Inhibition of Cell Surface Binding of Fibronectin and Fibronectin-Promoted Cell Migration by Synthetic Peptides in Sea Urchin Primary Mesenchyme Cells In Vitro

The role of a site of fibronectin molecule in the cell binding and cell migration was examined in vitro using sea urchin primary mesenchyme cells and synthetic peptides that contain a particular amino acid sequence, Arg-Gly-Asp-Ser.
The binding of fibronectin to the cell surface was inhibited by addition of larger synthetic peptides, Gly-Arg-Gly-Asp-Ser-Pro-Cys (HP) or Arg-Gly-Asp-Ser-Pro-Ala-Ser-Ser-Lys-Pro (DP), but not by a smaller synthetic peptide Gly-Arg-Gly-Asp-Ser (PP). The inhibition was recovered by addition of excess amount of fibronectin to the medium.
The fibronectin-promoted cell migration, by contraries, was conspicuously inhibited by addition of the PP to the cell culture medium which has alrady contained sufficient amount of fibronectin for the migration, but not so obviously by addition of the larger peptides, the HP or the DP. The inhibition was also recovered by addition of excess amount of fibronectin.
These results indicated that fibronectin utilizes Arg-Gly-Asp-Ser in the molecule as an active cell binding and a cell migration promotion site. Slightly different effects seen between the smaller peptide and the larger ones were discussed.