DNA Replication Arrest and DNA Damage Responses Induced by Alkylating Minor Groove Binders

摘要

Alkylating minor groove DNA binder adozelesin is capable of inhibiting DNA replication in treated cells through a trans-acting mechanism. The trans-acting replication factor that becomes deficient upon the action of adozelesin has been identified as replication protein A (RPA). Loss of RPA function can be caused by two possible mechanisms: RPA inactivation and/or loss RPA protein. To study the possibility of RPA inactivation, we purified large amount of RPA from adozelesin-treated cells and examined its function in RPA- dependent as says. We found that RPA purified from cells treated with adozelesin has the same single-stranded DNA binding activity and support nucleotide excision repair as normal RPA, but is not able to support SV40 DNA replication in vitro. Using purified proteins in DNA replication initiation assays, we found that RPA purified from cells treated with adozelesin in not able to be involved in the functional interaction with DNA polymerase 0:/primase and SV40 large T antigen.