• Species Reactivity

  Human

• Specificity

  Detects human Dkk-4 in ELISAs and Western blots. In direct ELISAs and Western blots, less than 2% cross-reactivity with recombinant mouse (rm) Dkk-4 is observed and no cross-reactivity with recombinant human (rh) Dkk-1 or rhDkk-3 is observed. In sandwich immunoassays, less than 2% cross-reactivity with rmDkk-4 is observed and no cross-reactivity with rhDkk-1, recombinant rat Dkk-1, rmDkk‑1, or rhDkk-3 is observed.

• Source

  Monoclonal Mouse IgG    _2B Clone # 185709

• Purification

  Protein A or G purified from hybridoma culture supernatant

• Immunogen

  Mouse myeloma cell line NS0-derived recombinant human Dkk-4    
  Leu19-Leu224    
  Accession # Q9UBT3

• 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.

• Endotoxin Level

  <0.10 EU per 1 μg of the antibody by the LAL method.  

• Label

  Unconjugated

Applications

• Recommended    
  Concentration

  Sample

• Western Blot

  1 µg/mL

  Recombinant Human Dkk‑4 (Catalog # ) under non-reducing conditions only

• 
  

• Human Dkk-4 Sandwich Immunoassay

  Reagent    

• ELISA Capture (Matched Antibody Pair)

  2-8 µg/mL 

  Human Dkk‑4 Antibody (Catalog # )

• ELISA Detection (Matched Antibody Pair)

  0.1-0.4 µg/mL 

  Human Dkk‑4 Biotinylated Antibody (Catalog # )

• ELISA Standard

   

  Recombinant Human Dkk-4 Protein (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

• Reconstitution

  Reconstitute at 0.5 mg/mL in sterile PBS.

• 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: Dkk-4

Dickkopf related protein 4 (Dkk-4) is a member of the Dkk protein family that includes Dkk-1, -2, -3, and -4 (1). All four members are secreted proteins that are synthesized as precursor proteins with an N-terminal signal peptide and 2 conserved cysteine-rich domains, which are separated by a linker region. Dkk proteins have potential furin type proteolytic cleavage sites, and short forms of Dkk-2 and Dkk-4 containing only the second cysteine-rich domain can be generated by proteolytic processing (1). Dkk proteins have distinct patterns of expression in adult and embryonic tissues, suggesting that they may play diverse roles in these tissues.

The Dkk proteins have distinct effects on Wnt signaling. Dkk-1 and Dkk-4 are Wnt antagonists. Dkk-3 has not been demonstrated to affect Wnt signaling, and Dkk-2 acts as an agonist or antagonist, depending on the cellular context. Wnt signaling regulates many important developmental processes including neural crest differentiation, brain development, kidney morphogenesis, and sex determination. In addition, Wnt signaling has also been implicated in tumor formation. Canonical Wnt signaling via the beta-catenin pathway is transduced by a receptor complex composed of the Frizzled proteins (Fz) and low-density lipoprotein (LDL) receptor-related proteins (LRP5/6) (2, 3). Unlike many soluble Wnt antagonists that function by binding extracellular Wnt ligands to prevent interaction of Wnt with the Fz‑LRP5/6 receptor complex, Dkk-1 and Dkk-4 antagonize Wnt/beta-catenin signaling by direct high-affinity binding to the Wnt coreceptor LRP5/6 and inhibiting interaction of LRP5/6 with the Wnt-Frizzled complex (4). Dkk-1 and Dkk-4 also bind the transmembrane proteins Kremen1 (Krm1) and Krm2 with high-affinity (5). Krm2 has been shown to form a ternary complex with Dkk-1 or -4 and LRP5/6 to trigger internalization of the complex and removal of LRP6 from the cell surface. Thus, Dkk-1/4 and Kremens function synergistically to antagonize LRP5/6-mediated Wnt activity. Dkk-2 also binds to LRP5/6 and the Kremens, but Dkk-2 acts as an antagonist of the Wnt signaling pathway only in the presence of Krm2 (5, 6). Dkk-2 binding to LRP5/6 in the absence of Krm2 activates rather than inhibits Wnt signalling (6).

• References:

1. Krupnik, V.E. et al. (1999) Gene 238:301.

2. Zorn, A.M. (2001) Current Biology R592.

3. Mao, J. et al. (2001) Mol. Cell 7:801.

4. Nusse, R. et al. (2001) Nature 411:255.

5. Mao, J. et al. (2002) Nature 417:664.

6. Mao, B. and C. Niehrs (2003) Gene 302:179.

• Long Name:

  Dickkopf-4

• Entrez Gene IDs:

  27121 (Human); 234130 (Mouse)

• Alternate Names:

  dickkopf (Xenopus laevis) homolog 4; dickkopf homolog 4 (Xenopus laevis); dickkopf-4; dickkopf-related protein 4; Dkk4; Dkk-4; hDkk-4; MGC129562; MGC129563