Extended Data Fig. 10: Lysine-tryptophan cation-π interactions could be modulated via lysine post-translational modifications.

a) Crystal structure of NPM1 C-terminal domain (PDB: 2llh) with two native tryptophan residues on the surface shown in stick form. b) NPM1 W288 and W290 are located at the C-terminus, which is the RRM domain for nucleic acid binding. c) NPM1 W288, W290, and K248 are highly conserved across diverse species, while K292 only occurs in mammals. d) Western blot after streptavidin enrichment showed that NPM1 labelling is diminished after tryptophan to alanine mutations, establishing the high specificity for Trp-CLiC method for identifying the two hyperreactive tryptophan residues of this protein target. Results are representative of two biological replicates. e) Heat map of acetylation of NPM1 lysine sites upon treatment of diverse HDAC or Sirtuin or CBP/p300 inhibitors indicated that Nicotinamide and Bufexamac could globally inhibit NPM1 de-acetylation, while A-485 could globally inhibit NPM1 acetylation. f) Scheme of proposed mechanisms of three inhibitors. g) Representative images of cells overexpressing NPM1 mutants treated with different inhibitors or stresses. Scale bar: 5 µm.