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Cycloheximide inhibits cellular, but not SV40, DNA replication
D Schulte1, R Knippers, T Dreier
1Fakultät für Biologie, Universität Konstanz, Germany.
FEBS Letters
|March 9, 1992
Summary
Cycloheximide inhibits cellular DNA replication by blocking essential functions. Simian virus-40 (SV40) DNA replication, however, remains resistant, suggesting T antigen performs these functions for the virus.
Area of Science:
- Molecular Biology
- Virology
- Cell Biology
Background:
- Simian virus-40 (SV40) DNA replication requires both viral and cellular factors.
- Cycloheximide is a known inhibitor of protein synthesis in eukaryotic cells.
Purpose of the Study:
- To investigate the differential effects of cycloheximide on SV40 DNA replication versus cellular DNA replication.
- To elucidate the role of cellular functions in SV40 DNA replication.
Main Methods:
- Preparation of cell extracts from cycloheximide-treated cells.
- In vitro replication assays using SV40 DNA and large T antigen.
- In vivo analysis of DNA replication using DNA fiber autoradiography and alkaline sucrose gradient centrifugation.
Main Results:
- Cycloheximide-treated cell extracts supported SV40 DNA replication in vitro when supplemented with large T antigen.
- SV40 DNA replication in vivo exhibited greater resistance to cycloheximide than cellular DNA replication.
- Cycloheximide treatment suppressed cellular replicon initiation and reduced replication fork movement rate.
Conclusions:
- SV40 T antigen likely performs essential cellular functions that are blocked by cycloheximide during cellular DNA replication.
- This highlights a critical dependency of cellular DNA replication on protein synthesis, which is bypassed by SV40.
- The findings provide insights into the distinct mechanisms governing viral and cellular DNA replication.