1
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Pfitzner AK, Zivkovic H, Bernat-Silvestre C, West M, Peltier T, Humbert F, Odorizzi G, Roux A. Vps60 initiates alternative ESCRT-III filaments. J Cell Biol 2023; 222:e202206028. [PMID: 37768378 PMCID: PMC10538557 DOI: 10.1083/jcb.202206028] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2022] [Revised: 03/08/2023] [Accepted: 06/12/2023] [Indexed: 09/29/2023] Open
Abstract
Endosomal sorting complex required for transport-III (ESCRT-III) participates in essential cellular functions, from cell division to endosome maturation. The remarkable increase of its subunit diversity through evolution may have enabled the acquisition of novel functions. Here, we characterize a novel ESCRT-III copolymer initiated by Vps60. Membrane-bound Vps60 polymers recruit Vps2, Vps24, Did2, and Ist1, as previously shown for Snf7. Snf7- and Vps60-based filaments can coexist on membranes without interacting as their polymerization and recruitment of downstream subunits remain spatially and biochemically separated. In fibroblasts, Vps60/CHMP5 and Snf7/CHMP4 are both recruited during endosomal functions and cytokinesis, but their localization is segregated and their recruitment dynamics are different. Contrary to Snf7/CHMP4, Vps60/CHMP5 is not recruited during nuclear envelope reformation. Taken together, our results show that Vps60 and Snf7 form functionally distinct ESCRT-III polymers, supporting the notion that diversification of ESCRT-III subunits through evolution is linked to the acquisition of new cellular functions.
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Affiliation(s)
| | - Henry Zivkovic
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | | | - Matt West
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Tanner Peltier
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Frédéric Humbert
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
| | - Greg Odorizzi
- Department of Molecular Cellular and Developmental Biology, University of Colorado, Boulder, CO, USA
| | - Aurélien Roux
- Department of Biochemistry, University of Geneva, Geneva, Switzerland
- National Center of Competence in Research in Chemical Biology, University of Geneva, Geneva, Switzerland
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2
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Wang C, Chen Y, Hu S, Liu X. Insights into the function of ESCRT and its role in enveloped virus infection. Front Microbiol 2023; 14:1261651. [PMID: 37869652 PMCID: PMC10587442 DOI: 10.3389/fmicb.2023.1261651] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2023] [Accepted: 09/20/2023] [Indexed: 10/24/2023] Open
Abstract
The endosomal sorting complex required for transport (ESCRT) is an essential molecular machinery in eukaryotic cells that facilitates the invagination of endosomal membranes, leading to the formation of multivesicular bodies (MVBs). It participates in various cellular processes, including lipid bilayer remodeling, cytoplasmic separation, autophagy, membrane fission and re-modeling, plasma membrane repair, as well as the invasion, budding, and release of certain enveloped viruses. The ESCRT complex consists of five complexes, ESCRT-0 to ESCRT-III and VPS4, along with several accessory proteins. ESCRT-0 to ESCRT-II form soluble complexes that shuttle between the cytoplasm and membranes, mainly responsible for recruiting and transporting membrane proteins and viral particles, as well as recruiting ESCRT-III for membrane neck scission. ESCRT-III, a soluble monomer, directly participates in vesicle scission and release, while VPS4 hydrolyzes ATP to provide energy for ESCRT-III complex disassembly, enabling recycling. Studies have confirmed the hijacking of ESCRT complexes by enveloped viruses to facilitate their entry, replication, and budding. Recent research has focused on the interaction between various components of the ESCRT complex and different viruses. In this review, we discuss how different viruses hijack specific ESCRT regulatory proteins to impact the viral life cycle, aiming to explore commonalities in the interaction between viruses and the ESCRT system.
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Affiliation(s)
- Chunxuan Wang
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Yu Chen
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Shunlin Hu
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
| | - Xiufan Liu
- Animal Infectious Disease Laboratory, College of Veterinary Medicine, Yangzhou University, Yangzhou, China
- Jiangsu Co-innovation Center for Prevention and Control of Important Animal Infectious Diseases and Zoonosis, Yangzhou University, Yangzhou, China
- Jiangsu Key Laboratory of Zoonosis, Yangzhou University, Yangzhou, China
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3
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Mardi N, Haiaty S, Rahbarghazi R, Mobarak H, Milani M, Zarebkohan A, Nouri M. Exosomal transmission of viruses, a two-edged biological sword. Cell Commun Signal 2023; 21:19. [PMID: 36691072 PMCID: PMC9868521 DOI: 10.1186/s12964-022-01037-5] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2022] [Accepted: 12/28/2022] [Indexed: 01/24/2023] Open
Abstract
As a common belief, most viruses can egress from the host cells as single particles and transmit to uninfected cells. Emerging data have revealed en bloc viral transmission as lipid bilayer-cloaked particles via extracellular vesicles especially exosomes (Exo). The supporting membrane can be originated from multivesicular bodies during intra-luminal vesicle formation and autophagic response. Exo are nano-sized particles, ranging from 40-200 nm, with the ability to harbor several types of signaling molecules from donor to acceptor cells in a paracrine manner, resulting in the modulation of specific signaling reactions in target cells. The phenomenon of Exo biogenesis consists of multiple and complex biological steps with the participation of diverse constituents and molecular pathways. Due to similarities between Exo biogenesis and virus replication and the existence of shared pathways, it is thought that viruses can hijack the Exo biogenesis machinery to spread and evade immune cells. To this end, Exo can transmit complete virions (as single units or aggregates), separate viral components, and naked genetic materials. The current review article aims to scrutinize challenges and opportunities related to the exosomal delivery of viruses in terms of viral infections and public health. Video Abstract.
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Affiliation(s)
- Narges Mardi
- Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Sanya Haiaty
- Infectious and Tropical Diseases Research Center, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Reza Rahbarghazi
- Stem Cell Research Center, Tabriz University of Medical Sciences, Imam Reza St., Golgasht St., Tabriz, Iran
- Department of Applied Cell Sciences, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Halimeh Mobarak
- Stem Cell Research Center, Tabriz University of Medical Sciences, Imam Reza St., Golgasht St., Tabriz, Iran
| | - Morteza Milani
- Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Amir Zarebkohan
- Department of Medical Nanotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
| | - Mohammad Nouri
- Department of Medical Biotechnology, Faculty of Advanced Medical Sciences, Tabriz University of Medical Sciences, Tabriz, Iran
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4
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‘Come Together’—The Regulatory Interaction of Herpesviral Nuclear Egress Proteins Comprises both Essential and Accessory Functions. Cells 2022; 11:cells11111837. [PMID: 35681532 PMCID: PMC9180862 DOI: 10.3390/cells11111837] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2022] [Revised: 05/31/2022] [Accepted: 06/01/2022] [Indexed: 02/01/2023] Open
Abstract
Herpesviral nuclear egress is a fine-tuned regulatory process that defines the nucleocytoplasmic release of viral capsids. Nuclear capsids are unable to traverse via nuclear pores due to the fact of their large size; therefore, herpesviruses evolved to develop a vesicular transport pathway mediating the transition across the two leaflets of the nuclear membrane. The entire process involves a number of regulatory proteins, which support the local distortion of the nuclear envelope. In the case of the prototype species of β-Herpesvirinae, the human cytomegalovirus (HCMV), the nuclear egress complex (NEC) is determined by the core proteins pUL50 and pUL53 that oligomerize, form capsid docking lattices and mediate multicomponent assembly with NEC-associated viral and cellular proteins. The NEC-binding principle is based on the hook-into-groove interaction through an N-terminal hook-like pUL53 protrusion that embraces an α-helical pUL50 binding groove. Thus far, the function and characteristics of herpesviral core NECs have been well studied and point to the groove proteins, such as pUL50, as the multi-interacting, major determinants of NEC formation and egress. This review provides closer insight into (i) sequence and structure conservation of herpesviral core NEC proteins, (ii) experimentation on cross-viral core NEC interactions, (iii) the essential functional roles of hook and groove proteins for viral replication, (iv) an establishment of assay systems for NEC-directed antiviral research and (v) the validation of NEC as putative antiviral drug targets. Finally, this article provides new insights into the conservation, function and antiviral targeting of herpesviral core NEC proteins and, into the complex regulatory role of hook and groove proteins during the assembly, egress and maturation of infectious virus.
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5
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Sokolinskaya EL, Putlyaeva LV, Gorshkova AA, Lukyanov KA. Intermembrane oligomerization of SARS-CoV-2 M-protein: possible role in viral budding. BULLETIN OF RUSSIAN STATE MEDICAL UNIVERSITY 2022. [DOI: 10.24075/brsmu.2022.029] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Despite the extensive research spurred by the catastrophic effects of COVID-19 pandemic, precise molecular mechanisms of some stages in SARS-CoV-2 life cycle remain elusive. One of such stages is the detachment of viral particles during budding. Using confocal fluorescence microscopy, we observed formation of specific structures by endoplasmic reticulum in human cells expressing SARS-CoV-2 M-protein, implicating oligomerization of M-protein across parallel membranes. In our opinion, such intermembrane oligomerization may provide a driving force for pinching off the viral particles during SARS-CoV-2 budding.
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Affiliation(s)
- EL Sokolinskaya
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow, Russia
| | - LV Putlyaeva
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow, Russia
| | - AA Gorshkova
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow, Russia
| | - KA Lukyanov
- Center for Molecular and Cellular Biology, Skolkovo Institute of Science and Technology, Moscow, Russia
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6
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An ESCRT/VPS4 envelopment trap to examine the mechanism of alphaherpesvirus assembly and transport in neurons. J Virol 2022; 96:e0217821. [PMID: 35045266 DOI: 10.1128/jvi.02178-21] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
The assembly and egress of alphaherpesviruses, including Herpes simplex virus type 1 (HSV-1) and Pseudorabies virus (PRV), within neurons is poorly understood. A key unresolved question is the structure of the viral particle that moves by anterograde transport along the axon, and two alternative mechanisms have been described. In the "Married" model capsids acquire their envelopes in the cell body, then traffic along axons as enveloped virions within a bounding organelle. In the "Separate" model non-enveloped capsids travel from the cell body into and along the axon, eventually encountering their envelopment organelles at a distal site such as the nerve cell terminal. Here we describe an "envelopment trap" to test these models using the dominant negative terminal ESCRT component VPS4-EQ. GFP-tagged VPS4-EQ was used to arrest HSV-1 or PRV capsid envelopment, inhibit downstream trafficking and GFP-label envelopment intermediates. We found that GFP-VPS4-EQ inhibited trafficking of HSV-1 capsids into and along the neurites and axons of mouse CAD cells and rat embryonic primary cortical neurons, consistent with egress via the married pathway. In contrast, transport of HSV-1 capsids was unaffected in the neurites of human SK-N-SH neuroblastoma cells, consistent with the separate mechanism. Unexpectedly, PRV (generally thought to utilize the married pathway) also appeared to employ the separate mechanism in SK-N-SH cells. We propose that apparent differences in the methods of HSV-1 and PRV egress are more likely a reflection of the host neuron in which transport is studied, rather than true biological differences between the viruses themselves. IMPORTANCE Alphaherpesviruses, including Herpes simplex virus type 1 (HSV-1) and Pseudorabies virus (PRV), are pathogens of the nervous system. They replicate in the nerve cell body then travel great distances along axons to reach nerve termini and spread to adjacent epithelial cells, however key aspects of how these viruses travel along axons remain controversial. Here we test two alternative mechanisms for transport, the married and separate models, by blocking envelope assembly, a critical step in viral egress. When we arrest formation of the viral envelope using a mutated component of the cellular ESCRT apparatus we find that entry of viral particles into axons is blocked in some types of neuron, but not others. This approach allows us to determine whether envelope assembly occurs prior to entry of viruses into axons, or afterwards, and thus to distinguish between the alternative models for viral transport.
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7
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The Role of Exosome and the ESCRT Pathway on Enveloped Virus Infection. Int J Mol Sci 2021; 22:ijms22169060. [PMID: 34445766 PMCID: PMC8396519 DOI: 10.3390/ijms22169060] [Citation(s) in RCA: 30] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2021] [Revised: 08/20/2021] [Accepted: 08/20/2021] [Indexed: 02/06/2023] Open
Abstract
The endosomal sorting complex required for transport (ESCRT) system consists of peripheral membrane protein complexes ESCRT-0, -I, -II, -III VPS4-VTA1, and ALIX homodimer. This system plays an important role in the degradation of non-essential or dangerous plasma membrane proteins, the biogenesis of lysosomes and yeast vacuoles, the budding of most enveloped viruses, and promoting membrane shedding of cytokinesis. Recent results show that exosomes and the ESCRT pathway play important roles in virus infection. This review mainly focuses on the roles of exosomes and the ESCRT pathway in virus assembly, budding, and infection of enveloped viruses. The elaboration of the mechanism of exosomes and the ESCRT pathway in some enveloped viruses provides important implications for the further study of the infection mechanism of other enveloped viruses.
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8
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Wilson DW. Motor Skills: Recruitment of Kinesins, Myosins and Dynein during Assembly and Egress of Alphaherpesviruses. Viruses 2021; 13:v13081622. [PMID: 34452486 PMCID: PMC8402756 DOI: 10.3390/v13081622] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2021] [Revised: 08/11/2021] [Accepted: 08/13/2021] [Indexed: 12/14/2022] Open
Abstract
The alphaherpesviruses are pathogens of the mammalian nervous system. Initial infection is commonly at mucosal epithelia, followed by spread to, and establishment of latency in, the peripheral nervous system. During productive infection, viral gene expression, replication of the dsDNA genome, capsid assembly and genome packaging take place in the infected cell nucleus, after which mature nucleocapsids emerge into the cytoplasm. Capsids must then travel to their site of envelopment at cytoplasmic organelles, and enveloped virions need to reach the cell surface for release and spread. Transport at each of these steps requires movement of alphaherpesvirus particles through a crowded and viscous cytoplasm, and for distances ranging from several microns in epithelial cells, to millimeters or even meters during egress from neurons. To solve this challenging problem alphaherpesviruses, and their assembly intermediates, exploit microtubule- and actin-dependent cellular motors. This review focuses upon the mechanisms used by alphaherpesviruses to recruit kinesin, myosin and dynein motors during assembly and egress.
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Affiliation(s)
- Duncan W. Wilson
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA; ; Tel.: +1-718-430-2305
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
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9
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Tognarelli EI, Reyes A, Corrales N, Carreño LJ, Bueno SM, Kalergis AM, González PA. Modulation of Endosome Function, Vesicle Trafficking and Autophagy by Human Herpesviruses. Cells 2021; 10:cells10030542. [PMID: 33806291 PMCID: PMC7999576 DOI: 10.3390/cells10030542] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2021] [Revised: 02/23/2021] [Accepted: 02/25/2021] [Indexed: 12/27/2022] Open
Abstract
Human herpesviruses are a ubiquitous family of viruses that infect individuals of all ages and are present at a high prevalence worldwide. Herpesviruses are responsible for a broad spectrum of diseases, ranging from skin and mucosal lesions to blindness and life-threatening encephalitis, and some of them, such as Kaposi’s sarcoma-associated herpesvirus (KSHV) and Epstein–Barr virus (EBV), are known to be oncogenic. Furthermore, recent studies suggest that some herpesviruses may be associated with developing neurodegenerative diseases. These viruses can establish lifelong infections in the host and remain in a latent state with periodic reactivations. To achieve infection and yield new infectious viral particles, these viruses require and interact with molecular host determinants for supporting their replication and spread. Important sets of cellular factors involved in the lifecycle of herpesviruses are those participating in intracellular membrane trafficking pathways, as well as autophagic-based organelle recycling processes. These cellular processes are required by these viruses for cell entry and exit steps. Here, we review and discuss recent findings related to how herpesviruses exploit vesicular trafficking and autophagy components by using both host and viral gene products to promote the import and export of infectious viral particles from and to the extracellular environment. Understanding how herpesviruses modulate autophagy, endolysosomal and secretory pathways, as well as other prominent trafficking vesicles within the cell, could enable the engineering of novel antiviral therapies to treat these viruses and counteract their negative health effects.
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Affiliation(s)
- Eduardo I. Tognarelli
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Antonia Reyes
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Nicolás Corrales
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Leandro J. Carreño
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Programa de Inmunología, Instituto de Ciencias Biomédicas, Facultad de Medicina, Universidad de Chile, Santiago 8380453, Chile
| | - Susan M. Bueno
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
| | - Alexis M. Kalergis
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Endocrinología, Facultad de Medicina, Escuela de Medicina, Pontificia Universidad Católica de Chile, Santiago 8320000, Chile
| | - Pablo A. González
- Millennium Institute on Immunology and Immunotherapy, Santiago 8330025, Chile; (E.I.T.); (A.R.); (N.C.); (L.J.C.); (S.M.B.); (A.M.K.)
- Departamento de Genética Molecular y Microbiología, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Santiago 8331150, Chile
- Correspondence:
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10
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Hernandez-Gonzalez M, Larocque G, Way M. Viral use and subversion of membrane organization and trafficking. J Cell Sci 2021; 134:jcs252676. [PMID: 33664154 PMCID: PMC7610647 DOI: 10.1242/jcs.252676] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023] Open
Abstract
Membrane trafficking is an essential cellular process conserved across all eukaryotes, which regulates the uptake or release of macromolecules from cells, the composition of cellular membranes and organelle biogenesis. It influences numerous aspects of cellular organisation, dynamics and homeostasis, including nutrition, signalling and cell architecture. Not surprisingly, malfunction of membrane trafficking is linked to many serious genetic, metabolic and neurological disorders. It is also often hijacked during viral infection, enabling viruses to accomplish many of the main stages of their replication cycle, including entry into and egress from cells. The appropriation of membrane trafficking by viruses has been studied since the birth of cell biology and has helped elucidate how this integral cellular process functions. In this Review, we discuss some of the different strategies viruses use to manipulate and take over the membrane compartments of their hosts to promote their replication, assembly and egress.
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Affiliation(s)
- Miguel Hernandez-Gonzalez
- Cellular Signalling and Cytoskeletal Function Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Gabrielle Larocque
- Cellular Signalling and Cytoskeletal Function Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
| | - Michael Way
- Cellular Signalling and Cytoskeletal Function Laboratory, The Francis Crick Institute, 1 Midland Road, London NW1 1AT, UK
- Department of Infectious Disease, Imperial College, London W2 1PG, UK
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11
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Ahmad I, Wilson DW. HSV-1 Cytoplasmic Envelopment and Egress. Int J Mol Sci 2020; 21:ijms21175969. [PMID: 32825127 PMCID: PMC7503644 DOI: 10.3390/ijms21175969] [Citation(s) in RCA: 35] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Revised: 08/14/2020] [Accepted: 08/16/2020] [Indexed: 12/25/2022] Open
Abstract
Herpes simplex virus type 1 (HSV-1) is a structurally complex enveloped dsDNA virus that has evolved to replicate in human neurons and epithelia. Viral gene expression, DNA replication, capsid assembly, and genome packaging take place in the infected cell nucleus, which mature nucleocapsids exit by envelopment at the inner nuclear membrane then de-envelopment into the cytoplasm. Once in the cytoplasm, capsids travel along microtubules to reach, dock, and envelope at cytoplasmic organelles. This generates mature infectious HSV-1 particles that must then be sorted to the termini of sensory neurons, or to epithelial cell junctions, for spread to uninfected cells. The focus of this review is upon our current understanding of the viral and cellular molecular machinery that enables HSV-1 to travel within infected cells during egress and to manipulate cellular organelles to construct its envelope.
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Affiliation(s)
- Imran Ahmad
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA;
| | - Duncan W. Wilson
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA;
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
- Correspondence:
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12
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Wu L, Cheng A, Wang M, Jia R, Yang Q, Wu Y, Zhu D, Zhao X, Chen S, Liu M, Zhang S, Ou X, Mao S, Gao Q, Sun D, Wen X, Liu Y, Yu Y, Zhang L, Tian B, Pan L, Chen X. Alphaherpesvirus Major Tegument Protein VP22: Its Precise Function in the Viral Life Cycle. Front Microbiol 2020; 11:1908. [PMID: 32849477 PMCID: PMC7427429 DOI: 10.3389/fmicb.2020.01908] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 07/21/2020] [Indexed: 12/19/2022] Open
Abstract
Alphaherpesviruses are zoonotic pathogens that can cause a variety of diseases in humans and animals and severely damage health. Alphaherpesvirus infection is a slow and orderly process that can lie dormant for the lifetime of the host but may be reactivated when the immune system is compromised. All alphaherpesviruses feature a protein layer called the tegument that lies between the capsid and the envelope. Virus protein (VP) 22 is one of the most highly expressed tegument proteins; there are more than 2,000 copies of this protein in each viral particle. VP22 can interact with viral proteins, cellular proteins, and chromatin, and these interactions play important roles. This review summarizes the latest literature and discusses the roles of VP22 in viral gene transcription, protein synthesis, virion assembly, and viral cell-to-cell spread with the purpose of enhancing understanding of the life cycle of herpesviruses and other pathogens in host cells. The molecular interaction information herein provides important reference data.
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Affiliation(s)
- Liping Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Anchun Cheng
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Mingshu Wang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Renyong Jia
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qiao Yang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ying Wu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Dekang Zhu
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xinxin Zhao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Shun Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Mafeng Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Shaqiu Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xuming Ou
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Sai Mao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Qun Gao
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Di Sun
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xinjian Wen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yunya Liu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Yanling Yu
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Ling Zhang
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Bin Tian
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Leichang Pan
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
| | - Xiaoyue Chen
- Institute of Preventive Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
- Key Laboratory of Animal Disease and Human Health of Sichuan Province, Sichuan Agricultural University, Chengdu, China
- Avian Disease Research Center, College of Veterinary Medicine, Sichuan Agricultural University, Chengdu, China
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13
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Diwaker D, Murray JW, Barnes J, Wolkoff AW, Wilson DW. Deletion of the Pseudorabies Virus gE/gI-US9p complex disrupts kinesin KIF1A and KIF5C recruitment during egress, and alters the properties of microtubule-dependent transport in vitro. PLoS Pathog 2020; 16:e1008597. [PMID: 32511265 PMCID: PMC7302734 DOI: 10.1371/journal.ppat.1008597] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2020] [Revised: 06/18/2020] [Accepted: 05/04/2020] [Indexed: 01/18/2023] Open
Abstract
During infection of neurons by alphaherpesviruses including Pseudorabies virus (PRV) and Herpes simplex virus type 1 (HSV-1) viral nucleocapsids assemble in the cell nucleus, become enveloped in the cell body then traffic into and down axons to nerve termini for spread to adjacent epithelia. The viral membrane protein US9p and the membrane glycoprotein heterodimer gE/gI play critical roles in anterograde spread of both HSV-1 and PRV, and several models exist to explain their function. Biochemical studies suggest that PRV US9p associates with the kinesin-3 motor KIF1A in a gE/gI-stimulated manner, and the gE/gI-US9p complex has been proposed to recruit KIF1A to PRV for microtubule-mediated anterograde trafficking into or along the axon. However, as loss of gE/gI-US9p essentially abolishes delivery of alphaherpesviruses to the axon it is difficult to determine the microtubule-dependent trafficking properties and motor-composition of Δ(gE/gI-US9p) particles. Alternatively, studies in HSV-1 have suggested that gE/gI and US9p are required for the appearance of virions in the axon because they act upstream, to help assemble enveloped virions in the cell body. We prepared Δ(gE/gI-US9p) mutant, and control parental PRV particles from differentiated cultured neuronal or porcine kidney epithelial cells and quantitated the efficiency of virion assembly, the properties of microtubule-dependent transport and the ability of viral particles to recruit kinesin motors. We find that loss of gE/gI-US9p has no significant effect upon PRV particle assembly but leads to greatly diminished plus end-directed traffic, and enhanced minus end-directed and bidirectional movement along microtubules. PRV particles prepared from infected differentiated mouse CAD neurons were found to be associated with either kinesin KIF1A or kinesin KIF5C, but not both. Loss of gE/gI-US9p resulted in failure to recruit KIF1A and KF5C, but did not affect dynein binding. Unexpectedly, while KIF5C was expressed in undifferentiated and differentiated CAD neurons it was only found associated with PRV particles prepared from differentiated cells.
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Affiliation(s)
- Drishya Diwaker
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - John W. Murray
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
- Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Jenna Barnes
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Allan W. Wolkoff
- Department of Anatomy and Structural Biology, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
- Marion Bessin Liver Research Center, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
| | - Duncan W. Wilson
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, Bronx, New York, New York, United States of America
- * E-mail:
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14
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Butt BG, Owen DJ, Jeffries CM, Ivanova L, Hill CH, Houghton JW, Ahmed MF, Antrobus R, Svergun DI, Welch JJ, Crump CM, Graham SC. Insights into herpesvirus assembly from the structure of the pUL7:pUL51 complex. eLife 2020; 9:e53789. [PMID: 32391791 PMCID: PMC7289601 DOI: 10.7554/elife.53789] [Citation(s) in RCA: 17] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 05/07/2020] [Indexed: 12/19/2022] Open
Abstract
Herpesviruses acquire their membrane envelopes in the cytoplasm of infected cells via a molecular mechanism that remains unclear. Herpes simplex virus (HSV)-1 proteins pUL7 and pUL51 form a complex required for efficient virus envelopment. We show that interaction between homologues of pUL7 and pUL51 is conserved across human herpesviruses, as is their association with trans-Golgi membranes. We characterized the HSV-1 pUL7:pUL51 complex by solution scattering and chemical crosslinking, revealing a 1:2 complex that can form higher-order oligomers in solution, and we solved the crystal structure of the core pUL7:pUL51 heterodimer. While pUL7 adopts a previously-unseen compact fold, the helix-turn-helix conformation of pUL51 resembles the cellular endosomal complex required for transport (ESCRT)-III component CHMP4B and pUL51 forms ESCRT-III-like filaments, suggesting a direct role for pUL51 in promoting membrane scission during virus assembly. Our results provide a structural framework for understanding the role of the conserved pUL7:pUL51 complex in herpesvirus assembly.
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Affiliation(s)
- Benjamin G Butt
- Department of Pathology, University of CambridgeCambridgeUnited Kingdom
| | - Danielle J Owen
- Department of Pathology, University of CambridgeCambridgeUnited Kingdom
| | - Cy M Jeffries
- European Molecular Biology Laboratory (EMBL) Hamburg SiteHamburgGermany
| | - Lyudmila Ivanova
- Department of Pathology, University of CambridgeCambridgeUnited Kingdom
| | - Chris H Hill
- Department of Pathology, University of CambridgeCambridgeUnited Kingdom
| | - Jack W Houghton
- Cambridge Institute for Medical Research, University of CambridgeCambridgeUnited Kingdom
| | - Md Firoz Ahmed
- Department of Pathology, University of CambridgeCambridgeUnited Kingdom
| | - Robin Antrobus
- Cambridge Institute for Medical Research, University of CambridgeCambridgeUnited Kingdom
| | - Dmitri I Svergun
- European Molecular Biology Laboratory (EMBL) Hamburg SiteHamburgGermany
| | - John J Welch
- Department of Genetics, University of CambridgeCambridgeUnited Kingdom
| | - Colin M Crump
- Department of Pathology, University of CambridgeCambridgeUnited Kingdom
| | - Stephen C Graham
- Department of Pathology, University of CambridgeCambridgeUnited Kingdom
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15
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The ESCRT-II Subunit EAP20/VPS25 and the Bro1 Domain Proteins HD-PTP and BROX Are Individually Dispensable for Herpes Simplex Virus 1 Replication. J Virol 2020; 94:JVI.01641-19. [PMID: 31748394 DOI: 10.1128/jvi.01641-19] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2019] [Accepted: 11/14/2019] [Indexed: 12/14/2022] Open
Abstract
Capsid envelopment during assembly of the neurotropic herpesviruses herpes simplex virus 1 (HSV-1) and pseudorabies virus (PRV) in the infected cell cytoplasm is thought to involve the late-acting cellular ESCRT (endosomal sorting complex required for transport) components ESCRT-III and VPS4 (vacuolar protein sorting 4). However, HSV-1, unlike members of many other families of enveloped viruses, does not appear to require the ESCRT-I subunit TSG101 or the Bro1 domain-containing protein ALIX (Alg-2-interacting protein X) to recruit and activate ESCRT-III. Alternative cellular factors that are known to be capable of regulating ESCRT-III function include the ESCRT-II complex and other members of the Bro1 family. We therefore used small interfering RNA (siRNA) to knock down the essential ESCRT-II subunit EAP20/VPS25 (ELL-associated protein 20/vacuolar protein sorting 25) and the Bro1 proteins HD-PTP (His domain-containing protein tyrosine phosphatase) and BROX (Bro1 domain and CAAX motif containing). We demonstrated reductions in levels of the targeted proteins by Western blotting and used quantitative microscopic assays to confirm loss of ESCRT-II and HD-PTP function. We found that in single-step replication experiments, the final yields of HSV-1 were unchanged following loss of EAP20, HD-PTP, or BROX.IMPORTANCE HSV-1 is a pathogen of the human nervous system that uses its own virus-encoded proteins and the normal cellular ESCRT machinery to drive the construction of its envelope. How HSV-1 structural proteins interact with ESCRT components and which subsets of cellular ESCRT proteins are utilized by the virus remain largely unknown. Here, we demonstrate that an essential component of the ESCRT-II complex and two ESCRT-associated Bro1 proteins are dispensable for HSV-1 replication.
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16
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Abstract
The human betaherpesviruses, human cytomegalovirus (HCMV; species Human betaherpesvirus 5) and human herpesviruses 6A, 6B, and 7 (HHV-6A, -6B, and -7; species Human betaherpesviruses 6A, 6B, and 7) are highly prevalent and can cause severe disease in immune-compromised and immune-naive populations in well- and under-developed communities. Herpesvirus virion assembly is an intricate process that requires viral orchestration of host systems. In this review, we describe recent advances in some of the many cellular events relevant to assembly and egress of betaherpesvirus virions. These include modifications of host metabolic, immune, and autophagic/recycling systems. In addition, we discuss unique aspects of betaherpesvirus virion structure, virion assembly, and the cellular pathways employed during virion egress.
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17
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Diwaker D, Wilson DW. Microtubule-Dependent Trafficking of Alphaherpesviruses in the Nervous System: The Ins and Outs. Viruses 2019; 11:v11121165. [PMID: 31861082 PMCID: PMC6950448 DOI: 10.3390/v11121165] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2019] [Revised: 12/13/2019] [Accepted: 12/15/2019] [Indexed: 12/12/2022] Open
Abstract
The Alphaherpesvirinae include the neurotropic pathogens herpes simplex virus and varicella zoster virus of humans and pseudorabies virus of swine. These viruses establish lifelong latency in the nuclei of peripheral ganglia, but utilize the peripheral tissues those neurons innervate for productive replication, spread, and transmission. Delivery of virions from replicative pools to the sites of latency requires microtubule-directed retrograde axonal transport from the nerve terminus to the cell body of the sensory neuron. As a corollary, during reactivation newly assembled virions must travel along axonal microtubules in the anterograde direction to return to the nerve terminus and infect peripheral tissues, completing the cycle. Neurotropic alphaherpesviruses can therefore exploit neuronal microtubules and motors for long distance axonal transport, and alternate between periods of sustained plus end- and minus end-directed motion at different stages of their infectious cycle. This review summarizes our current understanding of the molecular details by which this is achieved.
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Affiliation(s)
- Drishya Diwaker
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA;
| | - Duncan W. Wilson
- Department of Developmental and Molecular Biology, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA;
- Dominick P. Purpura Department of Neuroscience, Albert Einstein College of Medicine, 1300 Morris Park Avenue, Bronx, NY 10461, USA
- Correspondence: ; Tel.: +1-(718)-430-2305
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18
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Grzesik P, Pryce EN, Bhalala A, Vij M, Ahmed R, Etienne L, Perez P, McCaffery JM, Desai APJ. Functional Domains of the Herpes Simplex Virus Type 1 Tegument Protein pUL37: The Amino Terminus is Dispensable for Virus Replication in Tissue Culture. Viruses 2019; 11:E853. [PMID: 31540043 PMCID: PMC6783895 DOI: 10.3390/v11090853] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 09/09/2019] [Accepted: 09/11/2019] [Indexed: 01/01/2023] Open
Abstract
The herpes simplex virus type 1 (HSV-1) UL37 gene encodes for a multifunctional component of the virion tegument, which is necessary for secondary envelopment in the cytoplasm of infected cells, for motility of the viral particle, and for the first steps in the initiation of virus infection. This 120 kDa protein has several known viral interacting partners, including pUL36, gK/pUL20, pUS10, and VP26, and cellular interacting proteins which include TRAF6, RIG-I, and dystonin. These interactions are likely important for the functions of pUL37 at both early and late stages of infection. We employed a genetic approach to determine essential domains and amino acid residues of pUL37 and their associated functions in cellular localization and virion morphogenesis. Using marker-rescue/marker-transfer methods, we generated a library of GFP-tagged pUL37 mutations in the HSV-1 strain KOS genome. Through viral growth and ultra-structural analysis, we discovered that the C-terminus is essential for replication. The N-terminal 480 amino acids are dispensable for replication in cell culture, although serve some non-essential function as viral titers are reduced in the presence of this truncation. Furthermore, the C-terminal 133 amino acids are important in so much that their absence leads to a lethal phenotype. We further probed the carboxy terminal half of pUL37 by alanine scanning mutagenesis of conserved residues among alphaherpesviruses. Mutant viruses were screened for the inability to form plaques-or greatly reduced plaque size-on Vero cells, of which 22 mutations were chosen for additional analysis. Viruses discovered to have the greatest reduction in viral titers on Vero cells were examined by electron microscopy (EM) and by confocal light microscopy for pUL37-EGFP cellular localization. This genetic approach identified both essential and non-essential domains and residues of the HSV-1 UL37 gene product. The mutations identified in this study are recognized as significant candidates for further analysis of the pUL37 function and may unveil previously undiscovered roles and interactions of this essential tegument gene.
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Affiliation(s)
- Peter Grzesik
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, The Johns Hopkins University, Baltimore, MD 21231, USA.
| | - Erin N Pryce
- Integrated Imaging Center, Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA.
| | - Akshay Bhalala
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, The Johns Hopkins University, Baltimore, MD 21231, USA.
| | - Mannika Vij
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, The Johns Hopkins University, Baltimore, MD 21231, USA.
| | - Ray Ahmed
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, The Johns Hopkins University, Baltimore, MD 21231, USA.
| | - Lyns Etienne
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, The Johns Hopkins University, Baltimore, MD 21231, USA.
| | - Patric Perez
- Integrated Imaging Center, Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA.
| | - J Michael McCaffery
- Integrated Imaging Center, Department of Biology, The Johns Hopkins University, Baltimore, MD 21218, USA.
| | - And Prashant J Desai
- Department of Oncology, The Sidney Kimmel Comprehensive Cancer Center at Johns Hopkins, The Johns Hopkins University, Baltimore, MD 21231, USA.
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