Extended Data Fig. 5: The LIG1/FEN1:WDR48-USP1 genetic interactions involve the enzymatic activities of LIG1, FEN1, and USP1.
From: Comprehensive interrogation of synthetic lethality in the DNA damage response
a, All genetic interactions of LIG1 identified in the SPIDR screen. b-c, Quantification of dual-color competitive growth assays with the indicated (DOX)-inducible FEN1 and LIG1 cDNAs. Dox concentration, 0.5 μg ml−1. Day 3 values are shown. Unpaired, two-tailed Student’s t-test. d, Western blots validating FEN1 and LIG1 cDNA expression (n = 1). e, Flow cytometric quantifications of the genetic interactions between FEN1/LIG1 and the genes encoding the WDR48-interacting proteins USP1, USP12, and USP46. Values acquired on day 14 and day 18 are shown respectively. f, Quantification of competitive growth assays with cells transduced with the indicated sgRNAs. Cell populations were monitored by flow cytometry after a 12-day treatment with DMSO or USP1i (KSQ-4279, 6 μM). g, Left: Dual-color flow cytometry for the LIG1:WDR48 interaction in cells expressing CTRL or FANCL sgRNA. Right: RT-qPCR data showing relative mRNA expression of FANCL in sgCTRL and sgFANCL cells. h, Quantification of competitive growth assays with cells transduced with the indicated sgRNAs. Cell populations were monitored by flow cytometry after a 10-day treatment with DMSO or FEN1i (10 μM). i, Clonogenic survival assay of cells transduced with either a CTRL or RAD18 sgRNA. Cells were cultured for 10 days in the presence of DMSO, FEN1i (5 μM) and/or the USP1 inhibitor KSQ-4279 (2 μM). Data are representative of two experimental replicates. j-k, The indicated cells were treated with KSQ-4279 (25 μM, 24 h), and cells lysates were subjected to diGly capture proteomics. The fold change of individual ubiquitylated peptides is shown. Three technical replicates are shown for b, c & e-h. Error bars represent mean ± s.d.
