Cell Signaling Technology

Product Pathways - Tyrosine Kinase / Adaptors

Phospho-HER2/ErbB2 (Tyr877) Antibody #2241

Applications Reactivity Sensitivity MW (kDa) Source
W H (M) (R) Endogenous 185 Rabbit

Applications Key:  W=Western Blotting
Reactivity Key:  H=Human  M=Mouse  R=Rat
Species cross-reactivity is determined by western blot. Species enclosed in parentheses are predicted to react based on 100% sequence homology.

Protocols

Specificity / Sensitivity

Phospho-HER2/ErbB2 (Tyr877) Antibody detects endogenous levels of ErbB2 only when phosphorylated at tyrosine 877. The antibody may cross-react with other ErbB family members (e.g., EGF receptor) when phosphorylated at their tyrosine residues.

Source / Purification

Polyclonal antibodies are produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Tyr877 of human ErbB2. Antibodies are purified by protein A and peptide affinity chromatography.

Western Blotting

Western Blotting

Western blot analysis of extracts from MCF-7 cells, untreated or treated with neuregulin (NRG), using Phospho-HER2/ErbB2 (Tyr877) Antibody (upper) and HER2/ErbB2 Antibody #2242 (lower).

Background

The ErbB2 (HER2) proto-oncogene encodes a 185 kDa transmembrane, receptor-like glycoprotein with intrinsic tyrosine kinase activity (1). While ErbB2 lacks an identified ligand, ErbB2 kinase activity can be activated in the absence of a ligand when overexpressed and through heteromeric associations with other ErbB family members (2). Amplification of the ErbB2 gene and overexpression of its product are detected in almost 40% of human breast cancers (3). Binding of the c-Cbl ubiquitin ligase to ErbB2 at Tyr1112 leads to ErbB2 poly-ubiquitination and enhances degradation of this kinase (4). ErbB2 is a key therapeutic target in the treatment of breast cancer and other carcinomas and targeting the regulation of ErbB2 degradation by the c-Cbl-regulated proteolytic pathway is one potential therapeutic strategy. Phosphorylation of the kinase domain residue Tyr877 of ErbB2 (homologous to Tyr416 of pp60c-Src) may be involved in regulating ErbB2 biological activity. The major autophosphorylation sites in ErbB2 are Tyr1248 and Tyr1221/1222; phosphorylation of these sites couples ErbB2 to the Ras-Raf-MAP kinase signal transduction pathway (1,5).

  1. Muthuswamy, S.K. et al. (1999) Mol Cell Biol 19, 6845-57.
  2. Qian, X. et al. (1994) Proc Natl Acad Sci USA 91, 1500-4.
  3. Dittadi, R. and Gion, M. (2000) J Natl Cancer Inst 92, 1443-4.
  4. Klapper, L.N. et al. (2000) Cancer Res 60, 3384-8.
  5. Kwon, Y.K. et al. (1997) J Neurosci 17, 8293-9.

Application References

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Companion Products

This product is intended for research purposes only. The product is not intended to be used for therapeutic or diagnostic purposes in humans or animals.

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