Figure 3. Analysis of photobleaching events for EGFR without EGF, in the Xenopus assay.
(A) Histogram of one-step and two-step photobleaching events for wild-type EGFR in the absence of EGF. This histogram represents the number of counted events. For subsequent analysis, the fraction of two-step events (3%) seen for a monomer control protein (Claudin-16) in a similar experiment at a comparable density was subtracted from the fraction of two-step events seen for EGFR and EGFR variants. The fraction of two-step photobleaching events for wild-type EGFR (WT) is compared to that for mutants. (B) Δ-arm, deletion of the dimerization arm, residues 242 to 259. (C) Δ-tether, mutation in Domain IV that breaks the autoinhibitory interaction, (D563A, H566A and deletion of residues 575 to 585).