osteopontin 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. Belongs to the osteopontin family. Bone. Found in plasma. 5 alternatively spliced human isoforms have been reported. Note: This description may include information from UniProtKB.
Protein type: Secreted; Secreted, signal peptide
Chromosomal Location of rat Ortholog: 14p22
Cellular Component:  apical part of cell; cell projection; cytoplasm; extracellular space; Golgi apparatus; perinuclear region of cytoplasm; vesicle
Molecular Function:  cytokine activity; extracellular matrix binding; integrin binding; ion binding; small molecule binding
Biological Process:  androgen catabolic process; bone mineralization; calcium ion homeostasis; cell adhesion; cell differentiation; cellular response to fluid shear stress; cellular response to leukemia inhibitory factor; cellular response to testosterone stimulus; collecting duct development; intracellular calcium ion homeostasis; intracellular chloride ion homeostasis; intracellular phosphate ion homeostasis; intracellular sodium ion homeostasis; negative regulation of collateral sprouting of intact axon in response to injury; neutrophil chemotaxis; ossification; osteoblast differentiation; positive regulation of bone resorption; positive regulation of cell-substrate adhesion; positive regulation of DNA-templated transcription; positive regulation of estradiol secretion; response to macrophage colony-stimulating factor; response to organic substance; response to steroid hormone; response to vitamin D; signal transduction; urate biosynthetic process
Reference #:  P08721 (UniProtKB)
Alt. Names/Synonyms: 2b7; Bone sialoprotein 1; OSP; Osteopontin; OSTP; Secreted phosphoprotein 1; Sialoprotein (osteopontin); SPP-1; Spp1
Gene Symbols: Spp1
Molecular weight: 34,963 Da
Basal Isoelectric point: 4.35  Predict pI for various phosphorylation states
Select Structure to View Below


Protein Structure Not Found.

Cross-references to other databases:  AlphaFold  |  STRING  |  Reactome  |  BioGPS  |  Pfam  |  Phospho.ELM  |  NetworKIN  |  UniProtKB  |  Entrez-Gene