scholarly journals Functional Domains of Murine Cytomegalovirus Nuclear Egress Protein M53/p38

2006 ◽  
Vol 80 (1) ◽  
pp. 73-84 ◽  
Author(s):  
Mark Lötzerich ◽  
Zsolt Ruzsics ◽  
Ulrich H. Koszinowski
Keyword(s):  
Binding Site ◽  
Random Mutagenesis ◽  
Murine Cytomegalovirus ◽  
Homologous Proteins ◽  
Herpes Simplex Virus 1 ◽  
Nuclear Egress ◽  
C Terminus ◽  
Localization Signal ◽  
Definition Of ◽  
Simplex Virus

ABSTRACT Two conserved herpes simplex virus 1 proteins, UL31 and UL34, form a complex at the inner nuclear membrane which governs primary envelopment and nuclear egress of the herpesvirus nucleocapsids. In mouse cytomegalovirus, a member of the betaherpesvirus subfamily, the homologous proteins M53/p38 and M50/p35 form the nuclear egress complex (NEC). Since the interaction of these proteins is essential for functionality, the definition of the mutual binding sites is a prerequisite for further analysis. Using a comprehensive random mutagenesis procedure, we have mapped the M53/p38 binding site of M50/p35 (A. Bubeck, M. Wagner, Z. Ruzsics, M. Lötzerich, M. Iglesias, I. R. Singh, and U. H. Koszinowski, J. Virol. 78:8026-8035). Here we describe a corresponding analysis for the UL31 homolog M53/p38. A total of 72 individual mutants were reinserted into the genome to test the complementation of the lethal M53 null phenotype. The mutants were also studied for colocalization and for coprecipitation with M50/p35. The analysis revealed that the nonconserved N-terminal one-third of M53/p38 provides the nuclear localization signal as an essential function. The collective results for many mutants localized the binding site for M50/p35 to amino acids (aa) 112 to 137. No single aa exchange for alanine could destroy NEC formation, but virus attenuation revealed a major role for aa K128, Y129, and L130. The lethal phenotype of several insertion and stop mutants indicated the functional importance of the C terminus of the protein.

scholarly journals Identification of the Capsid Binding Site in the Herpes Simplex Virus 1 Nuclear Egress Complex and Its Role in Viral Primary Envelopment and Replication

2019 ◽  
Vol 93 (21) ◽  
Author(s):  
Kosuke Takeshima ◽  
Jun Arii ◽  
Yuhei Maruzuru ◽  
Naoto Koyanagi ◽  
Akihisa Kato ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Binding Site ◽  
Nuclear Membrane ◽  
Capsid Proteins ◽  
Herpes Simplex Virus 1 ◽  
Nuclear Egress ◽  
Perinuclear Space ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT During nuclear egress of nascent progeny herpesvirus nucleocapsids, the nucleocapsids acquire a primary envelope by budding through the inner nuclear membrane of infected cells into the perinuclear space between the inner and outer nuclear membranes. Herpes simplex virus 1 (HSV-1) UL34 and UL31 proteins form a nuclear egress complex (NEC) and play critical roles in this budding process, designated primary envelopment. To clarify the role of NEC binding to progeny nucleocapsids in HSV-1 primary envelopment, we established an assay system for HSV-1 NEC binding to nucleocapsids and capsid proteins in vitro. Using this assay system, we showed that HSV-1 NEC bound to nucleocapsids and to capsid protein UL25 but not to the other capsid proteins tested (i.e., VP5, VP23, and UL17) and that HSV-1 NEC binding of nucleocapsids was mediated by the interaction of NEC with UL25. UL31 residues arginine-281 (R281) and aspartic acid-282 (D282) were required for efficient NEC binding to nucleocapsids and UL25. We also showed that alanine substitution of UL31 R281 and D282 reduced HSV-1 replication, caused aberrant accumulation of capsids in the nucleus, and induced an accumulation of empty vesicles that were similar in size and morphology to primary envelopes in the perinuclear space. These results suggested that NEC binding via UL31 R281 and D282 to nucleocapsids, and probably to UL25 in the nucleocapsids, has an important role in HSV-1 replication by promoting the incorporation of nucleocapsids into vesicles during primary envelopment. IMPORTANCE Binding of HSV-1 NEC to nucleocapsids has been thought to promote nucleocapsid budding at the inner nuclear membrane and subsequent incorporation of nucleocapsids into vesicles during nuclear egress of nucleocapsids. However, data to directly support this hypothesis have not been reported thus far. In this study, we have present data showing that two amino acids in the membrane-distal face of the HSV-1 NEC, which contains the putative capsid binding site based on the solved NEC structure, were in fact required for efficient NEC binding to nucleocapsids and for efficient incorporation of nucleocapsids into vesicles during primary envelopment. This is the first report showing direct linkage between NEC binding to nucleocapsids and an increase in nucleocapsid incorporation into vesicles during herpesvirus primary envelopment.

scholarly journals Herpes Simplex Virus 1 UL34 Protein Regulates the Global Architecture of the Endoplasmic Reticulum in Infected Cells

2017 ◽  
Vol 91 (12) ◽  
Author(s):  
Fumio Maeda ◽  
Jun Arii ◽  
Yoshitaka Hirohata ◽  
Yuhei Maruzuru ◽  
Naoto Koyanagi ◽  
...  
Keyword(s):  
Endoplasmic Reticulum ◽  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Null Mutation ◽  
Wild Type ◽  
Herpes Simplex Virus 1 ◽  
Nuclear Egress ◽  
Infected Cells ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT Upon herpes simplex virus 1 (HSV-1) infection, the CD98 heavy chain (CD98hc) is redistributed around the nuclear membrane (NM), where it promotes viral de-envelopment during the nuclear egress of nucleocapsids. In this study, we attempted to identify the factor(s) involved in CD98hc accumulation and demonstrated the following: (i) the null mutation of HSV-1 UL34 caused specific dispersion throughout the cytoplasm of CD98hc and the HSV-1 de-envelopment regulators, glycoproteins B and H (gB and gH); (ii) as observed with CD98hc, gB, and gH, wild-type HSV-1 infection caused redistribution of the endoplasmic reticulum (ER) markers calnexin and ERp57 around the NM, whereas the UL34-null mutation caused cytoplasmic dispersion of these markers; (iii) the ER markers colocalized efficiently with CD98hc, gB, and gH in the presence and absence of UL34 in HSV-1-infected cells; (iv) at the ultrastructural level, wild-type HSV-1 infection caused ER compression around the NM, whereas the UL34-null mutation caused cytoplasmic dispersion of the ER; and (v) the UL34-null mutation significantly decreased the colocalization efficiency of lamin protein markers of the NM with CD98hc and gB. Collectively, these results indicate that HSV-1 infection causes redistribution of the ER around the NM, with resulting accumulation of ER-associated CD98hc, gB, and gH around the NM and that UL34 is required for ER redistribution, as well as for efficient recruitment to the NM of the ER-associated de-envelopment factors. Our study suggests that HSV-1 induces remodeling of the global ER architecture for recruitment of regulators mediating viral nuclear egress to the NM. IMPORTANCE The ER is an important cellular organelle that exists as a complex network extending throughout the cytoplasm. Although viruses often remodel the ER to facilitate viral replication, information on the effects of herpesvirus infections on ER morphological integrity is limited. Here, we showed that HSV-1 infection led to compression of the global ER architecture around the NM, resulting in accumulation of ER-associated regulators associated with nuclear egress of HSV-1 nucleocapsids. We also identified HSV-1 UL34 as a viral factor that mediated ER remodeling. Furthermore, we demonstrated that UL34 was required for efficient targeting of these regulators to the NM. To our knowledge, this is the first report showing that a herpesvirus remodels ER global architecture. Our study also provides insight into the mechanism by which the regulators for HSV-1 nuclear egress are recruited to the NM, where this viral event occurs.

scholarly journals Definition of a major p53 binding site on Ad2E1B58K protein and a possible nuclear localization signal on the Ad12E1B54K protein

Oncogene ◽  
1999 ◽  
Vol 18 (4) ◽  
pp. 955-965 ◽  
Author(s):  
Roger JA Grand ◽  
Julian Parkhill ◽  
Tadge Szestak ◽  
Susan M Rookes ◽  
Sally Roberts ◽  
...  
Keyword(s):  
Binding Site ◽  
Nuclear Localization ◽  
Nuclear Localization Signal ◽  
Localization Signal ◽  
Definition Of

scholarly journals Roles of the Interhexamer Contact Site for Hexagonal Lattice Formation of the Herpes Simplex Virus 1 Nuclear Egress Complex in Viral Primary Envelopment and Replication

2019 ◽  
Vol 93 (14) ◽  
Author(s):  
Jun Arii ◽  
Kosuke Takeshima ◽  
Yuhei Maruzuru ◽  
Naoto Koyanagi ◽  
Akihisa Kato ◽  
...  
Keyword(s):  
Viral Replication ◽  
Lattice Structure ◽  
Hexagonal Lattice ◽  
Contact Site ◽  
Herpes Simplex Virus 1 ◽  
Nuclear Egress ◽  
Infected Cells ◽  
Lattice Formation ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACT During the nuclear export of nascent nucleocapsids of herpes simplex virus 1 (HSV-1), the nucleocapsids acquire a primary envelope by budding through the inner nuclear membrane into the perinuclear space between the inner and outer nuclear membranes. This unique budding process, termed primary envelopment, is initiated by the nuclear egress complex (NEC), composed of the HSV-1 UL31 and UL34 proteins. Earlier biochemical approaches have shown that the NEC has an intrinsic ability to vesiculate membranes through the formation of a hexagonal lattice structure. The significance of intrahexamer interactions of the NEC in the primary envelopment of HSV-1-infected cells has been reported. In contrast, the contribution of lattice formation of the NEC hexamer to primary envelopment in HSV-1-infected cells remains to be elucidated. Therefore, we constructed and characterized a recombinant HSV-1 strain carrying an amino acid substitution in a UL31 residue that is an interhexamer contact site for the lattice formation of the NEC hexamer. This mutation was reported to destabilize the interhexamer interactions of the HSV-1 NEC. Here, we demonstrate that the mutation causes the aberrant accumulation of nucleocapsids in the nucleus and reduces viral replication in Vero and HeLa cells. Thus, the ability of HSV-1 to form the hexagonal lattice structure of the NEC was linked to an increase in primary envelopment and viral replication. Our results suggest that the lattice formation of the NEC hexamer has an important role in HSV-1 replication by regulating primary envelopment. IMPORTANCE The scaffolding proteins of several envelope viruses required for virion assembly form high-order lattice structures. However, information on the significance of their lattice formation in infected cells is limited. Herpesviruses acquire envelopes twice during their viral replication. The first envelop acquisition (primary envelopment) is one of the steps in the vesicle-mediated nucleocytoplasmic transport of nascent nucleocapsids, which is unique in biology. HSV-1 NEC, thought to be conserved in all members of the Herpesviridae family, is critical for primary envelopment and was shown to form a hexagonal lattice structure. Here, we investigated the significance of the interhexamer contact site for hexagonal lattice formation of the NEC in HSV-1-infected cells and present evidence suggesting that the lattice formation of the NEC hexamer has an important role in HSV-1 replication by regulating primary envelopment. Our results provide insights into the mechanisms of the envelopment of herpesviruses and other envelope viruses.

scholarly journals Involvement of the UL24 protein in herpes simplex virus 1-induced dispersal of B23 and in nuclear egress

Virology ◽  
2011 ◽  
Vol 412 (2) ◽  
pp. 341-348 ◽  
Author(s):  
Maria H. Lymberopoulos ◽  
Amélie Bourget ◽  
Nawel Ben Abdeljelil ◽  
Angela Pearson
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Herpes Simplex Virus 1 ◽  
Nuclear Egress ◽  
Simplex Virus

scholarly journals Role of Herpes Simplex Virus 1 Immediate Early Protein ICP22 in Viral Nuclear Egress

2014 ◽  
Vol 88 (13) ◽  
pp. 7445-7454 ◽  
Author(s):  
Y. Maruzuru ◽  
K. Shindo ◽  
Z. Liu ◽  
M. Oyama ◽  
H. Kozuka-Hata ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Immediate Early ◽  
Herpes Simplex Virus 1 ◽  
Nuclear Egress ◽  
Early Protein ◽  
Simplex Virus

scholarly journals Herpes Simplex Virus 1 UL47 Interacts with Viral Nuclear Egress Factors UL31, UL34, and Us3 and Regulates Viral Nuclear Egress

2014 ◽  
Vol 88 (9) ◽  
pp. 4657-4667 ◽  
Author(s):  
Z. Liu ◽  
A. Kato ◽  
K. Shindo ◽  
T. Noda ◽  
H. Sagara ◽  
...  
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Herpes Simplex Virus 1 ◽  
Nuclear Egress ◽  
Simplex Virus

scholarly journals Dominant Negative Mutants of the Murine Cytomegalovirus M53 Gene Block Nuclear Egress and Inhibit Capsid Maturation

2010 ◽  
Vol 84 (18) ◽  
pp. 9035-9046 ◽  
Author(s):  
Mirela Popa ◽  
Zsolt Ruzsics ◽  
Mark Lötzerich ◽  
Lars Dölken ◽  
Christopher Buser ◽  
...  
Keyword(s):  
Unit Length ◽  
Virus Production ◽  
Dominant Negative ◽  
Murine Cytomegalovirus ◽  
Phenotypic Characterization ◽  
Reading Frame ◽  
Viral Capsids ◽  
Gene Block ◽  
Nuclear Egress ◽  
C Terminus

ABSTRACT The alphaherpesvirus proteins UL31 and UL34 and their homologues in other herpesvirus subfamilies cooperate at the nuclear membrane in the export of nascent herpesvirus capsids. We studied the respective betaherpesvirus proteins M53 and M50 in mouse cytomegalovirus (MCMV). Recently, we established a random approach to identify dominant negative (DN) mutants of essential viral genes and isolated DN mutants of M50 (B. Rupp, Z. Ruzsics, C. Buser, B. Adler, P. Walther and U. H. Koszinowski, J. Virol 81:5508-5517). Here, we report the identification and phenotypic characterization of DN alleles of its partner, M53. While mutations in the middle of the M53 open reading frame (ORF) resulted in DN mutants inhibiting MCMV replication by ∼100-fold, mutations at the C terminus resulted in up to 1,000,000-fold inhibition of virus production. C-terminal DN mutants affected nuclear distribution and steady-state levels of the nuclear egress complex and completely blocked export of viral capsids. In addition, they induced a marked maturation defect of viral capsids, resulting in the accumulation of nuclear capsids with aberrant morphology. This was associated with a two-thirds reduction in the total amount of unit length genomes, indicating an accessory role for M53 in DNA packaging.

scholarly journals The Torsin Activator LULL1 Is Required for Efficient Growth of Herpes Simplex Virus 1

2015 ◽  
Vol 89 (16) ◽  
pp. 8444-8452 ◽  
Author(s):  
Elizabeth M. Turner ◽  
Rebecca S. H. Brown ◽  
Ethan Laudermilch ◽  
Pei-Ling Tsai ◽  
Christian Schlieker
Keyword(s):  
Herpes Simplex Virus ◽  
Herpes Simplex ◽  
Genome Engineering ◽  
Phenotypic Analysis ◽  
Double Knockout ◽  
Herpes Simplex Virus 1 ◽  
Aaa Atpase ◽  
Nuclear Egress ◽  
Simplex Virus ◽  
Hsv 1

ABSTRACTTorsinA is a membrane-tethered AAA+ ATPase implicated in nuclear envelope dynamics as well as the nuclear egress of herpes simplex virus 1 (HSV-1). The activity of TorsinA and the related ATPase TorsinB strictly depends on LAP1 and LULL1, type II transmembrane proteins that are integral parts of the Torsin/cofactor AAA ring, forming a composite, membrane-spanning assembly. Here, we use CRISPR/Cas9-mediated genome engineering to create single- and double knockout (KO) cell lines of TorA and TorB as well as their activators, LAP1 and LULL1, to investigate the effect on HSV-1 production. Consistent with LULL1 being the more potent Torsin activator, a LULL1 KO reduces HSV-1 growth by one order of magnitude, while the deletion of other components of the Torsin system in combination causes subtle defects. Notably, LULL1 deficiency leads to a 10-fold decrease in the number of viral genomes per host cell without affecting viral protein production, allowing us to tentatively assign LULL1 to an unexpected role that precedes HSV-1 nuclear egress.IMPORTANCEIn this study, we conduct the first comprehensive genetic and phenotypic analysis of the Torsin/cofactor system in the context of HSV-1 infection, establishing LULL1 as the most important component of the Torsin system with respect to viral production.

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