Co-localization in replication foci and interaction of human Y-family members, DNA polymerase polh and Rev1 protein

The progress of replicative DNA polymerases along the replication fork may be impeded by the presence of lesions in the genome. One way to circumvent such hurdles involves the recruitment of specialized DNA polymerases that perform limited incorporation of nucleotides in the vicinity of the damaged site. This process entails DNA polymerase switch between replicative and specialized DNA polymerases. Five eukaryotic proteins can carry out translesion synthesis (TLS) of damaged DNA in vitro, DNA polymerases ?, ?, ?, and ?, and REV1. To identify novel proteins that interact with hpol?, we performed a yeast two-hybrid screen. In this paper, we show that hREV1 interacts with hpol? as well as with hpol? and poorly with hpol?. Furthermore, cellular localization analysis demonstrates that hREV1 is present, with hpol? in replication factories at stalled replication forks and is tightly associated with nuclear structures. This hREV1 nuclear localization occurs independently of the presence of hpol?. Taken together, our data suggest a central role for hREV1 as a scaffold that recruits DNA polymerases involved in TLS.