E2 Tyrosine 102 Regulates MmuPV1 Pathogenesis In Vivo

Area of Science:

• Virology
• Molecular Biology
• Oncology

Background:

• The papillomavirus (PV) life cycle involves infection, maintenance, and amplification.
• The PV E2 protein regulates viral transcription and replication by interacting with viral and host factors.
• Tyrosine 102 in the E2 protein is conserved across several papillomaviruses.

Purpose of the Study:

• To investigate the in vivo role of tyrosine 102 in the MmuPV1 E2 protein during the viral life cycle.
• To determine the impact of phosphorylation at tyrosine 102 on MmuPV1 replication and infectivity.

Main Methods:

• Generated Y102E (phosphorylation mimetic) and Y102F (phosphorylation deficient) MmuPV1 E2 mutants.
• Assessed transcriptional activation and replication capabilities of E2 mutants in cell culture.
• Introduced E2-mutated MmuPV1 genomes into immunocompromised mice to evaluate papilloma development and progeny virus production.

Main Results:

• The Y102F mutant retained transcriptional activation and transient replication abilities.
• The Y102E mutant showed defects in replication but could still associate with E1 and Brd4.
• Only the Y102F mutant induced papilloma development and infectious progeny virus in vivo.

Conclusions:

• Tyrosine 102 in the MmuPV1 E2 protein is not essential for viral replication or infectivity.
• The chemical nature of the amino acid at position 102 influences E2 activity and the MmuPV1 life cycle.
• Conserved residues may not be strictly required, highlighting the adaptability of viral proteins.