Cell Signaling Technology
XP Monoclonal Antibody

Product Pathways - Tyrosine Kinase / Adaptors

HER2/ErbB2 (D8F12) XP® Rabbit mAb #4290

Applications Reactivity Sensitivity MW (kDa) Isotype
W IHC-P H (M) (R) Endogenous 185 Rabbit IgG

Applications Key:  W=Western Blotting  IHC-P=Immunohistochemistry (Paraffin)
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

HER2/ErbB2 (D8F12) XP® Rabbit mAb detects endogenous levels of total HER/ErbB2 protein. This antibody may cross-react slightly with other overexpressed RTKs.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic peptide corresponding to residues near the amino terminus of human HER2/ErbB2 protein.

Western Blotting

Western Blotting

Western blot analysis of extracts from SK-BR-3 and MCF-7 cells using HER2/ErbB2 (D8F12) XP® Rabbit mAb.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human breast carcinoma using HER2/ErbB2 (D8F12) XP® Rabbit mAb.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded SK-BR-3 (Her2 high, left) and MCF-7 cell pellets (Her2 low, right) using HER2/ErbB2 (D8F12) XP® Rabbit mAb.


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

For Research Use Only. Not For Use In Diagnostic Procedures.

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