Herpes Simplex Virus-1 ICP27 Nuclear Export Signal Mutants Exhibit Cell Type-Dependent Deficits in Replication and...

Area of Science:

• Virology
• Molecular Biology
• Cell Biology

Background:

• Herpes simplex virus type-1 (HSV-1) immediate early (IE) protein ICP27 regulates viral gene expression.
• Previous studies on ICP27 mutants primarily used interferon-deficient Vero cells.

Purpose of the Study:

• To investigate the cell type-dependent replication of ICP27 mutants.
• To elucidate the role of ICP27's nuclear export signal (NES) in viral replication and gene expression.

Main Methods:

• Replication analysis of ICP27 mutants in various cell types, including human fibroblasts.
• Assessment of viral DNA replication and gene expression (ICP4, viral RNA).

Main Results:

• ICP27 NES mutants showed cell type-dependent growth, with severe defects in human cells.
• Replication failure in human cells correlated with impaired viral DNA synthesis.
• NES mutants exhibited reduced expression of ICP4 and defects in ICP4 mRNA export.

Conclusions:

• ICP27's NES is essential for HSV-1 replication in most human cell types.
• ICP27 plays a significant role in the early expression of ICP4, impacting viral gene transcription.