• Species Reactivity

  Human

• Specificity

  Detects human Osteoactivin/GPNMB in direct ELISAs and Western blots. In direct ELISAs, no cross-reactivity with recombinant mouse Osteoactivin is observed.

• Source

  Monoclonal Mouse IgG    _2B Clone # 303822

• Purification

  Protein A or G purified from hybridoma culture supernatant

• Immunogen

  Mouse myeloma cell line NS0-derived recombinant human Osteoactivin/GPNMB isoform 2    
  Ala22-Asn486    
  Accession # NP_002501

• Formulation

  Supplied 0.2 mg/mL in a saline solution containing BSA and Sodium Azide.

• Label

  Alexa Fluor 750

Applications

• Recommended    
  Concentration

  Sample

• Intracellular Staining by Flow Cytometry

  0.25-1 µg/10    ⁶ cells

  MG‑63 human osteosarcoma cell line fixed with Flow Cytometry Fixation Buffer (Catalog # ) and permeabilized with Flow Cytometry Permeabilization/Wash Buffer I (Catalog # )

• 
  

Please Note: Optimal dilutions should be determined by each laboratory for each application.  are available in the Technical Information section on our website.

Preparation and Storage

• Shipping

  The product is shipped with polar packs. Upon receipt, store it immediately at the temperature recommended below.

• Stability & Storage

  Protect from light.    Do not freeze.    

• 12 months from date of receipt, 2 to 8 °C as supplied.

Background: Osteoactivin/GPNMB

Osteoactivin (also GPNMB and DC-HIL) is a variably glycosylated 75-125 kDa member of the NMB/pMEL-17 family of molecules. It is found in multiple subcellular sites, but is most often associated with the endosomal/lysosomal compartment (1-3). Human Osteoactivin is a 560 amino acid (aa) type I transmembrane protein. Its precursor contains a 21 aa signal sequence, a 465 aa luminal/extracellular domain, a 21 aa transmembrane segment and a 53 aa cytoplasmic tail (4, 5). The luminal region contains an N-terminal heparin-binding motif (aa 23-26), multiple glycosylation sites, an RGD motif (aa 64-66) and an 88 aa PKD domain (aa 240-327). The intracellular tail has an ITAM (Y-x-x-I) and lysosomal targeting (L-L) motif (4, 5). The extracellular/luminal region shares 74% and 77% aa identity with the equivalent regions in mouse and canine, respectively. Multiple isoforms would appear to exist. There is one alternate splice form known that shows a 12 aa insert between aa 339-340 (6). An addtional 206 aa isoform shows a mutation at position # 181 that results in a 26 aa substitution for the C-terminal 380 amino acids (7, 8). This has the potential to be soluble and may represent a counterpart to a secreted isoform of rat Osteoactivin (9). Cells known to express Osteoactivin include macrophages/Kupffer cells, fibroblasts, osteoblasts, myeloid dendritic cells, retinal pigment epithelial cells and melanocytes, plus fetal chondrocytes and stratum basale keratinocytes (3-5, 10-12). In mice, Osteoactivin is reported to bind to heparan sulfate-proteoglycan, possibly on the surface of endothelial cells and may also interact with integrins (13). It also appears to act as an inflammatory suppressor gene, as its expression downregulates the macrophage inflammatory response by inhibiting IL-6 and IL-12 p40 production (3).

• References:

1. Bachner, D. et al. (2002) Gene Exp. Patterns 1:159.

2. Safadi, F.F. et al. (2002) J. Cell. Biochem. 84:12.

3. Ripoll, V.M. et al. (2007) J. Immunol. 178:6557. 

4. Owen, T.A. et al. (2003) Crit. Rev. Eukaryot. Gene Expr. 13:205. 

5. Weterman, M.A.J. et al. (1995) Int. J. Cancer 60:73. 

6. Kuan, C-T. et al. (2006) Clin. Cancer Res. 12:1970. 

7. Lennerz, V. et al. (2005) Proc. Natl. Acad. Sci. USA 102:16013.

8. Genbank Accession # AAH11595.

9. Abdelmagid, S.M. et al. (2007) J. Cell. Physiol. 210:26.

10. Haralanova-Ilieva, B. et al. (2005) J. Hepatol. 42:565.

11. Ahn, J.H. et al. (2002) Blood 100:1742.

12. Anderson, M.G. et al. (2002) Nat. Genet. 30:81.

13. Shikano, S. et al. (2001) J. Biol. Chem. 276:8125.

• Long Name:

  Glycoprotein Non-Metastatic Melanoma Protein B

• Entrez Gene IDs:

  10457 (Human); 93695 (Mouse)

• Alternate Names:

  DC-HIL; glycoprotein (transmembrane) nmb; glycoprotein NMB; GPNMB; HGFIN; HGFINglycoprotein nmb-like protein; NMBosteoactivin; Osteoactivin; Transmembrane glycoprotein HGFIN; transmembrane glycoprotein NMB