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Localization of replicating DNA of simian virus 40 in monkey kidney cells
Abstract:
Approximately 80-85% of the DNA synthesized by cells infected with simian virus 40 during a short pulse with [(3)H]thymidine is associated with host nuclear membrane components, as defined by the M-band technique. A substantial portion of this membrane-associated DNA has been shown to be viral specific by sedimentation studies and by DNA.DNA hybridization. Examination of DNA associated and unassociated with nuclear M-band by neutral sucrose gradient analysis suggested that while replicating DNA of simian virus 40 is attached to the nuclear membrane, mature component I DNA of simian virus 40 is released from the membrane upon completion of replication.
Insights
Simian virus 40 DNA replication occurs at the host cell's nuclear membrane. Newly synthesized viral DNA remains membrane-associated, but mature DNA detaches after replication.
Area of Science:
- Molecular Biology
- Virology
- Cell Biology
Background:
- Simian virus 40 (SV40) is a DNA tumor virus.
- Viral DNA replication is a critical process in the viral life cycle.
- Understanding the localization of viral DNA synthesis provides insights into replication mechanisms.
Purpose of the Study:
- To investigate the association of newly synthesized simian virus 40 DNA with host cell nuclear membranes.
- To determine the localization of replicating and mature viral DNA during the infection process.
Main Methods:
- Short pulse labeling of infected cells with [(3)H]thymidine.
- Isolation of host nuclear membrane components using the M-band technique.
- Analysis of DNA association with M-band components.
- Sedimentation studies and DNA.DNA hybridization to identify viral DNA.
- Neutral sucrose gradient analysis to differentiate DNA forms.
Main Results:
- 80-85% of newly synthesized simian virus 40 DNA associates with host nuclear membrane components.
- A significant portion of this membrane-associated DNA is confirmed as viral DNA.
- Replicating SV40 DNA is attached to the nuclear membrane.
- Mature component I SV40 DNA is released from the membrane post-replication.
Conclusions:
- The host cell nuclear membrane serves as a site for simian virus 40 DNA replication.
- Viral DNA undergoes a transition from membrane-bound replicating forms to released mature forms.