Skip to main content

SPP1

Function

Major non-collagenous bone protein that binds tightly to hydroxyapatite. Appears to form an integral part of the mineralized matrix. Probably important to cell-matrix interaction.

Acts as a cytokine involved in enhancing production of interferon-gamma and interleukin-12 and reducing production of interleukin-10 and is essential in the pathway that leads to type I immunity.

Post-translational modifications

Forms covalent cross-links mediated by transglutaminase TGM2, between a glutamine and the epsilon-amino group of a lysine residue, forming homopolymers and heteropolymers, increasing its collagen binding properties.

Extensively phosphorylated by FAM20C in the extracellular medium at multiple sites within the S-x-E/pS motif.

O-glycosylated. Isoform 5 is GalNAc O-glycosylated at Thr-59 or Ser-62.

Sequence similarities

Belongs to the osteopontin family.

Tissue specificity

Bone. Found in plasma.

Cellular localization

  • Secreted

Alternative names

  • Osteopontin
  • Bone sialoprotein 1
  • Nephropontin
  • Secreted phosphoprotein 1
  • Urinary stone protein
  • Uropontin
  • SPP-1
  • PSEC0156
  • OPN
  • BNSP
  • SPP1

Target type

Proteins

Primary research area

Immuno-oncology

Other research areas

  • Immunology & Infectious Disease
  • Neuroscience
  • Oncology

Molecular weight

35423Da