FIG. 1. Growth factor induced Ras isoform activation in normal and endocytosis-defective (K44A) HeLa cells.
Serum-starved HeLa cells were stimulated with either 100ng/ml HGF or EGF for 5 min (A) or 5 and 30 min (B). Activated Ras was pulled-down using GST-RBD (K85A), 30μg of each lysate was immunoblotted with isoform-specific Ras antibodies to normalise for Ras content (B). (C) Equivalent Ras activation assays (5 minute stimulation) were performed in serum-starved K44A dynamin-expressing mutant HeLa cells. Only K-Ras activation is insensitive to inhibition of endocytosis (Tet-).