• Species Reactivity

  Human

• Specificity

  Detects human ULBP‑4/RAET1E in direct ELISAs and Western blots. In Western blots, approximately 20% cross‑reactivity with recombinant human (rh) ULBP-2 is observed and no cross-reactivity with rhULBP‑1 or rhULBP-3 is observed.

• Source

  Monoclonal Mouse IgG    _2B Clone # 709116

• Purification

  Protein A or G purified from hybridoma culture supernatant

• Immunogen

  Mouse myeloma cell line NS0-derived recombinant human ULBP‑4/RAET1E    
  Gly30-Asp225    
  Accession # Q8TD07

• Formulation

  Lyophilized from a 0.2 μm filtered solution in PBS with Trehalose. *Small pack size (SP) is supplied as a 0.2 µm filtered solution in PBS.

• Label

  Unconjugated

Applications

• 
  

  Recommended    
  Concentration

  Sample

• Western Blot

  1 µg/mL

  See below

• 
  

• Flow Cytometry

  0.25 µg/10    ⁶ cells

  See below

• 
  

• Immunohistochemistry

  8-25 µg/mL

  See below

• 
  

• CyTOF-ready

  Ready to be labeled using established conjugation methods. No BSA or other carrier proteins that could interfere with conjugation.

• 
  

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

Data Examples

Preparation and Storage

• Reconstitution

  Sterile PBS to a final concentration of 0.5 mg/mL.

• Shipping

  The product is shipped at ambient temperature. Upon receipt, store it immediately at the temperature recommended below. *Small pack size (SP) is shipped with polar packs. Upon receipt, store it immediately at -20 to -70 °C

• Stability & Storage

  Use a manual defrost freezer and avoid repeated freeze-thaw cycles.    

• 12 months from date of receipt, -20 to -70 °C as supplied.

• 1 month, 2 to 8 °C under sterile conditions after reconstitution.

• 6 months, -20 to -70 °C under sterile conditions after reconstitution.

Background: ULBP-4/RAET1E

ULBP-4 (cytomegalovirus glycoprotein UL16 binding protein 4), also called RAET1E (retinoic acid early transcript 1E), Letal (lymphocyte effector cell toxicity activating ligand) and NKG2DL4 (NKG2D ligand 4), is a 40-50 kDa member of the ULBP/RAET1 family of cell surface proteins that function as ligands for NKG2D (1‑6). While most family members are GPI-anchored, only ULBP-4/RAET1E and ULBP-5/RAET1G express a transmembrane form (1, 4, 6, 7). Human ULBP-4 mRNA encodes 263 amino acids (aa) including a 30 aa signal sequence, a 195 aa extracellular domain (ECD), a 23 aa transmembrane domain, and a 15 aa cytoplasmic sequence. A soluble 35 kDa form diverges at aa 208 and is thought to antagonize the transmembrane form (5). Other potential splice variants of 220, 227 and 280 aa are transmembrane proteins (8). Within the ECD, ULBP-4 shares 34-41% aa sequence identity with family members (1, 7). Rodent NKG2D ligands Rae-1 alpha -epsilon are, like human ULBP and MIB proteins, distantly related to MHC class I proteins, but none of the families share significant sequence identity (2, 4). Low expression of ULBP‑4 mRNA is found in normal tissues, with high expression variably reported in the small intestine (3) and skin (4). Expression is stimulated by TNF-alpha and down‑regulated by retinoic acid (3). ULBP-4 is abnormally expressed on most colon cancer and some other tumor cell lines and virus-infected peripheral blood cells (3, 6). ULBP-4 binds and costimulates NKG2D-expressing effector cells including NK cells, NKT cells, gamma δ T cells, and CD8  ⁺ alpha beta T cells, activating cytolytic activity and/or cytokine production (3, 4, 7). In some gamma δ T cells, direct ULBP-4 binding to both TCR gamma δ and NKG2D has been demonstrated (6). ULBP-4 is also thought to function as a minor histocompatibility antigen in humans (1).

• References:

1. Radosavljevic, M. et al. (2002) Genomics 79:114.

2. Kondo, M. et al. (2010) Immunogenetics 62:441.

3. Conejo-Garcia, J.R. et al. (2003) Cancer Biol. Ther. 2:446.

4. Chalupny, N.J. et al. (2003) Biochem. Biophys. Res. Commun. 305:129.

5. Cao, W. et al. (2007) J. Biol. Chem. 282:18922.

6. Kong, Y. et al. (2009) Blood 114:310.

7. Bacon, L. et al. (2004) J. Immunol. 173:1078.

8. Cao, W. et al. (2008) Int. Immunol. 20:981.

• Long Name:

  UL16 Binding Protein-4

• Entrez Gene IDs:

  135250 (Human); 379043 (Mouse); 292461 (Rat)

• Alternate Names:

  bA350J20.7; LETAL; LETALRAE-1-like transcript 4; Lymphocyte effector toxicity activation ligand; MGC125309; N2DL4; N2DL-4; NKG2D ligand 4; NKG2DL4; RAET1E; RAET1E2; retinoic acid early transcript 1ERL-4; RL-4; ULBP4; ULBP-4; ULBP4MGC125308