FIGURE 2.

Notch1 activation in LADII fibroblasts. A, LADII (black line) and control (gray line) fibroblasts were examined for binding of biotinylated-AAL by flow cytometry detected by FITC-streptavidin. The shaded profile is FITC-streptavidin alone. B, binding of FITC-conjugated PSA. The shaded profile is unstained LADII fibroblasts. C, binding of FITC-conjugated L-PHA. The shaded profile is unstained LADII fibroblasts. D, LADII and control fibroblasts were co-cultured with Delta1/L, Jagged1/L cells, or control ligand cells (L). After 6 h, lysates were analyzed by Western blot using anti-N1^Val1744 antibody. Cleaved endogenous Notch1 (N1-ICD) was at 110 kDa. The asterisk indicates nonspecific bands on the same gel. The lower panel in D served as loading control. This is representative of 4 independent experiments. E, the experiment in D was performed for LADII fibroblasts incubated with 2 μm GSI L-685,458 or DMSO in the co-culture medium. Mouse β-actin was a loading control. This is a representative result from 2 independent experiments.