Figure 4.

Adhesion of adult dermal fibroblasts to fibronectin results in ERK phosphorylation. Normal adult dermal fibroblasts were cultured and detached as described in Materials and Methods and in the legend for Figure 1. Fibroblasts were allowed to adhere to six-well plates that had been coated with CCN2 (10 μg/ml) as described above. Protein extracts were prepared after adhesion at the times indicated. The resultant protein extracts (20 μg/lane) were subjected to SDS-PAGE and Western blot analysis with anti-ERK and anti-phospho-ERK antibodies. Densitometry was performed on the resultant autoradiograms, and ratio of phosphorylated/non-phosphorylated ERK is shown.