Related Experiment Video
Updated: Aug 26, 2026
Analysis of Group IV Viral SSHHPS Using In Vitro and In Silico Methods
Published on: December 21, 2019
Simultaneous deletion of pseudorabies virus tegument protein UL11 and glycoprotein M severely impairs secondary
Martina Kopp1, Harald Granzow, Walter Fuchs
1Institutes of Molecular Biology. Infectology, Friedrich-Loeffler-Institutes, Federal Research Centre for Virus Diseases of Animals, D-17493 Greifswald-Insel Riems, Germany.
Abstract:
The pseudorabies virus (PrV) proteins UL11, glycoprotein E (gE), and gM are involved in secondary envelopment of tegumented nucleocapsids in the cytoplasm. To assess the relative contributions of these proteins to the envelopment process, virus mutants with deletions of either UL11, gM, or gE as well as two newly constructed mutant viruses with simultaneous deletions of UL11 and gE or of UL11 and gM were analyzed in cell culture for their growth phenotype. We show here that simultaneous deletion of UL11 and gE reduced plaque size in an additive manner over the reduction observed by deletion of only UL11 or gE. However, one-step growth was not further impaired beyond the level of the UL11 deletion mutant. Moreover, in electron microscopic analyses PrV-DeltaUL11/gE exhibited a phenotype similar to that of the UL11 mutant virus. In contrast, plaque formation was virtually abolished by the simultaneous absence of UL11 and gM, and one-step growth was significantly reduced. Electron microscopy showed the presence of huge intracytoplasmic inclusions in PrV-DeltaUL11/gM-infected cells, with a size reaching 3 micro m and containing nucleocapsids embedded in tegument. We hypothesize that UL11 and gM are involved in different steps during secondary envelopment and that simultaneous deletion of both interrupts both processes, resulting in the observed drastic impairment of secondary envelopment.
Insights
Pseudorabies virus (PrV) proteins UL11 and gM are crucial for secondary envelopment. Deleting both UL11 and gM severely impairs PrV replication and causes large cytoplasmic inclusions.
Area of Science:
- Virology
- Cell Biology
- Molecular Biology
Background:
- Pseudorabies virus (PrV) requires specific proteins for secondary envelopment.
- Proteins UL11, glycoprotein E (gE), and gM are implicated in this process.
Purpose of the Study:
- To determine the individual and combined roles of PrV proteins UL11, gE, and gM in viral secondary envelopment.
- To analyze the impact of deleting these proteins on viral growth and morphology.
Main Methods:
- Construction and analysis of PrV deletion mutants (UL11, gE, gM, UL11/gE, UL11/gM).
- Assessment of viral growth phenotype, including plaque size and one-step growth curves.
- Electron microscopy to visualize intracellular viral structures.
Main Results:
- Simultaneous deletion of UL11 and gE had an additive effect on plaque size reduction but did not further impair one-step growth compared to UL11 deletion alone.
- PrV-DeltaUL11/gE showed a similar phenotype to the UL11 deletion mutant in electron microscopy.
- Simultaneous deletion of UL11 and gM virtually abolished plaque formation and significantly reduced one-step growth.
- Massive intracytoplasmic inclusions containing nucleocapsids were observed in PrV-DeltaUL11/gM infected cells.
Conclusions:
- UL11 and gM play distinct roles in different stages of secondary envelopment.
- The combined absence of UL11 and gM severely disrupts the envelopment process, leading to a drastic reduction in viral infectivity.
- These findings highlight the synergistic importance of UL11 and gM in PrV replication.
More Related Videos
Related Concept Videos
01:19Inhibitors of Virion Maturation and Assembly
02:28Leaky Scanning