Osteopontin

SPP1
Available structures PDB Ortholog search: PDBe RCSB List of PDB id codes 3CXD, 3DSF
Identifiers
Aliases	SPP1, BNSP, BSPI, ETA-1, OPN, secreted phosphoprotein 1, Osteopontin
External IDs	OMIM: 166490; MGI: 98389; HomoloGene: 20156; GeneCards: SPP1; OMA:SPP1 - orthologs
Gene location (Human) Chr. Chromosome 4 (human)[1] Band 4q22.1 Start 87,975,667 bp[1] End 87,983,532 bp[1]
Gene location (Mouse) Chr. Chromosome 5 (mouse)[2] Band 5 E5|5 50.68 cM Start 104,582,984 bp[2] End 104,588,916 bp[2]
RNA expression pattern Bgee Human Mouse (ortholog) Top expressed in gallbladder middle frontal gyrus inferior ganglion of vagus nerve C1 segment periodontal fiber subthalamic nucleus pons human kidney beta cell corpus callosum Top expressed in calvaria body of femur stroma of bone marrow tibiofemoral joint lactiferous gland vestibular sensory epithelium decidua gastrula right kidney stria vascularis More reference expression data BioGPS More reference expression data
Gene ontology Molecular function cytokine activity protein binding extracellular matrix binding Cellular component cell projection extracellular region perinuclear region of cytoplasm extracellular exosome extracellular space Golgi apparatus vesicle endoplasmic reticulum lumen Biological process cell differentiation response to vitamin D ossification biomineral tissue development response to steroid hormone extracellular matrix disassembly extracellular matrix organization response to organic substance negative regulation of collateral sprouting of intact axon in response to injury decidualization inflammatory response embryo implantation osteoblast differentiation positive regulation of bone resorption cell adhesion androgen catabolic process post-translational protein modification positive regulation of transcription, DNA-templated cellular response to testosterone stimulus positive regulation of estradiol secretion regulation of signaling receptor activity Sources:Amigo / QuickGO
Orthologs Species Human Mouse Entrez 6696 20750 Ensembl ENSG00000118785 ENSMUSG00000029304 UniProt P10451 P10923 RefSeq (mRNA) NM_001251830 NM_000582 NM_001040058 NM_001040060 NM_001251829 NM_001204201 NM_001204202 NM_001204203 NM_001204233 NM_009263 RefSeq (protein) NP_000573 NP_001035147 NP_001035149 NP_001238758 NP_001238759 NP_001035147.1 NP_001191130 NP_001191131 NP_001191132 NP_001191162 NP_033289 Location (UCSC) Chr 4: 87.98 – 87.98 Mb Chr 5: 104.58 – 104.59 Mb PubMed search [3] [4]
Wikidata
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Osteopontin (OPN), also known as bone /sialoprotein I (BSP-1 or BNSP), early T-lymphocyte activation (ETA-1), secreted phosphoprotein 1 (SPP1), 2ar and Rickettsia resistance (Ric),^[5] is a protein that in humans is encoded by the SPP1 gene (secreted phosphoprotein 1). The murine ortholog is Spp1. Osteopontin is a SIBLING (glycoprotein) that was first identified in 1986 in osteoblasts.

The prefix osteo- indicates that the protein is expressed in bone, although it is also expressed in other tissues. The suffix -pontin is derived from "pons," the Latin word for bridge, and signifies osteopontin's role as a linking protein. Osteopontin is an extracellular structural protein and therefore an organic component of bone.

The gene has 7 exons, spans 5 kilobases in length and in humans it is located on the long arm of chromosome 4 region 22 (4q1322.1). The protein is composed of ~300 amino acids residues and has ~30 carbohydrate residues attached, including 10 sialic acid residues, which are attached to the protein during post-translational modification in the Golgi apparatus. The protein is rich in acidic residues: 30-36% are either aspartic or glutamic acid.