Fig. 1: RIF1-L-dependent resistance against replication stress requires Serine 2265.

A Schematic diagram of human RIF1 gene with magnified view of C-terminal region. Exons are represented by boxes. Alternative splicing produces two protein isoforms, RIF1-Short (S) and RIF1-Long (L). Exon 31 is spliced out from RIF1-S while included in RIF1-L mRNA. B Schematic diagram of the two RIF1 protein isoforms. RIF1-L Exon 31 is represented by pink box. Protein phosphatase 1-interacting sites are represented by purple bars. RIF1-L-APKF mutant has RIF1-L Ser2265 residue mutated to Ala. C Protein sequence conservation of RIF1-L Exon 31. D–F Colony formation assay of Flp-In T-REx 293 cells expressing indicated RIF1 constructs. Cells were treated with siRIF1 to deplete endogenous RIF1, and then cultured in Doxycycline-containing medium for induction of ectopic GFP-RIF1 constructs. After treatment with replication inhibitors hydroxyurea (HU), aphidicolin (APH) or camptothecin (CPT), cells were grown for seven days and colony number was counted. Survival percentage values are normalised to the no drug treatment control. Means and standard errors of technical triplicates (n = 3) are plotted. Source data are provided as a Source Data file.