Figure 6.

Modulation of ERK signaling by recombinant laminin LG domains. The presence of ERK1 and phosphorylated forms of ERK1/2 and MEK1/2 was measured by immunoblotting. The quantification of results is shown below the gels. (A) WI-26 VA4 cells were cultured for 80 min in the presence or absence of recombinant laminin fragments, first preincubated in suspension for 20 min, and then allowed to attach for 60 min to wells precoated overnight with integrin α6 antibodies (10 μg/ml). Cells kept in solution served as control. Similar results were seen in three experiments. (B) ERK activation after 30 min in response to attachment of WI-26 VA4 cells to integrin α6 antibodies, laminin-1, -10/11, or E8 fragment of laminin-1 at a concentration of 10 μg/ml. The same results were seen in two experiments. (C) The cells were preincubated in the presence of soluble recombinant laminin LG modules as indicated and then allowed to attach to the E8 fragment of laminin-1 (10 μg/ml). The ERK activation was detected after 30 min of attachment. Similar results were seen in three experiments.