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Szilvay AM, Sarria SV, Mannelqvist M, Aasland R, Furnes C. Proteolytic activity assayed by subcellular localization switching of a substrate. Biochem Biophys Rep 2016; 8:23-28. [PMID: 28955937 PMCID: PMC5613695 DOI: 10.1016/j.bbrep.2016.07.011] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2016] [Revised: 06/27/2016] [Accepted: 07/13/2016] [Indexed: 10/24/2022] Open
Abstract
An approach to assay proteolytic activity in vivo by altering the subcellular localization of a labelled substrate was demonstrated. The assay included a protein shuttling between different cellular compartments and a site-specific recombinant protease. The shuttle protein used was the human immunodeficiency virus type 1 (HIV-1) Rev protein tandemly fused to the enhanced green fluorescent protein (EGFP) and the red fluorescent protein (RFP), while the protease was the site-specific protease VP24 from the herpes simplex virus type 1 (HSV-1). The fluorescent proteins in the Rev fusion protein were separated by a cleavage site specific for the VP24 protease. When co-expressed in COS-7 cells proteolysis was observed by fluorescence microscopy as a shift from a predominantly cytoplasmic localization of the fusion protein RevEGFP to a nuclear localization while the RFP part of the fusion protein remained in the cytoplasm. The cleavage of the fusion protein by VP24 was confirmed by Western blot analysis. The activity of VP24, when tagged N-terminally by the Myc-epitope, was found to be comparable to VP24. These results demonstrates that the activity and localization of a recombinantly expressed protease can be assessed by protease-mediated cleavage of fusion proteins containing a specific protease cleavage site.
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Affiliation(s)
- Anne-Marie Szilvay
- Department of Molecular Biology, University of Bergen, HIB, Post-box 7800, N-5020 Bergen, Norway
| | | | - Monica Mannelqvist
- Department of Molecular Biology, University of Bergen, HIB, Post-box 7800, N-5020 Bergen, Norway.,Centre for Cancer Biomarkers CCBIO, Department of Clinical Medicine, University of Bergen, HIB, Post-box 7800, N-5020 Bergen, Norway
| | - Rein Aasland
- Department of Molecular Biology, University of Bergen, HIB, Post-box 7800, N-5020 Bergen, Norway
| | - Clemens Furnes
- Department of Molecular Biology, University of Bergen, HIB, Post-box 7800, N-5020 Bergen, Norway.,Centre for Organelle Research (CORE), University of Stavanger, Norway
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Narayanan A, Iordanskiy S, Das R, Van Duyne R, Santos S, Jaworski E, Guendel I, Sampey G, Dalby E, Iglesias-Ussel M, Popratiloff A, Hakami R, Kehn-Hall K, Young M, Subra C, Gilbert C, Bailey C, Romerio F, Kashanchi F. Exosomes derived from HIV-1-infected cells contain trans-activation response element RNA. J Biol Chem 2013; 288:20014-33. [PMID: 23661700 PMCID: PMC3707700 DOI: 10.1074/jbc.m112.438895] [Citation(s) in RCA: 232] [Impact Index Per Article: 21.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2012] [Revised: 05/03/2013] [Indexed: 12/20/2022] Open
Abstract
Exosomes are nano-sized vesicles produced by healthy and virus-infected cells. Exosomes derived from infected cells have been shown to contain viral microRNAs (miRNAs). HIV-1 encodes its own miRNAs that regulate viral and host gene expression. The most abundant HIV-1-derived miRNA, first reported by us and later by others using deep sequencing, is the trans-activation response element (TAR) miRNA. In this study, we demonstrate the presence of TAR RNA in exosomes from cell culture supernatants of HIV-1-infected cells and patient sera. TAR miRNA was not in Ago2 complexes outside the exosomes but enclosed within the exosomes. We detected the host miRNA machinery proteins Dicer and Drosha in exosomes from infected cells. We report that transport of TAR RNA from the nucleus into exosomes is a CRM1 (chromosome region maintenance 1)-dependent active process. Prior exposure of naive cells to exosomes from infected cells increased susceptibility of the recipient cells to HIV-1 infection. Exosomal TAR RNA down-regulated apoptosis by lowering Bim and Cdk9 proteins in recipient cells. We found 10(4)-10(6) copies/ml TAR RNA in exosomes derived from infected culture supernatants and 10(3) copies/ml TAR RNA in the serum exosomes of highly active antiretroviral therapy-treated patients or long term nonprogressors. Taken together, our experiments demonstrated that HIV-1-infected cells produced exosomes that are uniquely characterized by their proteomic and RNA profiles that may contribute to disease pathology in AIDS.
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Affiliation(s)
- Aarthi Narayanan
- From the National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Sergey Iordanskiy
- From the National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
- the Department of Microbiology, Immunology and Tropical Medicine, George Washington University, Washington D. C. 20037
| | - Ravi Das
- From the National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Rachel Van Duyne
- From the National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
- the Department of Microbiology, Immunology and Tropical Medicine, George Washington University, Washington D. C. 20037
| | - Steven Santos
- the Department of Microbiology, Immunology and Tropical Medicine, George Washington University, Washington D. C. 20037
| | - Elizabeth Jaworski
- From the National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Irene Guendel
- From the National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Gavin Sampey
- From the National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Elizabeth Dalby
- From the National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Maria Iglesias-Ussel
- the Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Anastas Popratiloff
- the Department of Microbiology, Immunology and Tropical Medicine, George Washington University, Washington D. C. 20037
| | - Ramin Hakami
- From the National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Kylene Kehn-Hall
- From the National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Mary Young
- the Washington Metropolitan Women's Interagency HIV Study, Division of Infectious Diseases, Georgetown University Medical Center, Washington, D. C. 20007, and
| | - Caroline Subra
- the Department of Microbiology, Infectiology, and Immunology, Medicine Faculty, Laval University Center Hospitalier Universitaire de Quebec Research Center, City of Quebec, Quebec G1R2J6, Canada
| | - Caroline Gilbert
- the Department of Microbiology, Infectiology, and Immunology, Medicine Faculty, Laval University Center Hospitalier Universitaire de Quebec Research Center, City of Quebec, Quebec G1R2J6, Canada
| | - Charles Bailey
- From the National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
| | - Fabio Romerio
- the Department of Microbiology and Immunology, University of Maryland School of Medicine, Baltimore, Maryland 21201
| | - Fatah Kashanchi
- From the National Center for Biodefense and Infectious Diseases, George Mason University, Manassas, Virginia 20110
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Host-encoded reporters for the detection and purification of multiple enveloped viruses. J Virol Methods 2010; 167:178-85. [PMID: 20399809 PMCID: PMC2916077 DOI: 10.1016/j.jviromet.2010.04.002] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2009] [Revised: 03/31/2010] [Accepted: 04/08/2010] [Indexed: 02/07/2023]
Abstract
The identification of host cell factors for virus replication holds great promise for the development of new antiviral therapies. Recently, high-throughput screening methods have emerged as powerful tools to identify candidate host factors for therapeutic intervention. The development of assay systems suitable for large-scale automated screening is of particular importance for novel viruses with high pathogenic potential for which limited biological information can be developed in a short period of time. This report presents a general enzymatic reporter system for the detection and characterization of multiple enveloped viruses that does not rely on engineering of the virus. Instead, reporter enzymes are incorporated into virus particles by targeting to lipid microdomains in producer cells. The approach allows a variety of human pathogenic enveloped viruses to be detected by sensitive, inexpensive and automatable enzymatic assays. Tagged viruses can be purified quickly and efficiently by a magnetic bead-based capture method. The method allows general detection of enveloped viruses without prior reference to their sequence.
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