• 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 the ability of the immobilized protein to support the adhesion of Neuro‑2A mouse neuroblastoma cells. When 5 x 10    ⁴ cells/well are added to rhFLRT3 coated plates (5 μg/mL, 100 μL/well), approximately 50%-70% will adhere after 30 minutes at 37° C.    
     Optimal dilutions should be determined by each laboratory for each application.  

• Source

  Mouse myeloma cell line, NS0-derived Lys29-Pro528, with a C-terminal 6-His tag

• Accession #

• N-terminal Sequence    
  Analysis

  Lys29

• Predicted Molecular Mass

  57.3 kDa     

• SDS-PAGE

  70-90 kDa, under reducing conditions

Background: FLRT3

FLRT3 is one of three FLRT (fibronectin, leucine rich repeat, transmembrane) glycoproteins expressed in distinct areas of the developing brain and other tissues (1, 2). The 85 - 95 kDa type I transmembrane (TM) human FLRT3 is synthesized as a 649 amino acid (aa) precursor with a 28 aa signal sequence, a 500 aa extracellular domain (ECD), a 21 aa TM segment and a 100 aa cytoplasmic region. The ECD contains 10 N-terminal leucine-rich repeats flanked by cysteine-rich areas, and a juxtamembrane fibronectin type III domain (1). The human FLRT3 ECD shares 96%, 96%, 97%, 97%, 98% and 81% aa sequence identity with mouse, rat, canine, bovine, equine and Xenopus FLRT3 ECD, respectively, and 61% and 48% aa identity to human FLRT2 and FLRT3 ECDs, respectively. The fibronectin domain is responsible for binding to FGF receptors, and is thought to regulate FGF signaling during development (2, 3). The LRR domains are responsible for both the localization in areas of cell contact and homotypic cell-cell association (4). This may be through direct interaction with other FLRT molecules, or alternatively, by regulating internalization of adhesion molecules such as cadherins (4, 5). Developmentally, FLRT3 is located in somitic regions on dermatomyotomal muscle precursors and myotomal cells before their migration to the myotome and syndetome, respectively (2). FLRT3 is also expressed at the midbrain/hindbrain boundary and in the apical ectodermal ridge where it may influence FGF signaling (2). Genetic deletion in mouse embryos results in defective headfold fusion and endoderm migration (6). Postnatally, FLRT3 mRNA is widely expressed (1). It is upregulated and promotes neurite outgrowth following experimental peripheral nerve injury in rats (7, 8).

• References:

1. Lacy, S. E. et al. (1999) Genomics 62:417.

2. Haines, B. P. et al. (2006) Dev. Biol. 297:14.

3. Bottcher, R. T. et al. (2004) Nat. Cell Biol. 6:38.

4. Karaulanov, E. E. et al. (2006) EMBO Rep. 7:283.

5. Ogata, S. et al. (2007) Genes Dev. 21:1817.

6. Maretto, S. et al. (2008) Dev. Biol. 318:184.

7. Tsuji, L. et al. (2004) Biochem. Biophys. Res. Commun. 313:1086.

8. Robinson, M. et al. (2004) Mol. Cell. Neurosci. 27:202.

• Long Name:

  Fibronectin Leucine Rich Transmembrane Protein 3

• Entrez Gene IDs:

  23767 (Human)

• Alternate Names:

  fibronectin leucine rich transmembrane protein 3; Fibronectin-like domain-containing leucine-rich transmembrane protein 3; FLRT3; HH21; KIAA1469; leucine-rich repeat transmembrane protein FLRT3