NRG1: 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. The cytoplasmic domain interacts with the LIM domain region of LIMK1. Interacts with ERBB3 and ERBB4. Type I isoforms are the predominant forms expressed in the endocardium. Isoform alpha is expressed in breast, ovary, testis, prostate, heart, skeletal muscle, lung, placenta liver, kidney, salivary gland, small intestine and brain, but not in uterus, stomach, pancreas, and spleen. Isoform 3 is the predominant form in mesenchymal cells and in non-neuronal organs, whereas isoform 6 is the major neuronal form. Isoform 8 is expressed in spinal cord and brain. Isoform 9 is the major form in skeletal muscle cells; in the nervous system it is expressed in spinal cord and brain. Also detected in adult heart, placenta, lung, liver, kidney, and pancreas. Isoform 10 is expressed in nervous system: spinal cord motor neurons, dorsal root ganglion neurons, and brain. Predominant isoform expressed in sensory and motor neurons. Not detected in adult heart, placenta, lung, liver, skeletal muscle, kidney, and pancreas. Not expressed in fetal lung, liver and kidney. Type IV isoforms are brain-specific. Belongs to the neuregulin family. 10 isoforms of the human protein are produced by alternative splicing.
Protein type: Cell development/differentiation; Cytokine; Ligand, receptor tyrosine kinase; Membrane protein, integral; Motility/polarity/chemotaxis
Chromosomal Location of Human Ortholog: 16q12.3
Cellular Component: apical plasma membrane; axolemma; axon; cytoplasm; dendrite; external side of plasma membrane; extracellular region; extracellular space; integral component of membrane; integral component of plasma membrane; intracellular; neuromuscular junction; nucleoplasm; nucleus; plasma membrane; synapse
Molecular Function: chemorepellent activity; ErbB-2 class receptor binding; ErbB-3 class receptor binding; growth factor activity; integrin binding; protein tyrosine kinase activator activity; receptor binding; receptor tyrosine kinase binding; transcription cofactor activity
Biological Process: activation of MAPK activity; activation of protein kinase B activity; activation of transmembrane receptor protein tyrosine kinase activity; animal organ development; axon ensheathment; brain development; cardiac muscle cell differentiation; cardiac muscle tissue development; cell migration; cell morphogenesis; cell proliferation; cellular protein complex disassembly; chemorepulsion involved in interneuron migration from the subpallium to the cortex; glial cell differentiation; glial cell fate commitment; heart development; locomotory behavior; MAPK cascade; memory; muscle organ development; negative regulation of protein catabolic process; negative regulation of secretion; negative regulation of transcription, DNA-dependent; nervous system development; neurogenesis; neuron fate commitment; neurotransmitter receptor metabolic process; oligodendrocyte differentiation; peripheral nervous system development; positive regulation of axon extension; positive regulation of axon regeneration; positive regulation of cardiac muscle cell proliferation; positive regulation of cell adhesion; positive regulation of cell growth; positive regulation of cell proliferation; positive regulation of myelination; positive regulation of peptidyl-tyrosine phosphorylation; positive regulation of phosphoinositide 3-kinase cascade; positive regulation of protein kinase activity; positive regulation of protein kinase B signaling; positive regulation of Ras protein signal transduction; positive regulation of striated muscle cell differentiation; positive regulation of transcription from RNA polymerase II promoter; regulation of cell differentiation; regulation of protein heterodimerization activity; response to progesterone; startle response; synaptogenesis; transmembrane receptor protein tyrosine kinase signaling pathway; ventricular cardiac muscle cell differentiation; wound healing
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