Related Experiment Videos
The papillomavirus E8-E2C protein represses DNA replication from extrachromosomal origins
Thomas Zobel1, Thomas Iftner, Frank Stubenrauch
1Sektion Experimentelle Virologie, Institut für Medizinische Virologie und Epidemiologie der Viruskrankheiten, Universitätsklinikum Tübingen, Elfriede-Aulhorn-Strasse 6, D-72076 Tübingen, Germany.
Molecular and Cellular Biology
|October 31, 2003
Summary
High-risk human papillomaviruses (HPV) use viral proteins to control DNA replication, unlike Epstein-Barr Virus (EBV). A novel repressor domain in HPV E8-E2C protein inhibits viral DNA replication, offering potential therapeutic targets.
Area of Science:
- Virology
- Molecular Biology
- Oncology
Background:
- Persistent infections by carcinogenic DNA viruses like HPV and EBV involve low-copy-number plasmid replication.
- EBV DNA replication is regulated by host cell licensing, while HPV replication relies on viral proteins E2 and E8-E2C.
Purpose of the Study:
- To investigate the mechanism of HPV genome copy number control by viral proteins.
- To identify novel viral replication repressor domains and assess their potential as therapeutic targets.
Main Methods:
- Analysis of HPV31 mutant genomes to identify residues critical for E8-E2C function.
- Domain swap experiments to isolate and test the repressor activity of E8-E2C domains.
- Construction and testing of E8-E2C fusion proteins to evaluate their effect on viral replication.
Main Results:
- Residues outside the DNA-binding domain of HPV E8-E2C are crucial for limiting viral DNA replication.
- The N-terminal 21 amino acids of E8-E2C constitute a transferable DNA replication repressor domain.
- This E8-E2C repressor domain inhibits EBV's extrachromosomal replication origin, suggesting a general repressor function.
Conclusions:
- HPV copy number control is independent of cellular licensing and relies on specific viral protein domains.
- The E8-E2C repressor domain represents a novel mechanism for controlling viral DNA replication.
- This discovery holds promise for developing new therapies against persistent DNA tumor virus infections.