FIGURE 2. GBM mutations selectively enhance EREG-induced EGFR dimerization.

a.-e. SAXS studies of dimerisation of WT or mutated sEGFR (70 μM) induced by EGF and EREG (84 μM). Guinier plots (see Methods) show the natural logarithm of mass-normalised scattering intensity at angle q, I(q), plotted against q². Extrapolation to the y axis gives I(0)/c, proportional to weight-averaged molecular mass. EREG fails to dimerise WT sEGFR, but induces dimers of all GBM variants. Representative data are shown for 3 biological replicates; see Extended Data Fig. 2a for quantitation.

f. Representative (n = 3) Coomassie stained gel from chemical cross-linking experiments showing that the R84K mutation promotes sEGFR dimerisation by all low-affinity EGFR ligands (adding 60 μM ligand to 5 μM sEGFR). See Supplementary Fig. 1 for gel source data.