• Purity

  >95%, 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 binding ability in a functional ELISA. When Recombinant Human Plexin A4 is immobilized at 5 μg/mL, Recombinant Human Semaphorin 6A Fc Chimera (Catalog # ) binds with an apparent K    _D <20 nM.  

• Source

  Chinese Hamster Ovary cell line, CHO-derived Thr24-Pro1237, with a C-terminal 6-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  Thr24

• Structure / Form

  Noncovalently-linked homodimer    
   

• Predicted Molecular Mass

  135.9 kDa (monomer)

• SDS-PAGE

  140-150 kDa, reducing conditions

Background: Plexin A4

Plexin A4 is a 220‑230 kDa member of the plexin A subfamily, plexin family of proteins (1). It is found on sensory, autonomic and motor neurons and oligodendrocytes, plus T cells and dendritic cells (1‑8). Mature human Plexin A4 is an 1871 amino acid (aa) type I transmembrane glycoprotein with a 23 aa signal sequence, a 1214 aa extracellular domain (ECD), and a 636 aa cytoplasmic region. The ECD contains one Sema-domain (aa 51‑482), three PSI domains (aa 509‑856) and four IPT regions (aa 858‑1230) that contain a phosphoserine at aa 946 (1). Of three isoform variants, one shows a 65 aa substitution for aa 458‑1894, a second shows an 80 aa substitution for aa 1292‑1894, and a third shows the just mentioned 80 aa substitution coupled to a 14 aa substitution for aa 1‑535 (9). The human Plexin A4 ECD shares 97% aa identity with mouse, equine, canine, and bovine Plexin A4. Full‑length Plexin A4 also shares 67% aa identity with the most related family member, Plexin A2. Plexin A4 regulates cell migration, activation and axon guidance via repulsion (1‑5). It serves as a receptor for transmembrane semaphorins, Sema6A and 6B, and as a coreceptor with neuropilin-1 for the secreted semaphorin, Sema3A (1‑8). During development, it plays a role in nerve migration and midline crossing and down‑regulates dendrite formation (2‑8). It is often co‑expressed with Plexin A3, which can also engage class 6 semaphorins but prefers Sema3F/ neuropilin‑2 to Sema3A/neuropilin-1 (3, 8). Thus, Plexins A3 and A4 are redundant in some functions, but unique in others. In T cells, Plexin A4 engages Sema3A and negatively regulates TCR signals (6).

• References:

1. Suto, F. et al. (2003) Mech. Dev. 120:385.

2. Suto, F. et al. (2005) J. Neurosci. 25:3628.

3. Faulkner, R.L. et al. (2008) Neural Dev. 3:21.

4. Waimey, K.E. et al. (2008) Dev. Biol. 315:448.

5. Runker, A.E. et al. (2008) Neural Dev. 3:34.

6. Yamamoto, M. et al. (2008) Int. Immunol. 20:413.

7. Okada, A. et al. (2007) Biochem. Biophys. Res. Commun. 352:158.

8. Yaron, A. et al. (2005) Neuron 45:513.

9. Protein Accession # NP_861440, EAW83796, EAL24077.

• Entrez Gene IDs:

  91584 (Human); 243743 (Mouse); 312213 (Rat)

• Alternate Names:

  A; DKFZp434G0625; FAYV2820; FLJ35026; FLJ38287; KIAA1550DKFZp566O0546; PLEXA4; Plexin A4; plexin A4, B; plexin-A4; PLXNA4; PLXNA4A; PLXNA4B; PRO34003