Inhibition of DNA replication by an anti-PCNA aptamer/PCNA complex.

ABSTRACT: Proliferating cell nuclear antigen (PCNA) is a multifunctional protein present in the nuclei of eukaryotic cells that plays an important role as a component of the DNA replication machinery, as well as DNA repair systems. PCNA was recently proposed as a potential non-oncogenic target for anti-cancer therapy. In this study, using the Systematic Evolution of Ligands by EXponential enrichment (SELEX) method, we developed a short DNA aptamer that binds human PCNA. In the presence of PCNA, the anti-PCNA aptamer inhibited the activity of human DNA polymerase ? and ? at nM concentrations. Moreover, PCNA protected the anti-PCNA aptamer against the exonucleolytic activity of these DNA polymerases. Investigation of the mechanism of anti-PCNA aptamer-dependent inhibition of DNA replication revealed that the aptamer did not block formation, but was a component of PCNA/DNA polymerase ? or ? complexes. Additionally, the anti-PCNA aptamer competed with the primer-template DNA for binding to the PCNA/DNA polymerase ? or ? complex. Based on the observations, a model of anti-PCNA aptamer/PCNA complex-dependent inhibition of DNA replication was proposed.

SUBMITTER: Kowalska E 

PROVIDER: S-EPMC5758903 | biostudies-other | 2018 Jan

REPOSITORIES: biostudies-other