Figure 3: CtIP protein turnover is impaired in KLHL15 knockout cells.

(a) Lysates from a stable HEK293^Cas9 wild-type (wt) cell clone or from six different HEK293^Cas9 cell clones generated with the same sgRNA targeting KLHL15 (see Supplementary Fig. 3a) were subjected to western blotting with the indicated antibodies. (b) Total (T) cell extracts and chromatin-enriched (Chr.) fractions of HEK293^Cas9/wt and HEK293^{Cas9/KLHL15Δ} cells were analysed by immunoblotting using the indicated antibodies. (c) Same cells as in b were either mock-treated, treated with CHX (100 μg ml⁻¹) or MG-132 (20 μM) for the indicated time points and lysates were subjected to western blotting with the indicated antibodies (upper panel). SE and LE; short- and long-exposure times of the same immunoblot. Relative CtIP protein levels were determined by quantification of CtIP band intensity (normalized to TFIIH) with the ImageJ software (lower panels). Data are represented as mean values of densitometric quantification±s.e.m. (n=3).