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Post-replicative base excision repair in replication foci

Authors :
Oddmund Bakke
Per Arne Aas
Kristin Solum Steinsbekk
Emma Warbrick
Mansour Akbari
Terje Haug
Marit Otterlei
Hans E. Krokan
Toril A. Nagelhus
Geir Slupphaug
Publication Year :
1999

Abstract

Base excision repair (BER) is initiated by a DNA glycosylase and is completed by alternative routes, one of which requires proliferating cell nuclear antigen (PCNA) and other proteins also involved in DNA replication. We report that the major nuclear uracil-DNA glycosylase (UNG2) increases in S phase, during which it co-localizes with incorporated BrdUrd in replication foci. Uracil is rapidly removed from replicatively incorporated dUMP residues in isolated nuclei. Neutralizing antibodies to UNG2 inhibit this removal, indicating that UNG2 is the major uracil-DNA glycosylase responsible. PCNA and replication protein A (RPA) co-localize with UNG2 in replication foci, and a direct molecular interaction of UNG2 with PCNA (one binding site) and RPA (two binding sites) was demonstrated using two-hybrid assays, a peptide SPOT assay and enzyme-linked immunosorbent assays. These results demonstrate rapid post-replicative removal of incorporated uracil by UNG2 and indicate the formation of a BER complex that contains UNG2, RPA and PCNA close to the replication fork.

Details

Language :
English
Database :
OpenAIRE
Accession number :
edsair.doi.dedup.....6fafea0c820444e73d9825ddb522dadd