CST, 4791L, Phospho-HER3/ErbB3 (Tyr1289) (21D3) Rabbit Monoclonal Antibody

Monoclonal Antibody for studying HER3/ErbB3 (Tyr1289) phosphate. Validated for WB,WB,IP,IHC. Available in 3 sizes. Highly specific and rigorously validated in-house, Phospho-HER3/ErbB3 (Tyr1289) (21D3) Rabbit Monoclonal Antibody (CST #4791) is ready to ship. Product Usage Information Western Blotting: 1:1000 Simple Western™: 1:50 - 1:250 Immunoprecipitation: 1:100 Immunohistochemistry (Paraffin): 1:500 - 1:2000 Storage Supplied in 10 mM sodium HEPES (pH 7.5), 150 mM NaCl, 100 µg/ml BSA, 50% glycerol and less than 0.02% sodium azide. Store at -20°C. Do not aliquot the antibody. For a carrier free (BSA and azide free) version of this product see product # 73367 . Protocol Available protocols: Western Blotting, Immunoprecipitation, Immunohistochemistry (Paraffin) Specificity / Sensitivity Phospho-HER3/ErbB3 (Tyr1289) (21D3) Rabbit Monoclonal Antibody detects endogenous HER3/ErbB3 proteins only when phosphorylated at tyrosine 1289. This antibody cross-reacts with overexpressed EGFR. This antibody may cross-react with overexpressed receptor tyrosine kinases in IHC. Species Reactivity: Human, Mouse Source / Purification Monoclonal antibody is produced by immunizing animals with a synthetic phosphopeptide corresponding to residues surrounding Tyr1289 of human HER3/ErbB3. Background HER3/ErbB3 is a member of the ErbB receptor protein tyrosine kinase family, but it 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 PI3K (4). Investigators have found that ErbB3 is highly expressed in many cancer cells (5) and activation of the ErbB3/PI3K pathway is correlated with malignant phenotypes of adenocarcinomas (6). Research studies have demonstrated that 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, investigators view inhibiting interaction between ErbB3 and ErbB tyrosine kinases as a novel strategy for anti-tumor therapy. Alternate Names c-erbB-3; c-erbB3; erb-b2 receptor tyrosine kinase 3; ErbB-3; ERBB3; erbB3-S; FERLK; HER3; human epidermal growth factor receptor 3; LCCS2; MDA-BF-1; MGC88033; p180-ErbB3; p45-sErbB3; p85-sErbB3; Proto-oncogene-like protein c-ErbB-3; Receptor tyrosine-protein kinase erbB-3; Tyrosine kinase-type cell surface receptor HER3; v-erb-b2 avian erythroblastic leukemia viral oncogene homolog 3; v-erb-b2 erythroblastic leukemia viral oncogene homolog 3 (avian) Specification REACTIVITY: H M SENSITIVITY: Endogenous MW (kDa): 185 Source/Isotype: Rabbit IgG