scholarly journals Human Papillomavirus Major Capsid Protein L1 Remains Associated with the Incoming Viral Genome throughout the Entry Process

2017 ◽  
Vol 91 (16) ◽  
Author(s):  
Stephen DiGiuseppe ◽  
Malgorzata Bienkowska-Haba ◽  
Lucile G. M. Guion ◽  
Timothy R. Keiffer ◽  
Martin Sapp
Keyword(s):  
Human Papillomavirus ◽  
Capsid Protein ◽  
Conformational Changes ◽  
Viral Genome ◽  
Neutralizing Antibodies ◽  
Major Capsid Protein ◽  
Mitotic Chromosomes ◽  
Viral Dna ◽  
Minor Capsid Protein ◽  
L1 Protein

ABSTRACT During infectious entry, acidification within the endosome triggers uncoating of the human papillomavirus (HPV) capsid, whereupon host cyclophilins facilitate the release of most of the major capsid protein, L1, from the minor capsid protein L2 and the viral genome. The L2/DNA complex traffics to the trans-Golgi network (TGN). After the onset of mitosis, HPV-harboring transport vesicles bud from the TGN, followed by association with mitotic chromosomes. During this time, the HPV genome remains in a vesicular compartment until the nucleus has completely reformed. Recent data suggest that while most of L1 protein dissociates and is degraded in the endosome, some L1 protein remains associated with the viral genome. The L1 protein has DNA binding activity, and the L2 protein has multiple domains capable of interacting with L1 capsomeres. In this study, we report that some L1 protein traffics with L2 and viral genome to the nucleus. The accompanying L1 protein is mostly full length and retains conformation-dependent epitopes, which are recognized by neutralizing antibodies. Since more than one L1 molecule contributes to these epitopes and requires assembly into capsomeres, we propose that L1 protein is present in the form of pentamers. Furthermore, we provide evidence that the L1 protein interacts directly with viral DNA within the capsid. Based on our findings, we propose that the L1 protein, likely arranged as capsomeres, stabilizes the viral genome within the subviral complex during intracellular trafficking. IMPORTANCE After internalization, the nonenveloped human papillomavirus virion uncoats in the endosome, whereupon conformational changes result in a dissociation of a subset of the major capsid protein L1 from the minor capsid protein L2, which remains in complex with the viral DNA. Recent data suggest that some L1 protein may accompany the viral genome beyond the endosomal compartment. We demonstrate that conformationally intact L1 protein, likely still arranged as capsomeres, remains associated with the incoming viral genome throughout mitosis and transiently resides in the nucleus until after the viral DNA is released from the transport vesicle.

scholarly journals Identification of a Dynein Interacting Domain in the Papillomavirus Minor Capsid Protein L2

2006 ◽  
Vol 80 (13) ◽  
pp. 6691-6696 ◽  
Author(s):  
Luise Florin ◽  
Katrin A. Becker ◽  
Carsten Lambert ◽  
Thorsten Nowak ◽  
Cornelia Sapp ◽  
...  
Keyword(s):  
Amino Acids ◽  
Human Papillomavirus ◽  
Capsid Protein ◽  
Viral Genome ◽  
Promyelocytic Leukemia ◽  
Protein Bodies ◽  
Viral Dna ◽  
Microtubule Network ◽  
Promyelocytic Leukemia Protein ◽  
Minor Capsid Protein

ABSTRACT Papillomaviruses enter cells via endocytosis (H. C. Selinka et al., Virology 299:279-287, 2002). After egress from endosomes, the minor capsid protein L2 accompanies the viral DNA to the nucleus and subsequently to the subnuclear promyelocytic leukemia protein bodies (P. M. Day et al., Proc. Natl. Acad. Sci. USA 101:14252-14257, 2004), suggesting that this protein may be involved in the intracytoplasmic transport of the viral genome. We now demonstrate that the L2 protein is able to interact with the microtubule network via the motor protein dynein. L2 protein was found attached to microtubules after uncoating of incoming human papillomavirus pseudovirions. Based on immunofluorescence and coimmunoprecipitation analyses, the L2 region interacting with dynein is mapped to the C-terminal 40 amino acids. Mutations within this region abrogating the L2/dynein interaction strongly reduce the infectivity of pseudoviruses, indicating that this interaction mediates the minus-end-directed transport of the viral genome along microtubules towards the nucleus.

scholarly journals Topography of the Human Papillomavirus Minor Capsid Protein L2 during Vesicular Trafficking of Infectious Entry

2015 ◽  
Vol 89 (20) ◽  
pp. 10442-10452 ◽  
Author(s):  
Stephen DiGiuseppe ◽  
Timothy R. Keiffer ◽  
Malgorzata Bienkowska-Haba ◽  
Wioleta Luszczek ◽  
Lucile G. M. Guion ◽  
...  
Keyword(s):  
Human Papillomavirus ◽  
Host Cell ◽  
Capsid Protein ◽  
Conformational Changes ◽  
Transmembrane Protein ◽  
Vesicular Trafficking ◽  
Minor Capsid Protein ◽  
Intracellular Membranes ◽  
Cytosolic Side ◽  
Infectious Entry

ABSTRACTThe human papillomavirus (HPV) capsid is composed of the major capsid protein L1 and the minor capsid protein L2. During entry, the HPV capsid undergoes numerous conformational changes that result in endosomal uptake and subsequent trafficking of the L2 protein in complex with the viral DNA to thetrans-Golgi network. To facilitate this transport, the L2 protein harbors a number of putative motifs that, if capable of direct interaction, would interact with cytosolic host cell factors. These data imply that a portion of L2 becomes cytosolic during infection. Using a low concentration of digitonin to selectively permeabilize the plasma membrane of infected cells, we mapped the topography of the L2 protein during infection. We observed that epitopes within amino acid residues 64 to 81 and 163 to 170 and a C-terminal tag of HPV16 L2 are exposed on the cytosolic side of intracellular membranes, whereas an epitope within residues 20 to 38, which are upstream of a putative transmembrane region, is luminal. Corroborating these findings, we also found that L2 protein is sensitive to trypsin digestion during infection. These data demonstrate that the majority of the L2 protein becomes accessible on the cytosolic side of intracellular membranes in order to interact with cytosolic factors to facilitate vesicular trafficking.IMPORTANCEIn order to complete infectious entry, nonenveloped viruses have to pass cellular membranes. This is often achieved through the viral capsid protein associating with or integrating into intracellular membrane. Here, we determine the topography of HPV L2 protein in the endocytic vesicular compartment, suggesting that L2 becomes a transmembrane protein with a short luminal portion and with the majority facing the cytosolic side for interaction with host cell transport factors.

scholarly journals Modification of Human Papillomavirus Minor Capsid Protein L2 by Sumoylation

2010 ◽  
Vol 84 (21) ◽  
pp. 11585-11589 ◽  
Author(s):  
Martina Bergant Marušič ◽  
Nina Mencin ◽  
Mia Ličen ◽  
Lawrence Banks ◽  
Helena Šterlinko Grm
Keyword(s):  
Human Papillomavirus ◽  
Infected Cell ◽  
Host Cell ◽  
Capsid Protein ◽  
Major Capsid Protein ◽  
Capsid Assembly ◽  
Complex Interplay ◽  
Hpv 16 ◽  
Minor Capsid Protein ◽  
Viral Particles

ABSTRACT The human papillomavirus (HPV) minor capsid protein L2 plays important roles in the generation of infectious viral particles and in the initial steps of infection. Here we show that HPV-16 L2 protein is sumoylated at lysine 35 and that sumoylation affects its stability. Interestingly, the sumoylated form of L2 cannot bind to the major capsid protein L1, suggesting a mechanism by which capsid assembly may be modulated in an infected cell. Additionally, L2 appears to modulate the overall sumoylation status of the host cell. These observations indicate a complex interplay between the HPV L2 protein and the host sumoylation machinery.

scholarly journals Nuclear Localization but Not PML Protein Is Required for Incorporation of the Papillomavirus Minor Capsid Protein L2 into Virus-Like Particles

2004 ◽  
Vol 78 (3) ◽  
pp. 1121-1128 ◽  
Author(s):  
Katrin A. Becker ◽  
Luise Florin ◽  
Cornelia Sapp ◽  
Gerd G. Maul ◽  
Martin Sapp
Keyword(s):  
Capsid Protein ◽  
Nuclear Protein ◽  
Major Capsid Protein ◽  
Nuclear Translocation ◽  
Wild Type ◽  
Minor Capsid Protein ◽  
Virus Like Particles ◽  
Nuclear Domain ◽  
L1 Protein

ABSTRACT Recent reports suggest that nuclear domain(s) 10 (ND10) is the site of papillomavirus morphogenesis. The viral genome replicates in or close to ND10. In addition, the minor capsid protein, L2, accumulates in these subnuclear structures and recruits the major capsid protein, L1. We have now used cell lines deficient for promyelocytic leukemia (PML) protein, the main structural component of ND10, to study the role of this nuclear protein for L2 incorporation into virus-like particles (VLPs). L2 expressed in PML protein knockout (PML−/−) cells accumulated in nuclear dots, which resemble L2 aggregates forming at ND10 in PML protein-containing cells. These L2 assemblies also attracted L1 and the transcriptional repressor Daxx, suggesting that they are functional in the absence of PML protein. In addition, L2-containing VLPs assembled in PML−/− cells. In order to analyze whether incorporation of L2 into VLPs requires any specific subcellular localization, an L1 mutant defective for nuclear transport and L2 mutants deficient in nuclear translocation and/or ND10 localization were constructed. Using this approach, we identified two independent L2 domains interacting with L1. Mutant L2 proteins not accumulating in ND10 were incorporated into VLPs. Mutant L1 protein, which assembled into VLPs in the cytoplasm, did not incorporate L2 defective for nuclear translocation. The same mutant L2 protein, which passively diffuses into the nucleus, is incorporated into wild-type L1-VLPs in the nucleus. Our data demonstrate that the incorporation of L2 into VLPs requires nuclear but not ND10 localization.

scholarly journals The Papillomavirus Minor Capsid Protein, L2, Induces Localization of the Major Capsid Protein, L1, and the Viral Transcription/Replication Protein, E2, to PML Oncogenic Domains

1998 ◽  
Vol 72 (1) ◽  
pp. 142-150 ◽  
Author(s):  
Patricia M. Day ◽  
Richard B. S. Roden ◽  
Douglas R. Lowy ◽  
John T. Schiller
Keyword(s):  
Capsid Protein ◽  
Major Capsid Protein ◽  
Cultured Cells ◽  
Immunofluorescent Staining ◽  
Local Concentration ◽  
Bovine Papillomavirus ◽  
Viral Dna ◽  
Minor Capsid Protein ◽  
Nuclear Regions ◽  
L1 And L2

ABSTRACT We have used immunofluorescent staining and confocal microscopy to examine the subcellular localization of structural and nonstructural bovine papillomavirus (BPV) proteins in cultured cells that produce infectious virions. When expressed separately, L1, the major capsid protein, showed a diffuse nuclear distribution while L2, the minor capsid protein, was found to localize to punctate nuclear regions identified as promonocytic leukemia protein (PML) oncogenic domains (PODs). Coexpression of L1 and L2 induced a relocation of L1 into the PODs, leading to the colocalization of L1 and L2. The effect of L2 expression on the distribution of the nonstructural viral proteins E1 and E2, which are required for maintenance of the genome and viral DNA synthesis, was also examined. The localization of the E1 protein was unaffected by L2 expression. However, the pattern of anti-E2 staining was dramatically altered in L2-expressing cells. Similar to L1, E2 was shifted from a dispersed nuclear locality into the PODs and colocalized with L2. The recruitment of full-length E2 by L2 occurred in the absence of other viral components. L2 was shown previously to be essential for the generation of infectious BPV. Our present results provide evidence for a role for L2 in the organization of virion components by recruiting them to a distinct nuclear domain. This L2-dependent colocalization probably serves as a mechanism to promote the assembly of papillomaviruses either by increasing the local concentration of virion constituents or by providing the physical architecture necessary for efficient packaging and assembly. The data also suggest a role for a nonstructural viral protein, E2, in virion assembly, specifically the recruitment of the viral genome to the sites of assembly, through its high-affinity interaction with specific sequences in the viral DNA.

scholarly journals Head-to-Head Comparison of Modular Vaccines Developed Using Different Capsid Virus-Like Particle Backbones and Antigen Conjugation Systems

Vaccines ◽  
2021 ◽  
Vol 9 (6) ◽  
pp. 539
Author(s):  
Laurits Fredsgaard ◽  
Louise Goksøyr ◽  
Susan Thrane ◽  
Kara-Lee Aves ◽  
Thor G. Theander ◽  
...  
Keyword(s):  
Immune Response ◽  
Human Papillomavirus ◽  
Immune Responses ◽  
Capsid Protein ◽  
Major Capsid Protein ◽  
Molecular Scaffolds ◽  
Conjugation System ◽  
Virus Like Particles ◽  
Virus Like Particle ◽  
Specific Igg

Capsid virus-like particles (cVLPs) are used as molecular scaffolds to increase the immunogenicity of displayed antigens. Modular platforms have been developed whereby antigens are attached to the surface of pre-assembled cVLPs. However, it remains unknown to what extent the employed cVLP backbone and conjugation system may influence the immune response elicited against the displayed antigen. Here, we performed a head-to-head comparison of antigen-specific IgG responses elicited by modular cVLP-vaccines differing by their employed cVLP backbone or conjugation system, respectively. Covalent antigen conjugation (i.e., employing the SpyTag/SpyCatcher system) resulted in significantly higher antigen-specific IgG titers compared to when using affinity-based conjugation (i.e., using biotin/streptavidin). The cVLP backbone also influenced the antigen-specific IgG response. Specifically, vaccines based on the bacteriophage AP205 cVLP elicited significantly higher antigen-specific IgG compared to corresponding vaccines using the human papillomavirus major capsid protein (HPV L1) cVLP. In addition, the AP205 cVLP platform mediated induction of antigen-specific IgG with a different subclass profile (i.e., higher IgG2a and IgG2b) compared to HPV L1 cVLP. These results demonstrate that the cVLP backbone and conjugation system can individually affect the IgG response elicited against a displayed antigen. These data will aid the understanding and process of tailoring modular cVLP vaccines to achieve improved immune responses.

scholarly journals The U4 Antibody Epitope on Human Papillomavirus 16 Identified by Cryo-electron Microscopy

2015 ◽  
Vol 89 (23) ◽  
pp. 12108-12117 ◽  
Author(s):  
Jian Guan ◽  
Stephanie M. Bywaters ◽  
Sarah A. Brendle ◽  
Hyunwook Lee ◽  
Robert E. Ashley ◽  
...  
Keyword(s):  
Electron Microscopy ◽  
Monoclonal Antibody ◽  
Human Papillomavirus ◽  
Conformational Changes ◽  
Vaccine Development ◽  
Contact Point ◽  
Human Papillomavirus 16 ◽  
Cryo Electron Microscopy ◽  
C Terminus ◽  
L1 Protein

ABSTRACTThe human papillomavirus (HPV) major structural protein L1 composes capsomers that are linked together through interactions mediated by the L1 C terminus to constitute a T=7 icosahedral capsid. H16.U4 is a type-specific monoclonal antibody recognizing a conformation-dependent neutralizing epitope of HPV thought to include the L1 protein C terminus. The structure of human papillomavirus 16 (HPV16) complexed with H16.U4 fragments of antibody (Fab) was solved by cryo-electron microscopy (cryo-EM) image reconstruction. Atomic structures of virus and Fab were fitted into the corresponding cryo-EM densities to identify the antigenic epitope. The antibody footprint mapped predominately to the L1 C-terminal arm with an additional contact point on the side of the capsomer. This footprint describes an epitope that is presented capsid-wide. However, although the H16.U4 epitope suggests the presence of 360 potential binding sites exposed in the capsid valley between each capsomer, H16.U4 Fab bound only to epitopes located around the icosahedral five-fold vertex of the capsid. Thus, the binding characteristics of H16.U4 defined in this study showed a distinctive selectivity for local conformation-dependent interactions with specific L1 invading arms between five-fold related capsomers.IMPORTANCEHuman papillomavirus 16 (HPV16) is the most prevalent oncogenic genotype in HPV-associated anogenital and oral cancers. Here we use cryo-EM reconstruction techniques to solve the structures of the HPV16 capsid complexes using H16.U4 fragment of antibody (Fab). Different from most other antibodies directed against surface loops, H16.U4 monoclonal antibody is unique in targeting the C-terminal arm of the L1 protein. This monoclonal antibody (MAb) is used throughout the HPV research community in HPV serological and vaccine development and to define mechanisms of HPV uptake. The unique binding mode of H16.U4 defined here shows important conformation-dependent interactions within the HPV16 capsid. By targeting an important structural and conformational epitope, H16.U4 may identify subtle conformational changes in different maturation stages of the HPV capsid and provide a key probe to analyze the mechanisms of HPV uptake during the early stages of virus infection. Our analyses precisely define important conformational epitopes on HPV16 capsids that are key targets for successful HPV prophylactic vaccines.

scholarly journals Cloning and expression of Human Papilloma virus type 16 L1 capsid protein in bacteria

2019 ◽  
Vol 10 (2) ◽  
pp. 82-89
Author(s):  
Silvia Tri Widyaningtyas ◽  
Sofy Meilany ◽  
Budiman Bela
Keyword(s):  
Escherichia Coli ◽  
Cervical Cancer ◽  
Human Papillomavirus ◽  
Recombinant Protein ◽  
Capsid Protein ◽  
Recombinant Plasmid ◽  
Health Science ◽  
Science Journal ◽  
Hpv 16 ◽  
L1 Protein

Latar belakang: Secara alamiah protein kapsid L1 Human Papillomavirus (HPV) tipe 16 dapat mengalami auto assembly untuk membentuk Viral like particle (VLP). Terkait dengan penelitian vaksin HPV, VLP dapat digunakan untuk berbagai keperluan seperti vaksin, pseudovirion atau SpyTag-Spycatcher. Penelitian ini ditujukan untuk mendapatkan plasmid rekombinan yang digunakan untuk produksi protein L1 HPV 16. Metode: Gen penyandi protein L1 HPV 16 diklona ke dalam vector pQE80L, suatu plasmid yang mengandung sistem ekspresi untuk prokariota. DNA penyandi HPV 16 L1 disisipkan pada situs restriksi BamHI dan Hind III plasmid pQE80L. Plasmid rekombinan yang mengandung gen L1 HPV 16dikonfirmasi menggunakan PCR dan analisis enzim restriksi. Lebih lanjut untuk memastikan bahwa gen rekombinan L1 HPV 16 dapat diekspresikan dalam prokariota, plasmid rekombinan ditransformasikan ke bakteri Escherichia coli BL21 (DE3). Bakteri diinduksi dengan Isopropyl β-D-1-thiogalactopyranoside (IPTG) dengan berbagai konsentrasi dan berbagai waktu inkubasi. Hasil: protein rekombinan L1, berat 56 kDa, telah berhasil diekspresikan dalam sistem prokariota. Protein rekombinan L1 dapat dimurnikan menggunakan TalonR dalam kondisi denaturasi. Kesimpulan: gen L1 HPV 16 telah dikloning ke dalam pQE80L dan berhasil diekspresikan dalam sistem prokariota. (Health Science Journal of Indonesia 2019;10(2):82-9) Kata kunci: L1, HPV 16, cervical cancer   Abstract Background: Naturally Human Papillomavirus (HPV) type 16 L1 capsid protein can auto assemble to form Viral like particles (VLP). Concerning to vaccine development for HPV, VLP can be used for a variety of needs such as a vaccine, pseudovirion or SpyTag-Spycatcher. In this study, to obtain a vector expression that can be used in the production of HPV L1 protein, we cloned gene coding HPV 16 L1 protein into pQE80L a plasmid contains an expression system for prokaryote. Methods: The DNA coding HPV 16 L1 was inserted at BamHI and Hind III restriction sites of pQE80L plasmid. The recombinant plasmid containing the HPV L1 gene was confirmed using PCR colony and enzyme restriction. Further to ensure the recombinant HPV 16 L1 gene could be expressed in a prokaryote, the recombinant plasmid was transformed into bacteria Escherichia coli BL21 (DE3). The bacteria were induced with IPTG with various concentrations and various incubation time. Result: L1 recombinant protein, 56 kDa in weight, has successfully been expressed in prokaryote system. L1 recombinant protein can be purified using TalonR under denaturing conditions. Conclusion: L1 HPV 16 gene has been cloned into pQE80L and successfully expressed in prokaryote system. (Health Science Journal of Indonesia 2019;10(2):82-9) Keywords: L1, HPV 16, cervical cancer

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