RGD motif

The tripeptide Arg-Gly-Asp (RGD) was originally identified as the sequence within fibronectin that mediates cell attachment, and has been found in numerous proteins, including the integrins, a family of cell-surface proteins, which act as receptors for cell adhesion molecules. A subset of the integrins recognize the RGD motif within their ligands, the binding of which mediates both cell-substratum and cell-cell interactions.

NAPSA is another peptide shown to contain an RGD motif.