Figure 3.
Lysine 632 of the AR is methylated by SET9. (A) Left panel: 3H-SAM methylation assay incorporating SET9 and wild-type or point mutants of AR623–640 peptides. Right panel: mass spectrometry analysis of AR peptide (623–640) with (+SET9) and without (−SET9) SET9-mediated methylation. Numbers in italics represent detected fragments in the spectra. A shift of 14 Da at lysine 632 represents methylation and is apparent in both γ and β ion analysis. (B) HEK293T cells transiently transfected with Flag-tagged SET9 and AR or ARK632R were subject to IP using an anti-AR antibody followed by western analysis using anti-Flag and anti-pan-methyl-lysine antibodies.