TY - JOUR
T1 - Proliferating cell nuclear antigen promotes DNA synthesis past template lesions by mammalian DNA polymerase δ
AU - Mozzherin, Dmitry Ju
AU - Shibutani, Shinya
AU - Tan, Cheng Keat
AU - Downey, Kathleen M.
AU - Fisher, Paul A.
PY - 1997/6/10
Y1 - 1997/6/10
N2 - Consistent with previous observations, proliferating cell nuclear antigen (PCNA) promotes DNA synthesis by calf thymus DNA polymerase δ (pol δ) past several chemically defined template lesions including model abasic sites, 8-oxo-deoxyguanosine (dG) and aminofluorene-dG (but not acetylaminofluorene-dG). This synthesis is potentially mutagenic. The model abasic site was studied most extensively. When all deoxyribonucleoside triphosphates and a template bearing a model abasic site were present, DNA synthesis by pol δ beyond this site was stimulated 53-fold by addition of homologous PCNA. On an unmodified template (lacking any lesions), PCNA stimulated pol δ by 1.3-fold. Product analysis demonstrated that as expected from the 'A-rule,' fully and near-fully extended primers incorporated predominantly dAMP opposite the template lesion. Moreover, corollary primer extension studies demonstrated that in the presence (but not the absence) of PCNA, pol δ preferentially elongated primers containing dAMP opposite the model abasic template site. p21, a specific inhibitor of PCNA-dependent DNA replication, inhibits PCNA-stimulated synthesis past model abasic template sites. We propose that DNA synthesis past template lesions by pol δ promoted by PCNA results from the fundamental mechanism by which PCNA stimulates pol δ, i.e., stabilization of the pol δ-template-primer complex.
AB - Consistent with previous observations, proliferating cell nuclear antigen (PCNA) promotes DNA synthesis by calf thymus DNA polymerase δ (pol δ) past several chemically defined template lesions including model abasic sites, 8-oxo-deoxyguanosine (dG) and aminofluorene-dG (but not acetylaminofluorene-dG). This synthesis is potentially mutagenic. The model abasic site was studied most extensively. When all deoxyribonucleoside triphosphates and a template bearing a model abasic site were present, DNA synthesis by pol δ beyond this site was stimulated 53-fold by addition of homologous PCNA. On an unmodified template (lacking any lesions), PCNA stimulated pol δ by 1.3-fold. Product analysis demonstrated that as expected from the 'A-rule,' fully and near-fully extended primers incorporated predominantly dAMP opposite the template lesion. Moreover, corollary primer extension studies demonstrated that in the presence (but not the absence) of PCNA, pol δ preferentially elongated primers containing dAMP opposite the model abasic template site. p21, a specific inhibitor of PCNA-dependent DNA replication, inhibits PCNA-stimulated synthesis past model abasic template sites. We propose that DNA synthesis past template lesions by pol δ promoted by PCNA results from the fundamental mechanism by which PCNA stimulates pol δ, i.e., stabilization of the pol δ-template-primer complex.
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U2 - 10.1073/pnas.94.12.6126
DO - 10.1073/pnas.94.12.6126
M3 - Article
C2 - 9177181
AN - SCOPUS:0030986238
SN - 0027-8424
VL - 94
SP - 6126
EP - 6131
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 12
ER -