The E3 ligase RFWD3 stabilizes ORC in a p53-dependent manner

Abstract

RFWD3 is an E3 ubiquitin ligase that plays important roles in DNA damage response and DNA replication. We have previously demonstrated that the stabilization of RFWD3 by PCNA at the replication fork enables ubiquitination of the single-stranded binding protein, RPA and its subsequent degradation for replication progression. Here, we report that RFWD3 associates with the Origin Recognition Complex (ORC) and ORC-Associated (ORCA/LRWD1), components of the prereplicative complex required for the initiation of DNA replication. Overexpression of ORC/ORCA leads to the stabilization of RFWD3. Interestingly, RFWD3 seems to stabilize ORC/ORCA in cells expressing wild type p53, as the depletion of RFWD3 reduces the levels of ORC/ORCA. Further, the catalytic activity of RFWD3 is required for the stabilization of ORC. Our results indicate that the RFWD3 promotes the stability of ORC, enabling efficient pre-RC assembly.

The PRP19 Ubiquitin Ligase, Standing at the Cross-Roads of mRNA Processing and Genome Stability

“…In this context, the influence of PRP19 and RFWD3 on RPA and likely additional DDR-related substrates may ultimately lead to converging as well as diverging effects on the way various DNA lesions are handled. In this regard, it was recently proposed that RFWD3 interacts with and promotes PCNA ubiquitylation to regulate replication fork progression and translesion synthesis [ 118 , 119 , 120 ]. Whether PRP19 also participates in DNA damage tolerance pathways remains an open question but it is interesting that in yeast, Prp19/Pso4 promotes mitotic recombination while also participating in error-prone repair of DNA lesions [ 29 , 30 , 32 ].…”