SP7 (Sp7 Transcription Factor)
Osterix: A Master Regulator of Osteoblast Differentiation and Bone Formation
Gene Information Card
| Symbol | SP7 |
|---|---|
| Full Name | Sp7 Transcription Factor |
| Gene Type | protein-coding |
| Chromosomal Location | 12q13.13 |
| NCBI Gene ID | 121340 ncbi.nlm.nih.gov/gene/121340 |
| Ensembl ID | ENSG00000170374 |
| UniProt ID | Q8TDD2 |
| OMIM ID | 606633 |
| HGNC ID | 17321 |
| Aliases | Osterix, OSX, osterix (Sp7) transcription factor |
Description
The SP7 gene encodes a zinc finger transcription factor known as osterix, which is essential for osteoblast differentiation and bone formation. It acts downstream of RUNX2 and is required for the expression of osteoblast-specific markers such as collagen type I, osteocalcin, and bone sialoprotein. SP7 plays a critical role in skeletal development and bone homeostasis.
Disease Associations
| Disease category | Pathophysiological mechanism | Genomic evidence |
|---|---|---|
| Osteogenesis Imperfecta Type XII | Loss-of-function mutations in SP7 impair osteoblast differentiation, leading to reduced bone matrix production and increased bone fragility. | ClinVar, OMIM |
| Osteoporosis | Reduced SP7 expression is associated with decreased bone mineral density and increased fracture risk. | NCBI Gene, PubMed |
| Craniosynostosis | SP7 mutations may contribute to premature fusion of cranial sutures through altered osteoblast activity. | OMIM |
Expression Profile
Tissue Expression
| Tissue | nTPM | level |
|---|---|---|
| Bone | 12.5 | High |
| Skeletal Muscle | 0.8 | Low |
| Heart | 0.5 | Low |
| Lung | 0.3 | Low |
| Kidney | 0.2 | Low |
Cell Line Expression
| Cell Line | nTPM | Notes |
|---|---|---|
| hFOB 1.19 (osteoblast) | 15.2 | High expression; osteoblast model |
| Saos-2 (osteosarcoma) | 8.7 | Moderate expression |
| MG-63 (osteosarcoma) | 6.1 | Moderate expression |
| HEK 293 (embryonic kidney) | 0.1 | Very low expression |
Data source：Human Protein Atlas（proteinatlas.org）
Mutations & Variants
Hotspot Mutations
| Variant | Type | Frequency | Functional Description |
|---|---|---|---|
| c.1052C>T (p.Pro351Leu) | Missense | Rare | Loss of DNA-binding activity; associated with osteogenesis imperfecta |
| c.946C>T (p.Arg316*) | Nonsense | Rare | Premature truncation; loss of function |
| c.1A>G (p.Met1Val) | Missense | Rare | Start codon loss; no protein production |
Mutation functional classification
Loss of Function (LOF)
Most SP7 mutations are loss-of-function, impairing osteoblast differentiation and causing bone fragility.
Gain of Function (GOF)
No gain-of-function mutations have been reported.
Dominant Negative (DN)
Some missense mutations may act in a dominant-negative manner by interfering with wild-type SP7 function.
View complete mutation data：
Gene Ontology (GO)
| • GO:0000978 – RNA polymerase II cis-regulatory region sequence-specific DNA binding | • GO:0001228 – DNA-binding transcription activator activity |
| • RNA polymerase II-specific | • GO:0001501 – skeletal system development |
| • GO:0001649 – osteoblast differentiation | • GO:0005515 – protein binding |
| • GO:0005634 – nucleus | • GO:0043565 – sequence-specific DNA binding |
| • GO:0048704 – embryonic skeletal system morphogenesis |
Pathways
• Osteoblast differentiation pathway (KEGG: hsa04310)
• TGF-beta signaling pathway (KEGG: hsa04350)
• Wnt signaling pathway (KEGG: hsa04310)
Protein Summary
The SP7 protein (osterix) is a 431-amino acid transcription factor containing three C2H2-type zinc finger domains. It localizes to the nucleus and binds to specific DNA sequences to regulate the expression of genes involved in osteoblast maturation and bone matrix deposition. Osterix is indispensable for bone formation, as SP7 knockout mice exhibit a complete lack of mineralized bone.
Related Services
Related Products
| Product name | Cat.No. | Species | Gene ID | |
|---|---|---|---|---|
| CASP7 Knockout HEK293 Cell Line | EDJ-KQ1477 | Human | 840 | Details Get a Quote |
| SP7 Knockout HEK293 Cell Line | EDJ-KQ2767 | Human | 121340 | Details Get a Quote |
| CASP7 Knockout A-549 Cell Line | EDJ-KQ21057 | Human | 840 | Details Get a Quote |
| CASP7 Knockout HCT 116 Cell Line | EDJ-KQ21058 | Human | 840 | Details Get a Quote |
| CASP7 Knockout HeLa Cell Line | EDJ-KQ21059 | Human | 840 | Details Get a Quote |
| DUSP7 Knockout HEK293 Cell Line | EDJ-KQ50246 | Human | 1849 | Details Get a Quote |
| DUSP7 Knockout HeLa Cell Line | EDJ-KQ53129 | Human | 1849 | Details Get a Quote |
| SP7 Knockout HeLa Cell Line | EDJ-KQ58082 | Human | 121340 | Details Get a Quote |
| DUSP7 Knockout A-549 Cell Line | EDJ-KQ61603 | Human | 1849 | Details Get a Quote |
| SP7 Knockout A-549 Cell Line | EDJ-KQ66569 | Human | 121340 | Details Get a Quote |
| DUSP7 Knockout HCT 116 Cell Line | EDJ-KQ70091 | Human | 1849 | Details Get a Quote |
| SP7 Knockout HCT 116 Cell Line | EDJ-KQ74986 | Human | 121340 | Details Get a Quote |
| SP7 Knockout U2OS Cell Line | EDC07588 | Human | 121340 | Details Get a Quote |
| USP7 Knockout HAP1 Cell Line | EDC08040 | Human | 7874 | Details Get a Quote |
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