Cell Signaling Technology

Product Pathways - Tyrosine Kinase / Adaptors

Phospho-HER2/ErbB2 (Tyr1221/1222) (6B12) Rabbit mAb #2243

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

Applications Key:  W=Western Blotting  IHC-P=Immunohistochemistry (Paraffin)  IHC-F=Immunohistochemistry (Frozen)
Reactivity Key:  H=Human
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 (Tyr1221/1222) (6B12) Rabbit mAb detects endogenous levels of ErbB2 only when phosphorylated at tyrosines 1221/1222. The antibody does not detect other activated Erb family members or other tyrosine-phosphorylated proteins.

Source / Purification

Monoclonal antibody is produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding tyrosines 1221/1222 of human ErbB2 protein.

Western Blotting

Western Blotting

Western blot analysis of extracts from cells expressing different activated tyrosine kinase proteins, using Phospho-HER2/ErbB2 (Tyr1221/1222) (6B12) Rabbit mAb (upper) or Phospho-Tyrosine mAb (P-Tyr-100) #9411 (lower). Phospho-HER2/ErbB2 (Tyr1221/1222) (6B12) Rabbit mAb specifically detects phosphorylated HER2/ErbB2 but not other phosphorylated tyrosine kinases.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human breast carcinoma, showing membrane localization, using Phospho-HER2/ErbB2 (Tyr1221/1222) (6B12) Rabbit mAb.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded SkBr3 cell pellets untreated (left) EGF-treated (right) either untreated (top) or lambda-phosphatase-treated (bottom), using Phospho-HER2/ErbB2 (Tyr1221/1222) (6B12) Rabbit mAb.


IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human renal adenocarcinoma, using Phospho-HER2/ErbB2 (Tyr1221/1222) (6B12) Rabbit mAb in the presence of control peptide (left) or Phospho-HER2/ErbB2 (Tyr1221/1222) Blocking Peptide #1254 (right).

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human NCI-H358 xenograft, using Phospho-HER2/ErbB2 (Tyr1221/1222) (6B12) Rabbit mAb.

IHC-F (frozen)

IHC-F (frozen)

Immunohistochemical analysis of frozen HCC827 xenograft, using Phospho-Her2/ErbB2 (Tyr1221/1222)(6B12) 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

Have you published research involving the use of our products? If so we'd love to hear about it. Please let us know!

Companion Products

Rabbit Monoclonals Produced Using Epitomics® Technology, U.S. Patent No. 5,675,063.

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

Products