Cell Signaling Technology

Product Pathways - Tyrosine Kinase/ Adaptors

Phospho-EGF Receptor (Tyr1068) Blocking Peptide #1110

Description

This peptide is used to block Phospho-EGF Receptor (Tyr1068) Antibody #2234 reactivity.

Quality Control

The quality of the peptide was evaluated by reversed-phase HPLC and by mass spectrometry. The peptide blocks Phospho-EGF Receptor (Tyr1068) Antibody #2234 signal completely in Western blotting and immunohistochemistry.

Western Blotting

Western Blotting

Western blot analysis of extracts from A431 cells, untreated or EGF-stimulated, using Phospho-EGF Receptor (Tyr1068) Antibody #2234 (left) or the same antibody preincubated with Phospho-EGF Receptor (Tyr1068) Antibody Blocking Peptide (right).

Applications

Use as a blocking reagent to evaluate the specificity of antibody reactivity in Western immunoblotting and Immunohistochemistry protocols.

Directions for Use

For Western Immunoblotting, add 10 ul of antibody and 10 ul of blocking peptide to 10 ml of antibody dilution buffer, and incubate at room temperature for 1 hour before allowing to react with the blot.

For Immunohistochemistry, add twice the volume of peptide as volume of antibody used in a 100 ul total volume. Incubate for a minimum of 30 minutes prior to adding the entire volume to the slide. Recommended antibody dilutions can be found on the Phospho-EGF receptor (Tyr1068) Antibody #2234 and Phospho-EGF Receptor (Tyr1068) Mouse mAb #2236 data sheets.

Background

The epidermal growth factor (EGF) receptor is a 170 kDa transmembrane tyrosine kinase that belongs to the HER/ErbB protein family. Ligand binding results in receptor dimerization, autophosphorylation, activation of downstream signaling and lysosomal degradation (1,2). Phosphorylation of EGF receptor (EGFR) at Tyr845 in the kinase domain is implicated in stabilizing the activation loop, maintaining the active state enzyme and providing a binding surface for substrate proteins (3,4). c-Src is involved in phosphorylation of EGFR at Tyr845 (5). The SH2 domain of PLCγ binds at phospho-Tyr992, resulting in activation of PLCγ-mediated downstream signaling (6). Phosphorylation of EGFR at Tyr1045 creates a major docking site for c-Cbl, an adaptor protein that leads to receptor ubiquitination and degradation following EGFR activation (7,8). The GRB2 adaptor protein binds activated EGFR at phospho-Tyr1068 (9). A pair of phosphorylated residues (Tyr1148 and Tyr1173) provides a docking site for the SHC scaffold protein, with both sites involved in MAP kinase signaling activation (2). Phosphorylation of EGFR at specific serine and threonine residues attenuates EGFR kinase activity. EGFR carboxy-terminal residues Ser1046 and Ser1047 are phosphorylated by CaM kinase II; mutations to either of these serines results in upregulated EGFR tyrosine autokinase activity (10).

  1. Hackel, P.O. et al. (1999) Curr. Opin. Cell Biol. 11, 184-189.
  2. Zwick, E. et al. (1999) Trends Pharmacol. Sci. 20, 408-412.
  3. Cooper, J.A. and Howell, B. (1993) Cell 73, 1051-1054.
  4. Hubbard, S.R. et al. (1994) Nature 372, 746-754.
  5. Biscardi, J.S. et al. (1999) J. Biol. Chem. 274, 8335-8343.
  6. Emlet, D.R. et al. (1997) J. Biol. Chem. 272, 4079-4086.
  7. Levkowitz, G. et al. (1999) Mol. Cell 4, 1029-1040.
  8. Ettenberg, S.A. et al. (1999) Oncogene 18, 1855-1866.
  9. Rojas, M. et al. (1996) J. Biol. Chem. 271, 27456-27461.
  10. Feinmesser, R.L. et al. (1999) J. Biol. Chem. 274, 16168-16173.

Application References

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