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Rossi E, Meuser ME, Cunanan CJ, Cocklin S. Structure, Function, and Interactions of the HIV-1 Capsid Protein. Life (Basel) 2021; 11:100. [PMID: 33572761 DOI: 10.3390/life11020100] [Citation(s) in RCA: 21] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Revised: 01/25/2021] [Accepted: 01/27/2021] [Indexed: 11/30/2022] Open
Abstract
The capsid (CA) protein of the human immunodeficiency virus type 1 (HIV-1) is an essential structural component of a virion and facilitates many crucial life cycle steps through interactions with host cell factors. Capsid shields the reverse transcription complex from restriction factors while it enables trafficking to the nucleus by hijacking various adaptor proteins, such as FEZ1 and BICD2. In addition, the capsid facilitates the import and localization of the viral complex in the nucleus through interaction with NUP153, NUP358, TNPO3, and CPSF-6. In the later stages of the HIV-1 life cycle, CA plays an essential role in the maturation step as a constituent of the Gag polyprotein. In the final phase of maturation, Gag is cleaved, and CA is released, allowing for the assembly of CA into a fullerene cone, known as the capsid core. The fullerene cone consists of ~250 CA hexamers and 12 CA pentamers and encloses the viral genome and other essential viral proteins for the next round of infection. As research continues to elucidate the role of CA in the HIV-1 life cycle and the importance of the capsid protein becomes more apparent, CA displays potential as a therapeutic target for the development of HIV-1 inhibitors.
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Hou X, Liu R, Huang C, Jiang L, Zhou Y, Chen Q. Cyclophilin A was revealed as a candidate marker for human oral submucous fibrosis by proteomic analysis. Cancer Biomark 2018; 20:345-356. [PMID: 28826174 DOI: 10.3233/cbm-170142] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/05/2023]
Abstract
Oral submucous fibrosis (OSF) is a chronic insidious disease which predisposes to oral cancer. Understanding the molecular markers for OSF is critical for diagnosis and treatment of oral cancer. In this study, the proteins expression profile of OSF tissues was compared to normal mucous tissues by 2 dimensional electrophoresis (2-DE). The 2-DE images were analyzed through cut, spot detection and match analysis using mass spectrometry (MS). Differentially expressed genes were identified as candidates. RT-PCR, Western Blot and immunohistochemistry were performed to validate the difference in expression of the candidates between OSF and normal mucous tissues. The shRNA targeted to the candidates were then transfected by Lipofectamine2000 to the 3T3 cells to study gene function. Cell proliferation and apoptosis were measured by MTT, clonogenic formation, PI and TUNEL staining. From the proteomic analysis, 94 of the 182 selected spots with differential expression were identified by MS analysis and Cyclophilin A (CYPA) was determined to be the OSF-associated protein candidate. The significant differences in expression between OSF and normal tissues were verified and confirmed by RT-PCR, Western blot and Immunohistochemical analysis. Inhibition of CYPA expression by RNA interference suggested its potential activities involved in cell proliferation and apoptosis process. In conclusion, these results indicated a novel molecular mechanism of OSF pathogenesis and demonstrated CYPA as a potential biomarker and gene intervention targets of OSF. These data may help the development for therapeutics of oral cancer.
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Affiliation(s)
- Xiaohui Hou
- Laboratory of Oral Biomedical Science and Translational Medicine, School of Stomatology, Tongji University, Shanghai 200072, China.,State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China
| | - Rui Liu
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China
| | - Canhua Huang
- The State Key Laboratory of Biotherapy, West China Hospital, Sichuan University, Chengdu 610041, Sichuan, China
| | - Lu Jiang
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China
| | - Yu Zhou
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China
| | - Qianming Chen
- State Key Laboratory of Oral Diseases, West China Hospital of Stomatology, Sichuan University, Chengdu 610041, Sichuan, China
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Chen J, Zhang C, Zhou Y, Zhang X, Shen C, Ye X, Jiang W, Huang Z, Cong Y. A 3.0-Angstrom Resolution Cryo-Electron Microscopy Structure and Antigenic Sites of Coxsackievirus A6-Like Particles. J Virol 2018; 92:e01257-17. [PMID: 29093091 DOI: 10.1128/JVI.01257-17] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2017] [Accepted: 09/28/2017] [Indexed: 02/06/2023] Open
Abstract
Coxsackievirus A6 (CVA6) has recently emerged as one of the predominant causative agents of hand, foot, and mouth disease (HFMD). The structure of the CVA6 mature viral particle has not been solved thus far. Our previous work shows that recombinant virus-like particles (VLPs) of CVA6 represent a promising CVA6 vaccine candidate. Here, we report the first cryo-electron microscopy (cryo-EM) structure of the CVA6 VLP at 3.0-Å resolution. The CVA6 VLP exhibits the characteristic features of enteroviruses but presents an open channel at the 2-fold axis and an empty, collapsed VP1 pocket, which is broadly similar to the structures of the enterovirus 71 (EV71) VLP and coxsackievirus A16 (CVA16) 135S expanded particle, indicating that the CVA6 VLP is in an expanded conformation. Structural comparisons reveal that two common salt bridges within protomers are maintained in the CVA6 VLP and other viruses of the Enterovirus genus, implying that these salt bridges may play a critical role in enteroviral protomer assembly. However, there are apparent structural differences among the CVA6 VLP, EV71 VLP, and CVA16 135S particle in the surface-exposed loops and C termini of subunit proteins, which are often antigenic sites for enteroviruses. By immunological assays, we identified two CVA6-specific linear B-cell epitopes (designated P42 and P59) located at the GH loop and the C-terminal region of VP1, respectively, in agreement with the structure-based prediction of antigenic sites. Our findings elucidate the structural basis and important antigenic sites of the CVA6 VLP as a strong vaccine candidate and also provide insight into enteroviral protomer assembly.IMPORTANCE Coxsackievirus A6 (CVA6) is becoming one of the major pathogens causing hand, foot, and mouth disease (HFMD), leading to significant morbidity and mortality in children and adults. However, no vaccine is currently available to prevent CVA6 infection. Our previous work shows that recombinant virus-like particles (VLPs) of CVA6 are a promising CVA6 vaccine candidate. Here, we present a 3.0-Å structure of the CVA6 VLP determined by cryo-electron microscopy. The overall architecture of the CVA6 VLP is similar to those of the expanded structures of enterovirus 71 (EV71) and coxsackievirus A16 (CVA16), but careful structural comparisons reveal significant differences in the surface-exposed loops and C termini of each capsid protein of these particles. In addition, we identified two CVA6-specific linear B-cell epitopes and mapped them to the GH loop and the C-terminal region of VP1, respectively. Collectively, our findings provide a structural basis and important antigenic information for CVA6 VLP vaccine development.
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Ambrose Z, Aiken C. HIV-1 uncoating: connection to nuclear entry and regulation by host proteins. Virology 2014; 454-455:371-9. [PMID: 24559861 DOI: 10.1016/j.virol.2014.02.004] [Citation(s) in RCA: 124] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2013] [Revised: 12/27/2013] [Accepted: 02/04/2014] [Indexed: 11/25/2022]
Abstract
The RNA genome of human immunodeficiency virus type 1 (HIV-1) is enclosed by a capsid shell that dissociates within the cell in a multistep process known as uncoating, which influences completion of reverse transcription of the viral genome. Double-stranded viral DNA is imported into the nucleus for integration into the host genome, a hallmark of retroviral infection. Reverse transcription, nuclear entry, and integration are coordinated by a capsid uncoating process that is regulated by cellular proteins. Although uncoating is not well understood, recent studies have revealed insights into the process, particularly with respect to nuclear import pathways and protection of the viral genome from DNA sensors. Understanding uncoating will be valuable toward developing novel antiretroviral therapies for HIV-infected individuals.
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Affiliation(s)
- Zandrea Ambrose
- Division of Infectious Diseases, Department of Medicine, University of Pittsburgh, School of Medicine, Pittsburgh, PA 15261, USA.
| | - Christopher Aiken
- Department of Pathology, Microbiology and Immunology, Vanderbilt University, School of Medicine, Nashville, TN 37232, USA
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Abstract
INTRODUCTION X-ray crystallography plays an important role in structure-based drug design (SBDD), and accurate analysis of crystal structures of target macromolecules and macromolecule-ligand complexes is critical at all stages. However, whereas there has been significant progress in improving methods of structural biology, particularly in X-ray crystallography, corresponding progress in the development of computational methods (such as in silico high-throughput screening) is still on the horizon. Crystal structures can be overinterpreted and thus bias hypotheses and follow-up experiments. As in any experimental science, the models of macromolecular structures derived from X-ray diffraction data have their limitations, which need to be critically evaluated and well understood for structure-based drug discovery. AREAS COVERED This review describes how the validity, accuracy and precision of a protein or nucleic acid structure determined by X-ray crystallography can be evaluated from three different perspectives: i) the nature of the diffraction experiment; ii) the interpretation of an electron density map; and iii) the interpretation of the structural model in terms of function and mechanism. The strategies to optimally exploit a macromolecular structure are also discussed in the context of 'Big Data' analysis, biochemical experimental design and structure-based drug discovery. EXPERT OPINION Although X-ray crystallography is one of the most detailed 'microscopes' available today for examining macromolecular structures, the authors would like to re-emphasize that such structures are only simplified models of the target macromolecules. The authors also wish to reinforce the idea that a structure should not be thought of as a set of precise coordinates but rather as a framework for generating hypotheses to be explored. Numerous biochemical and biophysical experiments, including new diffraction experiments, can and should be performed to verify or falsify these hypotheses. X-ray crystallography will find its future application in drug discovery by the development of specific tools that would allow realistic interpretation of the outcome coordinates and/or support testing of these hypotheses.
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Affiliation(s)
- Heping Zheng
- University of Virginia, Department of Molecular Physiology and Biological Physics, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA
- Center for Structural Genomics of Infectious Diseases (CSGID)
- Midwest Center for Structural Genomics (MCSG), USA
- New York Structural Genomics Research Consortium (NYSGRC), USA
- Specializes in Protein Crystallography, Data Analytics and Data Mining, Research Scientist
| | - Jing Hou
- University of Virginia, Department of Molecular Physiology and Biological Physics, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA
- Center for Structural Genomics of Infectious Diseases (CSGID)
- Enzyme Structure Initiative (EFI), USA
- New York Structural Genomics Research Consortium (NYSGRC), USA
- Specializes in Protein Crystallography, Research Associate
| | - Matthew D Zimmerman
- University of Virginia, Department of Molecular Physiology and Biological Physics, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA
- Center for Structural Genomics of Infectious Diseases (CSGID)
- Enzyme Structure Initiative (EFI), USA
- Midwest Center for Structural Genomics (MCSG), USA
- New York Structural Genomics Research Consortium (NYSGRC), USA
- Specializes in Protein Crystallography, Data Mining and Management, Instructor of Research
| | - Alexander Wlodawer
- National Cancer Institute, Center for Cancer Research, Frederick, MD 21702, USA
- Specializes in Macromolecular Structure and Function, Chief of the Macromolecular Crystallography Laboratory
| | - Wladek Minor
- University of Virginia, Department of Molecular Physiology and Biological Physics, 1340 Jefferson Park Avenue, Charlottesville, VA 22908, USA
- Center for Structural Genomics of Infectious Diseases (CSGID)
- Enzyme Structure Initiative (EFI), USA
- Midwest Center for Structural Genomics (MCSG), USA
- New York Structural Genomics Research Consortium (NYSGRC), USA
- Specializes in Structural Biology, Data Mining and Management, Professor
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López CS, Tsagli SM, Sloan R, Eccles J, Barklis E. Second site reversion of a mutation near the amino terminus of the HIV-1 capsid protein. Virology 2013; 447:95-103. [PMID: 24210103 DOI: 10.1016/j.virol.2013.08.023] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2013] [Revised: 08/20/2013] [Accepted: 08/21/2013] [Indexed: 11/19/2022]
Abstract
During HIV-1 morphogenesis, the precursor Gag protein is processed to release capsid (CA) proteins that form the mature virus core. In this process, the CA proteins assemble a lattice in which N-terminal domain (NTD) helices 1-3 are critical for multimer formation. Mature core assembly requires refolding of the N-terminus of CA into a β-hairpin, but the precise contribution of the hairpin core morphogenesis is unclear. We found that mutations at isoleucine 15 (I15), between the β-hairpin and NTD helix 1 are incompatible with proper mature core assembly. However, a compensatory mutation of histidine 12 in the β-hairpin to a tyrosine was selected by long term passage of an I15 mutant virus in T cells. The tyrosine does not interact directly with residue 15, but with NTD helix 3, supporting a model in which β-hairpin folding serves to align helix 3 for mature NTD multimerization.
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Affiliation(s)
- Claudia S López
- Department of Molecular Microbiology and Immunology, Oregon Health Sciences University, 3181 SW Sam Jackson Park Road, Portland, Oregon 97239, USA.
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Zhang H, Curreli F, Zhang X, Bhattacharya S, Waheed AA, Cooper A, Cowburn D, Freed EO, Debnath AK. Antiviral activity of α-helical stapled peptides designed from the HIV-1 capsid dimerization domain. Retrovirology 2011; 8:28. [PMID: 21539734 PMCID: PMC3097154 DOI: 10.1186/1742-4690-8-28] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2010] [Accepted: 05/03/2011] [Indexed: 01/11/2023] Open
Abstract
Background The C-terminal domain (CTD) of HIV-1 capsid (CA), like full-length CA, forms dimers in solution and CTD dimerization is a major driving force in Gag assembly and maturation. Mutations of the residues at the CTD dimer interface impair virus assembly and render the virus non-infectious. Therefore, the CTD represents a potential target for designing anti-HIV-1 drugs. Results Due to the pivotal role of the dimer interface, we reasoned that peptides from the α-helical region of the dimer interface might be effective as decoys to prevent CTD dimer formation. However, these small peptides do not have any structure in solution and they do not penetrate cells. Therefore, we used the hydrocarbon stapling technique to stabilize the α-helical structure and confirmed by confocal microscopy that this modification also made these peptides cell-penetrating. We also confirmed by using isothermal titration calorimetry (ITC), sedimentation equilibrium and NMR that these peptides indeed disrupt dimer formation. In in vitro assembly assays, the peptides inhibited mature-like virus particle formation and specifically inhibited HIV-1 production in cell-based assays. These peptides also showed potent antiviral activity against a large panel of laboratory-adapted and primary isolates, including viral strains resistant to inhibitors of reverse transcriptase and protease. Conclusions These preliminary data serve as the foundation for designing small, stable, α-helical peptides and small-molecule inhibitors targeted against the CTD dimer interface. The observation that relatively weak CA binders, such as NYAD-201 and NYAD-202, showed specificity and are able to disrupt the CTD dimer is encouraging for further exploration of a much broader class of antiviral compounds targeting CA. We cannot exclude the possibility that the CA-based peptides described here could elicit additional effects on virus replication not directly linked to their ability to bind CA-CTD.
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Affiliation(s)
- Hongtao Zhang
- Laboratory of Molecular Modeling & Drug Design; Lindsley F, Kimball Research Institute of the New York Blood Center, 310 E 67th Street, New York, NY 10065, USA
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Curreli F, Zhang H, Zhang X, Pyatkin I, Victor Z, Altieri A, Debnath AK. Virtual screening based identification of novel small-molecule inhibitors targeted to the HIV-1 capsid. Bioorg Med Chem 2010; 19:77-90. [PMID: 21168336 DOI: 10.1016/j.bmc.2010.11.045] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2010] [Revised: 11/16/2010] [Accepted: 11/22/2010] [Indexed: 11/27/2022]
Abstract
The hydrophobic cavity of the C-terminal domain (CTD) of HIV-1 capsid has been recently validated as potential target for antiviral drugs by peptide-based inhibitors; however, there is no report yet of any small molecule compounds that target this hydrophobic cavity. In order to fill this gap and discover new classes of ant-HIV-1 inhibitors, we undertook a docking-based virtual screening and subsequent analog search, and medicinal chemistry approaches to identify small molecule inhibitors against this target. This article reports for the first time, to the best of our knowledge, identification of diverse classes of inhibitors that efficiently inhibited the formation of mature-like viral particles verified under electron microscope (EM) and showed potential as anti-HIV-1 agents in a viral infectivity assay against a wide range of laboratory-adapted as well as primary isolates in MT-2 cells and PBMC. In addition, the virions produced after the HIV-1 infected cells were treated with two of the most active compounds showed drastically reduced infectivity confirming the potential of these compounds as anti-HIV-1 agents. We have derived a comprehensive SAR from the antiviral data. The SAR analyses will be useful in further optimizing the leads to potential anti-HIV-1 agents.
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Affiliation(s)
- Francesca Curreli
- Laboratory of Molecular Modeling & Drug Design, Lindsley F. Kimball Research Institute of the New York Blood Center, 310 E 67th Street, New York, NY 10065, USA
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Thai V, Renesto P, Fowler CA, Brown DJ, Davis T, Gu W, Pollock DD, Kern D, Raoult D, Eisenmesser EZ. Structural, biochemical, and in vivo characterization of the first virally encoded cyclophilin from the Mimivirus. J Mol Biol 2008; 378:71-86. [PMID: 18342330 PMCID: PMC2884007 DOI: 10.1016/j.jmb.2007.08.051] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2007] [Revised: 08/22/2007] [Accepted: 08/23/2007] [Indexed: 12/29/2022]
Abstract
Although multiple viruses utilize host cell cyclophilins, including severe acute respiratory syndrome (SARS) and human immunodeficiency virus type-1(HIV-1), their role in infection is poorly understood. To help elucidate these roles, we have characterized the first virally encoded cyclophilin (mimicyp) derived from the largest virus discovered to date (the Mimivirus) that is also a causative agent of pneumonia in humans. Mimicyp adopts a typical cyclophilin-fold, yet it also forms trimers unlike any previously characterized homologue. Strikingly, immunofluorescence assays reveal that mimicyp localizes to the surface of the mature virion, as recently proposed for several viruses that recruit host cell cyclophilins such as SARS and HIV-1. Additionally mimicyp lacks peptidyl-prolyl isomerase activity in contrast to human cyclophilins. Thus, this study suggests that cyclophilins, whether recruited from host cells (i.e. HIV-1 and SARS) or virally encoded (i.e. Mimivirus), are localized on viral surfaces for at least a subset of viruses.
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Key Words
- fiv, feline immunodeficiency virus
- hiv-1, human immunodeficiency virus type-1
- hcypa, human cyclophilin-a
- hcypb, human cyclophilin-b
- mimicyp, mimivirus cyclophilin
- ncldv, nuclear cytoplasmic large dna viruses
- ppiase, peptidyl-prolyl isomerase
- sars, sever acute respiratory syndrome
- vv, vaccinia virus
- sv, vesicular stomatitis virus
- csa, cyclosporine-a
- trosy-hsqc, transverse relaxation optimized spectroscopy-heteronuclear single quantum coherence
- dapi, diamidino-2-phylindole
- cyclophilin
- virus
- pneumonia
- peptidyl-prolyl isomerase
- mimivirus
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Affiliation(s)
- Vu Thai
- Department of Biochemistry, Brandeis University and Howard Hughes Medical Institute, Brandeis University, Waltham, MA 02454, USA
| | - Patricia Renesto
- Unité des Rickettsies, Faculté de Médecine, CNRSUMR6020, Université de la Méditerranée, 13385 Marseille Cedex 05, France
| | - C. Andrew Fowler
- Department of Chemistry & Biochemistry, University of Colorado at Boulder, Boulder, CO 80309, USA
| | - Darin J. Brown
- Department of Biochemistry & Molecular Genetics, University of Colorado Health Science Center, School of Medicine, 12801 E 17 Ave, Aurora, CO 80045, USA
| | - Tara Davis
- Structural Genomics Consortium and the Department of Physiology, University of Toronto, 100 College St., Toronto, ON, Canada M5G1L5
| | - Wanjun Gu
- Department of Biochemistry & Molecular Genetics, University of Colorado Health Science Center, School of Medicine, 12801 E 17 Ave, Aurora, CO 80045, USA
| | - David D. Pollock
- Department of Biochemistry & Molecular Genetics, University of Colorado Health Science Center, School of Medicine, 12801 E 17 Ave, Aurora, CO 80045, USA
| | - Dorothee Kern
- Department of Biochemistry, Brandeis University and Howard Hughes Medical Institute, Brandeis University, Waltham, MA 02454, USA
| | - Didier Raoult
- Unité des Rickettsies, Faculté de Médecine, CNRSUMR6020, Université de la Méditerranée, 13385 Marseille Cedex 05, France
| | - Elan Z. Eisenmesser
- Department of Biochemistry & Molecular Genetics, University of Colorado Health Science Center, School of Medicine, 12801 E 17 Ave, Aurora, CO 80045, USA
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Li Z, Zhao X, Bai S, Wang Z, Chen L, Wei Y, Huang C. Proteomics identification of cyclophilin a as a potential prognostic factor and therapeutic target in endometrial carcinoma. Mol Cell Proteomics 2008; 7:1810-23. [PMID: 18421009 DOI: 10.1074/mcp.m700544-mcp200] [Citation(s) in RCA: 88] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/23/2023] Open
Abstract
Endometrial carcinoma is one of the most common malignancies of the female genital tract, and there is an urgent need for discovery of novel factors for prognostic assessment and therapeutic targets to endometrial carcinoma. Herein a two-dimensional gel electrophoresis and MALDI-Q-TOF MS/MS-based proteomics approach was used to identify differentially expressed proteins in endometrial carcinoma. Of the 99 proteins identified, cyclophilin A was one of the most significantly altered proteins, and its overexpression was confirmed using RT-PCR and Western blot analyses. Immunohistochemistry suggested a link between cyclophilin A expression and poor differentiation and decreased survival (p < 0.01). Knockdown of cyclophilin A expression by RNA interference led to the significant suppression of the cell growth and the induction of apoptosis in endometrial carcinoma HEC-1-B cells in vitro (p < 0.01) and the inhibition of tumor growth in vivo (p < 0.01). These data suggest that cyclophilin A may serve as a novel prognostic factor and possibly an attractive therapeutic target for endometrial carcinoma.
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Affiliation(s)
- Zhengyu Li
- Department of Gynecology and Obstetrics, West China Second [corrected] Hospital, Sichuan University, Chengdu 610041, China
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Abdurahman S, Youssefi M, Höglund S, Vahlne A. Characterization of the invariable residue 51 mutations of human immunodeficiency virus type 1 capsid protein on in vitro CA assembly and infectivity. Retrovirology 2007; 4:69. [PMID: 17903253 PMCID: PMC2064932 DOI: 10.1186/1742-4690-4-69] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2007] [Accepted: 09/28/2007] [Indexed: 11/10/2022] Open
Abstract
BACKGROUND The mature HIV-1 conical core formation proceeds through highly regulated protease cleavage of the Gag precursor, which ultimately leads to substantial rearrangements of the capsid (CAp24) molecule involving both inter- and intra-molecular contacts of the CAp24 molecules. In this aspect, Asp51 which is located in the N-terminal domain of HIV-1 CAp24 plays an important role by forming a salt-bridge with the free imino terminus Pro1 following proteolytic cleavage and liberation of the CAp24 protein from the Pr55Gag precursor. Thus, previous substitution mutation of Asp51 to alanine (D51A) has shown to be lethal and that this invariable residue was found essential for tube formation in vitro, virus replication and virus capsid formation. RESULTS We extended the above investigation by introducing three different D51 substitution mutations (D51N, D51E, and D51Q) into both prokaryotic and eukaryotic expression systems and studied their effects on in vitro capsid assembly and virus infectivity. Two substitution mutations (D51E and D51N) had no substantial effect on in vitro capsid assembly, yet they impaired viral infectivity and particle production. In contrast, the D51Q mutant was defective both for in vitro capsid assembly and for virus replication in cell culture. CONCLUSION These results show that substitutions of D51 with glutamate, glutamine, or asparagine, three amino acid residues that are structurally related to aspartate, could partially rescue both in vitro capsid assembly and intra-cellular CAp24 production but not replication of the virus in cultured cells.
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Affiliation(s)
- Samir Abdurahman
- Division of Clinical Virology, Karolinska Institutet, F68 Karolinska University Hospital, SE-141 86 Stockholm, Sweden
| | - Masoud Youssefi
- Division of Clinical Virology, Karolinska Institutet, F68 Karolinska University Hospital, SE-141 86 Stockholm, Sweden
| | - Stefan Höglund
- Department of Biochemistry, Uppsala University, Uppsala, Sweden
| | - Anders Vahlne
- Division of Clinical Virology, Karolinska Institutet, F68 Karolinska University Hospital, SE-141 86 Stockholm, Sweden
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Lau TS, Li Y, Kameoka M, Ng TB, Wan DCC. Suppression of HIV replication using RNA interference against HIV-1 integrase. FEBS Lett 2007; 581:3253-9. [PMID: 17592732 DOI: 10.1016/j.febslet.2007.06.011] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2007] [Revised: 05/04/2007] [Accepted: 06/01/2007] [Indexed: 11/22/2022]
Abstract
RNA interference (RNAi) has become one of the most powerful and popular approach on gene silencing in clinical research study especially in virology due to the gene-specific suppression property of small interfering RNA (siRNA). In this report, we demonstrate that expression of vector-mediated small hairpin RNA (shRNA) against human immunodeficiency virus type 1 (HIV-1) integrase (IN), one of the three important enzymes in HIV infection by controlling the integration of viral RNA to host DNA, could suppress the protein synthesis of EGFP-tagged IN in HeLa cell model efficiently. Furthermore, we show that IN shRNA can successfully reduce the HIV particles production in 293T cells at the level similar to the positive control of HIV-1 tat shRNA. These results provide the therapeutic possibility of HIV replication using RNAi against HIV-1 integrase.
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Affiliation(s)
- Tat San Lau
- Department of Biochemistry, The Chinese University of Hong Kong, Shatin, NT, Hong Kong, China
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