Formation of vaccinia virus DNA-protein complex in the presence of isatin beta thiosemicarbazone (IBT)
View abstract on PubMed
Summary
Newly synthesized vaccinia virus DNA forms low-density complexes early in infection, unaffected by isatin beta thiosemicarbazone (IBT). IBT treatment at later stages results in abnormal high-density DNA-protein complexes lacking core polypeptides.
Area of Science:
- Virology
- Molecular Biology
- Cell Biology
Background:
- Vaccinia virus is a large DNA virus with a complex replication cycle.
- Understanding the assembly of viral DNA-protein complexes is crucial for comprehending viral replication and pathogenesis.
Purpose of the Study:
- To investigate the dynamic association of newly synthesized vaccinia virus DNA with cellular and viral proteins during infection.
- To determine the effect of isatin beta thiosemicarbazone (IBT) on viral DNA-protein complex formation and maturation.
Main Methods:
- HeLa cells were infected with vaccinia virus.
- Newly synthesized viral DNA-protein complexes were analyzed for density shifts over time using ultracentrifugation.
- The impact of isatin beta thiosemicarbazone (IBT) on complex formation was assessed at different time points post-infection.
Main Results:
- A transition from high-density to low-density DNA-protein complexes was observed between 3 and 6 hours post-infection.
- This density shift was independent of IBT treatment.
- At 22 hours post-infection, mature, high-density virions formed in the absence of IBT.
- In the presence of IBT, high-density DNA-protein complexes lacking key core viral polypeptides were formed.
Conclusions:
- The formation of low-density vaccinia virus DNA-protein complexes is an early event in infection, not dependent on poxvirus growth inhibition.
- Isatin beta thiosemicarbazone (IBT) interferes with the final maturation steps of vaccinia virus assembly, leading to the formation of aberrant DNA-protein complexes deficient in core proteins.