1
|
Ying Y, Yang Y, Chen AK. Roles of RNA scaffolding in nanoscale Gag multimerization and selective protein sorting at HIV membranes. Sci Adv 2024; 10:eadk8297. [PMID: 38394201 PMCID: PMC10889351 DOI: 10.1126/sciadv.adk8297] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Accepted: 01/19/2024] [Indexed: 02/25/2024]
Abstract
HIV-1 Gag proteins can multimerize upon the viral genomic RNA or multiple random cellular messenger RNAs to form a virus particle or a virus-like particle, respectively. To date, whether the two types of particles form via the same Gag multimerization process has remained unclarified. Using photoactivated localization microscopy to illuminate Gag organizations and dynamics at the nanoscale, here, we showed that genomic RNA mediates Gag multimerization in a more cluster-centric, cooperative, and spatiotemporally coordinated fashion, with the ability to drive dense Gag clustering dependent on its ability to act as a long-stranded scaffold not easily attainable by cellular messenger RNAs. These differences in Gag multimerization were further shown to affect downstream selective protein sorting into HIV membranes, indicating that the choice of RNA for packaging can modulate viral membrane compositions. These findings should advance the understanding of HIV assembly and further benefit the development of virus-like particle-based therapeutics.
Collapse
Affiliation(s)
- Yachen Ying
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing 100871, China
| | - Yantao Yang
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing 100871, China
| | - Antony K Chen
- Department of Biomedical Engineering, College of Future Technology, Peking University, Beijing 100871, China
- National Biomedical Imaging Center, Peking University, Beijing 100871, China
| |
Collapse
|
2
|
Banerjee P, Voth GA. Conformational transitions of the HIV-1 Gag polyprotein upon multimerization and gRNA binding. Biophys J 2024; 123:42-56. [PMID: 37978800 PMCID: PMC10808027 DOI: 10.1016/j.bpj.2023.11.017] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 10/25/2023] [Accepted: 11/16/2023] [Indexed: 11/19/2023] Open
Abstract
During the HIV-1 assembly process, the Gag polyprotein multimerizes at the producer cell plasma membrane, resulting in the formation of spherical immature virus particles. Gag-genomic RNA (gRNA) interactions play a crucial role in the multimerization process, which is yet to be fully understood. We performed large-scale all-atom molecular dynamics simulations of membrane-bound full-length Gag dimer, hexamer, and 18-mer. The inter-domain dynamic correlation of Gag, quantified by the heterogeneous elastic network model applied to the simulated trajectories, is observed to be altered by implicit gRNA binding, as well as the multimerization state of the Gag. The lateral dynamics of our simulated membrane-bound Gag proteins, with and without gRNA binding, agree with prior experimental data and help to validate our simulation models and methods. The gRNA binding is observed to affect mainly the SP1 domain of the 18-mer and the matrix-capsid linker domain of the hexamer. In the absence of gRNA binding, the independent dynamical motion of the nucleocapsid domain results in a collapsed state of the dimeric Gag. Unlike stable SP1 helices in the six-helix bundle, without IP6 binding, the SP1 domain undergoes a spontaneous helix-to-coil transition in the dimeric Gag. Together, our findings reveal conformational switches of Gag at different stages of the multimerization process and predict that the gRNA binding reinforces an efficient binding surface of Gag for multimerization, and also regulates the dynamic organization of the local membrane region itself.
Collapse
Affiliation(s)
- Puja Banerjee
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, Illinois
| | - Gregory A Voth
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, Illinois.
| |
Collapse
|
3
|
Tateishi H, Chinen T, Fukuda R, Radwan MO, Shimagaki K, Koga R, Masuda T, Okamoto Y, Sakamoto A, Misumi S, Otsuka M, Fujita M, Anraku K. HIV-1 Gag MA domain binds to cardiolipin in a binding mode distinct from virus assemble mediator PI(4,5)P 2. Chem Biol Drug Des 2024; 103:e14401. [PMID: 37985015 DOI: 10.1111/cbdd.14401] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2023] [Revised: 10/16/2023] [Accepted: 11/07/2023] [Indexed: 11/22/2023]
Abstract
The human immunodeficiency virus type 1 (HIV-1) Gag protein is responsible for facilitating HIV-1 virion assembly and budding. Our study demonstrates that cardiolipin (CL), a component found in the inner mitochondrial membrane, exhibits the highest binding affinity to the N-terminal MA domain of the HIV-1 Gag protein within the lipid group of host cells. To assess this binding interaction, we synthesized short acyl chain derivatives of CL and employed surface plasmon resonance (SPR) analysis to determine the dissociation constants (Kd) for CL and the MA domain. Simultaneously, we examined the Kd of D-myo-phosphatidylinositol 4,5-bisphosphate (PI(4,5)P2 ) derivatives, known to play a crucial role in virion formation. Among all the derivatives, Tetra-C7 -CL exhibited the lowest Kd value (Kd = 30.8 ± 6.9 μM) for MA binding on the CL analog-immobilized sensorchip, indicating a higher affinity. Similarly, the Kd value of Di-C7 -PIP2 (Kd = 36.6 ± 4.7 μM) was the lowest on the PI(4,5)P2 analog-immobilized sensorchip. Thus, Tetra-C7 -CL binds to the MA domain using a distinct binding mode while displaying a comparable binding affinity to Di-C7 -PIP2. This discovery holds significant implications for comprehending the virological importance of CL-MA domain binding, such as its subcellular distribution, including mitochondrial translocation, and involvement in viral particle formation in concert with PI(4,5)P2 . Furthermore, this study has the potential to contribute to the development of drugs in the future.
Collapse
Affiliation(s)
- Hiroshi Tateishi
- Medicinal and Biological Chemistry Science Farm Joint Research Laboratory, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Takuma Chinen
- Medicinal and Biological Chemistry Science Farm Joint Research Laboratory, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Ryota Fukuda
- Medicinal and Biological Chemistry Science Farm Joint Research Laboratory, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Mohamed O Radwan
- Medicinal and Biological Chemistry Science Farm Joint Research Laboratory, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
- Chemistry of Natural Compounds Department, Pharmaceutical and Drug Industries Research Division, National Research Centre, Cairo, Egypt
| | - Kazunori Shimagaki
- Medicinal and Biological Chemistry Science Farm Joint Research Laboratory, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Ryoko Koga
- Medicinal and Biological Chemistry Science Farm Joint Research Laboratory, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Takashi Masuda
- Medicinal and Biological Chemistry Science Farm Joint Research Laboratory, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Yoshinari Okamoto
- Department of Instrumental Analysis, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Arisa Sakamoto
- Medicinal and Biological Chemistry Science Farm Joint Research Laboratory, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
- Department of Medical Technology, Kumamoto Health Science University, Kumamoto, Japan
| | - Shogo Misumi
- Department of Environmental and Molecular Health Sciences, Global Center for Natural Resources Sciences, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Masami Otsuka
- Medicinal and Biological Chemistry Science Farm Joint Research Laboratory, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
- Science Farm Ltd., Kumamoto, Japan
| | - Mikako Fujita
- Medicinal and Biological Chemistry Science Farm Joint Research Laboratory, Faculty of Life Sciences, Kumamoto University, Kumamoto, Japan
| | - Kensaku Anraku
- Department of Medical Technology, Kumamoto Health Science University, Kumamoto, Japan
| |
Collapse
|
4
|
Tomishige N, Bin Nasim M, Murate M, Pollet B, Didier P, Godet J, Richert L, Sako Y, Mély Y, Kobayashi T. HIV-1 Gag targeting to the plasma membrane reorganizes sphingomyelin-rich and cholesterol-rich lipid domains. Nat Commun 2023; 14:7353. [PMID: 37990014 PMCID: PMC10663554 DOI: 10.1038/s41467-023-42994-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 08/30/2021] [Accepted: 10/26/2023] [Indexed: 11/23/2023] Open
Abstract
Although the human immunodeficiency virus type 1 lipid envelope has been reported to be enriched with host cell sphingomyelin and cholesterol, the molecular mechanism of the enrichment is not well understood. Viral Gag protein plays a central role in virus budding. Here, we report the interaction between Gag and host cell lipids using different quantitative and super-resolution microscopy techniques in combination with specific probes that bind endogenous sphingomyelin and cholesterol. Our results indicate that Gag in the inner leaflet of the plasma membrane colocalizes with the outer leaflet sphingomyelin-rich domains and cholesterol-rich domains, enlarges sphingomyelin-rich domains, and strongly restricts the mobility of sphingomyelin-rich domains. Moreover, Gag multimerization induces sphingomyelin-rich and cholesterol-rich lipid domains to be in close proximity in a curvature-dependent manner. Our study suggests that Gag binds, coalesces, and reorganizes pre-existing lipid domains during assembly.
Collapse
Affiliation(s)
- Nario Tomishige
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France.
- Cellular Informatics Laboratory, RIKEN CPR, Wako, Saitama, Japan.
| | - Maaz Bin Nasim
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
- Faculty of Pharmacy, The University of Lahore, Lahore, Pakistan
| | - Motohide Murate
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
- Cellular Informatics Laboratory, RIKEN CPR, Wako, Saitama, Japan
| | - Brigitte Pollet
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Pascal Didier
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Julien Godet
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Ludovic Richert
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France
| | - Yasushi Sako
- Cellular Informatics Laboratory, RIKEN CPR, Wako, Saitama, Japan
| | - Yves Mély
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France.
| | - Toshihide Kobayashi
- Laboratoire de Bioimagerie et Pathologies, UMR 7021 CNRS, Faculté de Pharmacie, Université de Strasbourg, Illkirch, France.
- Cellular Informatics Laboratory, RIKEN CPR, Wako, Saitama, Japan.
| |
Collapse
|
5
|
Maeda Y, Monde K, Terasawa H, Tanaka Y, Sawa T. Interaction of TSG101 with the PTAP Motif in Distinct Locations of Gag Determines the Incorporation of HTLV-1 Env into the Retroviral Virion. Int J Mol Sci 2023; 24:16520. [PMID: 38003710 PMCID: PMC10671467 DOI: 10.3390/ijms242216520] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 09/29/2023] [Revised: 11/16/2023] [Accepted: 11/18/2023] [Indexed: 11/26/2023] Open
Abstract
Human T-cell tropic virus type 1 (HTLV-1) is known to be mainly transmitted by cell-to-cell contact due to the lower infectivity of the cell-free virion. However, the reasons why cell-free HTLV-1 infection is poor remain unknown. In this study, we found that the retrovirus pseudotyped with HTLV-1 viral envelope glycoprotein (Env) was infectious when human immunodeficiency virus type 1 (HIV-1) was used to produce the virus. We found that the incorporation of HTLV-1 Env into virus-like particles (VLPs) was low when HTLV-1 Gag was used to produce VLPs, whereas VLPs produced using HIV-1 Gag efficiently incorporated HTLV-1 Env. The production of VLPs using Gag chimeras between HTLV-1 and HIV-1 Gag and deletion mutants of HIV-1 Gag showed that the p6 domain of HIV-1 Gag was responsible for the efficient incorporation of HTLV-1 Env into the VLPs. Further mutagenic analyses of the p6 domain of HIV-1 Gag revealed that the PTAP motif in the p6 domain of HIV-1 Gag facilitates the incorporation of HTLV-1 Env into VLPs. Since the PTAP motif is known to interact with tumor susceptibility gene 101 (TSG101) during the budding process, we evaluated the effect of TSG101 knockdown on the incorporation of HTLV-1 Env into VLPs. We found that TSG101 knockdown suppressed the incorporation of HTLV-1 Env into VLPs and decreased the infectivity of cell-free HIV-1 pseudotyped with HTLV-1 Env. Our results suggest that the interaction of TSG101 with the PTAP motif of the retroviral L domain is involved not only in the budding process but also in the efficient incorporation of HTLV-1 Env into the cell-free virus.
Collapse
Affiliation(s)
- Yosuke Maeda
- Department of Microbiology, Faculty of Life Sciences, Kumamoto University, Kumamoto 860-8556, Japan; (K.M.); (T.S.)
| | - Kazuaki Monde
- Department of Microbiology, Faculty of Life Sciences, Kumamoto University, Kumamoto 860-8556, Japan; (K.M.); (T.S.)
| | - Hiromi Terasawa
- Department of Microbiology, Faculty of Life Sciences, Kumamoto University, Kumamoto 860-8556, Japan; (K.M.); (T.S.)
| | - Yuetsu Tanaka
- Department of Immunology, Graduate School of Medicine, University of the Ryukyus, Okinawa 903-0215, Japan;
| | - Tomohiro Sawa
- Department of Microbiology, Faculty of Life Sciences, Kumamoto University, Kumamoto 860-8556, Japan; (K.M.); (T.S.)
| |
Collapse
|
6
|
Dibsy R, Bremaud E, Mak J, Favard C, Muriaux D. HIV-1 diverts cortical actin for particle assembly and release. Nat Commun 2023; 14:6945. [PMID: 37907528 PMCID: PMC10618566 DOI: 10.1038/s41467-023-41940-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 12/06/2022] [Accepted: 09/25/2023] [Indexed: 11/02/2023] Open
Abstract
Enveloped viruses assemble and bud from the host cell membranes. Any role of cortical actin in these processes have often been a source of debate. Here, we assessed if cortical actin was involved in HIV-1 assembly in infected CD4 T lymphocytes. Our results show that preventing actin branching not only increases HIV-1 particle release but also the number of individual HIV-1 Gag assembly clusters at the T cell plasma membrane. Indeed, in infected T lymphocytes and in in vitro quantitative model systems, we show that HIV-1 Gag protein prefers areas deficient in F-actin for assembling. Finally, we found that the host factor Arpin, an inhibitor of Arp2/3 branched actin, is recruited at the membrane of infected T cells and it can associate with the viral Gag protein. Altogether, our data show that, for virus assembly and particle release, HIV-1 prefers low density of cortical actin and may favor local actin debranching by subverting Arpin.
Collapse
Affiliation(s)
- Rayane Dibsy
- Institute of Research in Infectious disease of Montpellier (IRIM), University of Montpellier, UMR9004 CNRS, Montpellier, France
| | - Erwan Bremaud
- Institute of Research in Infectious disease of Montpellier (IRIM), University of Montpellier, UMR9004 CNRS, Montpellier, France
| | - Johnson Mak
- Institute for Glycomics, Griffith University, Brisbane, Australia
| | - Cyril Favard
- Institute of Research in Infectious disease of Montpellier (IRIM), University of Montpellier, UMR9004 CNRS, Montpellier, France
| | - Delphine Muriaux
- Institute of Research in Infectious disease of Montpellier (IRIM), University of Montpellier, UMR9004 CNRS, Montpellier, France.
| |
Collapse
|
7
|
Kaddis Maldonado R, Lambert GS, Rice BL, Sudol M, Flanagan JM, Parent LJ. The Rous sarcoma virus Gag Polyprotein Forms Biomolecular Condensates Driven by Intrinsically-disordered Regions. J Mol Biol 2023; 435:168182. [PMID: 37328094 PMCID: PMC10527454 DOI: 10.1016/j.jmb.2023.168182] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 01/04/2023] [Revised: 06/07/2023] [Accepted: 06/09/2023] [Indexed: 06/18/2023]
Abstract
Biomolecular condensates (BMCs) play important roles incellular structures includingtranscription factories, splicing speckles, and nucleoli. BMCs bring together proteins and other macromolecules, selectively concentrating them so that specific reactions can occur without interference from the surrounding environment. BMCs are often made up of proteins that contain intrinsically disordered regions (IDRs), form phase-separated spherical puncta, form liquid-like droplets that undergo fusion and fission, contain molecules that are mobile, and are disrupted with phase-dissolving drugs such as 1,6-hexanediol. In addition to cellular proteins, many viruses, including influenza A, SARS-CoV-2, and human immunodeficiency virus type 1 (HIV-1) encode proteins that undergo phase separation and rely on BMC formation for replication. In prior studies of the retrovirus Rous sarcoma virus (RSV), we observed that the Gag protein forms discrete spherical puncta in the nucleus, cytoplasm, and at the plasma membrane that co-localize with viral RNA and host factors, raising the possibility that RSV Gag forms BMCs that participate in the intracellular phase of the virion assembly pathway. In our current studies, we found that Gag contains IDRs in the N-terminal (MAp2p10) and C-terminal (NC) regions of the protein and fulfills many criteria of BMCs. Although the role of BMC formation in RSV assembly requires further study, our results suggest the biophysical properties of condensates are required for the formation of Gag complexes in the nucleus and the cohesion of these complexes as they traffic through the nuclear pore, into the cytoplasm, and to the plasma membrane, where the final assembly and release of virus particles occurs.
Collapse
Affiliation(s)
- Rebecca Kaddis Maldonado
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA; Department of Microbiology & Immunology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - Gregory S Lambert
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - Breanna L Rice
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - Malgorzata Sudol
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - John M Flanagan
- Department of Biochemistry & Molecular Biology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA
| | - Leslie J Parent
- Department of Medicine, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA; Department of Microbiology & Immunology, Penn State College of Medicine, 500 University Drive, Hershey, PA 17033, USA.
| |
Collapse
|
8
|
Guo S, Saha I, Saffarian S, Johnson ME. Structure of the HIV immature lattice allows for essential lattice remodeling within budded virions. eLife 2023; 12:e84881. [PMID: 37435945 PMCID: PMC10361719 DOI: 10.7554/elife.84881] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 11/12/2022] [Accepted: 07/12/2023] [Indexed: 07/13/2023] Open
Abstract
For HIV virions to become infectious, the immature lattice of Gag polyproteins attached to the virion membrane must be cleaved. Cleavage cannot initiate without the protease formed by the homo-dimerization of domains linked to Gag. However, only 5% of the Gag polyproteins, termed Gag-Pol, carry this protease domain, and they are embedded within the structured lattice. The mechanism of Gag-Pol dimerization is unknown. Here, we use spatial stochastic computer simulations of the immature Gag lattice as derived from experimental structures, showing that dynamics of the lattice on the membrane is unavoidable due to the missing 1/3 of the spherical protein coat. These dynamics allow for Gag-Pol molecules carrying the protease domains to detach and reattach at new places within the lattice. Surprisingly, dimerization timescales of minutes or less are achievable for realistic binding energies and rates despite retaining most of the large-scale lattice structure. We derive a formula allowing extrapolation of timescales as a function of interaction free energy and binding rate, thus predicting how additional stabilization of the lattice would impact dimerization times. We further show that during assembly, dimerization of Gag-Pol is highly likely and therefore must be actively suppressed to prevent early activation. By direct comparison to recent biochemical measurements within budded virions, we find that only moderately stable hexamer contacts (-12kBT<∆G<-8kBT) retain both the dynamics and lattice structures that are consistent with experiment. These dynamics are likely essential for proper maturation, and our models quantify and predict lattice dynamics and protease dimerization timescales that define a key step in understanding formation of infectious viruses.
Collapse
Affiliation(s)
- Sikao Guo
- TC Jenkins Department of Biophysics, Johns Hopkins UniversityBaltimoreUnited States
| | - Ipsita Saha
- Laboratory of Cell and Developmental Signaling, Center for Cancer Research, National Cancer Institute, National Institutes of HealthFrederickUnited States
| | - Saveez Saffarian
- Center for Cell and Genome Science, University of UtahSalt Lake CityUnited States
- Department of Physics and Astronomy, University of UtahSalt Lake CityUnited States
- School of Biological Sciences, University of UtahSalt Lake CityUnited States
| | - Margaret E Johnson
- TC Jenkins Department of Biophysics, Johns Hopkins UniversityBaltimoreUnited States
| |
Collapse
|
9
|
Hudait A, Hurley JH, Voth GA. Dynamics of upstream ESCRT organization at the HIV-1 budding site. Biophys J 2023; 122:2655-2674. [PMID: 37218128 PMCID: PMC10397573 DOI: 10.1016/j.bpj.2023.05.020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/09/2022] [Revised: 03/27/2023] [Accepted: 05/11/2023] [Indexed: 05/24/2023] Open
Abstract
In the late stages of the HIV-1 life cycle, membrane localization and self-assembly of Gag polyproteins induce membrane deformation and budding. Release of the virion requires direct interaction between immature Gag lattice and upstream ESCRT machinery at the viral budding site, followed by assembly of downstream ESCRT-III factors, culminating in membrane scission. However, molecular details of upstream ESCRT assembly dynamics at the viral budding site remain unclear. In this work, using coarse-grained (CG) molecular dynamics (MD) simulations, we investigated the interactions between Gag, ESCRT-I, ESCRT-II, and membrane to delineate the dynamical mechanisms by which upstream ESCRTs assemble templated by late-stage immature Gag lattice. We first systematically derived "bottom-up" CG molecular models and interactions of upstream ESCRT proteins from experimental structural data and extensive all-atom MD simulations. Using these molecular models, we performed CG MD simulations of ESCRT-I oligomerization and ESCRT-I/II supercomplex formation at the neck of the budding virion. Our simulations demonstrate that ESCRT-I can effectively oligomerize to higher-order complexes templated by the immature Gag lattice both in the absence of ESCRT-II and when multiple copies of ESCRT-II are localized at the bud neck. The ESCRT-I/II supercomplexes formed in our simulations exhibit predominantly columnar structures, which has important implications for the nucleation pathway of downstream ESCRT-III polymers. Importantly, ESCRT-I/II supercomplexes bound to Gag initiate membrane neck constriction by pulling the inner edge of the bud neck closer to the ESCRT-I headpiece ring. Our findings serve to elucidate a network of interactions between upstream ESCRT machinery, immature Gag lattice, and membrane neck that regulate protein assembly dynamics at the HIV-1 budding site.
Collapse
Affiliation(s)
- Arpa Hudait
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, Illinois
| | - James H Hurley
- Department of Molecular and Cell Biology and California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, California; California Institute for Quantitative Biosciences, University of California, Berkeley, Berkeley, California
| | - Gregory A Voth
- Department of Chemistry, Chicago Center for Theoretical Chemistry, Institute for Biophysical Dynamics, and James Franck Institute, The University of Chicago, Chicago, Illinois.
| |
Collapse
|
10
|
Herrmann D, Hanson HM, Zhou LW, Addabbo R, Willkomm NA, Angert I, Mueller JD, Mansky LM, Saad JS. Molecular Determinants of Human T-cell Leukemia Virus Type 1 Gag Targeting to the Plasma Membrane for Assembly. J Mol Biol 2022; 434:167609. [PMID: 35490898 PMCID: PMC10557380 DOI: 10.1016/j.jmb.2022.167609] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 02/28/2022] [Revised: 04/20/2022] [Accepted: 04/23/2022] [Indexed: 01/10/2023]
Abstract
Assembly of human T-cell leukemia virus type 1 (HTLV-1) particles is initiated by the trafficking of virally encoded Gag polyproteins to the inner leaflet of the plasma membrane (PM). Gag-PM interactions are mediated by the matrix (MA) domain, which contains a myristoyl group (myr) and a basic patch formed by lysine and arginine residues. For many retroviruses, Gag-PM interactions are mediated by phosphatidylinositol 4,5-bisphosphate [PI(4,5)P2]; however, previous studies suggested that HTLV-1 Gag-PM interactions and therefore virus assembly are less dependent on PI(4,5)P2. We have recently shown that PI(4,5)P2 binds directly to HTLV-1 unmyristoylated MA [myr(-)MA] and that myr(-)MA binding to membranes is significantly enhanced by inclusion of phosphatidylserine (PS) and PI(4,5)P2. Herein, we employed structural, biophysical, biochemical, mutagenesis, and cell-based assays to identify residues involved in MA-membrane interactions. Our data revealed that the lysine-rich motif (Lys47, Lys48, and Lys51) constitutes the primary PI(4,5)P2-binding site. Furthermore, we show that arginine residues 3, 7, 14 and 17 located in the unstructured N-terminus are essential for MA binding to membranes containing PS and/or PI(4,5)P2. Substitution of lysine and arginine residues severely attenuated virus-like particle production, but only the lysine residues could be clearly correlated with reduced PM binding. These results support a mechanism by which HTLV-1 Gag targeting to the PM is mediated by a trio engagement of the myr group, Arg-rich and Lys-rich motifs. These findings advance our understanding of a key step in retroviral particle assembly.
Collapse
Affiliation(s)
- Dominik Herrmann
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Heather M Hanson
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, United States
| | - Lynne W Zhou
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States
| | - Rayna Addabbo
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, United States; School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, United States
| | - Nora A Willkomm
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, United States
| | - Isaac Angert
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, United States; School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, United States
| | - Joachim D Mueller
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, United States; School of Physics and Astronomy, University of Minnesota, Minneapolis, MN 55455, United States
| | - Louis M Mansky
- Institute for Molecular Virology, University of Minnesota - Twin Cities, Minneapolis, MN 55455, United States.
| | - Jamil S Saad
- Department of Microbiology, University of Alabama at Birmingham, Birmingham, AL 35294, United States.
| |
Collapse
|
11
|
Lee MD, Creagh JW, Fredericks LR, Crabtree AM, Patel JS, Rowley PA. The Characterization of a Novel Virus Discovered in the Yeast Pichia membranifaciens. Viruses 2022; 14:v14030594. [PMID: 35337001 PMCID: PMC8951182 DOI: 10.3390/v14030594] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 01/05/2022] [Revised: 02/24/2022] [Accepted: 02/26/2022] [Indexed: 02/05/2023] Open
Abstract
Mycoviruses are widely distributed across fungi, including the yeasts of the Saccharomycotina subphylum. This manuscript reports the first double-stranded RNA (dsRNA) virus isolated from Pichia membranifaciens. This novel virus has been named Pichia membranifaciens virus L-A (PmV-L-A) and is a member of the Totiviridae. PmV-L-A is 4579 bp in length, with RNA secondary structures similar to the packaging, replication, and frameshift signals of totiviruses that infect Saccharomycotina yeasts. PmV-L-A was found to be part of a monophyletic group within the I-A totiviruses, implying a shared ancestry between mycoviruses isolated from the Pichiaceae and Saccharomycetaceae yeasts. Energy-minimized AlphaFold2 molecular models of the PmV-L-A Gag protein revealed structural conservation with the Gag protein of Saccharomyces cerevisiae virus L-A (ScV-L-A). The predicted tertiary structure of the PmV-L-A Pol and other homologs provided a possible mechanism for totivirus RNA replication due to structural similarities with the RNA-dependent RNA polymerases of mammalian dsRNA viruses. Insights into the structure, function, and evolution of totiviruses gained from yeasts are essential because of their emerging role in animal disease and their parallels with mammalian viruses.
Collapse
Affiliation(s)
- Mark D. Lee
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA; (M.D.L.); (J.W.C.); (L.R.F.); (A.M.C.); (J.S.P.)
| | - Jack W. Creagh
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA; (M.D.L.); (J.W.C.); (L.R.F.); (A.M.C.); (J.S.P.)
| | - Lance R. Fredericks
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA; (M.D.L.); (J.W.C.); (L.R.F.); (A.M.C.); (J.S.P.)
| | - Angela M. Crabtree
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA; (M.D.L.); (J.W.C.); (L.R.F.); (A.M.C.); (J.S.P.)
| | - Jagdish Suresh Patel
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA; (M.D.L.); (J.W.C.); (L.R.F.); (A.M.C.); (J.S.P.)
- Center for Modeling Complex Interactions, University of Idaho, Moscow, ID 83844, USA
| | - Paul A. Rowley
- Department of Biological Sciences, University of Idaho, Moscow, ID 83844, USA; (M.D.L.); (J.W.C.); (L.R.F.); (A.M.C.); (J.S.P.)
- Correspondence:
| |
Collapse
|
12
|
Bernacchi S. Visualization of Retroviral Gag-Genomic RNA Cellular Interactions Leading to Genome Encapsidation and Viral Assembly: An Overview. Viruses 2022; 14:v14020324. [PMID: 35215917 PMCID: PMC8876502 DOI: 10.3390/v14020324] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [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: 12/15/2021] [Revised: 01/25/2022] [Accepted: 02/03/2022] [Indexed: 11/16/2022] Open
Abstract
Retroviruses must selectively recognize their unspliced RNA genome (gRNA) among abundant cellular and spliced viral RNAs to assemble into newly formed viral particles. Retroviral gRNA packaging is governed by Gag precursors that also orchestrate all the aspects of viral assembly. Retroviral life cycles, and especially the HIV-1 one, have been previously extensively analyzed by several methods, most of them based on molecular biology and biochemistry approaches. Despite these efforts, the spatio-temporal mechanisms leading to gRNA packaging and viral assembly are only partially understood. Nevertheless, in these last decades, progress in novel bioimaging microscopic approaches (as FFS, FRAP, TIRF, and wide-field microscopy) have allowed for the tracking of retroviral Gag and gRNA in living cells, thus providing important insights at high spatial and temporal resolution of the events regulating the late phases of the retroviral life cycle. Here, the implementation of these recent bioimaging tools based on highly performing strategies to label fluorescent macromolecules is described. This report also summarizes recent gains in the current understanding of the mechanisms employed by retroviral Gag polyproteins to regulate molecular mechanisms enabling gRNA packaging and the formation of retroviral particles, highlighting variations and similarities among the different retroviruses.
Collapse
Affiliation(s)
- Serena Bernacchi
- Architecture et Réactivité de l'ARN-UPR 9002, IBMC, CNRS, Université de Strasbourg, F-67000 Strasbourg, France
| |
Collapse
|
13
|
Durand S, Seigneuret F, Burlaud-Gaillard J, Lemoine R, Tassi MF, Moreau A, Mougel M, Roingeard P, Tauber C, de Rocquigny H. Quantitative analysis of the formation of nucleoprotein complexes between HIV-1 Gag protein and genomic RNA using transmission electron microscopy. J Biol Chem 2022; 298:101500. [PMID: 34929171 PMCID: PMC8760521 DOI: 10.1016/j.jbc.2021.101500] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/03/2021] [Accepted: 12/05/2021] [Indexed: 01/06/2023] Open
Abstract
In HIV, the polyprotein precursor Gag orchestrates the formation of the viral capsid. In the current view of this viral assembly, Gag forms low-order oligomers that bind to the viral genomic RNA triggering the formation of high-ordered ribonucleoprotein complexes. However, this assembly model was established using biochemical or imaging methods that do not describe the cellular location hosting Gag-gRNA complex nor distinguish gRNA packaging in single particles. Here, we studied the intracellular localization of these complexes by electron microscopy and monitored the distances between the two partners by morphometric analysis of gold beads specifically labeling Gag and gRNA. We found that formation of these viral clusters occurred shortly after the nuclear export of the gRNA. During their transport to the plasma membrane, the distance between Gag and gRNA decreases together with an increase of gRNA packaging. Point mutations in the zinc finger patterns of the nucleocapsid domain of Gag caused an increase in the distance between Gag and gRNA as well as a sharp decrease of gRNA packaged into virions. Finally, we show that removal of stem loop 1 of the 5'-untranslated region does not interfere with gRNA packaging, whereas combined with the removal of stem loop 3 is sufficient to decrease but not abolish Gag-gRNA cluster formation and gRNA packaging. In conclusion, this morphometric analysis of Gag-gRNA cluster formation sheds new light on HIV-1 assembly that can be used to describe at nanoscale resolution other viral assembly steps involving RNA or protein-protein interactions.
Collapse
Affiliation(s)
- Stéphanie Durand
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France
| | - Florian Seigneuret
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France
| | - Julien Burlaud-Gaillard
- Microscopy IBiSA Platform, PPF ASB, University of Tours and CHRU of Tours, Tours Cedex 1, France
| | - Roxane Lemoine
- B Cell Ressources Platform, EA4245 "Transplantation, Immunology and Inflammation", University of Tours, Tours Cedex 1, France
| | - Marc-Florent Tassi
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France
| | - Alain Moreau
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France
| | - Marylène Mougel
- Équipe R2D2 Retroviral RNA Dynamics and Delivery, IRIM, CNRS UMR9004, University of Montpellier, Montpellier, France
| | - Philippe Roingeard
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France; Microscopy IBiSA Platform, PPF ASB, University of Tours and CHRU of Tours, Tours Cedex 1, France
| | - Clovis Tauber
- UMR U1253 iBrain, Inserm, University of Tours, Tours Cedex 1, France
| | - Hugues de Rocquigny
- Morphogenesis and Antigenicity of HIV and Hepatitis Viruses, Inserm - U1259 MAVIVH, Bretonneau Hospital, Tours Cedex 1, France.
| |
Collapse
|
14
|
Balakrishnan K, Jaguva Vasudevan AA, Mohareer K, Luedde T, Münk C, Banerjee S. Encapsidation of Staufen-2 Enhances Infectivity of HIV-1. Viruses 2021; 13:v13122459. [PMID: 34960728 PMCID: PMC8703407 DOI: 10.3390/v13122459] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Revised: 11/26/2021] [Accepted: 12/02/2021] [Indexed: 11/20/2022] Open
Abstract
Staufen, the RNA-binding family of proteins, affects various steps in the Human Immuno-Deficiency Virus (HIV-1) replication cycle. While our previous study established Staufen-2–HIV-1 Rev interaction and its role in augmenting nucleocytoplasmic export of RRE-containing viral RNA, viral incorporation of Staufen-2 and its effect on viral propagation were unknown. Here, we report that Staufen-2 interacts with HIV-1 Gag and is incorporated into virions and that encapsidated Staufen-2 boosted viral infectivity. Further, Staufen-2 gets co-packaged into virions, possibly by interacting with host factors Staufen-1 or antiviral protein APOBEC3G, which resulted in different outcomes on the infectivity of Staufen-2-encapsidated virions. These observations suggest that encapsidated host factors influence viral population dynamics and infectivity. With the explicit identification of the incorporation of Staufen proteins into HIV-1 and other retroviruses, such as Simian Immunodeficiency Virus (SIV), we propose that packaging of RNA binding proteins, such as Staufen, in budding virions of retroviruses is probably a general phenomenon that can drive or impact the viral population dynamics, infectivity, and evolution.
Collapse
Affiliation(s)
- Kannan Balakrishnan
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad 500046, India; (K.B.); (K.M.)
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany; (A.A.J.V.); (T.L.)
| | - Ananda Ayyappan Jaguva Vasudevan
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany; (A.A.J.V.); (T.L.)
| | - Krishnaveni Mohareer
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad 500046, India; (K.B.); (K.M.)
| | - Tom Luedde
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany; (A.A.J.V.); (T.L.)
| | - Carsten Münk
- Clinic for Gastroenterology, Hepatology, and Infectiology, Medical Faculty, Heinrich-Heine-University Düsseldorf, 40225 Düsseldorf, Germany; (A.A.J.V.); (T.L.)
- Correspondence: (C.M.); (S.B.); Tel.: +49-021-1811-0887 (C.M.); +91-40-2313-4573 (S.B.)
| | - Sharmistha Banerjee
- Department of Biochemistry, School of Life Sciences, University of Hyderabad, Gachibowli, Hyderabad 500046, India; (K.B.); (K.M.)
- Correspondence: (C.M.); (S.B.); Tel.: +49-021-1811-0887 (C.M.); +91-40-2313-4573 (S.B.)
| |
Collapse
|
15
|
Chameettachal A, Vivet-Boudou V, Pitchai F, Pillai V, Ali L, Krishnan A, Bernacchi S, Mustafa F, Marquet R, Rizvi T. A purine loop and the primer binding site are critical for the selective encapsidation of mouse mammary tumor virus genomic RNA by Pr77Gag. Nucleic Acids Res 2021; 49:4668-4688. [PMID: 33836091 PMCID: PMC8096270 DOI: 10.1093/nar/gkab223] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2020] [Revised: 03/15/2021] [Accepted: 03/24/2021] [Indexed: 12/22/2022] Open
Abstract
Retroviral RNA genome (gRNA) harbors cis-acting sequences that facilitate its specific packaging from a pool of other viral and cellular RNAs by binding with high-affinity to the viral Gag protein during virus assembly. However, the molecular intricacies involved during selective gRNA packaging are poorly understood. Binding and footprinting assays on mouse mammary tumor virus (MMTV) gRNA with purified Pr77Gag along with in cell gRNA packaging study identified two Pr77Gag binding sites constituting critical, non-redundant packaging signals. These included: a purine loop in a bifurcated stem-loop containing the gRNA dimerization initiation site, and the primer binding site (PBS). Despite these sites being present on both unspliced and spliced RNAs, Pr77Gag specifically bound to unspliced RNA, since only that could adopt the native bifurcated stem-loop structure containing looped purines. These results map minimum structural elements required to initiate MMTV gRNA packaging, distinguishing features that are conserved amongst divergent retroviruses from those perhaps unique to MMTV. Unlike purine-rich motifs frequently associated with packaging signals, direct involvement of PBS in gRNA packaging has not been documented in retroviruses. These results enhance our understanding of retroviral gRNA packaging/assembly, making it not only a target for novel therapeutic interventions, but also development of safer gene therapy vectors.
Collapse
Affiliation(s)
- Akhil Chameettachal
- Department of Microbiology & Immunology, College of Medicine and Health Sciences (CMHS), United Arab Emirates University (UAEU), Al Ain, United Arab Emirates
| | - Valérie Vivet-Boudou
- Université de Strasbourg, CNRS, Architecture et Réactivité de l’ARN, UPR 9002, Strasbourg, France
| | - Fathima Nuzra Nagoor Pitchai
- Department of Microbiology & Immunology, College of Medicine and Health Sciences (CMHS), United Arab Emirates University (UAEU), Al Ain, United Arab Emirates
| | - Vineeta N Pillai
- Department of Microbiology & Immunology, College of Medicine and Health Sciences (CMHS), United Arab Emirates University (UAEU), Al Ain, United Arab Emirates
| | - Lizna Mohamed Ali
- Department of Microbiology & Immunology, College of Medicine and Health Sciences (CMHS), United Arab Emirates University (UAEU), Al Ain, United Arab Emirates
| | - Anjana Krishnan
- Department of Microbiology & Immunology, College of Medicine and Health Sciences (CMHS), United Arab Emirates University (UAEU), Al Ain, United Arab Emirates
| | - Serena Bernacchi
- Université de Strasbourg, CNRS, Architecture et Réactivité de l’ARN, UPR 9002, Strasbourg, France
| | - Farah Mustafa
- Department of Biochemistry, College of Medicine and Health Sciences (CMHS), United Arab Emirates University (UAEU), Al Ain, United Arab Emirates
- Zayed Center for Health Sciences, United Arab Emirates University, United Arab Emirates
| | - Roland Marquet
- Université de Strasbourg, CNRS, Architecture et Réactivité de l’ARN, UPR 9002, Strasbourg, France
| | - Tahir A Rizvi
- Department of Microbiology & Immunology, College of Medicine and Health Sciences (CMHS), United Arab Emirates University (UAEU), Al Ain, United Arab Emirates
- Zayed Center for Health Sciences, United Arab Emirates University, United Arab Emirates
| |
Collapse
|
16
|
Aljahdali MO, Molla MHR, Ahammad F. Compounds Identified from Marine Mangrove Plant (Avicennia alba) as Potential Antiviral Drug Candidates Against WDSV, an In-Silico Approach. Mar Drugs 2021; 19:md19050253. [PMID: 33925208 PMCID: PMC8145693 DOI: 10.3390/md19050253] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2021] [Revised: 04/25/2021] [Accepted: 04/26/2021] [Indexed: 12/20/2022] Open
Abstract
Walleye dermal sarcoma virus (WDSV) is a type of retrovirus, which affects most of the adult walleye fishes during the spawning time. The virus causes multiple epithelial tumors on the fish’s skin and fins that are liable for more than 50% of the mortality rate of fish around the world. Till now, no effective antiviral drug or vaccine candidates have been developed that can block the progression of the disease caused by the pathogen. It was found that the 582-amino-acid (aa) residues long internal structural gag polyprotein of the virus plays an important role in virus budding and virion maturation outside of the cell. Inhibition of the protein can block the budding and virion maturation process and can be developed as an antiviral drug candidate against the virus. Therefore, the study aimed to identify potential natural antiviral drug candidates from the tropical mangrove marine plant Avicennia alba, which will be able to block the budding and virion maturation process by inhibiting the activity of the gag protein of the virus. Initially, a homology modeling approach was applied to identify the 3D structure, followed by refinement and validation of the protein. The refined protein structures were then utilized for molecular docking simulation. Eleven phytochemical compounds have been isolated from the marine plant and docked against the virus gag polyprotein. Three compounds, namely Friedlein (CID244297), Phytosterols (CID12303662), and 1-Triacontanol (CID68972) have been selected based on their docking score −8.5 kcal/mol, −8.0 kcal/mol and −7.9 kcal/mol, respectively, and were evaluated through ADME (Absorption, Distribution, Metabolism and Excretion), and toxicity properties. Finally, molecular dynamics (MD) simulation was applied to confirm the binding stability of the protein-ligands complex structure. The ADME and toxicity analysis reveal the efficacy and non-toxic properties of the compounds, where MD simulation confirmed the binding stability of the selected three compounds with the targeted protein. This computational study revealed the virtuous value of the selected three compounds against the targeted gag polyprotein and will be effective and promising antiviral candidates against the pathogen in a significant and worthwhile manner. Although in vitro and in vivo study is required for further evaluation of the compounds against the targeted protein.
Collapse
|
17
|
Chen X, Coric P, Larue V, Turcaud S, Wang X, Nonin-Lecomte S, Bouaziz S. The HIV-1 maturation inhibitor, EP39, interferes with the dynamic helix-coil equilibrium of the CA-SP1 junction of Gag. Eur J Med Chem 2020; 204:112634. [PMID: 32717487 DOI: 10.1016/j.ejmech.2020.112634] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2020] [Revised: 06/29/2020] [Accepted: 06/29/2020] [Indexed: 11/30/2022]
Abstract
During the maturation of HIV-1 particle, the Gag polyprotein is cleaved into several proteins by the HIV-1 protease. These proteins rearrange to form infectious virus particles. In this study, the solution structure and dynamics of a monomeric mutated domain encompassing the C-terminal of capsid, the spacer peptide SP1 and the nucleocapsid from Gag was characterized by Nuclear Magnetic Resonance in the presence of maturation inhibitor EP39, a more hydro-soluble derivative of BVM. We show that the binding of EP39 decreases the dynamics of CA-SP1 junction, especially the QVT motif in SP1, and perturbs the natural coil-helix equilibrium on both sides of the SP1 domain by stabilizing the transient alpha helical structure. Our results provide new insight into the structure and dynamics of the SP1 domain and how HIV-1 maturation inhibitors interfere with this domain. They offer additional clues for the development of new second generation inhibitors targeting HIV-1 maturation.
Collapse
Affiliation(s)
- Xiaowei Chen
- CiTCoM, CNRS, UMR 8038, Université de Paris, 4 Avenue de L'Observatoire, Paris, 75270, France
| | - Pascale Coric
- CiTCoM, CNRS, UMR 8038, Université de Paris, 4 Avenue de L'Observatoire, Paris, 75270, France
| | - Valery Larue
- CiTCoM, CNRS, UMR 8038, Université de Paris, 4 Avenue de L'Observatoire, Paris, 75270, France
| | - Serge Turcaud
- LCBPT, CNRS, UMR 8601, Université de Paris, Paris, 45 Rue des Saints Pères, 75270, France
| | - Xiao Wang
- CiTCoM, CNRS, UMR 8038, Université de Paris, 4 Avenue de L'Observatoire, Paris, 75270, France
| | - Sylvie Nonin-Lecomte
- CiTCoM, CNRS, UMR 8038, Université de Paris, 4 Avenue de L'Observatoire, Paris, 75270, France
| | - Serge Bouaziz
- CiTCoM, CNRS, UMR 8038, Université de Paris, 4 Avenue de L'Observatoire, Paris, 75270, France.
| |
Collapse
|
18
|
Donhauser N, Socher E, Millen S, Heym S, Sticht H, Thoma-Kress AK. Transfer of HTLV-1 p8 and Gag to target T-cells depends on VASP, a novel interaction partner of p8. PLoS Pathog 2020; 16:e1008879. [PMID: 32997728 PMCID: PMC7526893 DOI: 10.1371/journal.ppat.1008879] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2020] [Accepted: 08/12/2020] [Indexed: 12/16/2022] Open
Abstract
The Human T-cell leukemia virus type 1 (HTLV-1) orf I-encoded accessory protein p8 is cleaved from its precursor p12, and both proteins contribute to viral persistence. p8 induces cellular protrusions, which are thought to facilitate transfer of p8 to target cells and virus transmission. Host factors interacting with p8 and mediating p8 transfer are unknown. Here, we report that vasodilator-stimulated phosphoprotein (VASP), which promotes actin filament elongation, is a novel interaction partner of p8 and important for p8 and HTLV-1 Gag cell-to-cell transfer. VASP contains an Ena/VASP homology 1 (EVH1) domain that targets the protein to focal adhesions. Bioinformatics identified a short stretch in p8 (amino acids (aa) 24–45) which may mediate interactions with the EVH1 domain of VASP. Co-immunoprecipitations confirmed interactions of VASP:p8 in 293T, Jurkat and HTLV-1-infected MT-2 cells. Co-precipitation of VASP:p8 could be significantly blocked by peptides mimicking aa 26–37 of p8. Mutational studies revealed that the EVH1-domain of VASP is necessary, but not sufficient for the interaction with p8. Further, deletion of the VASP G- and F-actin binding domains significantly diminished co-precipitation of p8. Imaging identified areas of partial co-localization of VASP with p8 at the plasma membrane and in protrusive structures, which was confirmed by proximity ligation assays. Co-culture experiments revealed that p8 is transferred between Jurkat T-cells via VASP-containing conduits. Imaging and flow cytometry revealed that repression of both endogenous and overexpressed VASP by RNA interference or by CRISPR/Cas9 reduced p8 transfer to the cell surface and to target Jurkat T-cells. Stable repression of VASP by RNA interference in chronically infected MT-2 cells impaired both p8 and HTLV-1 Gag transfer to target Jurkat T-cells, while virus release was unaffected. Thus, we identified VASP as a novel interaction partner of p8, which is important for transfer of HTLV-1 p8 and Gag to target T-cells. The delta-retrovirus Human T-cell leukemia virus type 1 encodes the accessory protein p8, which is generated by proteolytic cleavage from p12. Earlier work has shown that p8 enhances the formation of cellular conduits between T-cells, is transferred through these conduits to target T-cells and increases HTLV-1 transmission. It was suggested that p8 dampens T-cell responses in target T-cells, thus facilitating HTLV-1 infection. Our work sheds light on the mechanism of p8 transfer to target T-cells. We show that vasodilator-stimulated phosphoprotein (VASP), a novel interaction partner of p8, contributes to transfer of p8 to target T-cells. Mechanistically, VASP is crucial for recruitment of p8 to the cell surface. Since VASP is known to promote elongation of actin filaments by preventing them from capping, interactions of p8 with VASP are an elegant strategy to exploit the host cell machinery for being transported to the cell surface, and as a consequence, to other cells. Given that VASP is also important for cell-to-cell transfer of the HTLV-1 Gag protein, our work proposes that VASP is a new cellular target to counteract HTLV-1 cell-to-cell transmission.
Collapse
Affiliation(s)
- Norbert Donhauser
- Institute of Clinical and Molecular Virology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Eileen Socher
- Division of Bioinformatics, Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Sebastian Millen
- Institute of Clinical and Molecular Virology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Stefanie Heym
- Institute of Clinical and Molecular Virology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Heinrich Sticht
- Division of Bioinformatics, Institute of Biochemistry, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
| | - Andrea K. Thoma-Kress
- Institute of Clinical and Molecular Virology, Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), Erlangen, Germany
- * E-mail:
| |
Collapse
|
19
|
Maldonado RJK, Rice B, Chen EC, Tuffy KM, Chiari EF, Fahrbach KM, Hope TJ, Parent LJ. Visualizing Association of the Retroviral Gag Protein with Unspliced Viral RNA in the Nucleus. mBio 2020; 11:e00524-20. [PMID: 32265329 PMCID: PMC7157774 DOI: 10.1128/mbio.00524-20] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [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: 03/07/2020] [Accepted: 03/12/2020] [Indexed: 11/20/2022] Open
Abstract
Packaging of genomic RNA (gRNA) by retroviruses is essential for infectivity, yet the subcellular site of the initial interaction between the Gag polyprotein and gRNA remains poorly defined. Because retroviral particles are released from the plasma membrane, it was previously thought that Gag proteins initially bound to gRNA in the cytoplasm or at the plasma membrane. However, the Gag protein of the avian retrovirus Rous sarcoma virus (RSV) undergoes active nuclear trafficking, which is required for efficient gRNA encapsidation (L. Z. Scheifele, R. A. Garbitt, J. D. Rhoads, and L. J. Parent, Proc Natl Acad Sci U S A 99:3944-3949, 2002, https://doi.org/10.1073/pnas.062652199; R. Garbitt-Hirst, S. P. Kenney, and L. J. Parent, J Virol 83:6790-6797, 2009, https://doi.org/10.1128/JVI.00101-09). These results raise the intriguing possibility that the primary contact between Gag and gRNA might occur in the nucleus. To examine this possibility, we created a RSV proviral construct that includes 24 tandem repeats of MS2 RNA stem-loops, making it possible to track RSV viral RNA (vRNA) in live cells in which a fluorophore-conjugated MS2 coat protein is coexpressed. Using confocal microscopy, we observed that both wild-type Gag and a nuclear export mutant (Gag.L219A) colocalized with vRNA in the nucleus. In live-cell time-lapse images, the wild-type Gag protein trafficked together with vRNA as a single ribonucleoprotein (RNP) complex in the nucleoplasm near the nuclear periphery, appearing to traverse the nuclear envelope into the cytoplasm. Furthermore, biophysical imaging methods suggest that Gag and the unspliced vRNA physically interact in the nucleus. Taken together, these data suggest that RSV Gag binds unspliced vRNA to export it from the nucleus, possibly for packaging into virions as the viral genome.IMPORTANCE Retroviruses cause severe diseases in animals and humans, including cancer and acquired immunodeficiency syndromes. To propagate infection, retroviruses assemble new virus particles that contain viral proteins and unspliced vRNA to use as gRNA. Despite the critical requirement for gRNA packaging, the molecular mechanisms governing the identification and selection of gRNA by the Gag protein remain poorly understood. In this report, we demonstrate that the Rous sarcoma virus (RSV) Gag protein colocalizes with unspliced vRNA in the nucleus in the interchromatin space. Using live-cell confocal imaging, RSV Gag and unspliced vRNA were observed to move together from inside the nucleus across the nuclear envelope, suggesting that the Gag-gRNA complex initially forms in the nucleus and undergoes nuclear export into the cytoplasm as a viral ribonucleoprotein (vRNP) complex.
Collapse
Affiliation(s)
| | - Breanna Rice
- Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Eunice C Chen
- Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Kevin M Tuffy
- Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Estelle F Chiari
- Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Kelly M Fahrbach
- Department of Cell and Molecular Biology, Northwestern University, Chicago, Illinois, USA
| | - Thomas J Hope
- Department of Cell and Molecular Biology, Northwestern University, Chicago, Illinois, USA
| | - Leslie J Parent
- Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
- Department of Microbiology and Immunology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| |
Collapse
|
20
|
Dick RA, Xu C, Morado DR, Kravchuk V, Ricana CL, Lyddon TD, Broad AM, Feathers JR, Johnson MC, Vogt VM, Perilla JR, Briggs JAG, Schur FKM. Structures of immature EIAV Gag lattices reveal a conserved role for IP6 in lentivirus assembly. PLoS Pathog 2020; 16:e1008277. [PMID: 31986188 PMCID: PMC7004409 DOI: 10.1371/journal.ppat.1008277] [Citation(s) in RCA: 33] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2019] [Revised: 02/06/2020] [Accepted: 12/11/2019] [Indexed: 01/11/2023] Open
Abstract
Retrovirus assembly is driven by the multidomain structural protein Gag. Interactions between the capsid domains (CA) of Gag result in Gag multimerization, leading to an immature virus particle that is formed by a protein lattice based on dimeric, trimeric, and hexameric protein contacts. Among retroviruses the inter- and intra-hexamer contacts differ, especially in the N-terminal sub-domain of CA (CANTD). For HIV-1 the cellular molecule inositol hexakisphosphate (IP6) interacts with and stabilizes the immature hexamer, and is required for production of infectious virus particles. We have used in vitro assembly, cryo-electron tomography and subtomogram averaging, atomistic molecular dynamics simulations and mutational analyses to study the HIV-related lentivirus equine infectious anemia virus (EIAV). In particular, we sought to understand the structural conservation of the immature lentivirus lattice and the role of IP6 in EIAV assembly. Similar to HIV-1, IP6 strongly promoted in vitro assembly of EIAV Gag proteins into virus-like particles (VLPs), which took three morphologically highly distinct forms: narrow tubes, wide tubes, and spheres. Structural characterization of these VLPs to sub-4Å resolution unexpectedly showed that all three morphologies are based on an immature lattice with preserved key structural components, highlighting the structural versatility of CA to form immature assemblies. A direct comparison between EIAV and HIV revealed that both lentiviruses maintain similar immature interfaces, which are established by both conserved and non-conserved residues. In both EIAV and HIV-1, IP6 regulates immature assembly via conserved lysine residues within the CACTD and SP. Lastly, we demonstrate that IP6 stimulates in vitro assembly of immature particles of several other retroviruses in the lentivirus genus, suggesting a conserved role for IP6 in lentiviral assembly.
Collapse
MESH Headings
- Amino Acid Sequence
- Animals
- Electron Microscope Tomography
- Equine Infectious Anemia/metabolism
- Equine Infectious Anemia/virology
- Gene Products, gag/chemistry
- Gene Products, gag/genetics
- Gene Products, gag/metabolism
- HIV Infections/metabolism
- HIV Infections/virology
- HIV-1/genetics
- HIV-1/physiology
- HIV-1/ultrastructure
- Horses
- Host-Pathogen Interactions
- Infectious Anemia Virus, Equine/chemistry
- Infectious Anemia Virus, Equine/genetics
- Infectious Anemia Virus, Equine/physiology
- Infectious Anemia Virus, Equine/ultrastructure
- Phytic Acid/metabolism
- Sequence Alignment
- Virion/genetics
- Virion/physiology
- Virion/ultrastructure
- Virus Assembly
- gag Gene Products, Human Immunodeficiency Virus/chemistry
- gag Gene Products, Human Immunodeficiency Virus/genetics
- gag Gene Products, Human Immunodeficiency Virus/metabolism
Collapse
Affiliation(s)
- Robert A. Dick
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
- * E-mail: (RAD); (FKMS)
| | - Chaoyi Xu
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware, United States of America
| | - Dustin R. Morado
- Structural Studies Division, Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
| | | | - Clifton L. Ricana
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri, United States of America
| | - Terri D. Lyddon
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri, United States of America
| | - Arianna M. Broad
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - J. Ryan Feathers
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Marc C. Johnson
- Department of Molecular Microbiology and Immunology, University of Missouri, Columbia, Missouri, United States of America
| | - Volker M. Vogt
- Department of Molecular Biology and Genetics, Cornell University, Ithaca, New York, United States of America
| | - Juan R. Perilla
- Department of Chemistry and Biochemistry, University of Delaware, Newark, Delaware, United States of America
| | - John A. G. Briggs
- Structural Studies Division, Medical Research Council Laboratory of Molecular Biology, Cambridge, United Kingdom
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
| | - Florian K. M. Schur
- Institute of Science and Technology Austria, Klosterneuburg, Austria
- Structural and Computational Biology Unit, European Molecular Biology Laboratory, Heidelberg, Germany
- * E-mail: (RAD); (FKMS)
| |
Collapse
|
21
|
Hakata Y, Li J, Fujino T, Tanaka Y, Shimizu R, Miyazawa M. Mouse APOBEC3 interferes with autocatalytic cleavage of murine leukemia virus Pr180gag-pol precursor and inhibits Pr65gag processing. PLoS Pathog 2019; 15:e1008173. [PMID: 31830125 PMCID: PMC6907756 DOI: 10.1371/journal.ppat.1008173] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2019] [Accepted: 10/30/2019] [Indexed: 01/01/2023] Open
Abstract
Mouse APOBEC3 (mA3) inhibits murine leukemia virus (MuLV) replication by a deamination-independent mechanism in which the reverse transcription is considered the main target process. However, other steps in virus replication that can be targeted by mA3 have not been examined. We have investigated the possible effect of mA3 on MuLV protease-mediated processes and found that mA3 binds both mature viral protease and Pr180gag-pol precursor polyprotein. Using replication-competent MuLVs, we also show that mA3 inhibits the processing of Pr65 Gag precursor. Furthermore, we demonstrate that the autoprocessing of Pr180gag-pol is impeded by mA3, resulting in reduced production of mature viral protease. This reduction appears to link with the above inefficient Pr65gag processing in the presence of mA3. Two major isoforms of mA3, exon 5-containing and -lacking ones, equally exhibit this antiviral activity. Importantly, physiologically expressed levels of mA3 impedes both Pr180gag-pol autocatalysis and Pr65gag processing. This blockade is independent of the deaminase activity and requires the C-terminal region of mA3. These results suggest that the above impairment of Pr180gag-pol autoprocessing may significantly contribute to the deaminase-independent antiretroviral activity exerted by mA3. Soon after the identification of the polynucleotide cytidine deaminase APOBEC3 as a host restriction factor against vif-deficient HIV, it was noticed that deamination-independent mechanisms are involved in the inhibition of viral replication in addition to the deaminase-dependent mechanism. We previously showed that mouse APOBEC3 (mA3) physiologically restricted mouse retrovirus replication in their natural hosts without causing significant G-to-A hypermutations. Inhibition of reverse transcription is reported to be the most plausible mechanism for the deamination-independent antiretroviral function. However, it remains unknown whether the inhibition of reverse transcription is the only way to explain the whole picture of deamination-independent antiviral activity exerted by APOBEC3. Here we show that mA3 targets the autoprocessing of Pr180gag-pol polyprotein. This activity does not require the deaminase catalytic center and mainly exerted by the C-terminal half of mA3. mA3 physically interacts with murine retroviral protease and its precursor Pr180gag-pol. mA3-induced disruption of the autocatalytic Pr180gag-pol cleavage leads to a significant reduction of mature viral protease, resulting in the inhibition of Pr65gag processing to mature Gag proteins. As the Pr180gag-pol autoprocessing is necessary for the maturation of other viral enzymes including the reverse transcriptase, its inhibition by host APOBEC3 may precede the previously described impairment of reverse transcription. Our discovery may lead to the development of novel antiretroviral drugs through the future identification of detailed molecular interfaces between retroviral Gag-Pol polyprotein and APOBEC3.
Collapse
Affiliation(s)
- Yoshiyuki Hakata
- Department of Immunology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka, Japan
- * E-mail: (YH); (MM)
| | - Jun Li
- Department of Immunology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka, Japan
- Ijunkai Medical Oncology, Endoscopy Clinic, Sakai-ku, Sakai, Osaka, Japan
| | - Takahiro Fujino
- Division of Analytical Bio-Medicine, Advanced Research Support Center (ADRES), Ehime University, Shitsukawa, Toon, Ehime, Japan
| | - Yuki Tanaka
- Division of Analytical Bio-Medicine, Advanced Research Support Center (ADRES), Ehime University, Shitsukawa, Toon, Ehime, Japan
| | - Rie Shimizu
- Department of Immunology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka, Japan
| | - Masaaki Miyazawa
- Department of Immunology, Kindai University Faculty of Medicine, Osaka-Sayama, Osaka, Japan
- Kindai University Anti-Aging Center, Higashiosaka, Osaka, Japan
- * E-mail: (YH); (MM)
| |
Collapse
|
22
|
Kordyukova M, Morgunova V, Olovnikov I, Komarov PA, Mironova A, Olenkina OM, Kalmykova A. Subcellular localization and Egl-mediated transport of telomeric retrotransposon HeT-A ribonucleoprotein particles in the Drosophila germline and early embryogenesis. PLoS One 2018; 13:e0201787. [PMID: 30157274 PMCID: PMC6114517 DOI: 10.1371/journal.pone.0201787] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2018] [Accepted: 07/23/2018] [Indexed: 12/17/2022] Open
Abstract
The study of the telomeric complex in oogenesis and early development is important for understanding the mechanisms which maintain genome integrity. Telomeric transcripts are the key components of the telomeric complex and are essential for regulation of telomere function. We study the biogenesis of transcripts generated by the major Drosophila telomere repeat HeT-A in oogenesis and early development with disrupted telomeric repeat silencing. In wild type ovaries, HeT-A expression is downregulated by the Piwi-interacting RNAs (piRNAs). By repressing piRNA pathway, we show that overexpressed HeT-A transcripts interact with their product, RNA-binding protein Gag-HeT-A, forming ribonucleoprotein particles (RNPs) during oogenesis and early embryonic development. Moreover, during early stages of oogenesis, in the nuclei of dividing cystoblasts, HeT-A RNP form spherical structures, which supposedly represent the retrotransposition complexes participating in telomere elongation. During the later stages of oogenesis, abundant HeT-A RNP are detected in the cytoplasm and nuclei of the nurse cells, as well as in the cytoplasm of the oocyte. Further on, we demonstrate that HeT-A products co-localize with the transporter protein Egalitarian (Egl) both in wild type ovaries and upon piRNA loss. This finding suggests a role of Egl in the transportation of the HeT-A RNP to the oocyte using a dynein motor. Following germline piRNA depletion, abundant maternal HeT-A RNP interacts with Egl resulting in ectopic accumulation of Egl close to the centrosomes during the syncytial stage of embryogenesis. Given the essential role of Egl in the proper localization of numerous patterning mRNAs, we suggest that its abnormal localization likely leads to impaired embryonic axis specification typical for piRNA pathway mutants.
Collapse
Affiliation(s)
- Maria Kordyukova
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Valeriya Morgunova
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Ivan Olovnikov
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Pavel A. Komarov
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
- Department of Biochemistry, Faculty of Biology, Lomonosov Moscow State University, Moscow, Russia
| | - Anastasia Mironova
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Oxana M. Olenkina
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
| | - Alla Kalmykova
- Institute of Molecular Genetics, Russian Academy of Sciences, Moscow, Russia
- * E-mail:
| |
Collapse
|
23
|
Lu W, Tirumuru N, St Gelais C, Koneru PC, Liu C, Kvaratskhelia M, He C, Wu L. N6-Methyladenosine-binding proteins suppress HIV-1 infectivity and viral production. J Biol Chem 2018; 293:12992-13005. [PMID: 29976753 PMCID: PMC6109920 DOI: 10.1074/jbc.ra118.004215] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [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: 05/28/2018] [Revised: 06/27/2018] [Indexed: 11/06/2022] Open
Abstract
The internal N6-methyladenosine (m6A) modification of cellular mRNA regulates post-transcriptional gene expression. The YTH domain family proteins (YTHDF1-3 or Y1-3) bind to m6A-modified cellular mRNAs and modulate their metabolism and processing, thereby affecting cellular protein translation. We previously reported that HIV-1 RNA contains the m6A modification and that Y1-3 proteins inhibit HIV-1 infection by decreasing HIV-1 reverse transcription activity. Here, we investigated the mechanisms of Y1-3-mediated inhibition of HIV-1 infection in target cells and the effect of Y1-3 on viral production levels in virus-producing cells. We found that Y1-3 protein overexpression in HIV-1 target cells decreases viral genomic RNA (gRNA) levels and inhibits both early and late reverse transcription. Purified recombinant Y1-3 proteins preferentially bound to the m6A-modified 5' leader sequence of gRNA compared with its unmodified RNA counterpart, consistent with the strong binding of Y1-3 proteins to HIV-1 gRNA in infected cells. HIV-1 mutants with two altered m6A modification sites in the 5' leader sequence of gRNA exhibited significantly lower infectivity than WT, replication-competent HIV-1, confirming that these sites alter viral infection. HIV-1 produced from cells in which endogenous Y1, Y3, or Y1-3 proteins were knocked down singly or together had increased viral infectivity compared with HIV-1 produced in control cells. Interestingly, we found that Y1-3 proteins and HIV-1 Gag protein formed a complex with RNA in HIV-1-producing cells. Overall, these results indicate that Y1-3 proteins inhibit HIV-1 infection and provide new insights into the mechanisms by which the m6A modification of HIV-1 RNA affects viral replication.
Collapse
Affiliation(s)
- Wuxun Lu
- From the Center for Retrovirus Research, Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio 43210
| | - Nagaraja Tirumuru
- From the Center for Retrovirus Research, Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio 43210
| | - Corine St Gelais
- From the Center for Retrovirus Research, Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio 43210
| | - Pratibha C Koneru
- the Division of Infectious Diseases, University of Colorado School of Medicine, Aurora, Colorado 80045, and
| | - Chang Liu
- the Departments of Chemistry and of Biochemistry and Molecular Biology, Institute for Biophysical Dynamics, and
- Howard Hughes Medical Institute, University of Chicago, Chicago, Illinois 60637
| | - Mamuka Kvaratskhelia
- the Division of Infectious Diseases, University of Colorado School of Medicine, Aurora, Colorado 80045, and
| | - Chuan He
- the Departments of Chemistry and of Biochemistry and Molecular Biology, Institute for Biophysical Dynamics, and
- Howard Hughes Medical Institute, University of Chicago, Chicago, Illinois 60637
| | - Li Wu
- From the Center for Retrovirus Research, Department of Veterinary Biosciences, Ohio State University, Columbus, Ohio 43210,
| |
Collapse
|
24
|
Paris J, Tobaly-Tapiero J, Giron ML, Burlaud-Gaillard J, Buseyne F, Roingeard P, Lesage P, Zamborlini A, Saïb A. The invariant arginine within the chromatin-binding motif regulates both nucleolar localization and chromatin binding of Foamy virus Gag. Retrovirology 2018; 15:48. [PMID: 29996845 PMCID: PMC6042332 DOI: 10.1186/s12977-018-0428-z] [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] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2018] [Accepted: 06/25/2018] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Nuclear localization of Gag is a property shared by many retroviruses and retrotransposons. The importance of this stage for retroviral replication is still unknown, but studies on the Rous Sarcoma virus indicate that Gag might select the viral RNA genome for packaging in the nucleus. In the case of Foamy viruses, genome encapsidation is mediated by Gag C-terminal domain (CTD), which harbors three clusters of glycine and arginine residues named GR boxes (GRI-III). In this study we investigated how PFV Gag subnuclear distribution might be regulated. RESULTS We show that the isolated GRI and GRIII boxes act as nucleolar localization signals. In contrast, both the entire Gag CTD and the isolated GRII box, which contains the chromatin-binding motif, target the nucleolus exclusively upon mutation of the evolutionary conserved arginine residue at position 540 (R540), which is a key determinant of FV Gag chromatin tethering. We also provide evidence that Gag localizes in the nucleolus during FV replication and uncovered that the viral protein interacts with and is methylated by Protein Arginine Methyltransferase 1 (PRMT1) in a manner that depends on the R540 residue. Finally, we show that PRMT1 depletion by RNA interference induces the concentration of Gag C-terminus in nucleoli. CONCLUSION Altogether, our findings suggest that methylation by PRMT1 might finely tune the subnuclear distribution of Gag depending on the stage of the FV replication cycle. The role of this step for viral replication remains an open question.
Collapse
Affiliation(s)
- Joris Paris
- CNRS UMR7212, Hôpital St Louis, Inserm U944, Institut Universitaire d’Hématologie, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Joëlle Tobaly-Tapiero
- CNRS UMR7212, Hôpital St Louis, Inserm U944, Institut Universitaire d’Hématologie, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Marie-Lou Giron
- CNRS UMR7212, Hôpital St Louis, Inserm U944, Institut Universitaire d’Hématologie, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Julien Burlaud-Gaillard
- Plateforme IBiSA de Microscopie Electronique, Université François Rabelais and CHRU de Tours, Tours, France
- INSERM U1259, Université François Rabelais and CHRU de Tours, Tours, France
| | - Florence Buseyne
- Institut Pasteur, Unité d’Epidémiologie et Physiopathologie des Virus Oncogènes, Paris, France
- CNRS UMR3569, Insitut Pasteur, Paris, France
| | - Philippe Roingeard
- Plateforme IBiSA de Microscopie Electronique, Université François Rabelais and CHRU de Tours, Tours, France
- INSERM U1259, Université François Rabelais and CHRU de Tours, Tours, France
| | - Pascale Lesage
- CNRS UMR7212, Hôpital St Louis, Inserm U944, Institut Universitaire d’Hématologie, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| | - Alessia Zamborlini
- CNRS UMR7212, Hôpital St Louis, Inserm U944, Institut Universitaire d’Hématologie, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
- CNRS UMR7212, Hôpital St Louis, Inserm U944, Institut Universitaire d’Hématologie, Université Paris Diderot, Sorbonne Paris Cité, Laboratoire PVM, Conservatoire National des Arts et Métiers (Cnam), Paris, France
| | - Ali Saïb
- CNRS UMR7212, Hôpital St Louis, Inserm U944, Institut Universitaire d’Hématologie, Université Paris Diderot, Sorbonne Paris Cité, Paris, France
| |
Collapse
|
25
|
Wanaguru M, Barry DJ, Benton DJ, O’Reilly NJ, Bishop KN. Murine leukemia virus p12 tethers the capsid-containing pre-integration complex to chromatin by binding directly to host nucleosomes in mitosis. PLoS Pathog 2018; 14:e1007117. [PMID: 29906285 PMCID: PMC6021111 DOI: 10.1371/journal.ppat.1007117] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2018] [Revised: 06/27/2018] [Accepted: 05/22/2018] [Indexed: 12/31/2022] Open
Abstract
The murine leukaemia virus (MLV) Gag cleavage product, p12, is essential for both early and late steps in viral replication. The N-terminal domain of p12 binds directly to capsid (CA) and stabilises the mature viral core, whereas defects in the C-terminal domain (CTD) of p12 can be rescued by addition of heterologous chromatin binding sequences (CBSs). We and others hypothesised that p12 tethers the pre-integration complex (PIC) to host chromatin ready for integration. Using confocal microscopy, we have observed for the first time that CA localises to mitotic chromatin in infected cells in a p12-dependent manner. GST-tagged p12 alone, however, did not localise to chromatin and mass-spectrometry analysis of its interactions identified only proteins known to bind the p12 region of Gag. Surprisingly, the ability to interact with chromatin was conferred by a single amino acid change, M63I, in the p12 CTD. Interestingly, GST-p12_M63I showed increased phosphorylation in mitosis relative to interphase, which correlated with an increased interaction with mitotic chromatin. Mass-spectrometry analysis of GST-p12_M63I revealed nucleosomal histones as primary interactants. Direct binding of MLV p12_M63I peptides to histones was confirmed by biolayer-interferometry (BLI) assays using highly-avid recombinant poly-nucleosomal arrays. Excitingly, using this method, we also observed binding between MLV p12_WT and nucleosomes. Nucleosome binding was additionally detected with p12 orthologs from feline and gibbon ape leukemia viruses using both pull-down and BLI assays, indicating that this a common feature of gammaretroviral p12 proteins. Importantly, p12 peptides were able to block the binding of the prototypic foamy virus CBS to nucleosomes and vice versa, implying that their docking sites overlap and suggesting a conserved mode of chromatin tethering for different retroviral genera. We propose that p12 is acting in a similar capacity to CPSF6 in HIV-1 infection by facilitating initial chromatin targeting of CA-containing PICs prior to integration.
Collapse
Affiliation(s)
- Madushi Wanaguru
- Retroviral Replication Laboratory, The Francis Crick Institute, London, United Kingdom
| | - David J. Barry
- Advanced Light Microscopy Facility, The Francis Crick Institute, London, United Kingdom
| | - Donald J. Benton
- Structural Biology of Disease Processes Laboratory, The Francis Crick Institute, London, United Kingdom
| | | | - Kate N. Bishop
- Retroviral Replication Laboratory, The Francis Crick Institute, London, United Kingdom
| |
Collapse
|
26
|
Melbourne JK, Chase KA, Feiner B, Rosen C, Sharma RP. Long non-coding and endogenous retroviral RNA levels are associated with proinflammatory cytokine mRNA expression in peripheral blood cells: Implications for schizophrenia. Psychiatry Res 2018; 262:465-468. [PMID: 28942956 PMCID: PMC5851803 DOI: 10.1016/j.psychres.2017.09.025] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/21/2016] [Revised: 09/08/2017] [Accepted: 09/11/2017] [Indexed: 11/17/2022]
Abstract
Recent research indicates that the expression of long non-coding and endogenous retroviral RNAs is coordinated with the activity of immune molecules often dysregulated in schizophrenia. We measured the expression of TMEVPG1, NRON, HERV-W env and HERV-W gag in blood cells from participants with schizophrenia and controls. We report that a) expression levels of these non-coding RNAs are correlated with proinflammatory cytokine mRNA expression in all participants, b) HERV-W transcripts are negatively correlated with atypical antipsychotic use in participants with schizophrenia, and c) that these RNAs are transcribed in response to proinflammatory stimuli in a THP-1 monocyte cell line.
Collapse
Affiliation(s)
- Jennifer K Melbourne
- The Psychiatric Institute, University of Illinois at Chicago, 1601 W. Taylor St., Chicago, IL 60612, USA
| | - Kayla A Chase
- The Psychiatric Institute, University of Illinois at Chicago, 1601 W. Taylor St., Chicago, IL 60612, USA; University of California, Department of Psychiatry, 9500 Gilman Drive, MC 8505, La Jolla, San Diego, CA 92037, USA
| | - Benjamin Feiner
- The Psychiatric Institute, University of Illinois at Chicago, 1601 W. Taylor St., Chicago, IL 60612, USA
| | - Cherise Rosen
- The Psychiatric Institute, University of Illinois at Chicago, 1601 W. Taylor St., Chicago, IL 60612, USA
| | - Rajiv P Sharma
- The Psychiatric Institute, University of Illinois at Chicago, 1601 W. Taylor St., Chicago, IL 60612, USA; Jesse Brown Veterans Affairs Medical Center, 820 South Damen Avenue (M/C 151), Chicago, IL 60612, USA.
| |
Collapse
|
27
|
Renner TM, Bélanger K, Lam C, Gerpe MCR, McBane JE, Langlois MA. Full-Length Glycosylated Gag of Murine Leukemia Virus Can Associate with the Viral Envelope as a Type I Integral Membrane Protein. J Virol 2018; 92:e01530-17. [PMID: 29298890 PMCID: PMC5827372 DOI: 10.1128/jvi.01530-17] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [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: 08/30/2017] [Accepted: 12/20/2017] [Indexed: 11/20/2022] Open
Abstract
The glycosylated Gag protein (gPr80) of murine leukemia viruses (MLVs) has been shown to exhibit multiple roles in facilitating retrovirus release, infection, and resistance to host-encoded retroviral restriction factors, such as APOBEC3, SERINC3, and SERINC5. One way in which gPr80 helps MLVs to escape host innate immune restriction is by increasing capsid stability, a feature that protects viral replication intermediates from being detected by cytosolic DNA sensors. gPr80 also increases the resistance of MLVs to deamination and restriction by mouse APOBEC3 (mA3). How the gPr80 accessory protein, with its three N-linked glycosylation sites, contributes to these resistance mechanisms is still not fully understood. Here we further characterized the function of gPr80 and, more specifically, revealed that the asparagines targeted for glycosylation in gPr80 also contribute to capsid stability through their parallel involvement in the Pr65 Gag structural polyprotein. In fact, we demonstrate that sensitivity to deamination by the mA3 and human A3 proteins is directly linked to capsid stability. We also show that full-length gPr80 is detected in purified viruses. However, our results suggest that gPr80 is inserted in the NexoCcyto orientation of a type I integral membrane protein. Additionally, our experiments have revealed the existence of a large population of Env-deficient virus-like particles (VLPs) harboring gPr80 inserted in the opposite (NcytoCexo) polarity, which is typical of type II integral membrane proteins. Overall this study provides new insight into the complex nature of the MLV gPr80 accessory protein.IMPORTANCE Viruses have evolved numerous strategies to infect, spread in, and persist in their hosts. Here we analyze the details of how the MLV-encoded glycosylated Gag (gPr80) protein protects the virus from being restricted by host innate immune defenses. gPr80 is a variant of the structural Pr65 Gag protein with an 88-amino-acid extended leader sequence that directs the protein for translation and glycosylation in the endoplasmic reticulum. This study dissects the specific contributions of gPr80 glycans and capsid stability in helping the virus to infect cells, spread, and counteract the effects of the host intrinsic restriction factor APOBEC3. Overall this study provides further insight into the elusive role of the gPr80 protein.
Collapse
Affiliation(s)
- Tyler Milston Renner
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Kasandra Bélanger
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Cindy Lam
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - María Carla Rosales Gerpe
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Joanne Eileen McBane
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Marc-André Langlois
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| |
Collapse
|
28
|
Barklis E, Staubus AO, Mack A, Harper L, Barklis RL, Alfadhli A. Lipid biosensor interactions with wild type and matrix deletion HIV-1 Gag proteins. Virology 2018; 518:264-271. [PMID: 29549788 DOI: 10.1016/j.virol.2018.03.004] [Citation(s) in RCA: 8] [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] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2018] [Revised: 03/03/2018] [Accepted: 03/06/2018] [Indexed: 11/19/2022]
Abstract
The matrix (MA) domain of the HIV-1 precursor Gag protein (PrGag) has been shown interact with the HIV-1 envelope (Env) protein, and to direct PrGag proteins to plasma membrane (PM) assembly sites by virtue of its affinity to phosphatidylinositol-4,5-bisphosphate (PI[4,5]P2). Unexpectedly, HIV-1 viruses with large MA deletions (ΔMA) have been shown to be conditionally infectious as long as they are matched with Env truncation mutant proteins or alternative viral glycoproteins. To characterize the interactions of wild type (WT) and ΔMA Gag proteins with PI(4,5)P2 and other acidic phospholipids, we have employed a set of lipid biosensors as probes. Our investigations showed marked differences in WT and ΔMA Gag colocalization with biosensors, effects on biosensor release, and association of biosensors with virus-like particles. These results demonstrate an alternative approach to the analysis of viral protein-lipid associations, and provide new data as to the lipid compositions of HIV-1 assembly sites.
Collapse
Affiliation(s)
- Eric Barklis
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97035, United States.
| | - August O Staubus
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97035, United States
| | - Andrew Mack
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97035, United States
| | - Logan Harper
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97035, United States
| | - Robin Lid Barklis
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97035, United States
| | - Ayna Alfadhli
- Department of Molecular Microbiology and Immunology, Oregon Health and Sciences University, 3181 SW Sam Jackson Park Road, Portland, OR 97035, United States
| |
Collapse
|
29
|
Hoyte AC, Jamin AV, Koneru PC, Kobe MJ, Larue RC, Fuchs JR, Engelman AN, Kvaratskhelia M. Resistance to pyridine-based inhibitor KF116 reveals an unexpected role of integrase in HIV-1 Gag-Pol polyprotein proteolytic processing. J Biol Chem 2017; 292:19814-19825. [PMID: 28972144 PMCID: PMC5712621 DOI: 10.1074/jbc.m117.816645] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [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: 09/07/2017] [Revised: 09/27/2017] [Indexed: 11/06/2022] Open
Abstract
The pyridine-based multimerization selective HIV-1 integrase (IN) inhibitors (MINIs) are a distinct subclass of allosteric IN inhibitors. MINIs potently inhibit HIV-1 replication during virion maturation by inducing hyper- or aberrant IN multimerization but are largely ineffective during the early steps of viral replication. Here, we investigated the mechanism for the evolution of a triple IN substitution (T124N/V165I/T174I) that emerges in cell culture with a representative MINI, KF116. We show that HIV-1 NL4-3(IN T124N/V165I/T174I) confers marked (>2000-fold) resistance to KF116. Two IN substitutions (T124N/T174I) directly weaken inhibitor binding at the dimer interface of the catalytic core domain but at the same time markedly impair HIV-1 replication capacity. Unexpectedly, T124N/T174I IN substitutions inhibited proteolytic processing of HIV-1 polyproteins Gag and Gag-Pol, resulting in immature virions. Strikingly, the addition of the third IN substitution (V165I) restored polyprotein processing, virus particle maturation, and significant levels of replication capacity. These results reveal an unanticipated role of IN for polyprotein proteolytic processing during virion morphogenesis. The complex evolutionary pathway for the emergence of resistant viruses, which includes the need for the compensatory V165I IN substitution, highlights a relatively high genetic barrier exerted by MINI KF116. Additionally, we have solved the X-ray structure of the drug-resistant catalytic core domain protein, which provides means for rational development of second-generation MINIs.
Collapse
Affiliation(s)
- Ashley C Hoyte
- From the Center for Retrovirus Research and
- Division of Infectious Diseases, University of Colorado School of Medicine, Aurora, Colorado 80045, and
| | - Augusta V Jamin
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02215
| | - Pratibha C Koneru
- From the Center for Retrovirus Research and
- Division of Infectious Diseases, University of Colorado School of Medicine, Aurora, Colorado 80045, and
| | | | | | - James R Fuchs
- Division of Medicinal Chemistry and Pharmacognosy, College of Pharmacy, The Ohio State University, Columbus, Ohio 43210
| | - Alan N Engelman
- Department of Cancer Immunology and Virology, Dana-Farber Cancer Institute and Department of Medicine, Harvard Medical School, Boston, Massachusetts 02215
| | - Mamuka Kvaratskhelia
- From the Center for Retrovirus Research and
- Division of Infectious Diseases, University of Colorado School of Medicine, Aurora, Colorado 80045, and
| |
Collapse
|
30
|
Qu N, Ma Z, Zhang M, Rushdi MN, Krueger CJ, Chen AK. Inhibition of retroviral Gag assembly by non-silencing miRNAs promotes autophagic viral degradation. Protein Cell 2017; 9:640-651. [PMID: 28884441 PMCID: PMC6019656 DOI: 10.1007/s13238-017-0461-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2017] [Accepted: 08/07/2017] [Indexed: 12/29/2022] Open
Abstract
We recently reported an unconventional mechanism by which miRNAs inhibit HIV-1 viral production. This occurs when miRNAs bind nonspecifically to the viral structural protein Gag, interfering with viral RNA-mediated Gag assembly at the plasma membrane. Consequently, misassembled viral complexes are redirected into the endocytic pathway where they are delivered to lysosomes for degradation. In this study, we demonstrate that autophagy is a critical mediator of the viral degradation pathway and that this pathway is not HIV-1 specific. Misassembled viral complexes were found to colocalize extensively with LC3 and p62 in late endosomes/lysosomes, demonstrating a convergence of autophagy with functional degradative compartments. Knocking down autophagosome formation machineries reduced this convergence, while treatment with autophagy-inducer rapamycin enhanced the convergence. Furthermore, similar autophagy-dependent nonspecific miRNA inhibition of murine leukemia virus (MLV) assembly was shown. Overall, these results reveal autophagy as a crucial regulator of the retroviral degradation pathway in host cells initiated by nonspecific miRNA-Gag interactions. These findings could have significant implications for understanding how cells may regulate retroviral complex assembly by miRNA expression and autophagy, and raise the possibility that similar regulations can occur in other biological contexts.
Collapse
Affiliation(s)
- Na Qu
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, 100871, China
| | - Zhao Ma
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, 100871, China
| | - Mengrao Zhang
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, 100871, China
| | - Muaz N Rushdi
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, 100871, China
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Christopher J Krueger
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, 100871, China
- Wallace H Coulter Department of Biomedical Engineering, Georgia Institute of Technology, Atlanta, GA, 30332, USA
| | - Antony K Chen
- Department of Biomedical Engineering, College of Engineering, Peking University, Beijing, 100871, China.
| |
Collapse
|
31
|
Balagopal V, Beemon KL. Rous Sarcoma Virus RNA Stability Element Inhibits Deadenylation of mRNAs with Long 3'UTRs. Viruses 2017; 9:v9080204. [PMID: 28763028 PMCID: PMC5580461 DOI: 10.3390/v9080204] [Citation(s) in RCA: 9] [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: 06/05/2017] [Revised: 07/14/2017] [Accepted: 07/26/2017] [Indexed: 12/15/2022] Open
Abstract
All retroviruses use their full-length primary transcript as the major mRNA for Group-specific antigen (Gag) capsid proteins. This results in a long 3′ untranslated region (UTR) downstream of the termination codon. In the case of Rous sarcoma virus (RSV), there is a 7 kb 3′UTR downstream of the gag terminator, containing the pol, env, and src genes. mRNAs containing long 3′UTRs, like those with premature termination codons, are frequently recognized by the cellular nonsense-mediated mRNA decay (NMD) machinery and targeted for degradation. To prevent this, RSV has evolved an RNA stability element (RSE) in the RNA immediately downstream of the gag termination codon. This 400-nt RNA sequence stabilizes premature termination codons (PTCs) in gag. It also stabilizes globin mRNAs with long 3′UTRs, when placed downstream of the termination codon. It is not clear how the RSE stabilizes the mRNA and prevents decay. We show here that the presence of RSE inhibits deadenylation severely. In addition, the RSE also impairs decapping (DCP2) and 5′-3′ exonucleolytic (XRN1) function in knockdown experiments in human cells.
Collapse
Affiliation(s)
- Vidya Balagopal
- Biology Department, Johns Hopkins University, Baltimore, MD 21218, USA.
| | - Karen L Beemon
- Biology Department, Johns Hopkins University, Baltimore, MD 21218, USA.
| |
Collapse
|
32
|
Błaszczyk L, Biesiada M, Saha A, Garfinkel DJ, Purzycka KJ. Structure of Ty1 Internally Initiated RNA Influences Restriction Factor Expression. Viruses 2017; 9:v9040074. [PMID: 28394277 PMCID: PMC5408680 DOI: 10.3390/v9040074] [Citation(s) in RCA: 9] [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: 02/01/2017] [Revised: 03/20/2017] [Accepted: 04/03/2017] [Indexed: 12/30/2022] Open
Abstract
The long-terminal repeat retrotransposon Ty1 is the most abundant mobile genetic element in many Saccharomyces cerevisiae isolates. Ty1 retrotransposons contribute to the genetic diversity of host cells, but they can also act as an insertional mutagen and cause genetic instability. Interestingly, retrotransposition occurs at a low level despite a high level of Ty1 RNA, even though S. cerevisiae lacks the intrinsic defense mechanisms that other eukaryotes use to prevent transposon movement. p22 is a recently discovered Ty1 protein that inhibits retrotransposition in a dose-dependent manner. p22 is a truncated form of Gag encoded by internally initiated Ty1i RNA that contains two closely-spaced AUG codons. Mutations of either AUG codon compromise p22 translation. We found that both AUG codons were utilized and that translation efficiency depended on the Ty1i RNA structure. Structural features that stimulated p22 translation were context dependent and present only in Ty1i RNA. Destabilization of the 5′ untranslated region (5′ UTR) of Ty1i RNA decreased the p22 level, both in vitro and in vivo. Our data suggest that protein factors such as Gag could contribute to the stability and translational activity of Ty1i RNA through specific interactions with structural motifs in the RNA.
Collapse
Affiliation(s)
- Leszek Błaszczyk
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan 61-704, Poland.
| | - Marcin Biesiada
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan 61-704, Poland.
| | - Agniva Saha
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602, USA.
| | - David J Garfinkel
- Department of Biochemistry & Molecular Biology, University of Georgia, Athens, GA 30602, USA.
| | - Katarzyna J Purzycka
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan 61-704, Poland.
| |
Collapse
|
33
|
Wang J, Wen S, Zhao R, Qi J, Liu Z, Li W, An J, Wood C, Wang Y. Covalent conjugation of the equine infectious anemia virus Gag with SUMO. Biochem Biophys Res Commun 2017; 486:712-719. [PMID: 28342872 DOI: 10.1016/j.bbrc.2017.03.103] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2017] [Accepted: 03/21/2017] [Indexed: 02/02/2023]
Abstract
The conjugation of small ubiquitin-like modifier (SUMO) to the target protein, namely, SUMOylation, is involved in the regulation of many important biological events including host-pathogen interaction. Some viruses have evolved to exploit the host SUMOylation machinery to modify their own protein. Retroviral Gag protein plays critical roles in the viral life cycle. The HIV-1 p6 and the Moloney murine leukemia virus CA have been reported to be conjugated with SUMO. In this study, we report for the first time, to our knowledge, the covalent conjugation of equine infectious anemia virus (EIAV) Gag with SUMO. The C-terminal p9 domain of Gag is a main target for SUMOylation and SUMO is attached to multiple sites of p9, including K30 whose mutation abolished p9 SUMOylation completely. The SUMOylation of p9, but not the p9-K30 mutant, was also detected in equine fibroblastic cells ATCC® CCL-57™. Ubc9 and its C93 residue are indispensable for the SUMOylation of p9. Using confocal microscopy, it is found that EIAV Gag localizes primarily, if not exclusively, in the cytoplasm of the cell and the co-localization of EIAV Gag with Ubc9 was observed. Our findings that EIAV Gag is SUMOylated at p9-K30, together with previous findings on the defects of p9-K30 mutant in viral DNA translocation from cytoplasm to the nucleus, suggests that SUMOylation of Gag may be involved in such functions.
Collapse
Affiliation(s)
- Jinzhong Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China; Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, 23 Hongda Street, TEDA, Tianjin 300457, China; Tianjin Key Laboratory of Microbial Functional Genomics, 23 Hongda Street, TEDA, Tianjin 300457, China
| | - Shuping Wen
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China
| | - Rui Zhao
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China
| | - Jing Qi
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China
| | - Zhao Liu
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China
| | - Weiwei Li
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China
| | - Jing An
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China
| | - Charles Wood
- Nebraska Center for Virology and School of Biological Sciences, University of Nebraska, Lincoln, NE 68583, USA.
| | - Ying Wang
- TEDA Institute of Biological Sciences and Biotechnology, Nankai University, 23 Hongda Street, TEDA, Tianjin 300457, China; Key Laboratory of Molecular Microbiology and Technology, Ministry of Education, 23 Hongda Street, TEDA, Tianjin 300457, China; Tianjin Key Laboratory of Microbial Functional Genomics, 23 Hongda Street, TEDA, Tianjin 300457, China.
| |
Collapse
|
34
|
Abstract
Assembly of HIV-1 viral particles is a critical step of the HIV-1 life cycle; yet many details of this complex process are unknown. The Gag polyprotein drives viral particle assembly at the plasma membrane via three different types of interactions: protein-protein, protein-RNA, and protein-membrane interactions. As an approach to tease apart the importance of these interactions during viral particle assembly, in particular at the step of Gag membrane binding, we have developed an in vitro liposome-binding assay. Below we describe how to prepare liposomes, which serve as model membranes, and how to assess their interaction with Gag by liposome flotation centrifugation. Additionally, we outline extensions of this basic assay that can be used to address the role of RNA in regulating Gag-membrane interactions.
Collapse
Affiliation(s)
- Gabrielle C Todd
- Department of Microbiology and Immunology, University of Michigan Medical School, 5736 Medical Science Building II, 1150 W. Medical Center Drive, Ann Arbor, MI, 48109, USA
| | - Akira Ono
- Department of Microbiology and Immunology, University of Michigan Medical School, 5736 Medical Science Building II, 1150 W. Medical Center Drive, Ann Arbor, MI, 48109, USA.
| |
Collapse
|
35
|
Thompson M, Heath SL, Sweeton B, Williams K, Cunningham P, Keele BF, Sen S, Palmer BE, Chomont N, Xu Y, Basu R, Hellerstein MS, Kwa S, Robinson HL. DNA/MVA Vaccination of HIV-1 Infected Participants with Viral Suppression on Antiretroviral Therapy, followed by Treatment Interruption: Elicitation of Immune Responses without Control of Re-Emergent Virus. PLoS One 2016; 11:e0163164. [PMID: 27711228 PMCID: PMC5053438 DOI: 10.1371/journal.pone.0163164] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2016] [Accepted: 08/14/2016] [Indexed: 12/01/2022] Open
Abstract
GV-TH-01, a Phase 1 open-label trial of a DNA prime—Modified Vaccinia Ankara (MVA) boost vaccine (GOVX-B11), was undertaken in HIV infected participants on antiretroviral treatment (ART) to evaluate safety and vaccine-elicited T cell responses, and explore the ability of elicited CD8+ T cells to control viral rebound during analytical treatment interruption (TI). Nine men who began antiretroviral therapy (ART) within 18 months of seroconversion and had sustained plasma HIV-1 RNA <50 copies/mL for at least 6 months were enrolled. Median age was 38 years, median pre-ART HIV-1 RNA was 140,000 copies/ml and mean baseline CD4 count was 755/μl. Two DNA, followed by 2 MVA, inoculations were given 8 weeks apart. Eight subjects completed all vaccinations and TI. Clinical and laboratory adverse events were generally mild, with no serious or grade 4 events. Only reactogenicity events were considered related to study drug. No treatment emergent viral resistance was seen. The vaccinations did not reduce viral reservoirs and virus re-emerged in all participants during TI, with a median time to re-emergence of 4 weeks. Eight of 9 participants had CD8+ T cells that could be stimulated by vaccine-matched Gag peptides prior to vaccination. Vaccinations boosted these responses as well as eliciting previously undetected CD8+ responses. Elicited T cells did not display signs of exhaustion. During TI, temporal patterns of viral re-emergence and Gag-specific CD8+ T cell expansion suggested that vaccine-specific CD8+ T cells had been stimulated by re-emergent virus in only 2 of 8 participants. In these 2, transient decreases in viremia were associated with Gag selection in known CD8+ T cell epitopes. We hypothesize that escape mutations, already archived in the viral reservoir, plus a poor ability of CD8+ T cells to traffic to and control virus at sites of re-emergence, limited the therapeutic efficacy of the DNA/MVA vaccine. TRIAL REGISTRATION clinicaltrials.gov NCT01378156.
Collapse
Affiliation(s)
- Melanie Thompson
- AIDS Research Consortium of Atlanta, Atlanta, Georgia, United States of America
| | - Sonya L. Heath
- Department of Medicine, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Bentley Sweeton
- AIDS Research Consortium of Atlanta, Atlanta, Georgia, United States of America
| | - Kathy Williams
- AIDS Research Consortium of Atlanta, Atlanta, Georgia, United States of America
| | - Pamela Cunningham
- Alabama Vaccine Research Clinic, University of Alabama at Birmingham, Birmingham, Alabama, United States of America
| | - Brandon F. Keele
- AIDS and Cancer Virus Program, Leidos Biomedical Research, Inc., Frederick National Laboratory for Cancer Research, Frederick, Maryland, United States of America
| | - Sharon Sen
- University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Brent E. Palmer
- University of Colorado Anschutz Medical Campus, Aurora, Colorado, United States of America
| | - Nicolas Chomont
- Centre de recherche du CHUM and Department of Microbiology, Infectiology and Immunology, Université de Montréal, Montreal, Canada
| | - Yongxian Xu
- Hope Clinic of the Emory Vaccine Center, Division of Infectious Diseases, Department of Medicine, School of Medicine, Emory University, Atlanta, Georgia, United States of America
| | - Rahul Basu
- GeoVax, Inc., Atlanta, Georgia, United States of America
| | | | - Suefen Kwa
- GeoVax, Inc., Atlanta, Georgia, United States of America
| | | |
Collapse
|
36
|
Chutiwitoonchai N, Siarot L, Takeda E, Shioda T, Ueda M, Aida Y. HIV-1 Vpr Abrogates the Effect of TSG101 Overexpression to Support Virus Release. PLoS One 2016; 11:e0163100. [PMID: 27648839 PMCID: PMC5029901 DOI: 10.1371/journal.pone.0163100] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 09/02/2016] [Indexed: 11/18/2022] Open
Abstract
HIV-1 budding requires interaction between Gag and cellular TSG101 to initiate viral particle assembly and release via the endosomal sorting complexes required for transport (ESCRT) pathway. However, some reports show that overexpression of TSG101 inhibits virus release by disruption of Gag targeting process. Since a HIV-1 accessory protein, Vpr binds to Gag p6 domain at the position close to the binding site for TSG101, whether Vpr implicates TSG101 overexpression effect has not been investigated. Here, we found that Vpr abrogates TSG101 overexpression effect to rescue viral production. Co-transfection of TSG101 and Gag with Vpr prevented TSG101-induced Gag accumulation in endosomes and lysosomes. In addition, Vpr rescued virus-like particle (VLP) production in a similar manner as a lysosomal inhibitor, Bafilomycin A1 indicating that Vpr inhibits TSG101-induced Gag downregulation via lysosomal pathway. Vpr and Gag interaction is required to counteract TSG101 overexpression effect since Vpr A30F mutant which is unable to interact with Gag and incorporate into virions, reduced ability to prevent Gag accumulation and to rescue VLP production. In addition, GST pull-down assays and Biacore analysis revealed that Vpr competed with TSG101 for Gag binding. These results indicate that Vpr overcomes the effects of TSG101 overexpression to support viral production by competing with TSG101 to bind Gag.
Collapse
Affiliation(s)
- Nopporn Chutiwitoonchai
- Viral Infectious Diseases Unit, RIKEN, Wako, Saitama, Japan
- Japan Foundation for AIDS Prevention, Chiyoda-ku, Tokyo, Japan
| | - Lowela Siarot
- Viral Infectious Diseases Unit, RIKEN, Wako, Saitama, Japan
- Graduate School of Agricultural and Life Sciences, The University of Tokyo, Bunkyo, Tokyo, Japan
| | - Eri Takeda
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Tatsuo Shioda
- Research Institute for Microbial Diseases, Osaka University, Suita, Osaka, Japan
| | - Motoki Ueda
- Nano Medical Engineering Laboratory, RIKEN, Wako, Saitama, Japan
| | - Yoko Aida
- Viral Infectious Diseases Unit, RIKEN, Wako, Saitama, Japan
- * E-mail:
| |
Collapse
|
37
|
Abstract
Like other retroviruses, human immunodeficiency virus type 1 (HIV-1) selectively packages genomic RNA (gRNA) during virus assembly. However, in the absence of the gRNA, cellular messenger RNAs (mRNAs) are packaged. While the gRNA is selected because of its cis-acting packaging signal, the mechanism of this selection is not understood. The affinity of Gag (the viral structural protein) for cellular RNAs at physiological ionic strength is not much higher than that for the gRNA. However, binding to the gRNA is more salt-resistant, implying that it has a higher non-electrostatic component. We have previously studied the spacer 1 (SP1) region of Gag and showed that it can undergo a concentration-dependent conformational transition. We proposed that this transition represents the first step in assembly, i.e., the conversion of Gag to an assembly-ready state. To explain selective packaging of gRNA, we suggest here that binding of Gag to gRNA, with its high non-electrostatic component, triggers this conversion more readily than binding to other RNAs; thus we predict that a Gag-gRNA complex will nucleate particle assembly more efficiently than other Gag-RNA complexes. New data shows that among cellular mRNAs, those with long 3'-untranslated regions (UTR) are selectively packaged. It seems plausible that the 3'-UTR, a stretch of RNA not occupied by ribosomes, offers a favorable binding site for Gag.
Collapse
Affiliation(s)
- Mauricio Comas-Garcia
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
| | - Sean R Davis
- Genetics Branch, Center for Cancer Research, National Cancer Institute, Bethesda, MD 20892, USA.
| | - Alan Rein
- HIV Dynamics and Replication Program, Center for Cancer Research, National Cancer Institute, Frederick, MD 21702, USA.
| |
Collapse
|
38
|
Rousvoal S, Bouyer B, López-Cristoffanini C, Boyen C, Collén J. Mutant swarms of a totivirus-like entities are present in the red macroalga Chondrus crispus and have been partially transferred to the nuclear genome. J Phycol 2016; 52:493-504. [PMID: 27151076 DOI: 10.1111/jpy.12427] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/20/2016] [Accepted: 03/15/2016] [Indexed: 06/05/2023]
Abstract
Chondrus crispus Stackhouse (Gigartinales) is a red seaweed found on North Atlantic rocky shores. Electrophoresis of RNA extracts showed a prominent band with a size of around 6,000 bp. Sequencing of the band revealed several sequences with similarity to totiviruses, double-stranded RNA viruses that normally infect fungi. This virus-like entity was named C. crispus virus (CcV). It should probably be regarded as an extreme viral quasispecies or a mutant swarm since low identity (<65%) was found between sequences. Totiviruses typically code for two genes: one capsid gene (gag) and one RNA-dependent RNA polymerase gene (pol) with a pseudoknot structure between the genes. Both the genes and the intergenic structures were found in the CcV sequences. A nonidentical gag gene was also found in the nuclear genome of C. crispus, with associated expressed sequence tags (EST) and upstream regulatory features. The gene was presumably horizontally transferred from the virus to the alga. Similar dsRNA bands were seen in extracts from different life cycle stages of C. crispus and from all geographic locations tested. In addition, similar bands were also observed in RNA extractions from other red algae; however, the significance of this apparently widespread phenomenon is unknown. Neither phenotype caused by the infection nor any virus particles or capsid proteins were identified; thus, the presence of viral particles has not been validated. These findings increase the known host range of totiviruses to include marine red algae.
Collapse
Affiliation(s)
- Sylvie Rousvoal
- CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, 29688, Roscoff Cedex, France
- UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, Sorbonne Universités, UPMC Univ Paris 06, CS 90074, 29688, Roscoff Cedex, France
| | - Betty Bouyer
- CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, 29688, Roscoff Cedex, France
- UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, Sorbonne Universités, UPMC Univ Paris 06, CS 90074, 29688, Roscoff Cedex, France
| | - Camilo López-Cristoffanini
- CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, 29688, Roscoff Cedex, France
- UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, Sorbonne Universités, UPMC Univ Paris 06, CS 90074, 29688, Roscoff Cedex, France
| | - Catherine Boyen
- CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, 29688, Roscoff Cedex, France
- UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, Sorbonne Universités, UPMC Univ Paris 06, CS 90074, 29688, Roscoff Cedex, France
| | - Jonas Collén
- CNRS, UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, CS 90074, 29688, Roscoff Cedex, France
- UMR 8227, Integrative Biology of Marine Models, Station Biologique de Roscoff, Sorbonne Universités, UPMC Univ Paris 06, CS 90074, 29688, Roscoff Cedex, France
| |
Collapse
|
39
|
Sabino Cunha M, Lima Sampaio T, Peterlin BM, Jesus da Costa L. A Truncated Nef Peptide from SIVcpz Inhibits the Production of HIV-1 Infectious Progeny. Viruses 2016; 8:v8070189. [PMID: 27399760 PMCID: PMC4974524 DOI: 10.3390/v8070189] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [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: 02/29/2016] [Revised: 06/08/2016] [Accepted: 06/14/2016] [Indexed: 12/02/2022] Open
Abstract
Nef proteins from all primate Lentiviruses, including the simian immunodeficiency virus of chimpanzees (SIVcpz), increase viral progeny infectivity. However, the function of Nef involved with the increase in viral infectivity is still not completely understood. Nonetheless, until now, studies investigating the functions of Nef from SIVcpz have been conducted in the context of the HIV-1 proviruses. In an attempt to investigate the role played by Nef during the replication cycle of an SIVcpz, a Nef-defective derivative was obtained from the SIVcpzWTGab2 clone by introducing a frame shift mutation at a unique restriction site within the nef sequence. This nef-deleted clone expresses an N-terminal 74-amino acid truncated peptide of Nef and was named SIVcpz-tNef. We found that the SIVcpz-tNef does not behave as a classic nef-deleted HIV-1 or simian immunodeficiency virus of macaques SIVmac. Markedly, SIVcpz-tNef progeny from both Hek-293T and Molt producer cells were completely non-infectious. Moreover, the loss in infectivity of SIVcpz-tNef correlated with the inhibition of Gag and GagPol processing. A marked accumulation of Gag and very low levels of reverse transcriptase were detected in viral lysates. Furthermore, these observations were reproduced once the tNef peptide was expressed in trans both in SIVcpzΔNef and HIV-1WT expressing cells, demonstrating that the truncated peptide is a dominant negative for viral processing and infectivity for both SIVcpz and HIV-1. We demonstrated that the truncated Nef peptide binds to GagPol outside the protease region and by doing so probably blocks processing of both GagPol and Gag precursors at a very early stage. This study demonstrates for the first time that naturally-occurring Nef peptides can potently block lentiviral processing and infectivity.
Collapse
Affiliation(s)
- Marcela Sabino Cunha
- Departamento de Virologia-Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373-CCS-Bloco I, Rio de Janeiro 21941-902, Brazil.
| | - Thatiane Lima Sampaio
- Departamento de Virologia-Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373-CCS-Bloco I, Rio de Janeiro 21941-902, Brazil.
| | - B Matija Peterlin
- Departments of Medicine, Microbiology and Immunology, University of California, San Francisco, 533 Parnassus Avenue, San Francisco, CA 94143, USA.
| | - Luciana Jesus da Costa
- Departamento de Virologia-Instituto de Microbiologia, Universidade Federal do Rio de Janeiro, Av. Carlos Chagas Filho 373-CCS-Bloco I, Rio de Janeiro 21941-902, Brazil.
| |
Collapse
|
40
|
Abstract
Due to the high number of drug-resistant HIV-1 mutants generated by highly active antiretroviral therapy (HAART), there is continuing demand for new types of inhibitors. Both the assembly of the Gag polyprotein into immature and mature HIV-1 particles are attractive candidates for the blocking of the retroviral life cycle. Currently, no therapeutically-used assembly inhibitor is available. One possible explanation is the lack of a reliable and simple assembly inhibitor screening method. To identify compounds potentially inhibiting the formation of both types of HIV-1 particles, we developed a new fluorescent high-throughput screening assay. This assay is based on the quantification of the assembly efficiency in vitro in a 96-well plate format. The key components of the assay are HIV-1 Gag-derived proteins and a dual-labelled oligonucleotide, which emits fluorescence only when the assembly of retroviral particles is inhibited. The method was validated using three (CAI, BM2, PF74) reported assembly inhibitors.
Collapse
Affiliation(s)
- Romana Hadravová
- Institute of Organic Chemistry and Biochemistry IOCB Research Centre & Gilead Sciences, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague, Czech Republic
| | - Michaela Rumlová
- Institute of Organic Chemistry and Biochemistry IOCB Research Centre & Gilead Sciences, Academy of Sciences of the Czech Republic, Flemingovo nám. 2, 166 10 Prague, Czech Republic; Department of Biotechnology, University of Chemistry and Technology, Prague, Technická 5, 166 28 Prague, Czech Republic.
| | - Tomáš Ruml
- Department of Biochemistry and Microbiology, University of Chemistry and Technology, Prague, Technická 3, 166 28 Prague, Czech Republic.
| |
Collapse
|
41
|
Nitta T, Ha D, Galvez F, Miyazawa T, Fan H. Human and murine APOBEC3s restrict replication of koala retrovirus by different mechanisms. Retrovirology 2015; 12:68. [PMID: 26253512 PMCID: PMC4528783 DOI: 10.1186/s12977-015-0193-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [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: 02/17/2015] [Accepted: 07/23/2015] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Koala retrovirus (KoRV) is an endogenous and exogenous retrovirus of koalas that may cause lymphoma. As for many other gammaretroviruses, the KoRV genome can potentially encode an alternate form of Gag protein, glyco-gag. RESULTS In this study, a convenient assay for assessing KoRV infectivity in vitro was employed: the use of DERSE cells (initially developed to search for infectious xenotropic murine leukemia-like viruses). Using infection of DERSE and other human cell lines (HEK293T), no evidence for expression of glyco-gag by KoRV was found, either in expression of glyco-gag protein or changes in infectivity when the putative glyco-gag reading frame was mutated. Since glyco-gag mediates resistance of Moloney murine leukemia virus to the restriction factor APOBEC3, the sensitivity of KoRV (wt or putatively mutant for glyco-gag) to restriction by murine (mA3) or human APOBEC3s was investigated. Both mA3 and hA3G potently inhibited KoRV infectivity. Interestingly, hA3G restriction was accompanied by extensive G → A hypermutation during reverse transcription while mA3 restriction was not. Glyco-gag status did not affect the results. CONCLUSIONS These results indicate that the mechanisms of APOBEC3 restriction of KoRV by hA3G and mA3 differ (deamination dependent vs. independent) and glyco-gag does not play a role in the restriction.
Collapse
Affiliation(s)
- Takayuki Nitta
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, 92697-3905, USA.
- Cancer Research Institute, University of California, Irvine, Irvine, CA, 92697-3905, USA.
- Department of Biology, Savannah State University, 3219 College St, Savannah, GA, 31404-5254, USA.
| | - Dat Ha
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, 92697-3905, USA.
- Cancer Research Institute, University of California, Irvine, Irvine, CA, 92697-3905, USA.
| | - Felipe Galvez
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, 92697-3905, USA.
- Cancer Research Institute, University of California, Irvine, Irvine, CA, 92697-3905, USA.
| | - Takayuki Miyazawa
- Laboratory of Signal Transduction, Department of Cell Biology, Institute for Virus Research, Kyoto University, 53 Shogoin-Kawaharacho, Sakyo-ku, Kyoto, 606-8507, Japan.
| | - Hung Fan
- Department of Molecular Biology and Biochemistry, University of California, Irvine, Irvine, CA, 92697-3905, USA.
- Cancer Research Institute, University of California, Irvine, Irvine, CA, 92697-3905, USA.
| |
Collapse
|
42
|
Zhang G, Sharon D, Jovel J, Liu L, Wine E, Tahbaz N, Indik S, Mason A. Pericentriolar Targeting of the Mouse Mammary Tumor Virus GAG Protein. PLoS One 2015; 10:e0131515. [PMID: 26121257 PMCID: PMC4486188 DOI: 10.1371/journal.pone.0131515] [Citation(s) in RCA: 7] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2015] [Accepted: 06/03/2015] [Indexed: 11/21/2022] Open
Abstract
The Gag protein of the mouse mammary tumor virus (MMTV) is the chief determinant of subcellular targeting. Electron microscopy studies show that MMTV Gag forms capsids within the cytoplasm and assembles as immature particles with MMTV RNA and the Y box binding protein-1, required for centrosome maturation. Other betaretroviruses, such as Mason-Pfizer monkey retrovirus (M-PMV), assemble adjacent to the pericentriolar region because of a cytoplasmic targeting and retention signal in the Matrix protein. Previous studies suggest that the MMTV Matrix protein may also harbor a similar cytoplasmic targeting and retention signal. Herein, we show that a substantial fraction of MMTV Gag localizes to the pericentriolar region. This was observed in HEK293T, HeLa human cell lines and the mouse derived NMuMG mammary gland cells. Moreover, MMTV capsids were observed adjacent to centrioles when expressed from plasmids encoding either MMTV Gag alone, Gag-Pro-Pol or full-length virus. We found that the cytoplasmic targeting and retention signal in the MMTV Matrix protein was sufficient for pericentriolar targeting, whereas mutation of the glutamine to alanine at position 56 (D56/A) resulted in plasma membrane localization, similar to previous observations from mutational studies of M-PMV Gag. Furthermore, transmission electron microscopy studies showed that MMTV capsids accumulate around centrioles suggesting that, similar to M-PMV, the pericentriolar region may be a site for MMTV assembly. Together, the data imply that MMTV Gag targets the pericentriolar region as a result of the MMTV cytoplasmic targeting and retention signal, possibly aided by the Y box protein-1 required for the assembly of centrosomal microtubules.
Collapse
Affiliation(s)
- Guangzhi Zhang
- Division of Gastroenterology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - David Sharon
- Division of Gastroenterology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Juan Jovel
- Division of Gastroenterology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
| | - Lei Liu
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Eytan Wine
- Department of Pediatrics, University of Alberta, Edmonton, Alberta, Canada
| | - Nasser Tahbaz
- Department of Cell Biology, University of Alberta, Edmonton, Alberta, Canada
| | - Stanislav Indik
- Research Institute for Virology and Biomedicine, University of Veterinary Medicine Vienna, Vienna, A-1210, Austria
| | - Andrew Mason
- Division of Gastroenterology, Department of Medicine, University of Alberta, Edmonton, Alberta, Canada
- * E-mail:
| |
Collapse
|
43
|
Rosales Gerpe MC, Renner TM, Bélanger K, Lam C, Aydin H, Langlois MA. N-linked glycosylation protects gammaretroviruses against deamination by APOBEC3 proteins. J Virol 2015; 89:2342-57. [PMID: 25505062 PMCID: PMC4338886 DOI: 10.1128/jvi.03330-14] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 12/01/2014] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED Retroviruses are pathogens with rapid infection cycles that can be a source of disease, genome instability, and tumor development in their hosts. Host intrinsic restriction factors, such as APOBEC3 (A3) proteins, are constitutively expressed and dedicated to interfering with the replication cycle of retroviruses. To survive, propagate, and persist, retroviruses must counteract these restriction factors, often by way of virus genome-encoded accessory proteins. Glycosylated Gag, also called glycosylated Pr80 Gag (gPr80), is a gammaretrovirus genome-encoded protein that inhibits the antiretroviral activity of mouse A3 (mA3). Here we show that gPr80 exerts two distinct inhibitory effects on mA3: one that antagonizes deamination-independent restriction and another one that inhibits its deaminase activity. More specifically, we find that the number of N-glycosylated residues in gPr80 inversely correlates with the sensitivity of a gammaretrovirus to deamination by mouse A3 and also, surprisingly, by human A3G. Finally, our work highlights that retroviruses which have successfully integrated into the mouse germ line generally express a gPr80 with fewer glycosylated sites than exogenous retroviruses. This observation supports the suggestion that modulation of A3 deamination intensity could be a desirable attribute for retroviruses to increase genetic diversification and avoid immune detection. Overall, we present here the first description of how gammaretroviruses employ posttranslational modification to antagonize and modulate the activity of a host genome-encoded retroviral restriction factor. IMPORTANCE APOBEC3 proteins are host factors that have a major role in protecting humans and other mammals against retroviruses. These enzymes hinder their replication and intensely mutate their DNA, thereby inactivating viral progeny and the spread of infection. Here we describe a newly recognized way in which some retroviruses protect themselves against the mutator activity of APOBEC3 proteins. We show that gammaretroviruses expressing an accessory protein called glycosylated Gag, or gPr80, use the host's posttranslational machinery and, more specifically, N-linked glycosylation as a way to modulate their sensitivity to mutations by APOBEC3 proteins. By carefully controlling the amount of mutations caused by APOBEC3 proteins, gammaretroviruses can find a balance that helps them evolve and persist.
Collapse
Affiliation(s)
- María Carla Rosales Gerpe
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Tyler Milston Renner
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Kasandra Bélanger
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Cindy Lam
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Halil Aydin
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| | - Marc-André Langlois
- Department of Biochemistry, Microbiology and Immunology, University of Ottawa, Ottawa, Ontario, Canada
| |
Collapse
|
44
|
Inlora J, Collins DR, Trubin ME, Chung JYJ, Ono A. Membrane binding and subcellular localization of retroviral Gag proteins are differentially regulated by MA interactions with phosphatidylinositol-(4,5)-bisphosphate and RNA. mBio 2014; 5:e02202. [PMID: 25491356 PMCID: PMC4324246 DOI: 10.1128/mbio.02202-14] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/27/2014] [Accepted: 11/07/2014] [Indexed: 01/29/2023] Open
Abstract
UNLABELLED The matrix (MA) domain of HIV-1 mediates proper Gag localization and membrane binding via interaction with a plasma-membrane (PM)-specific acidic phospholipid, phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P2]. HIV-1 MA also interacts with RNA, which prevents Gag from binding to membranes containing phosphatidylserine, a prevalent cellular acidic phospholipid. These results suggest that the MA-bound RNA promotes PM-specific localization of HIV-1 Gag by blocking nonspecific interactions with cellular membranes that do not contain PI(4,5)P2. To examine whether PI(4,5)P2 dependence and RNA-mediated inhibition collectively determine MA phenotypes across a broad range of retroviruses and elucidate the significance of their interrelationships, we compared a panel of Gag-leucine zipper constructs (GagLZ) containing MA of different retroviruses. We found that in vitro membrane binding of GagLZ via HIV-1 MA and Rous sarcoma virus (RSV) MA is both PI(4,5)P2 dependent and susceptible to RNA-mediated inhibition. The PM-specific localization and virus-like particle (VLP) release of these GagLZ proteins are severely impaired by overexpression of a PI(4,5)P2-depleting enzyme, polyphosphoinositide 5-phosphatase IV (5ptaseIV). In contrast, membrane binding of GagLZ constructs that contain human T-lymphotropic virus type 1 (HTLV-1) MA, murine leukemia virus (MLV) MA, and human endogenous retrovirus K (HERV-K) MA is PI(4,5)P2 independent and not blocked by RNA. The PM localization and VLP release of these GagLZ chimeras were much less sensitive to 5ptaseIV expression. Notably, single amino acid substitutions that confer a large basic patch rendered HTLV-1 MA susceptible to the RNA-mediated block, suggesting that RNA readily blocks MA containing a large basic patch, such as HIV-1 and RSV MA. Further analyses of these MA mutants suggest a possibility that HIV-1 and RSV MA acquired PI(4,5)P2 dependence to alleviate the membrane binding block imposed by RNA. IMPORTANCE MA basic residues in the HIV-1 structural protein Gag interact with phosphatidylinositol-(4,5)-bisphosphate [PI(4,5)P2] and RNA. RNA inhibits HIV-1 MA binding to non-PI(4,5)P2 acidic lipids. This inhibition may promote PM specificity of Gag membrane binding, an early essential step in virus assembly. However, whether and how relationships between these interactions have developed among retroviruses are poorly understood. In this study, by comparing diverse retroviral MA domains, we elucidated a strong correlation among PI(4,5)P2 dependence, susceptibility to RNA-mediated inhibition, and cellular behaviors of Gag. Mutagenesis analyses suggest that a large basic patch on MA is sufficient to confer susceptibility to RNA-mediated inhibition but not for PI(4,5)P2-dependent membrane binding. Our findings highlight RNA's role as a general blocker of large basic patches and suggest a possibility that some retroviruses, including HIV-1, have evolved to bind PI(4,5)P2, while others have adopted smaller basic patches on their MA domains, to overcome the RNA-mediated restriction of membrane binding.
Collapse
Affiliation(s)
- Jingga Inlora
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - David R Collins
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Marc E Trubin
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Ji Yeon J Chung
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| | - Akira Ono
- Department of Microbiology and Immunology, University of Michigan Medical School, Ann Arbor, Michigan, USA
| |
Collapse
|
45
|
Esteva MJ, Affranchino JL, González SA. Lentiviral Gag assembly analyzed through the functional characterization of chimeric simian immunodeficiency viruses expressing different domains of the feline immunodeficiency virus capsid protein. PLoS One 2014; 9:e114299. [PMID: 25462889 PMCID: PMC4252113 DOI: 10.1371/journal.pone.0114299] [Citation(s) in RCA: 8] [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] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2014] [Accepted: 11/07/2014] [Indexed: 12/18/2022] Open
Abstract
To gain insight into the functional relationship between the capsid (CA) domains of the Gag polyproteins of simian and feline immunodeficiency viruses (SIV and FIV, respectively), we constructed chimeric SIVs in which the CA-coding region was partially or totally replaced by the equivalent region of the FIV CA. The phenotypic characterization of the chimeras allowed us to group them into three categories: the chimeric viruses that, while being assembly-competent, exhibit a virion-associated unstable FIV CA; a second group represented only by the chimeric SIV carrying the N-terminal domain (NTD) of the FIV CA which proved to be assembly-defective; and a third group constituted by the chimeric viruses that produce virions exhibiting a mature and stable FIV CA protein, and which incorporate the envelope glycoprotein and contain wild-type levels of viral genome RNA and reverse transcriptase. Further analysis of the latter group of chimeric SIVs demonstrated that they are non-infectious due to a post-entry impairment, such as uncoating of the viral core, reverse transcription or nuclear import of the preintegration complex. Furthermore, we show here that the carboxyl-terminus domain (CTD) of the FIV CA has an intrinsic ability to dimerize in vitro and form high-molecular-weight oligomers, which, together with our finding that the FIV CA-CTD is sufficient to confer assembly competence to the resulting chimeric SIV Gag polyprotein, provides evidence that the CA-CTD exhibits more functional plasticity than the CA-NTD. Taken together, our results provide relevant information on the biological relationship between the CA proteins of primate and nonprimate lentiviruses.
Collapse
Affiliation(s)
- María J. Esteva
- Laboratorio de Virología, Universidad de Belgrano (UB) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - José L. Affranchino
- Laboratorio de Virología, Universidad de Belgrano (UB) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Silvia A. González
- Laboratorio de Virología, Universidad de Belgrano (UB) and Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- * E-mail:
| |
Collapse
|
46
|
Nogueira MADS, Gavioli CFB, Pereira NZ, de Carvalho GC, Domingues R, Aoki V, Sato MN. Human endogenous retrovirus expression is inversely related with the up-regulation of interferon-inducible genes in the skin of patients with lichen planus. Arch Dermatol Res 2014; 307:259-64. [PMID: 25384438 DOI: 10.1007/s00403-014-1524-0] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.5] [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: 04/25/2014] [Revised: 10/15/2014] [Accepted: 11/04/2014] [Indexed: 12/11/2022]
Abstract
Lichen planus (LP) is a common inflammatory skin disease of unknown etiology. Reports of a common transactivation of quiescent human endogenous retroviruses (HERVs) support the connection of viruses to the disease. HERVs are ancient retroviral sequences in the human genome and their transcription is often deregulated in cancer and autoimmune diseases. We explored the transcriptional activity of HERV sequences as well as the antiviral restriction factor and interferon-inducible genes in the skin from LP patients and healthy control (HC) donors. The study included 13 skin biopsies from patients with LP and 12 controls. Real-time PCR assay identified significant decrease in the HERV-K gag and env mRNA expression levels in LP subjects, when compared to control group. The expressions of HERV-K18 and HERV-W env were also inhibited in the skin of LP patients. We observed a strong correlation between HERV-K gag with other HERV sequences, regardless the down-modulation of transcripts levels in LP group. In contrast, a significant up-regulation of the cytidine deaminase APOBEC 3G (apolipoprotein B mRNA-editing), and the GTPase MxA (Myxovirus resistance A) mRNA expression level was identified in the LP skin specimens. Other transcript expressions, such as the master regulator of type I interferon-dependent immune responses, STING (stimulator of interferon genes) and IRF-7 (interferon regulatory factor 7), IFN-β and the inflammassome NALP3, had increased levels in LP, when compared to HC group. Our study suggests that interferon-inducible factors, in addition to their role in innate immunity against exogenous pathogens, contribute to the immune control of HERVs. Evaluation of the balance between HERV and interferon-inducible factor expression could possibly contribute to surveillance of inflammatory/malignant status of skin diseases.
Collapse
|
47
|
Valiente-Echeverría F, Melnychuk L, Vyboh K, Ajamian L, Gallouzi IE, Bernard N, Mouland AJ. eEF2 and Ras-GAP SH3 domain-binding protein (G3BP1) modulate stress granule assembly during HIV-1 infection. Nat Commun 2014; 5:4819. [PMID: 25229650 PMCID: PMC4978539 DOI: 10.1038/ncomms5819] [Citation(s) in RCA: 62] [Impact Index Per Article: 6.2] [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: 02/18/2014] [Accepted: 07/28/2014] [Indexed: 12/26/2022] Open
Abstract
Stress granules (SG) are translationally silent sites of RNA triage induced by environmental stresses including viral infection. Here we show that HIV-1 Gag blocks SG assembly irrespective of eIF2α phosphorylation and even when SG assembly is forced by overexpression of Ras-GAP SH3 domain-binding protein (G3BP1) or TIAR. The overexposed loops in the amino-terminal capsid domain of Gag and host eukaryotic elongation factor 2 (eEF2) are found to be critical for the SG blockade via interaction. Moreover, cyclophilin A (CypA) stabilizes the Gag-eEF2 association. eEF2 depletion not only lifts the SG blockade but also results in impaired virus production and infectivity. Gag also disassembles preformed SGs by recruiting G3BP1, thereby displacing eEF2, revealing another unsuspected virus-host interaction involved in the HIV-1-imposed SG blockade. Understanding how HIV-1 counters anti-viral stress responses will lay the groundwork for new therapeutic strategies to bolster host cell immune defences against HIV-1 and other pathogens.
Collapse
Affiliation(s)
- Fernando Valiente-Echeverría
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, Québec H3T 1E2, Canada
- Department of Medicine, McGill University, Montréal, Québec H3A 0G4, Canada
| | - Luca Melnychuk
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, Québec H3T 1E2, Canada
- Department of Microbiology and Immunology, McGill University, Montréal, Québec H3A 0G4, Canada
| | - Kishanda Vyboh
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, Québec H3T 1E2, Canada
- Department of Microbiology and Immunology, McGill University, Montréal, Québec H3A 0G4, Canada
| | - Lara Ajamian
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, Québec H3T 1E2, Canada
- Department of Medicine, McGill University, Montréal, Québec H3A 0G4, Canada
| | | | - Nicole Bernard
- Department of Medicine, McGill University, Montréal, Québec H3A 0G4, Canada
- Research Institute of the McGill University Health Centre, Montréal, Québec H3H 2R9, Canada
| | - Andrew J. Mouland
- HIV-1 RNA Trafficking Laboratory, Lady Davis Institute at the Jewish General Hospital, Montréal, Québec H3T 1E2, Canada
- Department of Medicine, McGill University, Montréal, Québec H3A 0G4, Canada
- Department of Microbiology and Immunology, McGill University, Montréal, Québec H3A 0G4, Canada
| |
Collapse
|
48
|
Nityanandam R, Serra-Moreno R. BCA2/Rabring7 targets HIV-1 Gag for lysosomal degradation in a tetherin-independent manner. PLoS Pathog 2014; 10:e1004151. [PMID: 24852021 PMCID: PMC4031200 DOI: 10.1371/journal.ppat.1004151] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2014] [Accepted: 04/14/2014] [Indexed: 12/04/2022] Open
Abstract
BCA2 (Rabring7, RNF115 or ZNF364) is a RING-finger E3 ubiquitin ligase that was identified as a co-factor in the restriction imposed by tetherin/BST2 on HIV-1. Contrary to the current model, in which BCA2 lacks antiviral activity in the absence of tetherin, we found that BCA2 possesses tetherin-independent antiviral activity. Here we show that the N-terminus of BCA2 physically interacts with the Matrix region of HIV-1 and other retroviral Gag proteins and promotes their ubiquitination, redistribution to endo-lysosomal compartments and, ultimately, lysosomal degradation. The targeted depletion of BCA2 in tetherin-expressing and tetherin-deficient cells results in a significant increase in virus release and replication, indicating that endogenous BCA2 possesses antiviral activity. Therefore, these results indicate that BCA2 functions as an antiviral factor that targets HIV-1 Gag for degradation, impairing virus assembly and release. Tetherin (also known as BST2, CD317 or HM1.24) is an interferon-inducible cellular factor that interferes with the release of enveloped viruses from infected cells. A recent study identified BCA2 (Breast Cancer-Associated gene 2, also known as RNF115, ZNF364 or Rabring7), a RING-finger E3 ubiquitin ligase, as a co-factor in the tetherin-mediated restriction of HIV-1. According to this model, BCA2 interacts with sequences in the N-terminus of tetherin to promote the internalization and lysosomal degradation of tethered HIV-1 particles, with no apparent antiviral activity in cells not expressing tetherin. However, here we show for the first time that BCA2 inhibits virus production for HIV-1 and other retroviruses in a tetherin-independent manner by reducing the cellular levels of Gag – the precursor of the structural proteins Matrix, Capsid, Nucleocapsid and p6. Hence, contrary to its reported role as a tetherin co-factor, BCA2 functions as a tetherin-independent antiviral factor that impairs virus assembly and release.
Collapse
Affiliation(s)
- Ramya Nityanandam
- Division of Immunology, New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts, United States of America
| | - Ruth Serra-Moreno
- Division of Immunology, New England Primate Research Center, Harvard Medical School, Southborough, Massachusetts, United States of America
- * E-mail:
| |
Collapse
|
49
|
Bann DV, Beyer AR, Parent LJ. A murine retrovirus co-Opts YB-1, a translational regulator and stress granule-associated protein, to facilitate virus assembly. J Virol 2014; 88:4434-50. [PMID: 24501406 PMCID: PMC3993753 DOI: 10.1128/jvi.02607-13] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2013] [Accepted: 01/28/2014] [Indexed: 11/20/2022] Open
Abstract
UNLABELLED The Gag protein of the murine retrovirus mouse mammary tumor virus (MMTV) orchestrates the assembly of immature virus particles in the cytoplasm which are subsequently transported to the plasma membrane for release from the cell. The morphogenetic pathway of MMTV assembly is similar to that of Saccharomyces cerevisiae retrotransposons Ty1 and Ty3, which assemble virus-like particles (VLPs) in intracytoplasmic ribonucleoprotein (RNP) complexes. Assembly of Ty1 and Ty3 VLPs depends upon cellular mRNA processing factors, prompting us to examine whether MMTV utilizes a similar set of host proteins to facilitate viral capsid assembly. Our data revealed that MMTV Gag colocalized with YB-1, a translational regulator found in stress granules and P bodies, in intracytoplasmic foci. The association of MMTV Gag and YB-1 in cytoplasmic granules was not disrupted by cycloheximide treatment, suggesting that these sites were not typical stress granules. However, the association of MMTV Gag and YB-1 was RNA dependent, and an MMTV RNA reporter construct colocalized with Gag and YB-1 in cytoplasmic RNP complexes. Knockdown of YB-1 resulted in a significant decrease in MMTV particle production, indicating that YB-1 plays a role in MMTV capsid formation. Analysis by live-cell imaging with fluorescence recovery after photobleaching (FRAP) revealed that the population of Gag proteins localized within YB-1 complexes was relatively immobile, suggesting that Gag forms stable complexes in association with YB-1. Together, our data imply that the formation of intracytoplasmic Gag-RNA complexes is facilitated by YB-1, which promotes MMTV virus assembly. IMPORTANCE Cellular mRNA processing factors regulate the posttranscriptional fates of mRNAs, affecting localization and utilization of mRNAs under normal conditions and in response to stress. RNA viruses such as retroviruses interact with cellular mRNA processing factors that accumulate in ribonucleoprotein complexes known as P bodies and stress granules. This report shows for the first time that mouse mammary tumor virus (MMTV), a mammalian retrovirus that assembles intracytoplasmic virus particles, commandeers the cellular factor YB-1, a key regulator of translation involved in the cellular stress response. YB-1 is essential for the efficient production of MMTV particles, a process directed by the viral Gag protein. We found that Gag and YB-1 localize together in cytoplasmic granules. Functional studies of Gag/YB-1 granules suggest that they may be sites where virus particles assemble. These studies provide significant insights into the interplay between mRNA processing factors and retroviruses.
Collapse
Affiliation(s)
- Darrin V. Bann
- Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Andrea R. Beyer
- Department of Microbiology and Immunology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| | - Leslie J. Parent
- Department of Medicine, Penn State College of Medicine, Hershey, Pennsylvania, USA
- Department of Microbiology and Immunology, Penn State College of Medicine, Hershey, Pennsylvania, USA
| |
Collapse
|
50
|
Hossain A, Ali K, Shin CG. Nuclear localization signals in prototype foamy viral integrase for successive infection and replication in dividing cells. Mol Cells 2014; 37:140-8. [PMID: 24598999 PMCID: PMC3935627 DOI: 10.14348/molcells.2014.2331] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2013] [Revised: 12/11/2013] [Accepted: 12/13/2013] [Indexed: 11/27/2022] Open
Abstract
We identified four basic amino acid residues as nuclear localization signals (NLS) in the C-terminal domain of the prototype foamy viral (PFV) integrase (IN) protein that were essential for viral replication. We constructed seven point mutants in the C-terminal domain by changing the lysine and arginine at residues 305, 308, 313, 315, 318, 324, and 329 to threonine or proline, respectively, to identify residues conferring NLS activity. Our results showed that mutation of these residues had no effect on expression assembly, release of viral particles, or in vitro recombinant IN enzymatic activity. However, mutations at residues 305 (R → T), 313(R → T), 315(R → P), and 329(R → T) lead to the production of defective viral particles with loss of infectivity, whereas non-defective mutations at residues 308(R → T), 318(K → T), and 324(K → T) did not show any adverse effects on subsequent production or release of viral particles. Sub-cellular fractionation and immunostaining for viral protein PFV-IN and PFV-Gag localization revealed predominant cytoplasmic localization of PFV-IN in defective mutants, whereas cytoplasmic and nuclear localization of PFV-IN was observed in wild type and non-defective mutants. However sub-cellular localization of PFV-Gag resulted in predominant nuclear localization and less presence in the cytoplasm of the wild type and non-defective mutants. But defective mutants showed only nuclear localization of Gag. Therefore, we postulate that four basic arginine residues at 305, 313, 315 and 329 confer the karyoplilic properties of PFV-IN and are essential for successful viral integration and replication.
Collapse
Affiliation(s)
- Alamgir Hossain
- Department of Biotechnology, Chung-Ang University, Ansung 456-756,
Korea
| | - Khadem Ali
- Department of Biotechnology, Chung-Ang University, Ansung 456-756,
Korea
| | - Cha-Gyun Shin
- Department of Biotechnology, Chung-Ang University, Ansung 456-756,
Korea
| |
Collapse
|