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Updated: Jun 10, 2026

Electrophoretic Analysis of Replication Through Structure-Prone DNA Repeats Within the SV40-Based Human Episome
05:22

Electrophoretic Analysis of Replication Through Structure-Prone DNA Repeats Within the SV40-Based Human Episome

Published on: September 13, 2024

Simian virus 40 activates ATR-Delta p53 signaling to override cell cycle and DNA replication control

Gabor Rohaly1, Katharina Korf, Silke Dehde

  • 1Heinrich-Pette-Institut für Experimentelle Virologie und Immunologie, Martinistr. 52, D-20251 Hamburg, Germany.

Journal of Virology
|August 6, 2010
PubMed

Insights

Simian virus 40 (SV40) exploits the host DNA damage response, specifically the ATR-Δp53-p21 pathway, to promote viral replication. This pathway maintains the host in S phase and generates a specific DNA polymerase form essential for SV40 DNA synthesis.

Area of Science:

  • Virology
  • Molecular Biology
  • Cellular Biology

Background:

  • Simian virus 40 (SV40) infection triggers host defense mechanisms, including the ATM/ATR-mediated DNA damage response.
  • Understanding host-viral interactions is crucial for developing antiviral strategies.

Purpose of the Study:

  • To elucidate the role of the ATR-Δp53-p21 pathway in SV40 replication.
  • To investigate how SV40 manipulates host cell cycle regulation for its own benefit.

Main Methods:

  • Investigated the interaction between ATR, p53 isoform Δp53, p21, and cyclin A-Cdk2/1 (AK) activity during SV40 infection.
  • Analyzed the recruitment of DNA polymerase α-primase (Polα) by SV40 large T antigen (T-Ag).
  • Assessed the impact of ATR-Δp53-p21 signaling inhibition on SV40 replication.

Main Results:

  • ATR directly activates Δp53, upregulating p21 and downregulating AK activity, forcing host cells into S phase.
  • Downregulated AK activity is necessary for generating hypophosphorylated Polα (hypo-Polα), which is recruited by T-Ag for viral DNA replication.
  • Inhibiting the ATR-Δp53-p21 pathway reduced hypo-Polα and SV40 replication efficiency.
  • The pathway promotes proteasomal degradation of non-T-Ag-interacting P-Polα, generating T-Ag-interacting hypo-Polα.

Conclusions:

  • The ATR-Δp53-p21 pathway creates an optimal S-phase environment for SV40 replication.
  • This pathway modulates host DNA replicase, facilitating SV40 amplification.
  • SV40 hijacks host cell cycle control to ensure its own replication and propagation.

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