Cloning and sequence analysis of rat bone sialoprotein (osteopontin) cDNA reveals an Arg-Gly-Asp cell-binding sequence

Proc Natl Acad Sci U S A. 1986 Dec;83(23):8819-23. doi: 10.1073/pnas.83.23.8819.


The primary structure of a bone-specific sialoprotein was deduced from cloned cDNA. One of the cDNA clones isolated from a rat osteosarcoma (ROS 17/2.8) phage lambda gt11 library had a 1473-base-pair-long insert that encoded a protein with 317 amino acid residues. This cDNA clone appears to represent the complete coding region of sialoprotein mRNA, including a putative AUG initiation codon and a signal peptide sequence. The amino acid sequence deduced from the cDNA contains several Ser-Xaa-Glu sequences, possibly representing attachment points for O-glycosidically linked oligosaccharides and one Asn-Xaa-Ser sequence representing a likely site for the N-glycosidically linked oligosaccharide. An interesting observation is the Gly-Arg-Gly-Asp-Ser sequence, which is identical to the cell-binding sequence identified in fibronectin. The presence of this sequence prompted us to investigate the cell-binding properties of sialoprotein. The ROS 17/2.8 cells attached and attained a spread morphology on surfaces coated with sialoprotein. We could demonstrate that synthetic Arg-Gly-Asp-containing peptides efficiently inhibited the attachment of cells to sialoprotein-coated substrates. The results show that the Arg-Gly-Asp sequence also confers cell-binding properties on bone-specific sialoprotein. To better reflect the potential function of bone sialoprotein--we propose the name "osteopontin" for this protein.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Bone and Bones / cytology
  • Bone and Bones / physiology*
  • Cell Adhesion
  • DNA / genetics
  • Hydroxyapatites / metabolism
  • Osteopontin
  • Rats
  • Receptors, Cell Surface / genetics*
  • Sialoglycoproteins / genetics*


  • Hydroxyapatites
  • Receptors, Cell Surface
  • Sialoglycoproteins
  • Spp1 protein, rat
  • Osteopontin
  • DNA

Associated data

  • GENBANK/M14656