Replication timing regulatory factor 1 (RIF1)

Replication timing regulatory factor 1 (RIF1) is a multifunctional, chromatin-associated protein that plays a central role in the regulation of DNA replication timing, repair of DNA double-strand breaks, maintenance of genome stability, and modulation of higher-order chromatin architecture[1][2][3][4]. RIF1 was originally discovered in yeast as a regulator of telomere length and later recognized in mammals for its key roles in controlling when and where DNA replication is initiated during S phase by organizing chromatin loop domains and recruiting protein phosphatase 1 (PP1) to reverse activating phosphorylation events on replication origins[2][5][6]. During DNA damage, RIF1 localizes to sites of double-strand breaks and, through interaction with TP53BP1, promotes non-homologous end joining (NHEJ) over homologous recombination by protecting DNA ends[1][3][4]. In addition, RIF1 is implicated in the transcriptional regulation of gene clusters and is overexpressed in embryonic stem cells, where it maintains stemness and influences differentiation[1][2]. Dysregulation or loss of RIF1 leads to defects in replication timing, abnormal DNA repair, genomic instability, and has been linked to cancer and other diseases characterized by defective genome maintenance[3]. No direct pharmacological inhibitors or clinical drugs are documented to target RIF1 as of now.

Other names

Telomere-associated protein RIF1Rap1-interacting factor 1 homologRAP1 interacting factor homologFLJ12870FLJ10599RIF1