Aphidicolin inhibits eukaryotic DNA replication and repair — Implications for involvement of DNA polymerase α in both processes

Normal human lymphocytes were stimulated with phytohemagglutinin or treated with UV radiation or N-methyl-N′-nitro-N-nitroso guanidine then rendered permeable to exogenously supplied nucleotides and used to measure the replicative and repair modes of DNA synthesis. Aphidicolin, N-ethyl maleimide and several other compounds inhibited both DNA replication and repair. Since aphidicolin and N-ethyl maleimide are selective inhibitors of DNA polymerase α, these findings suggest that DNA polymerase α is involved in both the replicative and repair modes of DNA synthesis.