High-mobility group protein A1 binds herpes simplex virus gene regulatory sequences and affects their expression

Area of Science:

• Molecular Biology
• Virology
• Epigenetics

Background:

• High-mobility group protein A1 (HMGA1) is a chromatin architectural protein regulating mammalian gene expression.
• Herpes simplex virus type 1 (HSV-1) gene expression is tightly controlled by viral and host factors.
• Understanding host-viral interactions is crucial for deciphering viral replication and pathogenesis.

Purpose of the Study:

• To investigate the binding of HMGA1 to HSV-1 regulatory regions.
• To determine the role of HMGA1 in modulating HSV-1 gene expression.
• To elucidate the influence of host chromatin proteins on viral transcription.

Main Methods:

• In vitro and in vivo binding assays to detect HMGA1 and viral protein interactions with HSV-1 DNA.
• Transient expression experiments to assess the effect of HMGA1 on viral gene transactivation.
• Analysis of HMGA1's impact on the function of viral transactivators like ICP4 and ICP0.

Main Results:

• HMGA1 binds to promoter regions of HSV-1 immediate early, early (tk), and late (gC) genes.
• HMGA1 enhances the in vitro binding of the major HSV-1 regulatory protein, Infected cell polypeptide (ICP) 4.
• HMGA1 modifies the effects of ICP4 and ICP0 on viral gene expression in a promoter-specific manner, without affecting VP16 transactivation.

Conclusions:

• Host-cell architectural chromatin proteins like HMGA1 can interact with viral DNA regulatory elements.
• HMGA1 influences the interplay between host and viral transcription factors during HSV-1 infection.
• These findings highlight a novel mechanism by which host factors modulate viral gene expression and potentially HSV-1 pathogenesis.