Does butylphenyl-deoxyguanosine triphosphate differentially inhibit DNA polymerase alpha and delta activities in permeabilized HeLa cells?
In eukaryotic cells, two enzymes, DNA polymerases alpha and delta, are thought to play major roles in DNA synthesis. I have used butylphenyl dGTP (BuPdGTP), a potent inhibitor of purified DNA polymerase alpha, to assess the relative activities of these enzymes in two permeabilized cell systems. In both instances BuPdGTP eliminated all of the activity which was sensitive to aphidicolin. However, no conditions were found where BuPdGTP preferentially inhibited the synthesis of Okazaki fragments--the presumed products of DNA polymerase alpha activity. This implies that DNA polymerase activities on the two sides of the replication fork are unable to operate independently, being just two elements of the integrated replication machinery that undertakes DNA synthesis in permeabilized cells.
Jackson
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Sir William Dunn School of Pathology, University of Oxford, UK.
D002463:Cell Membrane Permeability; D004256:DNA Polymerase I / Q000037:antagonists & inhibitors*; D004257:DNA Polymerase II / Q000037:antagonists & inhibitors*; D004261:DNA Replication / Q000187:drug effects*; D003848:Deoxyguanine Nucleotides / Q000494:pharmacology*; D006367:HeLa Cells / Q000201:enzymology*; D006801:Humans; D006982:Hypertonic Solutions; D007700:Kinetics
D003848:Deoxyguanine Nucleotides; D006982:Hypertonic Solutions; C040364:N(2)-(4-n-butylphenyl)-2'-deoxyguanosine 5'-triphosphate; D004256:DNA Polymerase I; D004257:DNA Polymerase II