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Published on: July 16, 2012
Complex roles for proliferating cell nuclear antigen in restricting human cytomegalovirus replication
Pierce Longmire1,2,3, Olivia Daigle4,5, Sebastian Zeltzer3
1Graduate Program in Molecular Medicine, University of Arizona, Tucson, Arizona, USA.
Mbio
|March 25, 2025
Summary
Proliferating cell nuclear antigen (PCNA) restricts human cytomegalovirus (HCMV) replication by influencing viral genome diversity. PCNA
Area of Science:
- Virology and Molecular Biology
- DNA Replication and Repair Mechanisms
Background:
- Human cytomegalovirus (HCMV) utilizes host DNA repair pathways for viral DNA synthesis.
- Specialized host DNA polymerases and proliferating cell nuclear antigen (PCNA) are recruited for HCMV replication.
- The precise role of PCNA in HCMV infection remains incompletely understood.
Purpose of the Study:
- To elucidate the function of PCNA in HCMV replication and viral genome regulation.
- To investigate the impact of PCNA modification, specifically monoubiquitination (mUb) at lysine 164 (K164), on viral processes.
- To differentiate PCNA-dependent and -independent roles of translesion synthesis (TLS) polymerases on viral DNA.
Main Methods:
- Analysis of PCNA modification levels (mUb-PCNA) during HCMV infection.
- Assessment of PCNA's role in viral genome integrity and diversity (structural variants, single nucleotide variants).
- Depletion studies to evaluate the impact of PCNA on viral DNA rearrangements.
Main Results:
- Monoubiquitinated PCNA (mUb-PCNA) levels increase during HCMV infection and are required for PCNA-mediated restriction of viral replication.
- PCNA promotes single nucleotide variants (SNVs) on viral DNA, a function distinct from its role in genome integrity.
- PCNA depletion does not lead to large-scale viral DNA rearrangements, suggesting separable functions from TLS polymerases.
Conclusions:
- PCNA acts as a complex restriction factor for HCMV, with distinct roles in regulating viral genome diversity.
- Host translesion synthesis (TLS) polymerases exhibit PCNA-dependent and -independent functions on viral DNA.
- These findings expand the understanding of host DNA synthesis and repair proteins hijacked during HCMV infection.
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