Fig. 6

N-MYC-P44L phosphorylation status and stability. A Graphical summary of the results of MS peptide analyses. The amino-termini of wild-type and P44L mutant HA-N-MYC are depicted with the corresponding amino acid residues and positions in the top. Blue lines represent peptides identified by MS after digestion with chymotrypsin. Identified protein modifications included phosphorylation (P, in red), oxidation of methionine (O, in yellow), protein N-terminal acetylation (A, in pink) and carbamidomethylation (C, in violet). Dashed boxes indicate the phosphorylated residues identified by MS, corresponding to positions S42, T43, T58 and S62. B Western blot analysis showing phosphorylation status of T58 and S62 in HA-N-MYC. C Immunoblots from protein stability assays of wild-type and mutant HA-N-MYC in stably transfected HEK293 cells. Inhibitor treatment with MG-132 and / or cycloheximide was performed for 0–90 min as indicated. GFP expression is coupled to MYCN via an IRES sequence (see Fig. S5)