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Si JY, Wu LJ, Xu FL, Cao XT, Lan JF. PHB2 inhibits WSSV replication by promoting the nuclear translocation of STAT. FISH & SHELLFISH IMMUNOLOGY 2024; 148:109503. [PMID: 38479567 DOI: 10.1016/j.fsi.2024.109503] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/19/2024] [Revised: 02/25/2024] [Accepted: 03/11/2024] [Indexed: 03/18/2024]
Abstract
Prohibitins (PHBs) are ubiquitously expressed conserved proteins in eukaryotes that are associated with apoptosis, cancer formation, aging, stress responses and cell proliferation. However, the function of the PHBs in immune regulation has largely not been determined. In the present study, we identified PHB2 in the red swamp crayfish Procambarus clarkii. PHB2 was found to be widely distributed in several tissues, and its expression was significantly upregulated by white spot syndrome virus (WSSV) challenge. PHB2 significantly reduced the amount of WSSV in crayfish and the mortality of WSSV-infected crayfish. Here, we observed that PHB2 promotes the nuclear translocation of STAT by binding to STAT. After blocking PHB2 or STAT with antibodies or interfering with PHB2 or STAT, the expression levels of the antiviral genes β-thymosin (PcThy-4) and crustin2 (Cru2) decreased. The gene sequence of PHB2 was analyzed and found to contain a nuclear introgression sequence (NIS). After in vivo injection of PHB2 with deletion of NIS (rΔNIS-PHB2), the nuclear translocation of STAT did not change significantly compared to that in the control group. These results suggest that PHB2 promoted the nuclear translocation of STAT through NIS and mediated the expression of antiviral proteins to inhibit WSSV infection.
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Affiliation(s)
- Jia-Yu Si
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, 271018, China
| | - Lian-Jie Wu
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, 271018, China
| | - Feng-Lin Xu
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, 271018, China
| | - Xiao-Tong Cao
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, 271018, China.
| | - Jiang-Feng Lan
- Shandong Provincial Key Laboratory of Animal Biotechnology and Disease Control and Prevention, College of Animal Science and Veterinary Medicine, Shandong Agricultural University, Taian, 271018, China.
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2
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Zhang B, Li W, Cao J, Zhou Y, Yuan X. Prohibitin 2: A key regulator of cell function. Life Sci 2024; 338:122371. [PMID: 38142736 DOI: 10.1016/j.lfs.2023.122371] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/17/2023] [Revised: 12/16/2023] [Accepted: 12/18/2023] [Indexed: 12/26/2023]
Abstract
The PHB2 gene is located on chromosome 12p13 and encodes prohibitin 2, a highly conserved protein of 37 kDa. PHB2 is a dimer with antiparallel coils, possessing a unique negatively charged region crucial for its mitochondrial molecular chaperone functions. Thus, PHB2 plays a significant role in cell life activities such as mitosis, mitochondrial autophagy, signal transduction, and cell death. This review discusses how PHB2 inhibits transcription factors or nuclear receptors to maintain normal cell functions; how PHB2 in the cytoplasm or membrane ensures normal cell mitosis and regulates cell differentiation; how PHB2 affects mitochondrial structure, function, and cell apoptosis through mitochondrial intimal integrity and mitochondrial autophagy; how PHB2 affects mitochondrial stress and inhibits cell apoptosis by regulating cytochrome c migration and other pathways; how PHB2 affects cell growth, proliferation, and metastasis through a mitochondrial independent mechanism; and how PHB2 could be applied in disease treatment. We provide a theoretical basis and an innovative perspective for a comprehensive understanding of the role and mechanism of PHB2 in cell function regulation.
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Affiliation(s)
- Bingjie Zhang
- Gastroenterology and Urology Department II, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, China; Cancer Research Institute, Basic School of Medicine, Central South University, Changsha, Hunan 410011, China
| | - Wentao Li
- Cancer Research Institute, Basic School of Medicine, Central South University, Changsha, Hunan 410011, China
| | - Jiaying Cao
- Cancer Research Institute, Basic School of Medicine, Central South University, Changsha, Hunan 410011, China
| | - Yanhong Zhou
- Cancer Research Institute, Basic School of Medicine, Central South University, Changsha, Hunan 410011, China.
| | - Xia Yuan
- Gastroenterology and Urology Department II, Hunan Cancer Hospital and The Affiliated Cancer Hospital of Xiangya School of Medicine, Central South University, Changsha, Hunan 410013, China.
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3
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Shoji M, Esumi T, Masuda T, Tanaka N, Okamoto R, Sato H, Watanabe M, Takahashi E, Kido H, Ohtsuki S, Kuzuhara T. Bakuchiol targets mitochondrial proteins, prohibitins and voltage-dependent anion channels: New insights into developing antiviral agents. J Biol Chem 2024; 300:105632. [PMID: 38199573 PMCID: PMC10862021 DOI: 10.1016/j.jbc.2024.105632] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Revised: 12/11/2023] [Accepted: 12/26/2023] [Indexed: 01/12/2024] Open
Abstract
We previously reported that bakuchiol, a phenolic isoprenoid anticancer compound, and its analogs exert anti-influenza activity. However, the proteins targeted by bakuchiol remain unclear. Here, we investigated the chemical structures responsible for the anti-influenza activity of bakuchiol and found that all functional groups and C6 chirality of bakuchiol were required for its anti-influenza activity. Based on these results, we synthesized a molecular probe containing a biotin tag bound to the C1 position of bakuchiol. With this probe, we performed a pulldown assay for Madin-Darby canine kidney cell lysates and purified the specific bakuchiol-binding proteins with SDS-PAGE. Using nanoLC-MS/MS analysis, we identified prohibitin (PHB) 2, voltage-dependent anion channel (VDAC) 1, and VDAC2 as binding proteins of bakuchiol. We confirmed the binding of bakuchiol to PHB1, PHB2, and VDAC2 in vitro using Western blot analysis. Immunofluorescence analysis showed that bakuchiol was bound to PHBs and VDAC2 in cells and colocalized in the mitochondria. The knockdown of PHBs or VDAC2 by transfection with specific siRNAs, along with bakuchiol cotreatment, led to significantly reduced influenza nucleoprotein expression levels and viral titers in the conditioned medium of virus-infected Madin-Darby canine kidney cells, compared to the levels observed with transfection or treatment alone. These findings indicate that reducing PHBs or VDAC2 protein, combined with bakuchiol treatment, additively suppressed the growth of influenza virus. Our findings indicate that bakuchiol exerts anti-influenza activity via a novel mechanism involving these mitochondrial proteins, providing new insight for developing anti-influenza agents.
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Affiliation(s)
- Masaki Shoji
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan.
| | - Tomoyuki Esumi
- Institute of Pharmacognosy Attached to Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | - Takeshi Masuda
- Department of Pharmaceutical Microbiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan; Institute for Advanced Biosciences, Keio University, Tsuruoka, Japan
| | - Narue Tanaka
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | - Risa Okamoto
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | - Hinako Sato
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | - Mihiro Watanabe
- Institute of Pharmacognosy Attached to Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan
| | - Etsuhisa Takahashi
- Division of Enzyme Chemistry, Institute for Enzyme Research, Tokushima University, Tokushima, Japan
| | - Hiroshi Kido
- Division of Enzyme Chemistry, Institute for Enzyme Research, Tokushima University, Tokushima, Japan
| | - Sumio Ohtsuki
- Department of Pharmaceutical Microbiology, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Takashi Kuzuhara
- Laboratory of Biochemistry, Faculty of Pharmaceutical Sciences, Tokushima Bunri University, Tokushima, Japan.
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4
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Viral and Host Factors Regulating HIV-1 Envelope Protein Trafficking and Particle Incorporation. Viruses 2022; 14:v14081729. [PMID: 36016351 PMCID: PMC9415270 DOI: 10.3390/v14081729] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2022] [Revised: 07/25/2022] [Accepted: 08/02/2022] [Indexed: 11/17/2022] Open
Abstract
The HIV-1 envelope glycoprotein (Env) is an essential structural component of the virus, serving as the receptor-binding protein and principal neutralizing determinant. Env trimers are incorporated into developing particles at the plasma membrane of infected cells. Incorporation of HIV-1 Env into particles in T cells and macrophages is regulated by the long Env cytoplasmic tail (CT) and the matrix region of Gag. The CT incorporates motifs that interact with cellular factors involved in endosomal trafficking. Env follows an unusual pathway to arrive at the site of particle assembly, first traversing the secretory pathway to the plasma membrane (PM), then undergoing endocytosis, followed by directed sorting to the site of particle assembly on the PM. Many aspects of Env trafficking remain to be defined, including the sequential events that occur following endocytosis, leading to productive recycling and particle incorporation. This review focuses on the host factors and pathways involved in Env trafficking, and discusses leading models of Env incorporation into particles.
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5
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Chandel S, Joon A, Ghosh S. Enteroaggregative Escherichia coli induces altered glycosylation in membrane proteins of cultured human intestinal epithelial cells. Biochimie 2022; 199:68-80. [DOI: 10.1016/j.biochi.2022.04.002] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2021] [Revised: 03/11/2022] [Accepted: 04/05/2022] [Indexed: 11/02/2022]
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6
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Prohibitin plays a role in the functional plasticity of macrophages. Mol Immunol 2022; 144:152-165. [DOI: 10.1016/j.molimm.2022.02.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2021] [Revised: 01/11/2022] [Accepted: 02/15/2022] [Indexed: 11/17/2022]
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Truncation of the Cytoplasmic Tail of Equine Infectious Anemia Virus Increases Virion Production by Improving Env Cleavage and Plasma Membrane Localization. J Virol 2021; 95:e0108721. [PMID: 34495693 PMCID: PMC8577380 DOI: 10.1128/jvi.01087-21] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Envelope glycoproteins (Envs) of lentiviruses harbor unusually long cytoplasmic tails (CTs). Natural CT truncations always occur in vitro and are accompanied by attenuated virulence, but their effects on viral replication have not been fully elucidated. The Env in equine infectious anemia virus (EIAV) harbors the longest CT in the lentiviral family, and a truncated CT was observed in a live attenuated vaccine. This study demonstrates that CT truncation significantly increased EIAV production, as determined by comparing the virion yields from EIAV infectious clones in the presence and absence of the CT. A significant increase in a cleaved product from the CT-truncated Env precursor, but not the full-length Env, was observed. We further confirmed that the presence of the CT inhibited the cleavage of the Env precursor and found that a functional domain located at the C terminus was responsible for this function. Moreover, CT-truncated Env was mainly localized at the plasma membrane (PM), while full-length Env was mainly localized in the cytoplasm. The CT truncation caused a dramatic reduction in the endocytosis of Env. These results suggest that the CT can modulate the processing and trafficking of EIAV Env and thus regulate EIAV replication. IMPORTANCE The mature lentivirus envelope glycoprotein (Env) is composed of a surface unit (SU) and a transmembrane unit (TM), which are cleaved products of the Env precursor. After mature Env is heterodimerically formed from the cleavage of the Env precursor, it is trafficked to the plasma membrane (PM) for incorporation and virion assembly. Env harbors a long cytoplasmic tail (CT), which has been increasingly found to play multiple roles in the Env biological cycle. Here, we revealed for the first time that the CT of equine infectious anemia virus (EIAV) Env inhibits cleavage of the Env precursor. Simultaneously, the CT promoted Env endocytosis, resulting in weakened Env localization at the PM. We also validated that the CT could significantly decrease EIAV production. These findings suggest that the CT regulates the processing and trafficking of EIAV Env to balance virion production.
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8
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Prohibitin-1 Contributes to Cell-to-Cell Transmission of Herpes Simplex Virus 1 via the MAPK/ERK Signaling Pathway. J Virol 2021; 95:JVI.01413-20. [PMID: 33177205 DOI: 10.1128/jvi.01413-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2020] [Accepted: 11/05/2020] [Indexed: 12/26/2022] Open
Abstract
Viral cell-to-cell spread, a method employed by several viral families for entrance via cell junctions, is highly relevant to the pathogenesis of various viral infections. Cell-to-cell spread of herpes simplex virus 1 (HSV-1) is known to depend greatly on envelope glycoprotein E (gE). However, the molecular mechanism by which gE acts in HSV-1 cell-to-cell spread and the mechanisms of cell-to-cell spread by other herpesviruses remain poorly understood. Here, we describe our identification of prohibitin-1 as a novel gE-interacting host cell protein. Ectopic expression of prohibitin-1 increased gE-dependent HSV-1 cell-to-cell spread. As observed with the gE-null mutation, decreased expression or pharmacological inhibition of prohibitin-1 reduced HSV-1 cell-to-cell spread without affecting the yield of virus progeny. Similar effects were produced by pharmacological inhibition of the mitogen-activated protein kinase/extracellular signal-regulated kinase (MAPK/ERK) pathway, wherein prohibitin-1 acts as a protein scaffold and is required for induction of this pathway. Furthermore, artificial activation of the MAPK/ERK pathway restored HSV-1 cell-to-cell spread impaired by the gE-null mutation. Notably, pharmacological inhibition of prohibitins or the MAPK/ERK pathway reduced viral cell-to-cell spread of representative members in all herpesvirus subfamilies. Our results suggest that prohibitin-1 contributes to gE-dependent HSV-1 cell-to-cell spread via the MAPK/ERK pathway and that this mechanism is conserved throughout the Herpesviridae, whereas gE is conserved only in the Alphaherpesvirinae subfamily.IMPORTANCE Herpesviruses are ubiquitous pathogens of various animals, including humans. These viruses primarily pass through cell junctions to spread to uninfected cells. This method of cell-to-cell spread is an important pathogenic characteristic of these viruses. Here, we show that the host cell protein prohibitin-1 contributes to HSV-1 cell-to-cell spread via a downstream intracellular signaling cascade, the MAPK/ERK pathway. We also demonstrate that the role of the prohibitin-1-mediated MAPK/ERK pathway in viral cell-to-cell spread is conserved in representative members of every herpesvirus subfamily. This study has revealed a common molecular mechanism of the cell-to-cell spread of herpesviruses.
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9
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Elucidating the Basis for Permissivity of the MT-4 T-Cell Line to Replication of an HIV-1 Mutant Lacking the gp41 Cytoplasmic Tail. J Virol 2020; 94:JVI.01334-20. [PMID: 32938764 DOI: 10.1128/jvi.01334-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2020] [Accepted: 09/07/2020] [Indexed: 12/11/2022] Open
Abstract
HIV-1 encodes an envelope glycoprotein (Env) that contains a long cytoplasmic tail (CT) harboring trafficking motifs implicated in Env incorporation into virus particles and viral transmission. In most physiologically relevant cell types, the gp41 CT is required for HIV-1 replication, but in the MT-4 T-cell line the gp41 CT is not required for a spreading infection. To help elucidate the role of the gp41 CT in HIV-1 transmission, in this study, we investigated the viral and cellular factors that contribute to the permissivity of MT-4 cells to gp41 CT truncation. We found that the kinetics of HIV-1 production and virus release are faster in MT-4 than in the other T-cell lines tested, but MT-4 cells express equivalent amounts of HIV-1 proteins on a per-cell basis relative to cells not permissive to CT truncation. MT-4 cells express higher levels of plasma-membrane-associated Env than nonpermissive cells, and Env internalization from the plasma membrane is less efficient than that from another T-cell line, SupT1. Paradoxically, despite the high levels of Env on the surface of MT-4 cells, 2-fold less Env is incorporated into virus particles produced from MT-4 than SupT1 cells. Contact-dependent transmission between cocultured 293T and MT-4 cells is higher than in cocultures of 293T with most other T-cell lines tested, indicating that MT-4 cells are highly susceptible to cell-to-cell infection. These data help to clarify the long-standing question of how MT-4 cells overcome the requirement for the HIV-1 gp41 CT and support a role for gp41 CT-dependent trafficking in Env incorporation and cell-to-cell transmission in physiologically relevant cell lines.IMPORTANCE The HIV-1 Env cytoplasmic tail (CT) is required for efficient Env incorporation into nascent particles and viral transmission in primary CD4+ T cells. The MT-4 T-cell line has been reported to support multiple rounds of infection of HIV-1 encoding a gp41 CT truncation. Uncovering the underlying mechanism of MT-4 T-cell line permissivity to gp41 CT truncation would provide key insights into the role of the gp41 CT in HIV-1 transmission. This study reveals that multiple factors contribute to the unique ability of a gp41 CT truncation mutant to spread in cultures of MT-4 cells. The lack of a requirement for the gp41 CT in MT-4 cells is associated with the combined effects of rapid HIV-1 protein production, high levels of cell-surface Env expression, and increased susceptibility to cell-to-cell transmission compared to nonpermissive cells.
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10
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Muriungi NG, Ueda K. TIMM29 interacts with hepatitis B virus preS1 to modulate the HBV life cycle. Microbiol Immunol 2020; 64:792-809. [PMID: 32970362 DOI: 10.1111/1348-0421.12852] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2020] [Revised: 09/15/2020] [Accepted: 09/18/2020] [Indexed: 12/28/2022]
Abstract
Hepatitis B virus (HBV), a major global health problem, can cause chronic hepatitis, liver cirrhosis, and hepatocellular carcinomas in chronically infected patients. However, before HBV infection can be adequately controlled, many mysteries about the HBV life cycle must be solved. In this study, TIMM29, an inner mitochondrial membrane protein, was identified as an interaction partner of the preS1 region of the HBV large S protein. The interaction was verified by both an immunoprecipitation with preS1 peptides and a GST-pulldown assay. Immunofluorescence studies also showed colocalization of preS1 and TIMM29. Moreover, it was determined that the preS1 bound with amino acids 92-189 of the TIMM29 protein. Infection of HBV in TIMM29-overexpressing NTCP/G2 cells resulted in a significant decrease of HBeAg and both extracellular particle-associated and core particle-associated HBV DNA without affecting cccDNA formation. Comparable results were obtained with TIMM29-overexpressing HB611 cells, which constitutively produce HBV. In contrast, knockout of TIMM29 in NTCP/G2 cells led to a higher production of HBV including HBeAg expression, as did knockout of TIMM29 in HB611. Collectively, these results suggested that TIMM29 interacts with the preS1 region of the HBV large S protein and modulates HBV amplification.
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Affiliation(s)
- Nelly Gakii Muriungi
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
| | - Keiji Ueda
- Division of Virology, Department of Microbiology and Immunology, Osaka University Graduate School of Medicine, 2-2 Yamada-oka, Suita, Osaka, 565-0871, Japan
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11
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Jin X, Xie J, Zabolocki M, Wang X, Jiang T, Wang D, Désaubry L, Bardy C, Proud CG. The prohibitin-binding compound fluorizoline affects multiple components of the translational machinery and inhibits protein synthesis. J Biol Chem 2020; 295:9855-9867. [PMID: 32430400 DOI: 10.1074/jbc.ra120.012979] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/10/2020] [Revised: 05/12/2020] [Indexed: 01/12/2023] Open
Abstract
Fluorizoline (FLZ) binds to prohibitin-1 and -2 (PHB1/2), which are pleiotropic scaffold proteins known to affect signaling pathways involved in several intracellular processes. However, it is not yet clear how FLZ exerts its effect. Here, we show that exposure of three different human cancer cell lines to FLZ increases the phosphorylation of key translation factors, particularly of initiation factor 2 (eIF2) and elongation factor 2 (eEF2), modifications that inhibit their activities. FLZ also impaired signaling through mTOR complex 1, which also regulates the translational machinery, e.g. through the eIF4E-binding protein 4E-BP1. In line with these findings, FLZ potently inhibited protein synthesis. We noted that the first phase of this inhibition involves very rapid eEF2 phosphorylation, which is catalyzed by a dedicated Ca2+-dependent protein kinase, eEF2 kinase (eEF2K). We also demonstrate that FLZ induces a swift and marked rise in intracellular Ca2+ levels, likely explaining the effects on eEF2. Disruption of normal Ca2+ homeostasis can also induce endoplasmic reticulum stress, and our results suggest that induction of this stress response contributes to the increased phosphorylation of eIF2, likely because of activation of the eIF2-modifying kinase PKR-like endoplasmic reticulum kinase (PERK). We show that FLZ induces cancer cell death and that this effect involves contributions from the phosphorylation of both eEF2 and eIF2. Our findings provide important new insights into the biological effects of FLZ and thus the roles of PHBs, specifically in regulating Ca2+ levels, cellular protein synthesis, and cell survival.
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Affiliation(s)
- Xin Jin
- Lifelong Health Theme, South Australian Health & Medical Research Institute, Adelaide, Australia.,Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology and School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Jianling Xie
- Lifelong Health Theme, South Australian Health & Medical Research Institute, Adelaide, Australia
| | - Michael Zabolocki
- Lifelong Health Theme, South Australian Health & Medical Research Institute, Adelaide, Australia.,Laboratory for Human Neurophysiology and Genetics, College of Medicine and Public Health, Flinders University, Adelaide, Australia
| | - Xuemin Wang
- Lifelong Health Theme, South Australian Health & Medical Research Institute, Adelaide, Australia.,School of Biological Sciences, University of Adelaide, Adelaide, Australia
| | - Tao Jiang
- Laboratory for Marine Drugs and Bioproducts, Qingdao National Laboratory for Marine Science and Technology and School of Medicine and Pharmacy, Ocean University of China, Qingdao, China
| | - Dong Wang
- Sino-French Joint Lab of Food Nutrition/Safety and Medicinal Chemistry, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China
| | - Laurent Désaubry
- Sino-French Joint Lab of Food Nutrition/Safety and Medicinal Chemistry, College of Biotechnology, Tianjin University of Science and Technology, Tianjin, China.,Laboratory of Medicinal Chemistry and Cardio-oncology, CNRS, Strasbourg, France
| | - Cedric Bardy
- Lifelong Health Theme, South Australian Health & Medical Research Institute, Adelaide, Australia.,Laboratory for Human Neurophysiology and Genetics, College of Medicine and Public Health, Flinders University, Adelaide, Australia
| | - Christopher G Proud
- Lifelong Health Theme, South Australian Health & Medical Research Institute, Adelaide, Australia .,School of Biological Sciences, University of Adelaide, Adelaide, Australia
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12
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Sutar J, Padwal V, Nagar V, Patil P, Patel V, Bandivdekar A. Analysis of sequence diversity and selection pressure in HIV-1 clade C gp41 from India. Virusdisease 2020; 31:277-291. [PMID: 32904888 DOI: 10.1007/s13337-020-00595-x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2020] [Accepted: 04/28/2020] [Indexed: 01/31/2023] Open
Abstract
Evaluation of viral diversity is critical for the rational design of treatment modalities against Human immunodeficiency virus (HIV). Predominated by HIV-1 clade C (HIV-1C), the epidemic in India represents the third largest population infected with HIV-1 globally. Glycoprotein 41 (gp41) is critical for viral replication and is a target for the design of therapeutic strategies. However, documentation of viral diversity of gp41 gene in infected individuals from India remains limited. Present study employed high throughput sequencing to examine variation in gp41 amplicons generated from blood derived viruses in 24 HIV-1C infected individuals from Mumbai, India. Sequence diversity profiles were documented in different functional domains of gp41. Furthermore, through a meta-analysis approach, all reported gp41 sequences from India (N = 70) were compared with those from South Africa (N = 126), country with the largest HIV epidemic globally, also predominated by HIV-1C. A total of 44 positions displayed statistically significant differential (p < 0.05) Shannon entropy in the two regions. This comparison also identified 11 codon sites undergoing distinct selection, 8 of which remained differentially selected in an extended comparison of data from Asia (N = 137) and Africa(N = 383). Assessment of correlated mutation networks associated with differentially selected residues revealed common as well as distinct interaction networks. Furthermore, codon usage analysis revealed 17 differentially selected codons (Mann-Whitney test, p < 0.001) in Asia and Africa. Dissimilar trends in GC content across codon positions were also observed. In depth understanding of these divergent evolutionary signatures through extended analysis with larger data-sets would assist development of effective interventions being considered for HIV-1C.
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Affiliation(s)
- Jyoti Sutar
- Department of Biochemistry, National Institute for Research in Reproductive Health (NIRRH), Indian Council of Medical Research (ICMR), Parel, Mumbai, India
| | - Varsha Padwal
- Department of Biochemistry, National Institute for Research in Reproductive Health (NIRRH), Indian Council of Medical Research (ICMR), Parel, Mumbai, India
| | - Vidya Nagar
- Department of Medicine, Grant Government Medical College, Byculla, Mumbai, India
| | - Priya Patil
- Department of Medicine, Grant Government Medical College, Byculla, Mumbai, India
| | - Vainav Patel
- Department of Biochemistry, National Institute for Research in Reproductive Health (NIRRH), Indian Council of Medical Research (ICMR), Parel, Mumbai, India
| | - Atmaram Bandivdekar
- Department of Biochemistry, National Institute for Research in Reproductive Health (NIRRH), Indian Council of Medical Research (ICMR), Parel, Mumbai, India
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13
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Interaction between PHB2 and Enterovirus A71 VP1 Induces Autophagy and Affects EV-A71 Infection. Viruses 2020; 12:v12040414. [PMID: 32276428 PMCID: PMC7232526 DOI: 10.3390/v12040414] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2020] [Revised: 03/30/2020] [Accepted: 04/03/2020] [Indexed: 12/14/2022] Open
Abstract
Enterovirus A71 (EV-A71) is a major pathogen that causes severe and fatal cases of hand-foot-and-mouth disease (HFMD). HFMD caused by EV-A71 seriously endangers children’s health. Although autophagy is an important antiviral defense mechanism, some viruses have evolved strategies to utilize autophagy to promote self-replication. EV-A71 can utilize autophagy vesicles as replication scaffolds, indicating that EV-A71 infection is closely related to its autophagy induction mechanism. VP1, a structural protein of EV-A71, has been reported to induce autophagy, but the underlying mechanism is still unclear. In this study, we found that the C-terminus (aa 251–297) of VP1 induces autophagy. Mass spectrometry analysis suggested that prohibitin 2 (PHB2) interacts with the C-terminus of the EV-A71 VP1 protein, and this was further verified by coimmunoprecipitation assays. After PHB2 knockdown, EV-A71 replication, viral particle release, and viral protein synthesis were reduced, and autophagy was inhibited. The results suggest that PHB2 interaction with VP1 is essential for induction of autophagy and the infectivity of EV-A71. Furthermore, we confirmed that EV-A71 induced complete autophagy that required autolysosomal acidification, thus affecting EV-A71 infection. In summary, this study revealed that the host protein PHB2 is involved in an autophagy mechanism during EV-A71 infection.
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14
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Li CW, Chen BS. Investigating HIV-Human Interaction Networks to Unravel Pathogenic Mechanism for Drug Discovery: A Systems Biology Approach. Curr HIV Res 2019; 16:77-95. [PMID: 29468972 DOI: 10.2174/1570162x16666180219155324] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Revised: 01/18/2018] [Accepted: 02/14/2018] [Indexed: 02/08/2023]
Abstract
BACKGROUND Two big issues in the study of pathogens are determining how pathogens infect hosts and how the host defends itself against infection. Therefore, investigating host-pathogen interactions is important for understanding pathogenicity and host defensive mechanisms and treating infections. METHODS In this study, we used omics data, including time-course data from high-throughput sequencing, real-time polymerase chain reaction, and human microRNA (miRNA) and protein-protein interaction to construct an interspecies protein-protein and miRNA interaction (PPMI) network of human CD4+ T cells during HIV-1 infection through system modeling and identification. RESULTS By applying a functional annotation tool to the identified PPMI network at each stage of HIV infection, we found that repressions of three miRNAs, miR-140-5p, miR-320a, and miR-941, are involved in the development of autoimmune disorders, tumor proliferation, and the pathogenesis of T cells at the reverse transcription stage. Repressions of miR-331-3p and miR-320a are involved in HIV-1 replication, replicative spread, anti-apoptosis, cell proliferation, and dysregulation of cell cycle control at the integration/replication stage. Repression of miR-341-5p is involved in carcinogenesis at the late stage of HIV-1 infection. CONCLUSION By investigating the common core proteins and changes in specific proteins in the PPMI network between the stages of HIV-1 infection, we obtained pathogenic insights into the functional core modules and identified potential drug combinations for treating patients with HIV-1 infection, including thalidomide, oxaprozin, and metformin, at the reverse transcription stage; quercetin, nifedipine, and fenbendazole, at the integration/replication stage; and staurosporine, quercetin, prednisolone, and flufenamic acid, at the late stage.
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Affiliation(s)
- Cheng-Wei Li
- Laboratory of Control and Systems Biology, Department of Electrical Engineering, National Tsing Hua University, Hsinchu, Taiwan
| | - Bor-Sen Chen
- Laboratory of Control and Systems Biology, Department of Electrical Engineering, National Tsing Hua University, Hsinchu, Taiwan
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15
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Klug YA, Schwarzer R, Rotem E, Charni M, Nudelman A, Gramatica A, Zarmi B, Rotter V, Shai Y. The HIV gp41 Fusion Protein Inhibits T-Cell Activation through the Lentiviral Lytic Peptide 2 Motif. Biochemistry 2019; 58:818-832. [PMID: 30602116 DOI: 10.1021/acs.biochem.8b01175] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
The human immunodeficiency virus enters its host cells by membrane fusion, initiated by the gp41 subunit of its envelope protein. gp41 has also been shown to bind T-cell receptor (TCR) complex components, interfering with TCR signaling leading to reduced T-cell activation. This immunoinhibitory activity is suggested to occur during the membrane fusion process and is attributed to various membranotropic regions of the gp41 ectodomain and to the transmembrane domain. Although extensively studied, the cytosolic region of gp41, termed the cytoplasmic tail (CT), has not been examined in the context of immune suppression. Here we investigated whether the CT inhibits T-cell activation in different T-cell models by utilizing gp41-derived peptides and expressed full gp41 proteins. We found that a conserved region of the CT, termed lentiviral lytic peptide 2 (LLP2), specifically inhibits the activation of mouse, Jurkat, and human primary T-cells. This inhibition resulted in reduced T-cell proliferation, gene expression, cytokine secretion, and cell surface expression of CD69. Differential activation of the TCR signaling cascade revealed that CT-based immune suppression occurs downstream of the TCR complex. Moreover, LLP2 peptide treatment of Jurkat and primary human T-cells impaired Akt but not NFκB and ERK1/2 activation, suggesting that immune suppression occurs through the Akt pathway. These findings identify a novel gp41 T-cell suppressive element with a unique inhibitory mechanism that can take place post-membrane fusion.
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Affiliation(s)
- Yoel A Klug
- Department of Biomolecular Sciences , Weizmann Institute of Science , Rehovot 7610001 , Israel
| | - Roland Schwarzer
- Gladstone Institute for Virology and Immunology , University of California, San Francisco , San Francisco , California 94158 , United States
| | - Etai Rotem
- Department of Biomolecular Sciences , Weizmann Institute of Science , Rehovot 7610001 , Israel
| | - Meital Charni
- Department of Molecular Cell Biology , Weizmann Institute of Science , Rehovot 7610001 , Israel
| | - Alon Nudelman
- Department of Biomolecular Sciences , Weizmann Institute of Science , Rehovot 7610001 , Israel
| | - Andrea Gramatica
- Gladstone Institute for Virology and Immunology , University of California, San Francisco , San Francisco , California 94158 , United States
| | - Batya Zarmi
- Department of Biomolecular Sciences , Weizmann Institute of Science , Rehovot 7610001 , Israel
| | - Varda Rotter
- Department of Molecular Cell Biology , Weizmann Institute of Science , Rehovot 7610001 , Israel
| | - Yechiel Shai
- Department of Biomolecular Sciences , Weizmann Institute of Science , Rehovot 7610001 , Israel
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16
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Ching KC, F P Ng L, Chai CLL. A compendium of small molecule direct-acting and host-targeting inhibitors as therapies against alphaviruses. J Antimicrob Chemother 2018; 72:2973-2989. [PMID: 28981632 PMCID: PMC7110243 DOI: 10.1093/jac/dkx224] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
Alphaviruses were amongst the first arboviruses to be isolated, characterized and assigned a taxonomic status. They are globally widespread, infecting a large variety of terrestrial animals, birds, insects and even fish. Moreover, they are capable of surviving and circulating in both sylvatic and urban environments, causing considerable human morbidity and mortality. The re-emergence of Chikungunya virus (CHIKV) in almost every part of the world has caused alarm to many health agencies throughout the world. The mosquito vector for this virus, Aedes, is globally distributed in tropical and temperate regions and capable of thriving in both rural and urban landscapes, giving the opportunity for CHIKV to continue expanding into new geographical regions. Despite the importance of alphaviruses as human pathogens, there is currently no targeted antiviral treatment available for alphavirus infection. This mini-review discusses some of the major features in the replication cycle of alphaviruses, highlighting the key viral targets and host components that participate in alphavirus replication and the molecular functions that were used in drug design. Together with describing the importance of these targets, we review the various direct-acting and host-targeting inhibitors, specifically small molecules that have been discovered and developed as potential therapeutics as well as their reported in vitro and in vivo efficacies.
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Affiliation(s)
- Kuan-Chieh Ching
- NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, #05-01, 28 Medical Drive, Singapore 117456.,Department of Pharmacy, Faculty of Science, National University of Singapore, Block S4A, Level 3, 18 Science Drive 4, Singapore 117543
| | - Lisa F P Ng
- Singapore Immunology Network, A*STAR, 8A Biomedical Grove, Immunos Building, #04-06, Singapore 138648.,Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Block MD6, Centre for Translational Medicine, 14 Medical Drive, #14-01T, Singapore 117599.,Institute of Infection and Global Health, University of Liverpool, Ronald Ross Building, 8 West Derby Street, Liverpool L697BE, UK
| | - Christina L L Chai
- NUS Graduate School for Integrative Sciences and Engineering, Centre for Life Sciences, #05-01, 28 Medical Drive, Singapore 117456.,Department of Pharmacy, Faculty of Science, National University of Singapore, Block S4A, Level 3, 18 Science Drive 4, Singapore 117543
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17
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Wong KZ, Chu JJH. The Interplay of Viral and Host Factors in Chikungunya Virus Infection: Targets for Antiviral Strategies. Viruses 2018; 10:E294. [PMID: 29849008 PMCID: PMC6024654 DOI: 10.3390/v10060294] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2018] [Revised: 05/13/2018] [Accepted: 05/28/2018] [Indexed: 12/14/2022] Open
Abstract
Chikungunya virus (CHIKV) has re-emerged as one of the many medically important arboviruses that have spread rampantly across the world in the past decade. Infected patients come down with acute fever and rashes, and a portion of them suffer from both acute and chronic arthralgia. Currently, there are no targeted therapeutics against this debilitating virus. One approach to develop potential therapeutics is by understanding the viral-host interactions. However, to date, there has been limited research undertaken in this area. In this review, we attempt to briefly describe and update the functions of the different CHIKV proteins and their respective interacting host partners. In addition, we also survey the literature for other reported host factors and pathways involved during CHIKV infection. There is a pressing need for an in-depth understanding of the interaction between the host environment and CHIKV in order to generate potential therapeutics.
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Affiliation(s)
- Kai Zhi Wong
- Laboratory of Molecular RNA Virology & Antiviral Strategies, Department of Microbiology & Immunology, Yong Loo Lin School of Medicine, National University Health System, 5 Science Drive 2, National University of Singapore, Singapore 117597, Singapore.
| | - Justin Jang Hann Chu
- Laboratory of Molecular RNA Virology & Antiviral Strategies, Department of Microbiology & Immunology, Yong Loo Lin School of Medicine, National University Health System, 5 Science Drive 2, National University of Singapore, Singapore 117597, Singapore.
- Institute of Molecular & Cell Biology, Agency for Science, Technology & Research (A*STAR), 61 Biopolis Drive, Proteos #06-05, Singapore 138673, Singapore.
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18
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Zi Xu YX, Ande SR, Mishra S. Prohibitin: A new player in immunometabolism and in linking obesity and inflammation with cancer. Cancer Lett 2018; 415:208-216. [DOI: 10.1016/j.canlet.2017.12.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/06/2017] [Revised: 11/30/2017] [Accepted: 12/01/2017] [Indexed: 12/13/2022]
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19
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Too IHK, Bonne I, Tan EL, Chu JJH, Alonso S. Prohibitin plays a critical role in Enterovirus 71 neuropathogenesis. PLoS Pathog 2018; 14:e1006778. [PMID: 29324904 PMCID: PMC5764453 DOI: 10.1371/journal.ppat.1006778] [Citation(s) in RCA: 48] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 11/28/2017] [Indexed: 12/14/2022] Open
Abstract
A close relative of poliovirus, enterovirus 71 (EV71) is regarded as an important neurotropic virus of serious public health concern. EV71 causes Hand, Foot and Mouth Disease and has been associated with neurological complications in young children. Our limited understanding of the mechanisms involved in its neuropathogenesis has hampered the development of effective therapeutic options. Here, using a two-dimensional proteomics approach combined with mass spectrometry, we have identified a unique panel of host proteins that were differentially and dynamically modulated during EV71 infection of motor-neuron NSC-34 cells, which are found at the neuromuscular junctions where EV71 is believed to enter the central nervous system. Meta-analysis with previously published proteomics studies in neuroblastoma or muscle cell lines revealed minimal overlapping which suggests unique host-pathogen interactions in NSC-34 cells. Among the candidate proteins, we focused our attention on prohibitin (PHB), a protein that is involved in multiple cellular functions and the target of anti-cancer drug Rocaglamide (Roc-A). We demonstrated that cell surface-expressed PHB is involved in EV71 entry into neuronal cells specifically, while membrane-bound mitochondrial PHB associates with the virus replication complex and facilitates viral replication. Furthermore, Roc-A treatment of EV71-infected neuronal cells reduced significantly virus yields. However, the inhibitory effect of Roc-A on PHB in NSC-34 cells was not through blocking the CRAF/MEK/ERK pathway as previously reported. Instead, Roc-A treated NSC-34 cells had lower mitochondria-associated PHB and lower ATP levels that correlated with impaired mitochondria integrity. In vivo, EV71-infected mice treated with Roc-A survived longer than the vehicle-treated animals and had significantly lower virus loads in their spinal cord and brain, whereas virus titers in their limb muscles were comparable to controls. Together, this study uncovers PHB as the first host factor that is specifically involved in EV71 neuropathogenesis and a potential drug target to limit neurological complications.
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Affiliation(s)
- Issac Horng Khit Too
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore
| | - Isabelle Bonne
- Electron Microscopy Laboratory, Life Sciences Institute, National University of Singapore, Singapore
| | - Eng Lee Tan
- Department of Pediatrics, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Centre for Biomedical & Life Sciences, Singapore Polytechnic, Singapore
| | - Justin Jang Hann Chu
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Sylvie Alonso
- Department of Microbiology and Immunology, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
- Immunology Programme, Life Sciences Institute, National University of Singapore, Singapore
- * E-mail:
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20
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Xu YR, Fan YS, Yang WX. Mitochondrial prohibitin and its ubiquitination during spermatogenesis of the swimming crab Charybdis japonica. Gene 2017. [DOI: 10.1016/j.gene.2017.06.025] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
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21
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Mishra S, Nyomba BG. Prohibitin - At the crossroads of obesity-linked diabetes and cancer. Exp Biol Med (Maywood) 2017; 242:1170-1177. [PMID: 28399645 DOI: 10.1177/1535370217703976] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
The promoter of a gene that is selectively expressed in just a few cell types provides unique opportunities to study: (1) the pleiotropic function of a protein in two different cell types including the cell compartment specific function, and (2) the crosstalk between two cell/tissue types at the systemic level. This is not possible with a ubiquitous or a highly specific gene promoter. The adipocyte protein-2 ( aP2) is one such gene. It is primarily expressed in adipocytes, but also selectively in monocytic macrophages and dendritic cells, among various immune cell types. Thus, the adipocyte protein-2 gene promoter provides an opportunity to simultaneously manipulate adipose and immune functions in a transgenic animal. Prohibitin (PHB) is a pleiotropic protein that has roles in both adipocytes and immune cells. Adipocyte specific functions of prohibitin are mediated through its mitochondrial function, whereas its immune functions are mediated in a phosphorylation-dependent manner. We capitalized on this attribute of prohibitin to explore the crosstalk between adipose and immune functions, and to discern mitochondrial and plasma membrane-associated cell signaling functions of prohibitin, by expressing wild type prohibitin (Mito-Ob) and a phospho-mutant form of prohibitin (m-Mito-Ob) from the protein-2 gene promoter, individually. Both transgenic mice develop obesity in a sex-neutral manner, but develop obesity-related metabolic dysregulation in a male sex-specific manner. Subsequently, the male Mito-Ob mice spontaneously developed type 2 diabetes and liver cancer, whereas the male m-Mito-Ob mice developed lymph node tumors or autoimmune diabetes in a context-dependent manner. This review provides a point of view on the role of prohibitin in mediating sex differences in adipose and immune functions at the systemic level. We discuss the unique attributes of prohibitin and provide a new paradigm in adipose-immune crosstalk mediated through a pleiotropic protein. Impact statement Prohibitin (PHB) is ubiquitously expressed and plays a role in adipocyte-immune cell cross-talk. Both male and female transgenic mice expressing wild-type PHB in adipose tissue and in macrophages are obese, but only males develop diabetes and liver cancer. When the mice express PHB mutated on tyrosine-114 in adipocytes and macrophages, both males and females are still obese, but none develops liver cancer; instead, males develop lymph node tumors. Adipocyte specific functions of PHB are mediated through its mitochondrial function, whereas its immune functions are mediated in a phosphorylation-dependent manner. Thus, PHB appears to be an important molecule linking obesity, diabetes, and cancer. In addition, this link appears to be affected by sex steroids. Therefore, targeting PHB may lead to a better understanding of the pathogenesis of obesity, diabetes and cancer.
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Affiliation(s)
- Suresh Mishra
- 1 Department of Internal Medicine, University of Manitoba, Winnipeg R3E3P4, Canada.,2 Department of Physiology & Pathophysiology, University of Manitoba, Winnipeg R3E3P4, Canada
| | - Bl Grégoire Nyomba
- 1 Department of Internal Medicine, University of Manitoba, Winnipeg R3E3P4, Canada
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22
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Japanese encephalitis virus induces human neural stem/progenitor cell death by elevating GRP78, PHB and hnRNPC through ER stress. Cell Death Dis 2017; 8:e2556. [PMID: 28102850 PMCID: PMC5386351 DOI: 10.1038/cddis.2016.394] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2016] [Revised: 10/17/2016] [Accepted: 10/25/2016] [Indexed: 12/20/2022]
Abstract
Japanese encephalitis virus (JEV), which is a causative agent of sporadic encephalitis, harbours itself inside the neural stem/progenitor cells. It is a well-known fact that JEV infects neural stem/progenitor cells and decreases their proliferation capacity. With mass spectrometry-based quantitative proteomic study, it is possible to reveal the impact of virus on the stem cells at protein level. Our aim was to perceive the stem cell proteomic response upon viral challenge. We performed a two-dimensional gel electrophoresis-based proteomic study of the human neural stem cells (hNS1 cell line) post JEV infection and found that 13 proteins were differentially expressed. The altered proteome profile of hNS1 cell line revealed sustained endoplasmic reticulum stress, which deteriorated normal cellular activities leading to cell apoptosis. The proteomic changes found in hNS1 cell line were validated in vivo in the subventricular zone of JE infected BALB/c mice. Congruent alterations were also witnessed in multipotent neural precursor cells isolated from human foetus and in autopsy samples of human brain clinically diagnosed as cases of JE patients. Endoplasmic reticulum resident chaperone GRP78, mitochondrial protein Prohibitin and heterogeneous nuclear ribonucleoprotein hnRNPC (C1/C2) have been shown to interact with viral RNA. Hence it is proposed that these are the principle candidates governing endoplasmic reticulum stress-induced apoptosis in JEV infection.
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23
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Sakurai Y, Kajimoto K, Harashima H. Anti-angiogenic nanotherapy via active targeting systems to tumors and adipose tissue vasculature. Biomater Sci 2017; 3:1253-65. [PMID: 26261854 DOI: 10.1039/c5bm00113g] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Sophisticated drug delivery systems (DDS) are required for delivering drugs, especially macromolecules such as nucleic acids or proteins, to their sites of action. Therefore it is a prerequisite that future DDS are designed to selectively target a tissue. In this review, we focus on systems that actively target the vasculature in tumors or adipose tissues. For targeting tumor vasculatur, a new strategy referred to as dual-targeting is proposed that uses a combination of a receptor specific ligand and a cell penetrating peptide, which can induce the synergistic enhancement of tissue selectivity under in vivo conditions. A novel pH-sensitive cationic lipid was designed to enhance the endosomal release of encapsulated compounds such as siRNA as well as to improve the stability in blood circulation after intravenous administration. A cyclic RGD peptide is used as an active targeting ligand. For targeting adipose vasculature, prohibitin, which is expressed on the surface of adipose endothelial cells, was targeted with KGGRAKD peptides on the surface of PEGylated nanoparticles. Prohibitin targeted nanoparticles (PTNP) encapsulating Cytochrome c (CytC) can selectively target adipose vasculature by optimizing the lengths of the PEG linkers and can deliver CytC to adipose endothelial cells. PTNP can successfully induce anti-obese effects as well as apoptosis by delivering CytC to the cytosol in endothelial cells. Unexpectedly, the EPR (enhanced permeability and retention) effect, which is usually observed in tumor tissue, was also observed in the adipose vasculature, especially in obese mice, where PEGylated nanoparticles can pass through the endothelial barriers in adipose tissue. We believe that these achievements in active targeting will allow a greatly expanded use of DDS for nanomedicines.
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Affiliation(s)
- Yu Sakurai
- Faculty of Pharmaceutical Sciences, Hokkaido University, Japan.
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The Envelope Cytoplasmic Tail of HIV-1 Subtype C Contributes to Poor Replication Capacity through Low Viral Infectivity and Cell-to-Cell Transmission. PLoS One 2016; 11:e0161596. [PMID: 27598717 PMCID: PMC5012655 DOI: 10.1371/journal.pone.0161596] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2016] [Accepted: 08/08/2016] [Indexed: 12/15/2022] Open
Abstract
The cytoplasmic tail (gp41CT) of the HIV-1 envelope (Env) mediates Env incorporation into virions and regulates Env intracellular trafficking. Little is known about the functional impact of variability in this domain. To address this issue, we compared the replication of recombinant virus pairs carrying the full Env (Env viruses) or the Env ectodomain fused to the gp41CT of NL4.3 (EnvEC viruses) (12 subtype C and 10 subtype B pairs) in primary CD4+ T-cells and monocyte-derived-macrophages (MDMs). In CD4+ T-cells, replication was as follows: B-EnvEC = B-Env>C-EnvEC>C-Env, indicating that the gp41CT of subtype C contributes to the low replicative capacity of this subtype. In MDMs, in contrast, replication capacity was comparable for all viruses regardless of subtype and of gp41CT. In CD4+ T-cells, viral entry, viral release and viral gene expression were similar. However, infectivity of free virions and cell-to-cell transmission of C-Env viruses released by CD4+ T-cells was lower, suggestive of lower Env incorporation into virions. Subtype C matrix only minimally rescued viral replication and failed to restore infectivity of free viruses and cell-to-cell transmission. Taken together, these results show that polymorphisms in the gp41CT contribute to viral replication capacity and suggest that the number of Env spikes per virion may vary across subtypes. These findings should be taken into consideration in the design of vaccines.
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Identifying possible sites for antibody neutralization escape: Implications for unique functional properties of the C-terminal tail of Human Immunodeficiency Virus Type 1 gp41. Immunol Lett 2016; 175:21-30. [PMID: 27157128 DOI: 10.1016/j.imlet.2016.04.005] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2015] [Revised: 04/09/2016] [Accepted: 04/11/2016] [Indexed: 11/21/2022]
Abstract
A previous amino acid sequence analyses from our laboratory reported nine potential sites in gp41 glycoprotein of HIV-1 that may contribute to virus escape from antibody neutralization. Besides four sites found outside the membrane of HIV-1 virus, five located in the C-terminal tail of gp41 specifically in the lentivirus lytic peptides motifs (LLPs). To further study the bioinformatical results, the virus infectivity assay and the standard neutralization assay were conducted on conservatively mutated virus. Two sites in the LLP3 domain stood out with the ability to alter the resistance of HIV-1 virus to certain broadly neutralizing antibodies (bNAbs). While the glycoprotein incorporation on the viral membrane and the interaction of the LLP3 domain with the lipid membrane remained unaltered, the increase in neutralization resistance of the mutant virus was associated with the changes on Env conformation. Our findings demonstrate different sensibility of bNAbs to mutations in the C-terminal tail and indicate an unrecognized potential role for even minor sequence variation in the C-terminal tail in modulating the antigenicity of the ectodomain of HIV-1 envelope glycoprotein complex.
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Wintachai P, Thuaud F, Basmadjian C, Roytrakul S, Ubol S, Désaubry L, Smith DR. Assessment of flavaglines as potential chikungunya virus entry inhibitors. Microbiol Immunol 2016; 59:129-41. [PMID: 25643977 PMCID: PMC7168458 DOI: 10.1111/1348-0421.12230] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2014] [Revised: 12/19/2014] [Accepted: 01/21/2015] [Indexed: 11/28/2022]
Abstract
Chikungunya virus (CHIKV) is a re‐emerging mosquito‐borne alphavirus that recently caused large epidemics in islands in, and countries around, the Indian Ocean. There is currently no specific drug for therapeutic treatment or for use as a prophylactic agent against infection and no commercially available vaccine. Prohibitin has been identified as a receptor protein used by chikungunya virus to enter mammalian cells. Recently, synthetic sulfonyl amidines and flavaglines (FLs), a class of naturally occurring plant compounds with potent anti‐cancer and cytoprotective and neuroprotective activities, have been shown to interact directly with prohibitin. This study therefore sought to determine whether three prohibitin ligands (sulfonyl amidine 1 m and the flavaglines FL3 and FL23) were able to inhibit CHIKV infection of mammalian Hek293T/17 cells. All three compounds inhibited infection and reduced virus production when cells were treated before infection but not when added after infection. Pretreatment of cells for only 15 minutes prior to infection followed by washing out of the compound resulted in significant inhibition of entry and virus production. These results suggest that further investigation of prohibitin ligands as potential Chikungunya virus entry inhibitors is warranted.
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Obesity-related abnormalities couple environmental triggers with genetic susceptibility in adult-onset T1D. Biochem Biophys Res Commun 2016; 470:94-100. [DOI: 10.1016/j.bbrc.2016.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2015] [Accepted: 01/01/2016] [Indexed: 12/18/2022]
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Koushyar S, Jiang WG, Dart DA. Unveiling the potential of prohibitin in cancer. Cancer Lett 2015; 369:316-22. [PMID: 26450374 DOI: 10.1016/j.canlet.2015.09.012] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 09/16/2015] [Accepted: 09/19/2015] [Indexed: 12/18/2022]
Abstract
Recently, research has shed new light on the role of Prohibitin (PHB) in cancer pathogenesis across an array of cancer types. Important mechanisms for PHB have been unveiled in several cancers, especially with regard to the androgen independent state of prostate cancer (PC) and oestrogen dependent breast cancer. However, PHB is often overlooked due to its complex but subtle roles within the cell. Having gathered both historical and current research exploring PHB's role in different cancer types including prostate and breast, here we aim to pair this information with its molecular properties in the hope of translating this information into a clinical perspective, thus discussing its possible use in future cancer therapy.
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Affiliation(s)
- Sarah Koushyar
- Cardiff China Medical Research Collaborative (CCMRC), Cardiff University, School of Medicine, Henry Welcome Building, Heath Park, Cardiff CF14 4XN, UK.
| | - Wen G Jiang
- Cardiff China Medical Research Collaborative (CCMRC), Cardiff University, School of Medicine, Henry Welcome Building, Heath Park, Cardiff CF14 4XN, UK
| | - D Alwyn Dart
- Cardiff China Medical Research Collaborative (CCMRC), Cardiff University, School of Medicine, Henry Welcome Building, Heath Park, Cardiff CF14 4XN, UK
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Liu S, Wang W, Brown LE, Qiu C, Lajkiewicz N, Zhao T, Zhou J, Porco JA, Wang TT. A Novel Class of Small Molecule Compounds that Inhibit Hepatitis C Virus Infection by Targeting the Prohibitin-CRaf Pathway. EBioMedicine 2015; 2:1600-6. [PMID: 26870784 PMCID: PMC4740292 DOI: 10.1016/j.ebiom.2015.09.018] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Revised: 09/02/2015] [Accepted: 09/11/2015] [Indexed: 01/20/2023] Open
Abstract
Identification of novel drug targets and affordable therapeutic agents remains a high priority in the fight against chronic hepatitis C virus (HCV) infection. Here, we report that the cellular proteins prohibitin 1 (PHB1) and 2 (PHB2) are pan-genotypic HCV entry factors functioning at a post-binding step. While predominantly found in mitochondria, PHBs localize to the plasma membrane of hepatocytes through their transmembrane domains and interact with both EGFR and CRaf. Targeting PHB by rocaglamide (Roc-A), a natural product that binds PHB1 and 2, reduced cell surface PHB1 and 2, disrupted PHB-CRaf interaction, and inhibited HCV entry at low nanomolar concentrations. A structure-activity analysis of 32 synthetic Roc-A analogs indicated that the chiral, racemic version of aglaroxin C, a natural product biosynthetically related to Roc-A, displayed improved potency and therapeutic index against HCV infection. This study reveals a new class of HCV entry inhibitors that target the PHB1/2-CRaf pathway. Cellular proteins prohibitins 1 and 2 are essential HCV entry factors that function at a post-binding step. The natural compound Roc-A potently blocks HCV infection by disrupting prohibitins-CRaf interaction The Roc-A derivative, aglaroxin C, displays improved potency and therapeutic index towards HCV infection
Current FDA-approved HCV drugs all target viral proteins. We now demonstrate that a group of small molecules, the rocaglates, potently block HCV entry at low nanomolar concentrations. Roc-A inhibits HCV entry by disrupting the important interaction between two pan-genomic HCV entry factors, PHB1 and 2, and the signaling molecule CRaf. Overall, Roc-A and related rocaglates represent a new class of compounds that hold significant therapeutic promise in treating HCV infection.
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Affiliation(s)
- Shufeng Liu
- Center for Immunology and Infectious Diseases, Biosciences Division, SRI International, Harrisonburg, VA 22802, USA
| | - Wenyu Wang
- Department of Chemistry, Center for Molecular Discovery (BU-CMD), Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA
| | - Lauren E Brown
- Department of Chemistry, Center for Molecular Discovery (BU-CMD), Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA
| | - Chao Qiu
- Shanghai Public Health Clinical Center, Institutes of Biomedical Sciences, Key Laboratory of Medical Molecular Virology of Ministry of Education/Health, Fudan University, 2901 Caolang Road, Shanghai 201508, China
| | - Neil Lajkiewicz
- Department of Chemistry, Center for Molecular Discovery (BU-CMD), Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA
| | - Ting Zhao
- College of Pharmacy, University of Michigan, Ann Arbor, MI 48109, USA
| | - Jianhua Zhou
- Department of Urology, School of Medicine, University of Pittsburgh Medical Center, Pittsburgh, PA 15232, USA
| | - John A Porco
- Department of Chemistry, Center for Molecular Discovery (BU-CMD), Boston University, 590 Commonwealth Avenue, Boston, MA 02215, USA
| | - Tony T Wang
- Center for Immunology and Infectious Diseases, Biosciences Division, SRI International, Harrisonburg, VA 22802, USA
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HIV-1 Cell-Free and Cell-to-Cell Infections Are Differentially Regulated by Distinct Determinants in the Env gp41 Cytoplasmic Tail. J Virol 2015; 89:9324-37. [PMID: 26136566 DOI: 10.1128/jvi.00655-15] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 06/23/2015] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The HIV-1 envelope (Env) glycoprotein mediates viral entry during both cell-free and cell-to-cell infection of CD4(+) T cells. The highly conserved long cytoplasmic tail (CT) of Env is required in a cell type-dependent manner for optimal infectivity of cell-free virus. To probe the role of the CT in cell-to-cell infection, we tested a panel of mutations in the CT region that maintain or attenuate cell-free infection to investigate whether the functions of the CT are conserved during cell-free and cell-to-cell infection. The mutations tested included truncations of structural motifs in the gp41 CT and two point mutations in lentiviral lytic peptide 3 (LLP-3) previously described as disrupting the infectivity of cell-free virus. We found that small truncations of 28 to 43 amino acids (aa) or two LLP-3 point mutations, YW_SL and LL_RQ, severely impaired single-round cell-free infectivity 10-fold or more relative to wild-type full-length CT. These mutants showed a modest 2-fold reduction in cell-to-cell infection assays. Conversely, large truncations of 93 to 124 aa severely impaired cell-to-cell infectivity 20-fold or more while resulting in a 50% increase in infectivity of cell-free viral particles when produced in 293T cells. Intermediate truncations of 46 to 90 aa showed profound impairment of both modes of infection. Our results show that the abilities of Env to support cell-free and cell-to-cell infection are genetically distinct. These differences are cell type dependent for large-CT-truncation mutants. Additionally, point mutants in LLP-3 can maintain multiround propagation from cell-to-cell in primary CD4(+) T cells. IMPORTANCE The functions of HIV Env gp41 CT remain poorly understood despite being widely studied in the context of cell-free infection. We have identified domains of the gp41 CT responsible for striking selective deficiencies in either cell-free or cell-to-cell infectivity. These differences may reflect a different intrinsic regulatory influence of the CT on cell-associated versus particle-associated Env or differential interaction with host or viral proteins. Our findings provide novel insight into the key regulatory potential of the gp41 CT in cell-free and cell-to-cell HIV-1 infection, particularly for short-truncation mutants of ≤43 amino acids or mutants with point mutations in the LLP-3 helical domain of the CT, which are able to propagate via cell-to-cell infection in the absence of infectious cell-free virus production. These mutants may also serve as tools to further define the contributions of cell-free and cell-to-cell infection in vitro and in vivo.
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Kim BA, Lim JY, Rhee JH, Kim YR. Characterization of Prohibitin 1 as a Host Partner of Vibrio vulnificus RtxA1 Toxin. J Infect Dis 2015; 213:131-8. [PMID: 26136468 DOI: 10.1093/infdis/jiv362] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Accepted: 06/22/2015] [Indexed: 11/14/2022] Open
Abstract
RtxA1 toxin, which results in cytoskeletal rearrangement, contact cytotoxicity, hemolysis, tissue invasion, and lethality in mice, is the most potent cytotoxic virulence factor of Vibrio vulnificus. Bioinformatics analysis of rtxA1 predicted 4 functional domains that presumably performed discrete functions during host cell killing. V. vulnificus RtxA1 has a unique domain designated as RtxA1-D2, corresponding to amino acids 1951-2574, which is absent in Vibrio cholerae multifunctional-autoprocessing repeats-in-toxin, suggesting that this domain confers specific biological functions to V. vulnificus RtxA1. HeLa cells expressing green fluorescent protein-RtxA1-D2 became round and lost their viability. A yeast 2-hybrid system identified prohibitin (PHB) 1 as the host partner of RtxA1-D2. The specific interaction of RtxA1-D2 with PHB1 was confirmed by performing immunoprecipitation. Interestingly, V. vulnificus RtxA1 up-regulated PHB1 expression on the cytoplasmic membrane of host cells. Extracellular signal-regulated kinase and p38 mitogen-activated protein kinase pathways were confirmed as being important in the up-regulation of PHB1 by using inhibitors. Down-regulation of PHB1 by small interfering RNAs decreased the cytotoxicity of RtxA1-D2 against HeLa cells. The pretreatment of an anti-PHB1 antibody impaired the cytotoxicity of V. vulnificus RtxA1. These results suggest that the involvement PHB1 in the RtxA1 cytotoxicity has significant implications for the pathogenesis of V. vulnificus infections.
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Affiliation(s)
- Bo A Kim
- Clinical Vaccine R&D Center, Chonnam National University Hwasun Hospital, Chonnam National University Medical School
| | - Ju Young Lim
- College of Pharmacy, Chonnam National University, Gwangju, Korea
| | - Joon Haeng Rhee
- Clinical Vaccine R&D Center, Chonnam National University Hwasun Hospital, Chonnam National University Medical School
| | - Young Ran Kim
- College of Pharmacy, Chonnam National University, Gwangju, Korea
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Prohibitin: A Novel Molecular Player in KDEL Receptor Signalling. BIOMED RESEARCH INTERNATIONAL 2015; 2015:319454. [PMID: 26064897 PMCID: PMC4442004 DOI: 10.1155/2015/319454] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 12/05/2014] [Accepted: 04/14/2015] [Indexed: 01/25/2023]
Abstract
The KDEL receptor (KDELR) is a seven-transmembrane-domain protein involved in retrograde transport of protein chaperones from the Golgi complex to the endoplasmic reticulum. Our recent findings have shown that the Golgi-localised KDELR acts as a functional G-protein-coupled receptor by binding to and activating Gs and Gq. These G proteins induce activation of PKA and Src and regulate retrograde and anterograde Golgi trafficking. Here we used an integrated coimmunoprecipitation and mass spectrometry approach to identify prohibitin-1 (PHB) as a KDELR interactor. PHB is a multifunctional protein that is involved in signal transduction, cell-cycle control, and stabilisation of mitochondrial proteins. We provide evidence that depletion of PHB induces intense membrane-trafficking activity at the ER–Golgi interface, as revealed by formation of GM130-positive Golgi tubules, and recruitment of p115, β-COP, and GBF1 to the Golgi complex. There is also massive recruitment of SEC31 to endoplasmic-reticulum exit sites. Furthermore, absence of PHB decreases the levels of the Golgi-localised KDELR, thus preventing KDELR-dependent activation of Golgi-Src and inhibiting Golgi-to-plasma-membrane transport of VSVG. We propose a model whereby in analogy to previous findings (e.g., the RAS-RAF signalling pathway), PHB can act as a signalling scaffold protein to assist in KDELR-dependent Src activation.
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Bavelloni A, Piazzi M, Raffini M, Faenza I, Blalock WL. Prohibitin 2: At a communications crossroads. IUBMB Life 2015; 67:239-54. [PMID: 25904163 DOI: 10.1002/iub.1366] [Citation(s) in RCA: 90] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2014] [Accepted: 02/06/2015] [Indexed: 01/02/2023]
Abstract
Prohibitins (PHBs) are a highly conserved class of proteins first discovered as inhibitors of cellular proliferation. Since then PHBs have been found to have a significant role in transcription, nuclear signaling, mitochondrial structural integrity, cell division, and cellular membrane metabolism, placing these proteins among the key regulators of pathologies such as cancer, neuromuscular degeneration, and other metabolic diseases. The human genome encodes two PHB proteins, prohibitin 1 (PHB1) and prohibitin 2 (PHB2), which function not only as a heterodimeric complex, but also independently. While many previous reviews have focused on the better characterized prohibitin, PHB1, this review focuses on PHB2 and new data concerning its cellular functions both in complex with PHB1 and independent of PHB1.
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Affiliation(s)
- Alberto Bavelloni
- Laboratory of Musculoskeletal Cell Biology, Rizzoli Orthopedic Institute, Bologna, Italy.,Laboratory RAMSES, Rizzoli Orthopedic Institute, Bologna, Italy
| | - Manuela Piazzi
- Department of Biomedical Sciences, University of Bologna, Bologna, Italy
| | - Mirco Raffini
- Laboratory RAMSES, Rizzoli Orthopedic Institute, Bologna, Italy
| | - Irene Faenza
- Department of Biomedical Sciences, University of Bologna, Bologna, Italy
| | - William L Blalock
- Laboratory of Musculoskeletal Cell Biology, Rizzoli Orthopedic Institute, Bologna, Italy.,National Research Council of Italy, Institute of Molecular Genetics, Bologna, Italy
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Luo Y, Muesing MA. Mass spectrometry-based proteomic approaches for discovery of HIV-host interactions. Future Virol 2014; 9:979-992. [PMID: 25544858 DOI: 10.2217/fvl.14.86] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
A molecular understanding of viral infection requires a multi-disciplinary approach. Mass spectrometry has emerged as an indispensable tool to investigate the complex and dynamic interactions between HIV-1 and its host. It has been employed to study protein associations, changes in protein abundance and post-translational modifications occurring after viral infection. Here, we review and provide examples of mass spectrometry-based proteomic approaches currently used to explore virus-host interaction. Efforts in this area are certain to accelerate the discovery of the unique molecular strategies utilized by the virus to commandeer the cell as well as mechanisms of host defense.
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Affiliation(s)
- Yang Luo
- Aaron Diamond AIDS Research Center, Affiliate of The Rockefeller University, 455 First Avenue 7th Floor, New York, NY 10016, USA
| | - Mark A Muesing
- Aaron Diamond AIDS Research Center, Affiliate of The Rockefeller University, 455 First Avenue 7th Floor, New York, NY 10016, USA
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DeBoer J, Jagadish T, Haverland NA, Madson CJ, Ciborowski P, Belshan M. Alterations in the nuclear proteome of HIV-1 infected T-cells. Virology 2014; 468-470:409-420. [PMID: 25240327 DOI: 10.1016/j.virol.2014.08.029] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2014] [Revised: 08/19/2014] [Accepted: 08/27/2014] [Indexed: 01/17/2023]
Abstract
Virus infection of a cell involves the appropriation of host factors and the innate defensive response of the cell. The identification of proteins critical for virus replication may lead to the development of novel, cell-based inhibitors. In this study we mapped the changes in T-cell nuclei during human immunodeficiency virus type 1 (HIV-1) at 20 hpi. Using a stringent data threshold, a total of 13 and 38 unique proteins were identified in infected and uninfected cells, respectively, across all biological replicates. An additional 15 proteins were found to be differentially regulated between infected and control nuclei. STRING analysis identified four clusters of protein-protein interactions in the data set related to nuclear architecture, RNA regulation, cell division, and cell homeostasis. Immunoblot analysis confirmed the differential expression of several proteins in both C8166-45 and Jurkat E6-1 T-cells. These data provide a map of the response in host cell nuclei upon HIV-1 infection.
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Affiliation(s)
- Jason DeBoer
- Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Teena Jagadish
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Nicole A Haverland
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, USA
| | - Christian J Madson
- Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA
| | - Pawel Ciborowski
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, USA; The Nebraska Center for Virology, University of Nebraska, Lincoln 68583, USA
| | - Michael Belshan
- Department of Medical Microbiology and Immunology, Creighton University, 2500 California Plaza, Omaha, NE 68178, USA; The Nebraska Center for Virology, University of Nebraska, Lincoln 68583, USA.
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Chen YA, Murakami Y, Ahmad S, Yoshimaru T, Katagiri T, Mizuguchi K. Brefeldin A-inhibited guanine nucleotide-exchange protein 3 (BIG3) is predicted to interact with its partner through an ARM-type α-helical structure. BMC Res Notes 2014; 7:435. [PMID: 24997568 PMCID: PMC4096751 DOI: 10.1186/1756-0500-7-435] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2014] [Accepted: 06/30/2014] [Indexed: 12/21/2022] Open
Abstract
Background Brefeldin A-inhibited guanine nucleotide-exchange protein 3 (BIG3) has been identified recently as a novel regulator of estrogen signalling in breast cancer cells. Despite being a potential target for new breast cancer treatment, its amino acid sequence suggests no association with any well-characterized protein family and provides little clues as to its molecular function. In this paper, we predicted the structure, function and interactions of BIG3 using a range of bioinformatic tools. Results Homology search results showed that BIG3 had distinct features from its paralogues, BIG1 and BIG2, with a unique region between the two shared domains, Sec7 and DUF1981. Although BIG3 contains Sec7 domain, the lack of the conserved motif and the critical glutamate residue suggested no potential guaninyl-exchange factor (GEF) activity. Fold recognition tools predicted BIG3 to adopt an α-helical repeat structure similar to that of the armadillo (ARM) family. Using state-of-the-art methods, we predicted interaction sites between BIG3 and its partner PHB2. Conclusions The combined results of the structure and interaction prediction led to a novel hypothesis that one of the predicted helices of BIG3 might play an important role in binding to PHB2 and thereby preventing its translocation to the nucleus. This hypothesis has been subsequently verified experimentally.
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Affiliation(s)
| | | | | | | | | | - Kenji Mizuguchi
- National Institute of Biomedical Innovation, 7-6-8 Saito-asagi, Ibaraki city, Osaka 567-0085, Japan.
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Begum A, Lin Q, Yu C, Kim Y, Yun Z. Interaction of delta-like 1 homolog (Drosophila) with prohibitins and its impact on tumor cell clonogenicity. Mol Cancer Res 2013; 12:155-64. [PMID: 24249679 DOI: 10.1158/1541-7786.mcr-13-0360] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
UNLABELLED Cancer stem cell characteristics, especially their self-renewal and clonogenic potentials, play an essential role in malignant progression and response to anticancer therapies. Currently, it remains largely unknown what pathways are involved in the regulation of cancer cell stemness and differentiation. Previously, we found that delta-like 1 homolog (Drosophila) or DLK1, a developmentally regulated gene, plays a critical role in the regulation of differentiation, self-renewal, and tumorigenic growth of neuroblastoma cells. Here, we show that DLK1 specifically interacts with the prohibitin 1 (PHB1) and PHB2, two closely related genes with pleiotropic functions, including regulation of mitochondrial function and gene transcription. DLK1 interacts with the PHB1-PHB2 complex via its cytoplasmic domain and regulates mitochondrial functions, including mitochondrial membrane potential and production of reactive oxygen species. We have further found that PHB1 and especially PHB2 regulate cancer cell self-renewal as well as their clonogenic potential. Hence, the DLK1-PHB interaction constitutes a new signaling pathway that maintains clonogenicity and self-renewal potential of cancer cells. IMPLICATIONS This study provides a new mechanistic insight into the regulation of the stem cell characteristics of cancer cells.
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Affiliation(s)
- Asma Begum
- Department of Therapeutic Radiology, Yale University School of Medicine, P.O. Box 208040, New Haven, CT 06520-8040.
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Ochoa-Campuzano C, Martínez-Ramírez AC, Contreras E, Rausell C, Real MD. Prohibitin, an essential protein for Colorado potato beetle larval viability, is relevant to Bacillus thuringiensis Cry3Aa toxicity. PESTICIDE BIOCHEMISTRY AND PHYSIOLOGY 2013; 107:299-308. [PMID: 24267691 DOI: 10.1016/j.pestbp.2013.09.001] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/04/2013] [Revised: 09/02/2013] [Accepted: 09/03/2013] [Indexed: 06/02/2023]
Abstract
Bacillus thuringienesis (Bt) Cry toxins constitute the most extensively used environmentally safe biopesticide and their mode of action relies on the interaction of the toxins with membrane proteins in the midgut of susceptible insects that mediate toxicity and insect specificity. Therefore, identification of Bt Cry toxin interacting proteins in the midgut of target insects and understanding their role in toxicity is of great interest to exploit their insecticidal action. Using ligand blot, we demonstrated that Bt Cry3Aa toxin bound to a 30kDa protein in Colorado potato beetle (CPB) larval midgut membrane, identified by sequence homology as prohibitin-1 protein. Prohibitins comprise a highly conserved family of proteins implicated in important cellular processes. We obtained the complete CPB prohibitin-1 DNA coding sequence of 828pb, in silico translated into a 276-amino acid protein. The analysis at the amino acid level showed that the protein contains a prohibitin-homology domain (Band7_prohibitin, cd03401) conserved among prohibitin proteins. A striking feature of the CPB identified prohibitin-1 is the predicted presence of cadherin elements, potential binding sites for Cry toxins described in other Bt susceptible insects. We also showed that CPB prohibitin-1 protein partitioned into both, detergent soluble and insoluble membrane fractions, as well as a prohibitin-2 homologous protein, previously reported to form functional complexes with prohibitin-1 in other organisms. Prohibitin complexes act as membrane scaffolds ensuring the recruitment of membrane proteases to facilitate substrate processing. Accordingly, sequestration of prohibitin-1 by an anti-prohibitin-1 antibody impaired the Cry3Aa toxin inhibition of the proteolytic cleavage of a fluorogenic synthetic substrate of an ADAM-like metalloprotease previously reported to proteolize this toxin. In this work, we also demonstrated that prohibitin-1 RNAi silencing in CPB larvae produced deleterious effects and together with a LD50 Cry3Aa toxin treatment resulted in a highly efficient short term response since 100% larval mortality was achieved just 5days after toxin challenge. Therefore, the combination of prohibitin RNAi and Cry toxin reveals as an effective strategy to improve crop protection.
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Affiliation(s)
- Camila Ochoa-Campuzano
- Departamento de Genética, Facultad de Ciencias Biológicas, Universidad de Valencia, Dr. Moliner 50, Burjassot, 46100 Valencia, Spain
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Prohibitin Interacts with envelope proteins of white spot syndrome virus and prevents infection in the red swamp crayfish, Procambarus clarkii. J Virol 2013; 87:12756-65. [PMID: 24049173 DOI: 10.1128/jvi.02198-13] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
Prohibitins (PHBs) are ubiquitously expressed conserved proteins in eukaryotes that are associated with apoptosis, cancer formation, aging, stress responses, cell proliferation, and immune regulation. However, the function of PHBs in crustacean immunity remains largely unknown. In the present study, we identified a PHB in Procambarus clarkii red swamp crayfish, which was designated PcPHB1. PcPHB1 was widely distributed in several tissues, and its expression was significantly upregulated by white spot syndrome virus (WSSV) challenge at the mRNA level and the protein level. These observations prompted us to investigate the role of PcPHB1 in the crayfish antiviral response. Recombinant PcPHB1 (rPcPHB1) significantly reduced the amount of WSSV in crayfish and the mortality of WSSV-infected crayfish. The quantity of WSSV in PcPHB1 knockdown crayfish was increased compared with that in the controls. The effects of RNA silencing were rescued by rPcPHB1 reinjection. We further confirmed the interaction of PcPHB1 with the WSSV envelope proteins VP28, VP26, and VP24 using pulldown and far-Western overlay assays. Finally, we observed that the colloidal gold-labeled PcPHB1 was located on the outer surface of the WSSV, which suggests that PcPHB1 specifically binds to the envelope proteins of WSSV. VP28, VP26, and VP24 are structural envelope proteins and are essential for attachment and entry into crayfish cells. Therefore, PcPHB1 exerts its anti-WSSV effect by binding to VP28, VP26, and VP24, preventing viral infection. This study is the first report on the antiviral function of PHB in the innate immune system of crustaceans.
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Thuaud F, Ribeiro N, Nebigil CG, Désaubry L. Prohibitin ligands in cell death and survival: mode of action and therapeutic potential. ACTA ACUST UNITED AC 2013; 20:316-31. [PMID: 23521790 PMCID: PMC7111013 DOI: 10.1016/j.chembiol.2013.02.006] [Citation(s) in RCA: 157] [Impact Index Per Article: 14.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2012] [Revised: 01/31/2013] [Accepted: 02/06/2013] [Indexed: 12/21/2022]
Abstract
Prohibitins (PHBs) are scaffold proteins that modulate many signaling pathways controlling cell survival, metabolism, and inflammation. Several drugs that target PHBs have been identified and evaluated for various clinical applications. Preclinical and clinical studies indicate that these PHB ligands may be useful in oncology, cardiology, and neurology, as well as against obesity. This review covers the physiological role of PHBs in health and diseases and current developments concerning PHB ligands.
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Affiliation(s)
- Frédéric Thuaud
- Therapeutic Innovation Laboratory UMR 7200, CNRS/Université de Strasbourg, Faculté de Pharmacie, 67401 Illkirch Cedex, France
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Fu P, Yang Z, Bach LA. Prohibitin-2 binding modulates insulin-like growth factor-binding protein-6 (IGFBP-6)-induced rhabdomyosarcoma cell migration. J Biol Chem 2013; 288:29890-900. [PMID: 24003225 DOI: 10.1074/jbc.m113.510826] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Insulin-like growth factor (IGF)-binding protein (IGFBP)-6 decreases cancer cell proliferation and survival by inhibiting the effects of IGF-II. More recently, IGFBP-6 was found to promote the migration of rhabdomyosarcoma (RMS) cells in an IGF-independent manner, and MAPK pathways were involved in this process. However, the precise molecular mechanisms of these IGF-independent migratory actions of IGFBP-6 are largely unknown. Here, we report that prohibitin-2 (PHB2), a single-span membrane protein, is a key regulator of IGFBP-6-induced RMS cell migration. PHB2 and IGFBP-6 co-localize on the RMS cell surface, and they specifically interact, as demonstrated by affinity chromatography, co-immunoprecipitation, biosensor analysis, and confocal microscopy. Binding affinities for PHB2 are 9.0 ± 1.0 nM for IGFBP-6 and 10.2 ± 0.5 nM for mIGFBP-6, a non-IGF-binding mutant of IGFBP-6. The C-domain but not the N-domain of IGFBP-6 is involved in PHB2 binding. In addition, IGFBP-6 indirectly increases PHB2 tyrosine phosphorylation on RMS membranes. Importantly, PHB2 knockdown completely abolished IGFBP-6-mediated RMS cell migration. In contrast, IGFBP-6-induced MAPK pathway activation was not affected, suggesting that PHB2 may act as a downstream effector of these pathways. These results indicate that PHB2 plays a key role in this IGF-independent action of IGFBP-6 and suggest a possible therapeutic target for RMS.
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Affiliation(s)
- Ping Fu
- From the Department of Medicine, Central Clinical School, Monash University, Alfred Medical Research and Education Precinct, Prahran, Victoria 3181, Australia and
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Pfeiffer T, Ruppert T, Schaal H, Bosch V. Detection and initial characterization of protein entities consisting of the HIV glycoprotein cytoplasmic C-terminal domain alone. Virology 2013; 441:85-94. [DOI: 10.1016/j.virol.2013.03.009] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2013] [Revised: 02/26/2013] [Accepted: 03/13/2013] [Indexed: 11/29/2022]
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Santos da Silva E, Mulinge M, Perez Bercoff D. The frantic play of the concealed HIV envelope cytoplasmic tail. Retrovirology 2013; 10:54. [PMID: 23705972 PMCID: PMC3686653 DOI: 10.1186/1742-4690-10-54] [Citation(s) in RCA: 44] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2012] [Accepted: 05/01/2013] [Indexed: 11/18/2022] Open
Abstract
Lentiviruses have unusually long envelope (Env) cytoplasmic tails, longer than those of other retroviruses. Whereas the Env ectodomain has received much attention, the gp41 cytoplasmic tail (gp41-CT) is one of the least studied parts of the virus. It displays relatively high conservation compared to the rest of Env. It has been long established that the gp41-CT interacts with the Gag precursor protein to ensure Env incorporation into the virion. The gp41-CT contains distinct motifs and domains that mediate both intensive Env intracellular trafficking and interactions with numerous cellular and viral proteins, optimizing viral infectivity. Although they are not fully understood, a multiplicity of interactions between the gp41-CT and cellular factors have been described over the last decade; these interactions illustrate how Env expression and incorporation into virions is a finely tuned process that has evolved to best exploit the host system with minimized genetic information. This review addresses the structure and topology of the gp41-CT of lentiviruses (mainly HIV and SIV), their domains and believed functions. It also considers the cellular and viral proteins that have been described to interact with the gp41-CT, with a particular focus on subtype-related polymorphisms.
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Chavez JD, Weisbrod CR, Zheng C, Eng JK, Bruce JE. Protein interactions, post-translational modifications and topologies in human cells. Mol Cell Proteomics 2013; 12:1451-67. [PMID: 23354917 PMCID: PMC3650351 DOI: 10.1074/mcp.m112.024497] [Citation(s) in RCA: 91] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2012] [Revised: 12/12/2012] [Indexed: 12/22/2022] Open
Abstract
The unique and remarkable physicochemical properties of protein surface topologies give rise to highly specific biomolecular interactions, which form the framework through which living systems are able to carry out their vast array of functions. Technological limitations undermine efforts to probe protein structures and interactions within unperturbed living systems on a large scale. Rapid chemical stabilization of proteins and protein complexes through chemical cross-linking offers the alluring possibility to study details of the protein structure to function relationships as they exist within living cells. Here we apply the latest technological advances in chemical cross-linking combined with mass spectrometry to study protein topologies and interactions from living human cells identifying a total of 368 cross-links. These include cross-links from all major cellular compartments including membrane, cytosolic and nuclear proteins. Intraprotein and interprotein cross-links were also observed for core histone proteins, including several cross-links containing post-translational modifications which are known histone marks conferring distinct epigenetic functions. Excitingly, these results demonstrate the applicability of cross-linking to make direct topological measurements on post-translationally modified proteins. The results presented here provide new details on the structures of known multi-protein complexes as well as evidence for new protein-protein interactions.
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Affiliation(s)
- Juan D. Chavez
- From the ‡Department of Genome Science, University of Washington, Seattle, Washington 98109
| | - Chad R. Weisbrod
- From the ‡Department of Genome Science, University of Washington, Seattle, Washington 98109
| | - Chunxiang Zheng
- From the ‡Department of Genome Science, University of Washington, Seattle, Washington 98109
| | - Jimmy K. Eng
- From the ‡Department of Genome Science, University of Washington, Seattle, Washington 98109
| | - James E. Bruce
- From the ‡Department of Genome Science, University of Washington, Seattle, Washington 98109
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Abstract
Envelope glycoproteins (Env) of lentiviruses typically possess unusually long cytoplasmic domains, often 150 amino acids or longer. It is becoming increasingly clear that these sequences contribute a diverse array of functional activities to the life cycle of their viruses. The cytoplasmic domain of gp41 (gp41CD) is required for replication of human immunodeficiency virus type 1 (HIV-1) in most but not all cell types, whereas it is largely dispensable for replication of simian immunodeficiency virus (SIV). Functionally, gp41CD has been shown to regulate rapid clathrin-mediated endocytosis of Env. The resultant low levels of Env expression at the cell surface likely serve as an immune avoidance mechanism to limit accessibility to the humoral immune response. Intracellular trafficking of Env is also regulated by gp41CD through interactions with a variety of cellular proteins. Furthermore, gp41CD has been implicated in the incorporation of Env into virions through an interaction with the virally encoded matrix protein. Most recently, the gp41CDs of HIV-1 and SIV were shown to activate the key cellular-transcription factor NF-κB via the serine/threonine kinase TAK1. Less well understood are the cytotoxicity- and apoptosis-inducing activities of gp41CD as well as potential roles in modulating the actin cytoskeleton and overcoming host cell restrictions. In this review, we summarize what is currently known about the cytoplasmic domains of HIV-1 and SIV and attempt to integrate the wealth of information in terms of defined functional activities.
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Affiliation(s)
- Thomas S. Postler
- New England Primate Research Center, Department of Microbiology and Immunobiology, Harvard Medical School, Southborough, Massachusetts, USA
- Institut für Klinische und Molekulare Virologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Ronald C. Desrosiers
- New England Primate Research Center, Department of Microbiology and Immunobiology, Harvard Medical School, Southborough, Massachusetts, USA
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The Natural Anticancer Compounds Rocaglamides Inhibit the Raf-MEK-ERK Pathway by Targeting Prohibitin 1 and 2. ACTA ACUST UNITED AC 2012; 19:1093-104. [DOI: 10.1016/j.chembiol.2012.07.012] [Citation(s) in RCA: 115] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2012] [Revised: 06/12/2012] [Accepted: 07/10/2012] [Indexed: 12/19/2022]
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Retroviral env glycoprotein trafficking and incorporation into virions. Mol Biol Int 2012; 2012:682850. [PMID: 22811910 PMCID: PMC3395148 DOI: 10.1155/2012/682850] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/29/2012] [Revised: 05/08/2012] [Accepted: 05/31/2012] [Indexed: 11/17/2022] Open
Abstract
Together with the Gag protein, the Env glycoprotein is a major retroviral structural protein and is essential for forming infectious virus particles. Env is synthesized, processed, and transported to certain microdomains at the plasma membrane and takes advantage of the same host machinery for its trafficking as that used by cellular glycoproteins. Incorporation of Env into progeny virions is probably mediated by the interaction between Env and Gag, in some cases with the additional involvement of certain host factors. Although several general models have been proposed to explain the incorporation of retroviral Env glycoproteins into virions, the actual mechanism for this process is still unclear, partly because structural data on the Env protein cytoplasmic tail is lacking. This paper presents the current understanding of the synthesis, trafficking, and virion incorporation of retroviral Env proteins.
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Postler TS, Desrosiers RC. The cytoplasmic domain of the HIV-1 glycoprotein gp41 induces NF-κB activation through TGF-β-activated kinase 1. Cell Host Microbe 2012; 11:181-93. [PMID: 22341466 PMCID: PMC3285415 DOI: 10.1016/j.chom.2011.12.005] [Citation(s) in RCA: 54] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2011] [Revised: 11/22/2011] [Accepted: 12/28/2011] [Indexed: 12/20/2022]
Abstract
The human and simian immunodeficiency viruses (HIV and SIV) primarily infect lymphocytes, which must be activated for efficient viral replication. We show that the cytoplasmic domain of the transmembrane glycoprotein gp41 (gp41CD) of both HIV-1 and SIV induces activation of NF-κB, a cellular factor important for proviral genome transcription and lymphocyte activation. This NF-κB activating property localized to a region 12-25 (SIV) or 59-70 (HIV-1) residues from the gp41 membrane-spanning domain. An siRNA-based screen of 42 key NF-κB regulators revealed that gp41CD-mediated activation occurs through the canonical NF-κB pathway via TGF-β-activated kinase 1 (TAK1). TAK1 activity was required for gp41CD-mediated NF-κB activation, and HIV-1-derived gp41CD physically interacted with TAK1 through the same region required for NF-κB activation. Importantly, an NF-κB activation-deficient HIV-1 mutant exhibited increased dependence on cellular activation for replication. These findings demonstrate an evolutionarily conserved role for gp41CD in activating NF-κB to promote infection.
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Affiliation(s)
- Thomas S. Postler
- New England Primate Research Center, Department of Microbiology and Molecular Genetics, Harvard Medical School, Southborough, Massachusetts 01772-9102, U.S.A
- Institut für Klinische und Molekulare Virologie, Friedrich-Alexander-Universität Erlangen-Nürnberg, Erlangen, Germany
| | - Ronald C. Desrosiers
- New England Primate Research Center, Department of Microbiology and Molecular Genetics, Harvard Medical School, Southborough, Massachusetts 01772-9102, U.S.A
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Checkley MA, Luttge BG, Freed EO. HIV-1 envelope glycoprotein biosynthesis, trafficking, and incorporation. J Mol Biol 2011; 410:582-608. [PMID: 21762802 PMCID: PMC3139147 DOI: 10.1016/j.jmb.2011.04.042] [Citation(s) in RCA: 328] [Impact Index Per Article: 25.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2011] [Revised: 04/14/2011] [Accepted: 04/15/2011] [Indexed: 12/13/2022]
Abstract
The HIV-1 envelope (Env) glycoproteins play an essential role in the virus replication cycle by mediating the fusion between viral and cellular membranes during the entry process. The Env glycoproteins are synthesized as a polyprotein precursor (gp160) that is cleaved by cellular proteases to the mature surface glycoprotein gp120 and the transmembrane glycoprotein gp41. During virus assembly, the gp120/gp41 complex is incorporated as heterotrimeric spikes into the lipid bilayer of nascent virions. These gp120/gp41 complexes then initiate the infection process by binding receptor and coreceptor on the surface of target cells. Much is currently known about the HIV-1 Env glycoprotein trafficking pathway and the structure of gp120 and the extracellular domain of gp41. However, the mechanism by which the Env glycoprotein complex is incorporated into virus particles remains incompletely understood. Genetic data support a major role for the cytoplasmic tail of gp41 and the matrix domain of Gag in Env glycoprotein incorporation. Still to be defined are the identities of host cell factors that may promote Env incorporation and the role of specific membrane microdomains in this process. Here, we review our current understanding of HIV-1 Env glycoprotein trafficking and incorporation into virions.
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Affiliation(s)
- Mary Ann Checkley
- Virus-Cell Interaction Section, HIV Drug Resistance Program National Cancer Institute Frederick, MD 21702
| | - Benjamin G. Luttge
- Virus-Cell Interaction Section, HIV Drug Resistance Program National Cancer Institute Frederick, MD 21702
| | - Eric O. Freed
- Virus-Cell Interaction Section, HIV Drug Resistance Program National Cancer Institute Frederick, MD 21702
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CaMK IV phosphorylates prohibitin 2 and regulates prohibitin 2-mediated repression of MEF2 transcription. Cell Signal 2011; 23:1686-90. [PMID: 21689744 PMCID: PMC7127762 DOI: 10.1016/j.cellsig.2011.06.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2011] [Accepted: 06/06/2011] [Indexed: 12/19/2022]
Abstract
Prohibitin 2 (PHB2) is an evolutionarily conserved and ubiquitously expressed multifunctional protein which is present in various cellular compartments including the nucleus. However, mechanisms underlying various functions of PHB2 are not fully explored yet. Previously we showed that PHB2 interacts with Akt and inhibits muscle differentiation by repressing the transcriptional activity of both MyoD and MEF2. Here we show that Calcium/Calmodulin-dependent kinase IV (CaMK IV) specifically binds to the C terminus of PHB2 and phosphorylates PHB2 at serine 91. Ectopic expression of CaMK IV and PHB2 in C2C12 cells results effectively in decreased PHB2-mediated repression of MEF2-dependent gene expression. Conversely, PHB2 mutant (S91A) resistant to CaMK IV phosphorylation has less effective in relieving the inhibition of MEF2 transcription by PHB2. Our findings suggest that CaMK IV interacts with and regulates PHB2 through phosphorylation, which could be one of the mechanisms underlying the CaMK-mediated activation of MEF2.
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