A functionally distinct TATA box required for late progression through the Epstein-Barr virus life cycle

Area of Science:

• Molecular Virology
• Gene Regulation
• Epigenetics

Background:

• Epstein-Barr virus (EBV) infection involves complex regulatory pathways.
• Late gene expression during EBV lytic replication is not fully understood.
• Trans-activation mechanisms controlling viral gene expression require further elucidation.

Purpose of the Study:

• To identify the specific DNA elements and regulatory mechanisms controlling EBV late gene expression.
• To investigate the role of core promoter sequences in EBV BcLF1 gene regulation.
• To understand how lytic DNA replication influences late gene transcription.

Main Methods:

• Promoter analysis of the EBV BcLF1 gene.
• Site-directed mutagenesis to alter the TATA box and flanking regions.
• Reporter gene assays to measure promoter activity.
• Analysis of gene expression in EBV-infected cells.

Main Results:

• A variant TATA box (TATTAAA) and the 3' flanking region of the BcLF1 gene were identified as key regulatory targets.
• The core promoter of the BcLF1 gene exhibits inherent late activity.
• Heterologous enhancers unexpectedly disrupted the late activity of the core promoter.

Conclusions:

• Late gene expression in EBV infection is regulated by specific core promoter sequences.
• The transcriptionally inert environment surrounding the core promoter is crucial for regulating late gene expression.
• This study reveals a novel mechanism for controlling viral late gene transcription during EBV infection.