Newt epidermal cell migration over collagen and fibronectin involves different mechanisms

Effects of the synthetic peptides, Arg-Gly-Asp-Ser (RGDS), the amino acid sequence representing the fibroblast attachment site in fibronectin, and Arg-Gly-Glu-Ser (RGES), on collagen- and fibronectin-mediated migration in newt epidermal cells were compared. When RGDS at 50 micrograms ml-1 was included in the incubation medium of skin explants, migration in fibronectin-coated dishes was almost totally blocked. In type I collagen-coated dishes, this concentration of RGDS also inhibited migration, but to a lesser degree than on fibronectin. With 250 micrograms ml-1 of RGES in the medium, the reverse was true. Here, migration on collagen was practically non-existent, while migration on fibronectin was affected only moderately. Collagen-mediated migration was sensitive to RGDS even when the peptide was added after migration on the coated substratum was well underway. At a coating concentration of 10 micrograms ml-1 CB3, a cyanogen bromide fragment of the collagen alpha 1(I) chain, which contains no RGD sequences, was as good a migration substratum as intact collagen applied at the same coating concentration. At lower concentrations intact collagen was somewhat better than equivalent concentrations of CB3. The presence of RGDS in the medium throughout an experiment inhibited migration in CB3-coated dishes in a manner similar to its effect in dishes coated with collagen. On both substrata there appeared to be a peptide-sensitive and a peptide-insensitive component to migration. The inhibitory effect of RGES on CB3-mediated migration was also similar to its effect in collagen-coated dishes.(ABSTRACT TRUNCATED AT 250 WORDS)