Anti-ERBB3 Antibody

Targeting the 180 kDa ERBB3 receptor, also known as HER3, this rabbit polyclonal IgG reagent from Antibodies.com detects endogenous levels of total ERBB3 protein across human, mouse, and rat samples. Supplied as a 50 µl vial of unconjugated antisera, the antibody is validated for Western blot and immunohistochemistry workflows and is intended for research use only.

ERBB3 harbors an intracellular kinase domain with markedly impaired catalytic activity, making transactivation through heterodimerization with partnering ErbB receptors the dominant route for downstream signaling. Direct recruitment of the p85 subunit of phosphoinositide 3-kinase by the ERBB3 C-terminal tail potently activates the PI3K-AKT survival axis, while heterodimer formation with HER2 or EGFR additionally engages MAPK, JAK, and SRC cascades implicated in tumor proliferation. The receptor is preferentially stimulated by neuregulin (heregulin) ligands and is unusual among ErbB family members in also dimerizing with non-ErbB partners such as MET and FGFR2. ERBB3 is therefore studied extensively in HER2-positive breast cancer, where compensatory receptor upregulation has been documented as a mechanism of acquired resistance against trastuzumab and other HER2-directed therapies, and is increasingly investigated as a co-target for combination regimens.

Researchers use this reagent to profile ERBB3 expression, map membrane and cytoplasmic localization patterns in tumor sections, monitor heregulin-driven receptor activation, and characterize HER2:ERBB3 heterodimer formation in both cultured cell models and patient-derived tissue. The vial is shipped refrigerated; upon arrival, aliquot and store at -20 °C to preserve activity and minimize damage from repeated freeze-thaw cycles.