scholarly journals Herpes Simplex Virus Tegument Protein VP22 Contains an Internal VP16 Interaction Domain and a C-Terminal Domain That Are Both Required for VP22 Assembly into the Virus Particle

2005 ◽  
Vol 79 (20) ◽  
pp. 13082-13093 ◽  
Author(s):  
Wali Hafezi ◽  
Emmanuelle Bernard ◽  
Rachelle Cook ◽  
Gillian Elliott
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Virus Assembly ◽  
Interaction Domain ◽  
Recombinant Viruses ◽  
Tegument Proteins ◽  
Terminal Domain ◽  
C Terminus ◽  
Simplex Virus ◽  
Mutant Forms

ABSTRACT Many steps along the herpesvirus assembly and maturation pathway remain unclear. In particular, the acquisition of the virus tegument is a poorly understood process, and the molecular interactions involved in tegument assembly have not yet been defined. Previously we have shown that the two major herpes simplex virus tegument proteins VP22 and VP16 are able to interact, although the relevance of this to virus assembly is not clear. Here we have constructed a number of recombinant viruses expressing N- and C-terminal truncations of VP22 and have used them to identify regions of the protein involved in its assembly into the virus structure. Analysis of the packaging of these VP22 variants into extracellular virions revealed that the C terminus of VP22 is absolutely required for this process, with removal of the C-terminal 89 residues abrogating its incorporation. However, while these 89 residues alone were sufficient for specific incorporation of small amounts of VP22 into the tegument, efficient packaging of VP22 to the levels of full-length protein required an additional 52 residues of the protein. Coimmunoprecipitation assays indicated that these 52 residues also contained the interaction domain for VP16. Furthermore, analysis of the subcellular localization of the mutant forms of VP22 revealed that only those truncations that were efficiently assembled formed characteristic cytoplasmic trafficking complexes, suggesting that these complexes may represent the cellular location for VP22 assembly into the virus. Taken together, these results suggest that there are two determinants involved in the packaging of VP22—a C-terminal domain and an internal VP16 interaction domain, both of which are required for the efficient recruitment of VP22 to sites of virus assembly.

scholarly journals Identification of Crucial Hydrogen-Bonding Residues for the Interaction of Herpes Simplex Virus DNA Polymerase Subunits via Peptide Display, Mutational, and Calorimetric Approaches

2001 ◽  
Vol 75 (11) ◽  
pp. 4990-4998 ◽  
Author(s):  
Kristie Grove Bridges ◽  
Connie S. Chow ◽  
Donald M. Coen
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Dna Polymerase ◽  
Antiviral Drug ◽  
Titration Calorimetry ◽  
Random Peptide ◽  
C Terminus ◽  
Simplex Virus ◽  
Mutant Forms ◽  
Peptide Display

ABSTRACT The catalytic subunit, Pol, of herpes simplex virus DNA polymerase interacts via its extreme C terminus with the processivity subunit, UL42. This interaction is critical for viral replication and thus a potential target for antiviral drug action. To investigate the Pol-binding region on UL42, we engineered UL42 mutations but also used random peptide display to identify artificial ligands of the Pol C terminus. The latter approach selected ligands with homology to residues 171 to 176 of UL42. Substitution of glutamine 171 with alanine greatly impaired binding to Pol and stimulation of long-chain DNA synthesis by Pol, identifying this residue as crucial for subunit interactions. To study these interactions quantitatively, we used isothermal titration calorimetry and wild-type and mutant forms of Pol-derived peptides and UL42. Each of three peptides corresponding to either the last 36, 27, or 18 residues of Pol bound specifically to UL42 in a 1:1 complex with a dissociation constant of 1 to 2 μM. Thus, the last 18 residues suffice for most of the binding energy, which was due mainly to a change in enthalpy. Substitutions at positions corresponding to Pol residue 1228 or 1229 or at UL42 residue 171 abolished or greatly reduced binding. These residues participate in hydrogen bonds observed in the crystal structure of the C terminus of Pol bound to UL42. Thus, interruption of these few bonds is sufficient to disrupt the interaction, suggesting that small molecules targeting the relevant side chains could interfere with Pol-UL42 binding.

scholarly journals Identification of a Motif in the C Terminus of Herpes Simplex Virus Regulatory Protein ICP4 That Contributes to Activation of Transcription

2002 ◽  
Vol 76 (1) ◽  
pp. 195-207 ◽  
Author(s):  
James W. Bruce ◽  
Kent W. Wilcox
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Specific Activity ◽  
Regulatory Protein ◽  
Productive Infection ◽  
Transactivation Domain ◽  
Promoter Activation ◽  
Recombinant Viruses ◽  
C Terminus ◽  
Simplex Virus

ABSTRACT Expression of most viral genes during productive infection by herpes simplex virus is regulated by the viral protein ICP4 (also called IE175 or Vmw175). The N-terminal portion of ICP4 contains well-defined transactivation, DNA binding, and dimerization domains that contribute to promoter regulation. The C-terminal half of ICP4 contributes to the activity of ICP4, but the functional motifs have not been well mapped. To localize functional motifs in the C-terminal half of ICP4, we have compared the relative specific activities of ICP4 variants in transient-transfection assays. Deletion of the C-terminal 56 residues reduces the specific activity more than 10-fold. Mutational analysis identified three consecutive residues (1252 to 1254) that are conserved in ICP4 orthologs and are essential for full activity, especially in the context of ICP4 variants with a deletion in the N-terminal transactivation domain. Recombinant viruses that encode variants of ICP4 with mutations in the N-terminal transactivation domain and/or the extreme C terminus were constructed. The phenotypes of these recombinant viruses support the hypothesis that efficient promoter activation by ICP4 requires motifs at both the N and C termini. The data suggest that the C terminus of ICP4 functions not as an independent transactivation domain but as an enhancer of the ICP4 N-terminal transactivation domain. The data provide further support for the hypothesis that some ICP4 motifs required for promoter activation are not required for promoter repression and suggest that ICP4 utilizes different cellular factors for activation or repression of viral promoters.

scholarly journals The conserved N-terminal domain of herpes simplex virus 1 UL24 protein is sufficient to induce the spatial redistribution of nucleolin

2008 ◽  
Vol 89 (5) ◽  
pp. 1142-1151 ◽  
Author(s):  
Luc Bertrand ◽  
Angela Pearson
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Nuclear Localization ◽  
Nuclear Staining ◽  
Herpes Simplex Virus 1 ◽  
Terminal Domain ◽  
C Terminus ◽  
Simplex Virus ◽  
Cellular Modifications ◽  
A Minor

UL24 is widely conserved among herpesviruses but its function during infection is poorly understood. Previously, we discovered a genetic link between UL24 and the herpes simplex virus 1-induced dispersal of the nucleolar protein nucleolin. Here, we report that in the absence of viral infection, transiently expressed UL24 accumulated in both the nucleus and the Golgi apparatus. In the majority of transfected cells, nuclear staining for UL24 was diffuse, but a minor staining pattern, whereby UL24 was present in nuclear foci corresponding to nucleoli, was also observed. Expression of UL24 correlated with the dispersal of nucleolin. This dispersal did not appear to be a consequence of a general disaggregation of nucleoli, as foci of fibrillarin staining persisted in cells expressing UL24. The conserved N-terminal region of UL24 was sufficient to cause this change in subcellular distribution of nucleolin. Interestingly, a bipartite nuclear localization signal predicted within the C terminus of UL24 was dispensable for nuclear localization. None of the five individual UL24 homology domains was required for nuclear or Golgi localization, but deletion of these domains resulted in the loss of nucleolin-dispersal activity. We determined that a nucleolar-targeting signal was contained within the first 60 aa of UL24. Our results show that the conserved N-terminal domain of UL24 is sufficient to specifically induce dispersal of nucleolin in the absence of other viral proteins or virus-induced cellular modifications. These results suggest that UL24 directly targets cellular factors that affect the composition of nucleoli.

scholarly journals Dual Function of the pUL7-pUL51 Tegument Protein Complex in Herpes Simplex Virus 1 Infection

2016 ◽  
Vol 91 (2) ◽  
Author(s):  
Anna Albecka ◽  
Danielle J. Owen ◽  
Lyudmila Ivanova ◽  
Juliane Brun ◽  
Rukayya Liman ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Virus Assembly ◽  
Focal Adhesions ◽  
Herpes Simplex Virus 1 ◽  
Tegument Proteins ◽  
Infected Cells ◽  
Complex Structural ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT The tegument of herpesviruses is a highly complex structural layer between the nucleocapsid and the envelope of virions. Tegument proteins play both structural and regulatory functions during replication and spread, but the interactions and functions of many of these proteins are poorly understood. Here we focus on two tegument proteins from herpes simplex virus 1 (HSV-1), pUL7 and pUL51, which have homologues in all other herpesviruses. We have now identified that HSV-1 pUL7 and pUL51 form a stable and direct protein-protein interaction, their expression levels rely on the presence of each other, and they function as a complex in infected cells. We demonstrate that expression of the pUL7-pUL51 complex is important for efficient HSV-1 assembly and plaque formation. Furthermore, we also discovered that the pUL7-pUL51 complex localizes to focal adhesions at the plasma membrane in both infected cells and in the absence of other viral proteins. The expression of pUL7-pUL51 is important to stabilize focal adhesions and maintain cell morphology in infected cells and cells infected with viruses lacking pUL7 and/or pUL51 round up more rapidly than cells infected with wild-type HSV-1. Our data suggest that, in addition to the previously reported functions in virus assembly and spread for pUL51, the pUL7-pUL51 complex is important for maintaining the attachment of infected cells to their surroundings through modulating the activity of focal adhesion complexes. IMPORTANCE Herpesviridae is a large family of highly successful human and animal pathogens. Virions of these viruses are composed of many different proteins, most of which are contained within the tegument, a complex structural layer between the nucleocapsid and the envelope within virus particles. Tegument proteins have important roles in assembling virus particles as well as modifying host cells to promote virus replication and spread. However, little is known about the function of many tegument proteins during virus replication. Our study focuses on two tegument proteins from herpes simplex virus 1 that are conserved in all herpesviruses: pUL7 and pUL51. We demonstrate that these proteins directly interact and form a functional complex that is important for both virus assembly and modulation of host cell morphology. Further, we identify for the first time that these conserved herpesvirus tegument proteins localize to focal adhesions in addition to cytoplasmic juxtanuclear membranes within infected cells.

scholarly journals Herpes simplex virus type 1 tegument proteins VP1/2 and UL37 are associated with intranuclear capsids

Virology ◽  
2007 ◽  
Vol 361 (2) ◽  
pp. 316-324 ◽  
Author(s):  
Michelle A. Bucks ◽  
Kevin J. O'Regan ◽  
Michael A. Murphy ◽  
John W. Wills ◽  
Richard J. Courtney
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Virus Type ◽  
Herpes Simplex Virus Type ◽  
Tegument Proteins ◽  
Simplex Virus

scholarly journals Herpes Simplex Virus Type 1 Corneal Infection Results in Periocular Disease by Zosteriform Spread

2001 ◽  
Vol 75 (11) ◽  
pp. 5069-5075 ◽  
Author(s):  
Bretton C. Summers ◽  
Todd P. Margolis ◽  
David A. Leib
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Skin Lesions ◽  
Ocular Infection ◽  
Trigeminal Ganglia ◽  
Corneal Infection ◽  
Recombinant Viruses ◽  
Viral Spread ◽  
Reporter Activity ◽  
Simplex Virus

ABSTRACT In humans and animal models of herpes simplex virus infection, zosteriform skin lesions have been described which result from anterograde spread of the virus following invasion of the nervous system. Such routes of viral spread have not been fully examined following corneal infection, and the possible pathologic consequences of such spread are unknown. To investigate this, recombinant viruses expressing reporter genes were generated to quantify and correlate gene expression with replication in eyes, trigeminal ganglia, and periocular tissue. Reporter activity peaked in eyes 24 h postinfection and rapidly fell to background levels by 48 h despite the continued presence of viral titers. Reporter activity rose in the trigeminal ganglia at 60 h and peaked at 72 h, concomitant with the appearance and persistence of infectious virus. Virus was present in the periocular skin from 24 h despite the lack of significant reporter activity until 84 h postinfection. This detection of reporter activity was followed by the onset of periocular disease on day 4. Corneal infection with a thymidine kinase-deleted reporter virus displayed a similar profile of reporter activity and viral titer in the eyes, but little or no detectable activity was observed in trigeminal ganglia or periocular tissue. In addition, no periocular disease symptoms were observed. These findings demonstrate that viral infection of periocular tissue and subsequent disease development occurs by zosteriform spread from the cornea to the periocular tissue via the trigeminal ganglion rather than by direct spread from cornea to the periocular skin. Furthermore, clinical evidence is discussed suggesting that a similar mode of spreading and disease occurs in humans following primary ocular infection.

scholarly journals A Domain of Herpes Simplex Virus pUL33 Required To Release Monomeric Viral Genomes from Cleaved Concatemeric DNA

2017 ◽  
Vol 91 (20) ◽  
Author(s):  
Kui Yang ◽  
Xiaoqun Dang ◽  
Joel D. Baines
Keyword(s):  
Amino Acids ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Viral Replication ◽  
Dna Cleavage ◽  
Artificial Chromosome ◽  
Viral Dna ◽  
Viral Genomes ◽  
C Terminus ◽  
Simplex Virus

ABSTRACT Monomeric herpesvirus DNA is cleaved from concatemers and inserted into preformed capsids through the actions of the viral terminase. The terminase of herpes simplex virus (HSV) is composed of three subunits encoded by UL15, UL28, and UL33. The UL33-encoded protein (pUL33) interacts with pUL28, but its precise role in the DNA cleavage and packaging reaction is unclear. To investigate the function of pUL33, we generated a panel of recombinant viruses with either deletions or substitutions in the most conserved regions of UL33 using a bacterial artificial chromosome system. Deletion of 11 amino acids (residues 50 to 60 or residues 110 to 120) precluded viral replication, whereas the truncation of the last 10 amino acids from the pUL33 C terminus did not affect viral replication or the interaction of pUL33 with pUL28. Mutations that replaced the lysine at codon 110 and the arginine at codon 111 with alanine codons failed to replicate, and the pUL33 mutant interacted with pUL28 less efficiently. Interestingly, genomic termini of the large (L) and small (S) components were detected readily in cells infected with these mutants, indicating that concatemeric DNA was cleaved efficiently. However, the release of monomeric genomes as assessed by pulsed-field gel electrophoresis was greatly diminished, and DNA-containing capsids were not observed. These results suggest that pUL33 is necessary for one of the two viral DNA cleavage events required to release individual genomes from concatemeric viral DNA. IMPORTANCE This paper shows a role for pUL33 in one of the two DNA cleavage events required to release monomeric genomes from concatemeric viral DNA. This is the first time that such a phenotype has been observed and is the first identification of a function of this protein relevant to DNA packaging other than its interaction with other terminase components.

Sign in / Sign up

Export Citation Format

Share Document