Fig 1: NELF complex interact with G4 structures and modulates the cellular response to G4 ligands. (A) MS-based quantitative proteomic analysis of the interaction of the NELF-complex proteins with contrained-G4 structures (extracted from Supplementary Table 1). Differentially interacting proteins were sorted out using a fold change ≥ 2 and p-value < 0.05, allowing to reach a false discovery rate (FDR) inferior to 5% according to the Benjamini–Hochberg procedure. (B) Quantification of the interaction of immunoprecipitated Flag NELF-E protein with constrained G4 structures (1a, 2) relative to cyclopeptide (CP-T23) and duplex control (8) constructions. Error bars represent SD from the means, n ≥ 3 independent experiments. p values were calculated using unpaired t-tests (without corrections for multiple comparisons). ns: p > 0.05; *: p < 0.05; **: p < 0.01; ***: p < 0.001; ****: p < 0.0001. ns non-significant difference. (C) Quantification and representative images γH2AX foci fluorescence signal (red) detected HeLa cells transfected with control (Ctrl), or two NELF-E siRNAs (independent sequences) and treated with PDS (20 µM) for 4 h. Error bars represent SD from the means, n ≥ 3 independent experiments. p values were calculated using an unpaired multiple Student’s t test. ns: p > 0.05; *: p < 0.05; **: p < 0.01; ***: p < 0.001; ****: p < 0.0001signals. Western-blotting analysis of NELF-E depletion in HeLa cells following siRNA treatment is shown.