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Temporal Analysis of the Nuclear-to-cytoplasmic Translocation of a Herpes Simplex Virus 1 Protein by Immunofluorescent Confocal Microscopy
Published on: November 4, 2018
Structural determinants for nuclear envelope localization and function of pseudorabies virus pUL34.
Franziska Schuster1, Barbara G Klupp, Harald Granzow
1Institutes of Molecular Biology, Friedrich-Loeffler-Institut, Greifswald-Insel Riems, Germany.
Journal of Virology
|December 14, 2011
Summary
Pseudorabies virus (PrV) pUL34 protein localization and function depend on its C-terminal domain. Chimeric proteins show that specific regions of pUL34 are crucial for nuclear egress and pUL31 binding.
Area of Science:
- Virology
- Molecular Biology
- Cell Biology
Background:
- Herpesvirus nuclear egress relies on the pUL34 and pUL31 protein complex at the inner nuclear membrane (INM).
- Pseudorabies virus (PrV) pUL34 is a type II membrane protein with structural similarities to cellular INM proteins.
Purpose of the Study:
- To investigate the functional relevance of specific domains within PrV pUL34 for its localization and role in nuclear egress.
- To identify which regions of pUL34 are essential for interaction with pUL31 and viral replication.
Main Methods:
- Construction of chimeric proteins by exchanging domains of PrV pUL34 with homologous regions from cellular INM proteins (Lap2ß, Emerin).
- Assessment of chimeric protein function through complementation assays in PrV-ΔUL34 mutants.
- Analysis of pUL31 binding to chimeric proteins.
Main Results:
- Chimeric proteins with substituted transmembrane (TM) regions and C-terminal domains complemented the replication defect of PrV-ΔUL34.
- Partial replacement of the C-terminus (50 aa) reduced but did not abolish complementation.
- Complete replacement of the C-terminus (100 aa) resulted in a nonfunctional protein, despite retained pUL31 binding.
- N-terminal domain replacement did not affect localization but abrogated pUL31 binding and function.
Conclusions:
- The C-terminal region of PrV pUL34, particularly beyond the TM domain, is critical for its function in nuclear egress.
- While pUL31 binding is necessary, it is not sufficient for pUL34 function, indicating other roles for the C-terminal domain.
- Specific domains of pUL34 dictate its localization and interaction with viral and cellular components for efficient herpesvirus replication.
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