Heregulin beta-1 (human), animal-free recombinant

Product Description: Neuregulin/Heregulin represents a group of closely related polypeptide growth factors generated from alternate gene splicing (NRG1, NRG2, NRG3, and NRG4). Currently, there are more than 14 soluble and membrane-bound proteins derived from the NRG1 gene. The extracellular segment of transmembrane NRG1 isoforms undergoes proteolytic cleavage, producing soluble growth factors. Notably, HRG1-beta1 comprises an Immunoglobulin (Ig) domain alongside an Epidermal Growth Factor (EGF)-like domain, the latter is crucial for binding directly to the receptor tyrosine kinases erb3 and erb4. This binding event initiates erb3 and erb4 heterodimerization with erb2, thereby activating intrinsic kinase activity and leading to tyrosine phosphorylation. While the precise biological impacts of HRG1-beta1 remain unclear, studies have shown its role in enhancing the movement and invasive properties of breast cancer cells, potentially involving the upregulation of autocrine motility-promoting factor (AMF) expression and functionality. Recombinant Human Heregulinbeta-1 (HRG1-B1) is a 7.5 kDa polypeptide composed solely of the EGF domain from heregulinbeta-1, spanning 65 amino acid residues. . Amino acid sequence: SHLVKCAEKE KTFCVNGGEC FMVKDLSNPS RYLCKCPNEF TGDRCQNYVM ASFYKHLGIE FMEAE. Endotoxin concentration: <0.1 EU/µg. Activity: The ED50 was determined by the dose-dependent stimulation of the proliferation of human MCF-7 cells is = 0.5 ng/ml, corresponding to a specific activity of > 2 x 10^6 units/mg. Contains no preservative. Protein function: Direct ligand for ERBB3 and ERBB4 tyrosine kinase receptors. Concomitantly recruits ERBB1 and ERBB2 coreceptors, resulting in ligand-stimulated tyrosine phosphorylation and activation of the ERBB receptors. The multiple isoforms perform diverse functions such as inducing growth and differentiation of epithelial, glial, neuronal, and skeletal muscle cells, inducing expression of acetylcholine receptor in synaptic vesicles during the formation of the neuromuscular junction, stimulating lobuloalveolar budding and milk production in the mammary gland and inducing differentiation of mammary tumor cells, stimulating Schwann cell proliferation, implication in the development of the myocardium such as trabeculation of the developing heart. Isoform 10 may play a role in motor and sensory neuron development. Binds to ERBB4 (PubMed:10867024, PubMed:7902537). Binds to ERBB3 (PubMed:20682778). Acts as a ligand for integrins and binds (via EGF domain) to integrins ITGAV:ITGB3 or ITGA6:ITGB4. Its binding to integrins and subsequent ternary complex formation with integrins and ERRB3 are essential for NRG1-ERBB signaling. Induces the phosphorylation and activation of MAPK3/ERK1, MAPK1/ERK2 and AKT1 (PubMed:20682778). Ligand-dependent ERBB4 endocytosis is essential for the NRG1-mediated activation of these kinases in neurons. [The UniProt Consortium]