Rat Neuregulin 1, NRG-1 ELI

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.

Binds to ERBB4 and ERBB3.

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 (By similarity).

Induces the phosphorylation and activation of MAPK3/ERK1, MAPK1/ERK2 and AKT1, and ligand-dependent ERBB4 endocytosis is essential for the NRG1-mediated activation of these kinases in neurons (PubMed: 17250808).