Assays

Parental and ITCH KO HeLa cells were cultured in lysine- and arginine-free DMEM supplemented with dialyzed FBS, 2 mM L-glutamine, 1 mM sodium pyruvate, penicillin/streptomycin and light (K0) lysine (38 μg/mL) and arginine (66 μg/ml). Heavy medium was the same except the light lysine was replaced with K8-lysine (L-Lysine, 2HCl U-13C U-15N, Cambridge Isotope Laboratories Inc). All cells were treated for 1 h with 1mM LLOMe (Sigma). Subsequently, cells were processed as described before (Fiskin et ...