Rad18 (D2B8) XP^® Rabbit mAb #9040

DNA damage, if not repaired, can lead to genome instability and tumorigenesis. Eukaryotic cells use multiple (sometimes overlapping) signaling pathways to respond to agents that cause various types of DNA lesions. Downstream molecules in DNA repair pathways converge on the sites of DNA damage, resulting in cell cycle arrest and repair or apoptosis (1). Rad18 is an E3 ubiquitin ligase recruited to sites of DNA damage. Along with the E2 ubiquitin ligase Rad6, Rad18 is responsible for monoubiquitination of DNA damage proteins including the replication clamp PCNA and the Fanconi anemia core protein FANCD2. Monoubiquitination of these proteins signals to downstream effector molecules and results in the repair of either post-replication repair lesions via the translesion synthesis (TLS) pathway or DNA double strand breaks via homologous recombination (2-4). Phospho-proteomic studies indicate that Ser403 of Rad18 may be phosphorylated by ATM/ATR in response to DNA damage-inducing agents (5,6).