Fig 2: Atrazine-induced expression of ATR, ATRIP and phosphorylation of Chk1 (Ser317) in MCF-10A cells. (A) Dose-response of atrazine–induced ATR, ATRIP and p-Chk1. MCF-10A cells (3 × 105) were incubated with the indicated concentrations of atrazine for 6 h and analyzed by Western blot; (B) time course of atrazine-induced ATR, ATRIP and p-Chk1in MCF-10A cells. MCF-10A cells (3 × 105) were treated with 0.1 µg/mL of atrazine for the indicated times and analyzed by Western blot. For each blot, the resulting fold-change of atrazine-mediated ATR, ATRIP and p-Chk1 expression over DMSO untreated controls is provided in the corresponding histogram (n = 3) with the signal normalized to actin as a loading control. * p < 0.05, ** p < 0.01 vs. controls.

Fig 3: ZFP161 mediates the RPA-ATRIP interaction. a, b Chromatin fractionations from HCT116 cells in presence or absence of ZFP161 following 10 mM HU treatment for 2 h were used for immunoblotting with indicated antibodies. c Whole cell lysates from HCT116 cells were used for immunoprecipitation with ZFP161 antibody. d The schema of ZFP161 constructs used to identify the minimal region required for its interaction with RPA32. e HEK293T cells were transfected with S-tagged RPA32 and ZFP161 vectors. After 48 h, the interaction between ZFP161 and RPA32 was determined by immunoprecipitation and immunoblotting with indicated antibodies. f, g Whole cell lysates from HCT116 cells were used for immunoprecipitation with ZFP161 (f), or ATRIP (g) antibodies. h The schema of ZFP161 constructs used to identify the minimal region required for its interaction with ATRIP. i HEK293T cells were transfected with the indicated ZFP161 vectors. Aftter 48 h, ZFP161 and ATRIP interaction was determined by immunoprecipitation and immunoblotting with indicated antibodies. j, k HCT116 cells expressing or lacking ZFP161 were transfected with constructs encoding Myc-ATRIP, ZFP161 (WT) and D3 mutant (j) or T2 mutant (k). Whole cell lysates were immunoprecipitated with Myc antibody and immunoblotted with indicated antibodies. l ZFP161 deficient HCT116 cells were incubated with EdU and HU. Replication fork proteins were isolated by iPOND and immunoblotted with indicated antibodies. m Biotin labeled single fork DNA was incubated with HCT116 whole cell lysates and pulled down with streptavidin beads. The interaction of ATRIP and RPA on DNA was determined by immunoblotting. < : ZPF161 full length and mutants bands. Source data are provided as a Source Data file.