UNIPROT #

P10451

PROTEIN NAME

Osteopontin

SYNONYMS

BNSP antibody; Bone sialoprotein 1 antibody; BSP I antibody; BSPI antibody; Early T lymphocyte activation 1 antibody; ETA 1 antibody; ETA1 antibody; MGC110940 antibody; Nephropontin antibody; OPN antibody; Osteopontin antibody; osteopontin/immunoglobulin alpha 1 heavy chain constant region fusion protein antibody; OSTP_HUMAN antibody; PSEC0156 antibody; secreted phosphoprotein 1 (osteopontin, bone sialoprotein I, early T-lymphocyte activation 1) antibody; Secreted phosphoprotein 1 antibody; SPP 1 antibody; SPP-1 antibody; SPP1 antibody; SPP1/CALPHA1 fusion antibody; Urinary stone protein antibody; Uropontin antibody

SEQUENCE SIMILARITIES

Belongs to the osteopontin family.

TISSUE SPECIFICITY

Bone. Found in plasma.

POST-TRANSLATIONAL MODIFICATION

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.

SUBCELLULAR LOCATION

Secreted.

FUNCTION

Osteopontin (OPN), also designated bone sialoprotein 1, urinary stone protein, spp-1, Eta-1, nephropontin and uropontin, is an extracellular matrix cell adhesion phosphoglycoprotein. OPN is deposited into unmineralized matrix prior to calcification leading to localization at various tissue interfaces including cement lines, lamina limitans and between collagen fibrils of fully matured hard tissues. While OPN is a major product of osteoblasts, it is also synthesized by brain and kidney cells. OPN isolated from or secreted by various tissues ranges in molecular weight due to posttranslational modifications. OPN functions as a substrate for transglutaminase and is involved in cell adhesion, chemoattraction and immunomodulation.