Phospho-HER4/ErbB4 (Tyr984) Recombinant Rabbit mAb (S-3502-53)

Phospho-HER4/ErbB4 (Tyr984) is the activated form of the HER4/ErbB4 receptor protein resulting from specific phosphorylation at tyrosine residue 984, indicating that the receptor is in a signaling-active state. HER4/ErbB4 is the fourth member of the epidermal growth factor receptor (EGFR) family and belongs to the receptor tyrosine kinase (RTK) family, with its intracellular kinase domain sharing high homology with EGFR and HER2 (79% and 77%, respectively), and it plays critical roles in the development of the nervous system, heart, and mammary glands. Upon ligand binding (such as neuregulins NRG1-4, BTC, HB-EGF, etc.), HER4 forms homo- or heterodimers, leading to autophosphorylation at multiple tyrosine residues in its C-terminal tail. Among these, Tyr984 (numbered according to the human sequence) is one of the key phosphorylation sites; phosphorylation at this site marks the activation of the receptor's kinase activity and provides docking sites for downstream signaling molecules, thereby activating multiple signaling pathways such as MAPK/ERK and PI3K/AKT to regulate cell proliferation, differentiation, migration, and apoptosis.