CD4+ T lymphocyte (represented by the Jurkat CD4+ T-cell line) and the monocyte-macrophage (represented by the U-937 cell line). Vpr was found primarily in speckles within the cytoplasm of the Jurkat T cells, whereas it accumulated predominantly intranuclearly in U-937 monocytic cells. These patterns differ from that observed in a bone marrow progenitor cell line (TF-1), wherein Vpr localized mainly at the nuclear envelope with some intranuclear punctuate staining. Within the CNS, we examined two astroglioma cell lines and found that Vpr displayed a perinuclear and cytoplasmic distribution. Conclusions The results suggest that the pattern of Vpr localization depends on cellular phenotype, probably owing to interactions between Vpr and cell type-specific host factors. These interactions, in turn, are likely coupled to specific roles that Vpr plays in each cell type within the context of the viral life cycle. Phenotype-specific Vpr localization patterns might also provide an explanation with respect to Vpr secretion or release from HIV-1-infected cells within the peripheral blood and CNS.
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Ong EBB, Watanabe N, Saito A, Futamura Y, Abd El Galil KH, Koito A, Najimudin N, Osada H. Vipirinin, a coumarin-based HIV-1 Vpr inhibitor, interacts with a hydrophobic region of VPR. J Biol Chem 2011; 286:14049-56. [PMID: 21357691 PMCID: PMC3077605 DOI: 10.1074/jbc.m110.185397] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2010] [Revised: 02/27/2011] [Indexed: 11/06/2022] Open
Abstract
The human immunodeficiency virus 1 (HIV-1) viral protein R (Vpr) is an accessory protein that has been shown to have multiple roles in HIV-1 pathogenesis. By screening chemical libraries in the RIKEN Natural Products Depository, we identified a 3-phenyl coumarin-based compound that inhibited the cell cycle arrest activity of Vpr in yeast and Vpr-dependent viral infection of human macrophages. We determined its minimal pharmacophore through a structure-activity relationship study and produced more potent derivatives. We detected direct binding, and by assaying a panel of Vpr mutants, we found the hydrophobic region about residues Glu-25 and Gln-65 to be potentially involved in the binding of the inhibitor. Our findings exposed a targeting site on Vpr and delineated a convenient approach to explore other targeting sites on the protein using small molecule inhibitors as bioprobes.
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Affiliation(s)
- Eugene Boon Beng Ong
- From the Chemical Biology Core Facility, Chemical Biology Department, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- the School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia, and
| | - Nobumoto Watanabe
- From the Chemical Biology Core Facility, Chemical Biology Department, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- the School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia, and
| | - Akiko Saito
- From the Chemical Biology Core Facility, Chemical Biology Department, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - Yushi Futamura
- From the Chemical Biology Core Facility, Chemical Biology Department, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
| | - Khaled Hussein Abd El Galil
- the Department of Retrovirology and Self-Defense, Faculty of Life Sciences, Kumamoto University, Kumamoto 860-8556, Japan
| | - Atsushi Koito
- the Department of Retrovirology and Self-Defense, Faculty of Life Sciences, Kumamoto University, Kumamoto 860-8556, Japan
| | - Nazalan Najimudin
- the School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia, and
| | - Hiroyuki Osada
- From the Chemical Biology Core Facility, Chemical Biology Department, RIKEN Advanced Science Institute, 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan
- the School of Biological Sciences, Universiti Sains Malaysia, 11800 Penang, Malaysia, and
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Solbak SM, Reksten TR, Wray V, Bruns K, Horvli O, Raae AJ, Henklein P, Henklein P, Röder R, Mitzner D, Schubert U, Fossen T. The intriguing cyclophilin A-HIV-1 Vpr interaction: prolyl cis/trans isomerisation catalysis and specific binding. BMC STRUCTURAL BIOLOGY 2010; 10:31. [PMID: 20920334 PMCID: PMC2959089 DOI: 10.1186/1472-6807-10-31] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/16/2010] [Accepted: 10/04/2010] [Indexed: 11/23/2022]
Abstract
Background Cyclophilin A (CypA) represents a potential target for antiretroviral therapy since inhibition of CypA suppresses human immunodeficiency virus type 1 (HIV-1) replication, although the mechanism through which CypA modulates HIV-1 infectivity still remains unclear. The interaction of HIV-1 viral protein R (Vpr) with the human peptidyl prolyl isomerase CypA is known to occur in vitro and in vivo. However, the nature of the interaction of CypA with Pro-35 of N-terminal Vpr has remained undefined. Results Characterization of the interactions of human CypA with N-terminal peptides of HIV-1 Vpr has been achieved using a combination of nuclear magnetic resonace (NMR) exchange spectroscopy and surface plasmon resonance spectroscopy (SPR). NMR data at atomic resolution indicate prolyl cis/trans isomerisation of the highly conserved proline residues Pro-5, -10, -14 and -35 of Vpr are catalyzed by human CypA and require only very low concentrations of the isomerase relative to that of the peptide substrates. Of the N-terminal peptides of Vpr only those containing Pro-35 bind to CypA in a biosensor assay. SPR studies of specific N-terminal peptides with decreasing numbers of residues revealed that a seven-residue motif centred at Pro-35 consisting of RHFPRIW, which under membrane-like solution conditions comprises the loop region connecting helix 1 and 2 of Vpr and the two terminal residues of helix 1, is sufficient to maintain strong specific binding. Conclusions Only N-terminal peptides of Vpr containing Pro-35, which appears to be vital for manifold functions of Vpr, bind to CypA in a biosensor assay. This indicates that Pro-35 is essential for a specific CypA-Vpr binding interaction, in contrast to the general prolyl cis/trans isomerisation observed for all proline residues of Vpr, which only involve transient enzyme-substrate interactions. Previously suggested models depicting CypA as a chaperone that plays a role in HIV-1 virulence are now supported by our data. In detail the SPR data of this interaction were compatible with a two-state binding interaction model that involves a conformational change during binding. This is in accord with the structural changes observed by NMR suggesting CypA catalyzes the prolyl cis/trans interconversion during binding to the RHFP35RIW motif of N-terminal Vpr.
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Affiliation(s)
- Sara M Solbak
- Department of Chemistry, University of Bergen, N-5007 Bergen, Norway
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Iera JA, Jenkins LMM, Kajiyama H, Kopp JB, Appella DH. Solid-phase synthesis and screening of N-acylated polyamine (NAPA) combinatorial libraries for protein binding. Bioorg Med Chem Lett 2010; 20:6500-3. [PMID: 20932761 DOI: 10.1016/j.bmcl.2010.09.054] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2010] [Revised: 09/08/2010] [Accepted: 09/10/2010] [Indexed: 10/19/2022]
Abstract
Inhibitors for protein-protein interactions are challenging to design, in part due to the unique and complex architectures of each protein's interaction domain. Most approaches to develop inhibitors for these interactions rely on rational design, which requires prior structural knowledge of the target and its ligands. In the absence of structural information, a combinatorial approach may be the best alternative to finding inhibitors of a protein-protein interaction. Current chemical libraries, however, consist mostly of molecules designed to inhibit enzymes. In this manuscript, we report the synthesis and screening of a library based on an N-acylated polyamine (NAPA) scaffold that we designed to have specific molecular features necessary to inhibit protein-protein interactions. Screens of the library identified a member with favorable binding properties to the HIV viral protein R (Vpr), a regulatory protein from HIV, that is involved in numerous interactions with other proteins critical for viral replication.
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Affiliation(s)
- Jaclyn A Iera
- Laboratory of Bioorganic Chemistry and Kidney Disease Section, NIDDK, NIH, DHHS, Bethesda, MD 20892, United States
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Fritz JV, Briant L, Mély Y, Bouaziz S, de Rocquigny H. HIV-1 viral protein r: from structure to function. Future Virol 2010. [DOI: 10.2217/fvl.10.47] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023]
Abstract
The viral protein r (Vpr) of HIV-1 binds several host proteins leading to pleiotropic functions, such as G2/M cell cycle arrest, apoptosis induction and gene transactivation. Vpr is encapsidated through the Gag C-terminus into the nascent viral particles, suggesting that Vpr plays several important functions in the early stages of the viral lifecycle. In this regard, Vpr interacts with nucleic acids and membranes to facilitate the preintegration complex migration and incorporation into the nucleus of nondividing cells. Thus, Vpr has to recruit several host and viral factors to promote its functions during HIV-1 pathogenesis. This article focuses on its interacting partners by giving an overview of the functional outcome of the different Vpr complexes, as well as the structural determinants of Vpr required for its binding properties.
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Affiliation(s)
- Joëlle V Fritz
- Department of Infectious Diseases, Virology, Universitätsklinikum, Im Neuenheimer Feld, 324, D-69120, Heidelberg, Germany
| | - Laurence Briant
- Université Montpellier 1, Centre d’études d’agents Pathogènes et Biotechnologies pour la Santé, CNRS, UMR 5236, CPBS, F-34965 Montpellier, France
| | - Yves Mély
- Laboratoire de Biophotonique et Pharmacologie, UMR 7213 CNRS, Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France
| | - Serge Bouaziz
- Laboratoire de Cristallographie et RMN Biologiques, CNRS UMR8015 UFR des Sciences Pharmaceutiques et Biologiques 4, Avenue de L’observatoire, 75006 Paris, France: Université de Strasbourg, Faculté de Pharmacie, 74, Route du Rhin, 67401 ILLKIRCH Cedex, France
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Hapgood JP, Tomasicchio M. Modulation of HIV-1 virulence via the host glucocorticoid receptor: towards further understanding the molecular mechanisms of HIV-1 pathogenesis. Arch Virol 2010; 155:1009-19. [PMID: 20446002 DOI: 10.1007/s00705-010-0678-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2009] [Accepted: 03/26/2010] [Indexed: 10/19/2022]
Abstract
The glucocorticoid receptor (GR) is a steroid receptor that regulates diverse functions, which include the immune response. In humans, the GR acts via binding to cortisol, resulting in the transcriptional modulation of key host genes. Several lines of evidence suggest that the host GR could be a key protein exploited by HIV at multiple levels to ensure its pathogenic success. Endogenous and therapeutic glucocorticoids play important roles in patients with HIV due to their well-established effects on immune function. AIDS patients develop glucocorticoid hypersensitivity, consistent with a mechanism involving an HIV-1-induced increase in expression or activity of the GR. Both the HIV-1 accessory protein Vpr and the host GR affect transcription of viral proteins from the long terminal repeat (LTR) region of the HIV-1 promoter. In addition, Vpr modulates host GR function to affect transcription of host genes, most likely via direct interaction with the GR. Vpr appears to regulate GR function by acting as a co-activator for the GR. Since both the GR and Vpr are involved in apoptosis in T cells and dendritic cells, crosstalk between these proteins may also regulate apoptosis in these and other cells. Given that cortisol is not the only ligand that activates the GR, other endogenous as well as synthetic GR ligands such as progestins may also modulate HIV pathogenesis, in particular in the cervicovaginal environment. Investigating the molecular determinants, ligand-selectivity and role in HIV pathogenesis of the GR-Vpr interaction may lead to new strategies for development of anti-HIV drugs.
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Affiliation(s)
- Janet Patricia Hapgood
- Department of Molecular and Cell Biology, University of Cape Town, Rondebosch 7701, South Africa.
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Kilareski EM, Shah S, Nonnemacher MR, Wigdahl B. Regulation of HIV-1 transcription in cells of the monocyte-macrophage lineage. Retrovirology 2009; 6:118. [PMID: 20030845 PMCID: PMC2805609 DOI: 10.1186/1742-4690-6-118] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2009] [Accepted: 12/23/2009] [Indexed: 12/20/2022] Open
Abstract
Human immunodeficiency virus type 1 (HIV-1) has been shown to replicate productively in cells of the monocyte-macrophage lineage, although replication occurs to a lesser extent than in infected T cells. As cells of the monocyte-macrophage lineage become differentiated and activated and subsequently travel to a variety of end organs, they become a source of infectious virus and secreted viral proteins and cellular products that likely initiate pathological consequences in a number of organ systems. During this process, alterations in a number of signaling pathways, including the level and functional properties of many cellular transcription factors, alter the course of HIV-1 long terminal repeat (LTR)-directed gene expression. This process ultimately results in events that contribute to the pathogenesis of HIV-1 infection. First, increased transcription leads to the upregulation of infectious virus production, and the increased production of viral proteins (gp120, Tat, Nef, and Vpr), which have additional activities as extracellular proteins. Increased viral production and the presence of toxic proteins lead to enhanced deregulation of cellular functions increasing the production of toxic cellular proteins and metabolites and the resulting organ-specific pathologic consequences such as neuroAIDS. This article reviews the structural and functional features of the cis-acting elements upstream and downstream of the transcriptional start site in the retroviral LTR. It also includes a discussion of the regulation of the retroviral LTR in the monocyte-macrophage lineage during virus infection of the bone marrow, the peripheral blood, the lymphoid tissues, and end organs such as the brain. The impact of genetic variation on LTR-directed transcription during the course of retrovirus disease is also reviewed.
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Affiliation(s)
- Evelyn M Kilareski
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N 15th St, Philadelphia, Pennsylvania 19102, USA
- Center for Molecular Therapeutics and Resistance, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N 15th St, Philadelphia, Pennsylvania 19102, USA
- Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 19129, USA
| | - Sonia Shah
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N 15th St, Philadelphia, Pennsylvania 19102, USA
- Center for Molecular Therapeutics and Resistance, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N 15th St, Philadelphia, Pennsylvania 19102, USA
- Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 19129, USA
| | - Michael R Nonnemacher
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N 15th St, Philadelphia, Pennsylvania 19102, USA
- Center for Molecular Therapeutics and Resistance, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N 15th St, Philadelphia, Pennsylvania 19102, USA
- Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 19129, USA
| | - Brian Wigdahl
- Center for Molecular Virology and Translational Neuroscience, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N 15th St, Philadelphia, Pennsylvania 19102, USA
- Center for Molecular Therapeutics and Resistance, Institute for Molecular Medicine and Infectious Disease, Drexel University College of Medicine, 245 N 15th St, Philadelphia, Pennsylvania 19102, USA
- Department of Microbiology and Immunology, Drexel University College of Medicine, 2900 Queen Lane, Philadelphia, Pennsylvania 19129, USA
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Hong HS, Bhatnagar N, Ballmaier M, Schubert U, Henklein P, Volgmann T, Heiken H, Schmidt RE, Meyer-Olson D. Exogenous HIV-1 Vpr disrupts IFN-α response by plasmacytoid dendritic cells (pDCs) and subsequent pDC/NK interplay. Immunol Lett 2009; 125:100-4. [DOI: 10.1016/j.imlet.2009.06.008] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2009] [Revised: 05/27/2009] [Accepted: 06/03/2009] [Indexed: 11/25/2022]
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Modulating the activity of the channel-forming segment of Vpr protein from HIV-1. EUROPEAN BIOPHYSICS JOURNAL: EBJ 2009; 39:1089-95. [PMID: 19629466 DOI: 10.1007/s00249-009-0518-x] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/26/2009] [Revised: 06/27/2009] [Accepted: 06/29/2009] [Indexed: 10/20/2022]
Abstract
Viral protein of regulation (Vpr) encoded by human immunodeficiency virus type 1 (HIV-1) is a short auxiliary protein that is 96 amino acids in length. During the viral life cycle, Vpr is released into the blood serum and is able to enter cellular membranes of noninfected cells. In this study a short peptide, Vpr(55-83), was shown to exhibit ion-channel-like activity when reconstituted into (1) planar lipid bilayers and (2) lipid bilayers held at the tip of a glass pipette. The two set-ups led to differences in the oligomerization state of the peptide, which was reflected in differences in the conductance levels. Experiments under applied hydrostatic pressure affect the dynamics of the protein within the membrane.
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HIV-1 infection and the PPARγ-dependent control of adipose tissue physiology. PPAR Res 2008; 2009:607902. [PMID: 19081837 PMCID: PMC2593159 DOI: 10.1155/2009/607902] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2008] [Accepted: 07/23/2008] [Indexed: 01/03/2023] Open
Abstract
PPARγ is a ligand-dependent master transcription factor controlling adipocyte differentiation as well as multiple biological processes taking place in other cells present in adipose tissue depots such as macrophages. Recent research indicates that HIV-1 infection-related events may alter adipose tissue biology through several mechanisms involving PPARγ, ranging from direct effects of HIV-1-encoded proteins on adipocytes to the promotion of a proinflammatory environment that interferes with PPARγ actions. This effect of HIV-1 on adipose tissue cells can occur even in the absence of direct infection of adipocytes, as soluble HIV-1-encoded proteins such as Vpr may enter cells and inhibit PPARγ action. Moreover, repression of PPARγ actions may relieve inhibitory pathways of HIV-1 gene transcription, thus enhancing HIV-1 effects in infected cells. HIV-1 infection-mediated interference of PPARγ-dependent pathways in adipocytes and other cells inside adipose depots such as macrophages is likely to create an altered local environment that, after antiretroviral treatment, leads to lipodystrophy in HIV-1-infected and HAART-treated patients.
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Kondo N, Ebihara A, Ru H, Kuramitsu S, Iwamoto A, Rao Z, Matsuda Z. Thermus thermophilus-derived protein tags that aid in preparation of insoluble viral proteins. Anal Biochem 2008; 385:278-85. [PMID: 19084492 DOI: 10.1016/j.ab.2008.10.050] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2008] [Revised: 10/09/2008] [Accepted: 10/21/2008] [Indexed: 10/21/2022]
Abstract
The expression and solubilization of insoluble proteins have been facilitated by the introduction of protein tags. In our analyses of viral protein R (Vpr) of human immunodeficiency virus 1 (HIV-1), however, several conventional tag proteins enhanced its expression but failed to solubilize it. Therefore, we decided to explore whether proteins derived from Thermus thermophilus HB8 (T. th.), a highly heat-stable bacterium, could be used as tag proteins to enhance the solubilization of Vpr. Based on the data accumulated during the recent structural genomics project of T. th., we selected 15 T. th. proteins with high expression levels and solubilities. From this group, we identified a T. th. tag protein that expressed Vpr in a soluble form. Furthermore, two T. th. tag proteins, including the identified one, were found to solubilize the extremely insoluble membrane-spanning domain of the envelope protein of HIV-1. When green fluorescent protein (GFP) was used as a passenger protein of T. th. tags, the brightness and stability of GFP were similar to those of untagged GFP, suggesting that the T. th. tags do not negatively affect the function of the passenger protein. Thus, data of structural genomics can be applied to generate a customized versatile protein tag for protein analyses.
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Affiliation(s)
- Naoyuki Kondo
- Research Center for Asian Infectious Diseases, Institute of Medical Science, University of Tokyo, Shirokanedai, Tokyo, Japan
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Fritz JV, Didier P, Clamme JP, Schaub E, Muriaux D, Cabanne C, Morellet N, Bouaziz S, Darlix JL, Mély Y, de Rocquigny H. Direct Vpr-Vpr interaction in cells monitored by two photon fluorescence correlation spectroscopy and fluorescence lifetime imaging. Retrovirology 2008; 5:87. [PMID: 18808682 PMCID: PMC2562391 DOI: 10.1186/1742-4690-5-87] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2008] [Accepted: 09/22/2008] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The human immunodeficiency virus type 1 (HIV-1) encodes several regulatory proteins, notably Vpr which influences the survival of the infected cells by causing a G2/M arrest and apoptosis. Such an important role of Vpr in HIV-1 disease progression has fuelled a large number of studies, from its 3D structure to the characterization of specific cellular partners. However, no direct imaging and quantification of Vpr-Vpr interaction in living cells has yet been reported. To address this issue, eGFP- and mCherry proteins were tagged by Vpr, expressed in HeLa cells and their interaction was studied by two photon fluorescence lifetime imaging microscopy and fluorescence correlation spectroscopy. RESULTS Results show that Vpr forms homo-oligomers at or close to the nuclear envelope. Moreover, Vpr dimers and trimers were found in the cytoplasm and in the nucleus. Point mutations in the three alpha helices of Vpr drastically impaired Vpr oligomerization and localization at the nuclear envelope while point mutations outside the helical regions had no effect. Theoretical structures of Vpr mutants reveal that mutations within the alpha-helices could perturb the leucine zipper like motifs. The DeltaQ44 mutation has the most drastic effect since it likely disrupts the second helix. Finally, all Vpr point mutants caused cell apoptosis suggesting that Vpr-mediated apoptosis functions independently from Vpr oligomerization. CONCLUSION We report that Vpr oligomerization in HeLa cells relies on the hydrophobic core formed by the three alpha helices. This oligomerization is required for Vpr localization at the nuclear envelope but not for Vpr-mediated apoptosis.
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Affiliation(s)
- Joëlle V Fritz
- Département de Pharmacologie et Physico-Chimie des Interactions Cellulaires et Moléculaires, UMR 7175 CNRS, Faculté de Pharmacie, Université Louis Pasteur, Strasbourg 1, 74, Route du Rhin, 67401 Illkirch Cedex, France
| | - Pascal Didier
- Département de Pharmacologie et Physico-Chimie des Interactions Cellulaires et Moléculaires, UMR 7175 CNRS, Faculté de Pharmacie, Université Louis Pasteur, Strasbourg 1, 74, Route du Rhin, 67401 Illkirch Cedex, France
| | - Jean-Pierre Clamme
- Department of Immunology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Emmanuel Schaub
- Département de Pharmacologie et Physico-Chimie des Interactions Cellulaires et Moléculaires, UMR 7175 CNRS, Faculté de Pharmacie, Université Louis Pasteur, Strasbourg 1, 74, Route du Rhin, 67401 Illkirch Cedex, France
| | - Delphine Muriaux
- LaboRétro Unité de Virologie Humaine INSERM 758, IFR 128 Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon, France
| | - Charlotte Cabanne
- Ecole Supérieure de Technologie des Biomolécules de Bordeaux, Université V Ségalen, Bordeaux 2, 146, rue Léo Saignat, 33076 Bordeaux Cedex, France
| | - Nelly Morellet
- Unité de Pharmacologie Chimique et Génétique, Inserm U640 CNRS UMR8151 UFR des Sciences Pharmaceutiques et Biologiques 4, Avenue de L'observatoire, 75006 Paris, France
| | - Serge Bouaziz
- Unité de Pharmacologie Chimique et Génétique, Inserm U640 CNRS UMR8151 UFR des Sciences Pharmaceutiques et Biologiques 4, Avenue de L'observatoire, 75006 Paris, France
| | - Jean-Luc Darlix
- LaboRétro Unité de Virologie Humaine INSERM 758, IFR 128 Ecole Normale Supérieure de Lyon, 46 allée d'Italie, 69364 Lyon, France
| | - Yves Mély
- Département de Pharmacologie et Physico-Chimie des Interactions Cellulaires et Moléculaires, UMR 7175 CNRS, Faculté de Pharmacie, Université Louis Pasteur, Strasbourg 1, 74, Route du Rhin, 67401 Illkirch Cedex, France
| | - Hugues de Rocquigny
- Département de Pharmacologie et Physico-Chimie des Interactions Cellulaires et Moléculaires, UMR 7175 CNRS, Faculté de Pharmacie, Université Louis Pasteur, Strasbourg 1, 74, Route du Rhin, 67401 Illkirch Cedex, France
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Andersen JL, Le Rouzic E, Planelles V. HIV-1 Vpr: mechanisms of G2 arrest and apoptosis. Exp Mol Pathol 2008; 85:2-10. [PMID: 18514189 DOI: 10.1016/j.yexmp.2008.03.015] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2007] [Accepted: 03/04/2008] [Indexed: 02/05/2023]
Abstract
Since the first isolation of HIV-1 from a patient with generalized lymphadenopathy in 1983, great progress has been made in understanding the viral life cycle and the functional nuances of each of the nine genes encoded by HIV-1. Considerable attention has been paid to four small HIV-1 open reading frames, vif, vpr, vpu and nef. These genes were originally termed "accessory" because their deletion failed to completely disable viral replication in vitro. More than twenty years after the cloning and sequencing of HIV-1, a great deal of information is available regarding the multiple functions of the accessory proteins and it is well accepted that, collectively, these gene products modulate the host cell biology to favor viral replication, and that they are largely responsible for the pathogenesis of HIV-1. Expression of Vpr, in particular, leads to cell cycle arrest in G(2), followed by apoptosis. Here we summarize our current understanding of Vpr biology with a focus on Vpr-induced G(2) arrest and apoptosis.
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Affiliation(s)
- Joshua L Andersen
- Center for the Study of Aging and Human Development, Department of Pharmacology and Cancer Biology, Duke University Medical Center, Durham, NC 27710, USA
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Xiao Y, Chen G, Richard J, Rougeau N, Li H, Seidah NG, Cohen EA. Cell-surface processing of extracellular human immunodeficiency virus type 1 Vpr by proprotein convertases. Virology 2007; 372:384-97. [PMID: 18061232 DOI: 10.1016/j.virol.2007.10.036] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2007] [Revised: 09/27/2007] [Accepted: 10/30/2007] [Indexed: 10/22/2022]
Abstract
Increasing evidence suggests that extracellular Vpr could contribute to HIV pathogenesis through its effect on bystander cells. Soluble forms of Vpr have been detected in the sera and cerebrospinal fluids of HIV-1-infected patients, and in vitro studies have implicated extracellular Vpr as an effector of cellular responses, including G2 arrest, apoptosis and induction of cytokines and chemokines production, presumably through its ability to transduce into multiple cell types. However, the mechanism underlying Vpr release from HIV-1-producing cells remains undefined and the biological modifications that the extracellular protein may undergo are largely unknown. We provide evidence indicating that soluble forms of Vpr are present in the extracellular medium of HIV-1-producing cells. Release of Vpr in the extracellular medium did not originate from decaying or disrupted HIV-1 virions that package Vpr but rather appeared associated with HIV-1-mediated cytopathicity. Interestingly, Vpr was found to undergo proteolytic processing at a very well conserved proprotein convertase (PC) cleavage site, R(85)QRR(88) downward arrow, located within the functionally important C-terminal arginine-rich domain of the protein. Vpr processing occurred extracellularly upon close contact to cells and most likely involved a cell surface-associated PC. Consistently, PC inhibitors suppressed Vpr processing, while expression of extracellular matrix-associated PC5 and PACE4 enhanced Vpr cleavage. PC-mediated processing of extracellular Vpr led to the production of a truncated Vpr product that was defective for the induction of cell cycle arrest and apoptosis when expressed in human cells. Collectively, these results suggest that cell surface processing of extracellular Vpr by PCs might regulate the levels of active soluble Vpr.
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Affiliation(s)
- Yong Xiao
- Laboratory of Human Retrovirology, Institut de recherches cliniques de Montréal, Montreal, Quebec, Canada
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Shrivastav S, Kino T, Cunningham T, Ichijo T, Schubert U, Heinklein P, Chrousos GP, Kopp JB. Human immunodeficiency virus (HIV)-1 viral protein R suppresses transcriptional activity of peroxisome proliferator-activated receptor {gamma} and inhibits adipocyte differentiation: implications for HIV-associated lipodystrophy. Mol Endocrinol 2007; 22:234-47. [PMID: 17932108 DOI: 10.1210/me.2007-0124] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
HIV-1-infected patients may develop lipodystrophy and insulin resistance. We investigated the effect of the HIV-1 accessory protein viral protein R (Vpr) on the activity of the peroxisome proliferator-activating receptor-gamma (PPARgamma), a key regulator of adipocyte differentiation and tissue insulin sensitivity. We studied expression of PPARgamma-responsive reporter genes in 3T3-L1 mouse adipocytes. We investigated Vpr interaction with the PPAR/retinoid X receptor (RXR)-binding site of the c-Cbl-associating protein (CAP) gene using the chromatin immunoprecipitation assay as well as the interaction of Vpr and PPARgamma using coimmunoprecipitation. Finally, we studied the ability of exogenous Vpr protein to enter cultured adipocytes and retard differentiation. We found that Vpr suppressed PPARgamma-induced transactivation in both undifferentiated and differentiated 3T3-L1 cells. Transcriptional suppression by Vpr required an intact LXXLL coactivator motif. Vpr suppressed mRNA expression of PPARgamma-responsive genes in undifferentiated 3T3-L1 cells and associated with the PPAR/RXR-binding site located in the promoter region of the CAP gene. Vpr interacted with the ligand-binding domain of PPARgamma in an agonist-dependent fashion in vitro. Vpr delivered either by an expression plasmid or as protein added to media suppressed PPARgamma agonist-induced adipocyte differentiation, assessed as lipid accumulation and mRNA expression of the adipocyte differentiation marker adipocyte P2 in 3T3-L1 cells. In conclusion, circulating Vpr or, alternatively, Vpr produced as a consequence of direct infection of adipocytes could suppress in vivo differentiation of preadipocytes by acting as a corepressor of PPARgamma-mediated gene transcription. Vpr may alter sensitivity to insulin and thereby contribute to the development of lipodystrophy and insulin resistance observed in HIV-1-infected patients.
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Affiliation(s)
- Shashi Shrivastav
- Kidney Disease Section, National Institute of Diabetes and Digestive and Kidney Disease/NIH, 10 Center Drive MSC 1268, Bethesda, MD 20892-1268, USA
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Siddiqui K, Del Valle L, Morellet N, Cui J, Ghafouri M, Mukerjee R, Urbanska K, Fan S, Pattillo CB, Deshmane SL, Kiani MF, Ansari R, Khalili K, Roques BP, Reiss K, Bouaziz S, Amini S, Srinivasan A, Sawaya BE. Molecular mimicry in inducing DNA damage between HIV-1 Vpr and the anticancer agent, cisplatin. Oncogene 2007; 27:32-43. [PMID: 17653096 DOI: 10.1038/sj.onc.1210632] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The human immunodeficiency virus type 1 (HIV-1) viral protein R (vpr) gene is an evolutionarily conserved gene among the primate lentiviruses. Several functions are attributed to Vpr including the ability to cause cell death, cell cycle arrest, apoptosis and DNA damage. The Vpr domain responsible for DNA damage as well as the mechanism(s) through which Vpr induces this damage is unknown. Using site-directed mutagenesis, we identified the helical domain II within Vpr (aa 37-50) as the region responsible for causing DNA damage. Interestingly, Vpr Delta(37-50) failed to cause cell cycle arrest or apoptosis, to induce Ku70 or Ku80 and to suppress tumor growth, but maintained its capability to activate the HIV-1 LTR, to localize to the nucleus and to promote nonhomologous end-joining. In addition, our cytogenetic data indicated that helical domain II induced chromosomal aberrations, which mimicked those induced by cisplatin, an anticancer agent. This novel molecular mimicry function of Vpr might lead to its potential therapeutic use as a tumor suppressor.
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Affiliation(s)
- K Siddiqui
- 1Department of Biology, College of Science and Technology, Temple University, Philadelphia, PA, USA
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