Title: The ubiquitin ligase CRL4-Cdt2 targets thymine DNA glycosylase for destruction during DNA replication and repair
Description: The E3 ubiquitin ligase CRL4Cdt2 targets proteins for destruction during DNA replication and following DNA damage (Havens and Walter, 2011). Its substrates contain "PIP degrons" that mediate substrate binding to the processivity factor PCNA at replication forks and damage sites. The resulting PCNA-PIP degron complex forms a docking site for CRL4Cdt2, which ubiquitylates the substrate on chromatin. Several CRL4Cdt2 substrates are known, including Cdt1, multiple CDK inhibitors, Drosophila E2f1, human Set8, S. pombe Spd1, and C. elegans Polη (Havens and Walter, 2011). An emerging theme is that CRL4Cdt2 targets proteins whose presence in S phase is toxic.