• Purity

  >90%, by SDS-PAGE under reducing conditions and visualized by silver stain.

• Endotoxin Level

  <0.01 EU per 1 μg of the protein by the LAL method.  

• Activity

  Measured by its ability to inhibit survival of SK‑OV‑3 human ovarian carcinoma cells. The ED    ₅₀ for this effect is typically 0.4-2 μg/mL. Measured by its binding ability in a functional ELISA. When Recombinant Human Plexin B2 (Catalog # ) is coated at 5 μg/mL, Recombinant Human Semaphorin 4D/CD100 Fc Chimera binds with an apparent K    _d <4 nM.  

• Source

  Chinese Hamster Ovary cell line, CHO-derived

  Human Semaphorin 4D (Met22-Arg734) Accession # Q92854	IEGRMD	Human IgG1 (Pro100-Lys330)
  N-terminus		C-terminus

• Accession #

• N-terminal Sequence    
  Analysis

  Met22 & Phe24

• Structure / Form

  Disulfide-linked homodimer

• Predicted Molecular Mass

  105.8 kDa (monomer)

• SDS-PAGE

  110-135 kDa, reducing conditions

Background: Semaphorin 4D/CD100

Semaphorin 4D (Sema4D/CD100, previously Sem J, G or C-like 2) is a 150 kDa type I transmembrane glycoprotein that belongs to the Class 4 family of transmembrane immune and nervous system semaphorins (1‑3). The human Sema4D cDNA encodes 862 amino acids (aa) that include a 21 aa signal sequence, a 713 aa extracellular domain (ECD), a 21 aa transmembrane segment and a 107 aa cytoplasmic tail. The Sema4D ECD contains one sema, PSI and immunoglobulin‑like domain, and over the full ECD (aa 22‑734), human Sema4D shares 85%, 85%, 86% and 80% aa sequence identity with mouse, rat, porcine and canine Sema4D ECDs, respectively. Sema4D is active as a homodimer that utilizes both a membrane‑proximal intermolecular disulfide bond and two hydrophobic interactions involving Phe244 and Phe246 (4, 5). Proteolysis by metalloproteinases such as TACE/ADAM17 and MMP-14 (MT1‑MMP) produce a soluble, active 120 kDa form that may also exist as a dimer (5‑7). Sema4D, produced by T cells, activated B cells and dendritic cells acts through a low affinity receptor termed CD72 in the immune system (1, 2). Unligated CD72 inhibits antigen presenting cells that express it, and this inhibition is relieved by Sema4D binding (8). Sema4D thus causes enhanced B cell survival, differentiation of macrophages and DC, and enhanced T cell antigen priming (2, 8, 9). In the CNS, Sema4D and a high affinity receptor Plexin B1 are expressed in complimentary patterns in several regions of the brain, and their interaction assists in the guidance of developing neurons (10). Intermediate affinity Sema4D:Plexin B2 binding also occurs during development, and enhances both radial and tangential neuronal migration (11). In cancer, Sema4D can also be produced by tumor‑associated macrophages, and bind to endothelial cell Plexin B1, thus promoting tumor angiogenesis (3, 6, 7, 12). While this suggests facilitation of the metastatic process, it is also recognized that semaphorins in general show both tumor promoter and suppressor functions (13, 14). For Sema4D, this is reflected in its ability to inhibit ovarian carcinoma cell survival. Finally, receptors that associate in cis with plexins, such as Met and ErbB2, are known to alter Sema4D‑mediated activities (3).

• References:

1. Furuyama, T. et al. (1996) J. Biol. Chem. 271:33376.

2. Kumanogoh, A. and H. Kikutani (2004) Cell. Mol. Life Sci. 61:292.

3. Ch’ng, E.S. and A. Kumanogoh (2010) Mol. Cancer 9:251.

4. Janssen, B.J.C. et al. (2010) Nature 467:1118.

5. Elhabazi, A. et al. (2001) J. Immunol. 166:4341.

6. Zhu, L. et al. (2007) Proc. Natl. Acad. Sci. USA 104:1621.

7. Basile, J.R. et al. (2007) J. Biol. Chem. 282:6899.

8. Kumanogoh, A. et al. (2005) Int. Immunol. 17:1277.

9. Ishida, I. et al. (2003) Int. Immunol. 15:1027.

10. Worzfield, T. et al. (2004) Eur. J. Neurosci. 19:2622.

11. Hirschberg, A. et al. (2010) Mol. Cell. Biol. 30:764.

12. Sierra, J.R. et al. (2008) J. Exp. Med. 205:1673.

13. Ye, S. et al. (2010) BMC Cancer 10:611.

14. Lu, T-P. et al. (2012) Transl. Cancer Res. 1:74.

• Entrez Gene IDs:

  10507 (Human); 20354 (Mouse); 306790 (Rat)

• Alternate Names:

  A8; BB18; CD100 antigen; CD100; CD100M-sema-G; COLL-4; FLJ33485; FLJ34282; FLJ39737; FLJ46484; immunoglobulin domain (Ig), transmembrane domain (TM) and shortcytoplasmic domain, 4D; MGC169138; MGC169141; M-sema-G; sema domain, immunoglobulin domain (Ig), transmembrane domain (TM) and shortcytoplasmic domain, (semaphorin) 4D; SEMA4D; SEMAJ; Semaphorin 4D; semaphorin-4D