Neuregulin-1 induces expression of Egr-1 and activates acetylcholine receptor transcription through an Egr-1-binding site.

Localization of acetylcholine receptors (AChRs) to neuromuscular synapses is mediated, in part, through selective transcription of AChR genes in myofiber synaptic nuclei. Neuregulin-1 (NRG-1) and its receptors, ErbBs, are concentrated at synaptic sites, and NRG-1 activates AChR synthesis in cultured muscle cells, suggesting that NRG-1-ErbB signaling functions to activate synapse-specific transcription. Previous studies have demonstrated that NRG-1-induced transcription is conferred by cis-acting elements located within 100 bp of 5' flanking DNA from the AChR epsilon subunit gene, and that it requires a GABP binding site within this region.