Fig. 4

Methylation of PCNA by EZH2. a Pan-lysine methylation of PCNA in hDPCs (S phase) and 293T cells was demonstrated with IP and IB. b IP shows the pan-lysine methylation status of PCNA after knocking down EZH2. c The pan-lysine methylation of PCNA after overexpressing EZH2 or EZH2 ∆SET in 293T cells. d Mass spectrometry analysis of trypsin-digested PCNA by LC–MS/MS. PCNA proteins were immunoprecipitated with anti-PCNA antibody from EZH2-overexpressing 293T cells. The tandem mass-fragmentation spectrum represents the PCNA peptide containing residues 92–110. A mass shift of + 28 was observed. IgGs were used as control antibodies for IP. Antibodies used for IP and western blot are labelled as IP and IB, respectively. Total lysate (10 μg) was used as an input control