Related Experiment Videos
Identification of cellular proteins required for simian virus 40 DNA replication
M S Wold1, D H Weinberg, D M Virshup
1Department of Molecular Biology and Genetics, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205.
The Journal of Biological Chemistry
|February 15, 1989
Summary
Researchers identified six essential cellular proteins for SV40 DNA replication using a cell-free system. These proteins, including replication protein-A and proliferating cell nuclear antigen, are crucial for DNA replication initiation and elongation in eukaryotes.
Area of Science:
- Molecular Biology
- Virology
- Biochemistry
Background:
- Understanding eukaryotic DNA replication is vital for cell biology.
- Simian virus 40 (SV40) serves as a model system for studying DNA replication.
- Viral proteins often elucidate cellular replication mechanisms.
Purpose of the Study:
- To identify and characterize cellular proteins essential for SV40 DNA replication in vitro.
- To elucidate the roles of these proteins in the replication process.
Main Methods:
- Utilized a cell-free system for replicating SV40 DNA.
- Performed systematic fractionation-reconstitution experiments on HeLa cytoplasmic extract.
- Purified key replication proteins to near homogeneity.
Main Results:
- Identified six essential cellular proteins and two partially purified fractions (CF IC, CF IIA) required for SV40 replication.
- Replication protein-A (single-stranded DNA binding protein) is crucial for T antigen-dependent unwinding.
- Proliferating cell nuclear antigen, DNA polymerase alpha-primase, and CF IIA are involved in nascent chain elongation.
Conclusions:
- SV40 DNA replication in vitro requires multiple cellular factors beyond viral T antigen.
- Replication protein-A plays a key role in the initiation phase.
- Other identified components are essential for the elongation phase of DNA replication.