Fig. 4: Pharmacological disruption of SHOC2–RAS PPI.
From: Targeting the SHOC2–RAS interaction in RAS-mutant cancers
a, Representation of SHOC2 bound to peptide 4 (light violet surface; PDB: 9BTN), compound (R)-5 (yellow spheres; PDB: 9OVJ) and NRAS(Q61R) (grey; PDB: 9BTM). Key regions of overlap highlight the RAS binding site on the concave face as uniquely ligandable on the SHOC2 surface. b, Top, compound (R)-5 interacts with R223 and Q269 via its carboxylic acid. Middle, benzo[d]oxazol-2(3H)-one mediates three hydrogen bonds. Bottom, aliphatic regions in multiple side chains form a shallow hydrophobic patch bound by the chloro-diphenyl moiety of (R)-5. Colours as in a. c, Top, TR-FRET data for the interaction between NRAS(Q61R) and SHOC2 in the presence of varying concentrations of compounds 1 (grey) or 6 (blue). Data represent two technical replicates. Bottom, table summarizing the slope and IC50 values (more repeats are shown in Table 1). d, NanoBiT results showing the compound 6 cellular displacement of SHOC2–NRAS(Q61mut) PPI versus a control pair (mean ± s.d., n = 3 biologically independent samples). e, Lysates from MELJUSO cells treated for 24 h with increasing doses of compound 6 and immunoblotted with the indicated antibodies. f, Lysates from MELJUSO (left) and A375 (right) cells treated with compound 6 (30 µM) and collected at different time points were immunoblotted with the indicated antibodies. g, Densitometry quantification of pCRAF/CRAF and pERK/ERK levels from the MELJUSO immunoblot in f. The images in e–g are representative of two independent experiments. h, Differences in 3D cell growth between MELJUSO (top) and A375 (bottom) BRAF cells treated twice a week with DMSO or compound 6 over time (mean ± s.d. from n = 6 biologically independent replicates). Graphs are representative of two independent experiments. i, Changes in mRNA expression of RAS/MAPK-induced genes and control genes (RPS14, NRAS and SHOC2) in MELJUSO cells treated with compound 6 or 7 versus DMSO at the indicated conditions (P-values were computed using the edgeR QLF test and FDR corrected). FC, fold change.
