Cell Signaling Technology

Product Pathways - Tyrosine Kinase/ Adaptors

Phospho-HER3/ErbB3 (Tyr1289) (21D3) Rabbit mAb #4791

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

Applications Key:  W=Western Blotting  IP=Immunoprecipitation  IHC-P=Immunohistochemistry (Paraffin)
Reactivity Key:  H=Human
Species cross-reactivity is determined by Western blot.

Specificity / Sensitivity

Phospho-HER3/ErbB3 (Tyr1289) (21D3) Rabbit mAb detects endogenous HER3/ErbB3 proteins only when phosphorylated at tyrosine 1289. The antibody does not cross-react with other phosphorylated receptor tyrosine kinases.

Source / Purification

Monoclonal antibodies are produced by immunizing rabbits with a synthetic phospho-peptide (KLH-coupled) corresponding to residues surrounding Tyr1289 of human HER3/ErbB3.

Western Blotting

Western Blotting

Phospho-HER3/ErbB3 (Tyr1289) (21D3) Rabbit mAb specifically binds to phosphorylated HER3/ErbB3 but not other phosphorylated tyrosine kinases. Western blot analysis of extracts from cells expressing different activated tyrosine kinase proteins, using Phospho-HER3/ErbB3 (Tyr1289) (21D3) Rabbit mAb (upper) or Phospho-Tyrosine mAb (P-Tyr-100) #9411 (lower).

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human breast carcinoma, using Phospho-HER3/ErbB3 (Tyr1289)(21D3) Rabbit mAb.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human lung carcinoma, using Phospho-HER3/ErbB3 (Tyr1289) (21D3) Rabbit mAb.


IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded MDA-MB-453 cells, untreated (left) or neuregulin-treated (right), using Phospho-HER3/ErbB3 (Tyr1289)(21D3) Rabbit mAb.

IHC-P (paraffin)

IHC-P (paraffin)

Immunohistochemical analysis of paraffin-embedded human prostate carcinoma, untreated (left) or Calf Intestinal Phosphatase (CIP)-treated (right), using Phospho-HER3/ErbB3 (Tyr1289)(21D3) Rabbit mAb.

Background

HER3/ErbB3 is a member of the ErbB receptor protein tyrosine kinase family, but lacks tyrosine kinase activity. Tyrosine phosphorylation of ErbB3 depends on its association with other ErbB tyrosine kinases. Upon ligand binding, heterodimers form between ErbB3 and other ErbB proteins and ErbB3 is phosphorylated on tyrosine residues by the activated ErbB kinase (1,2). There are at least 9 potential tyrosine phosphorylation sites in the carboxy-terminal tail of ErbB3. These sites serve as consensus binding sites for signal transducing proteins, including Src family members, Grb2 and the p85 subunit of PI3 kinase, which mediate ErbB-downstream signaling (3). Both Tyr1222 and Tyr1289 of ErbB3 reside within a YXXM motif and participate in signaling to PI3 kinase (4).ErbB3 is highly expressed in many cancer cells (5) and activation of the ErbB3/PI3 kinase pathway is correlated with malignant phenotypes of adenocarcinomas (6). In tumor development, ErbB3 may function as an oncogenic unit together with other ErbB members, e.g. ErbB2 requires ErbB3 to drive breast tumor cell proliferation (7). Thus, prevention of the interaction between ErbB3 and ErbB tyrosine kinases has become a novel anti-tumor strategy.

  1. Yarden, Y. and Sliwkowski, M.X. (2001) Nature Rev. Mol. Cell. Biol. 2, 127-137.
  2. Guy, P.M. et al. (1994) Proc. Natl. Acad. Sci. USA 91, 8132-8136.
  3. Songyang, Z. et al. (1993) Cell 72, 767-778.
  4. Kim, H.H. et al. (1994) J. Biol. Chem. 269, 24747-24755.
  5. Sithanandam, G. et al. (2003) Carcinogenesis 24, 1581-1592.
  6. Kobayashi, M. et al. (2003) Oncogene 22, 1294-1301.
  7. Holbro, T. et al. (2003) Proc. Natl. Acad. Sci. USA 100, 8933-8938.

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.

This product is for in vitro research use only and is not intended for use in humans or animals. This product is not intended for use as therapeutic or in diagnostic procedures.

Product Pathways

Drug Discovery Tools

Featured Technologies

Protein Classes