Summary

Abstract

Neuregulins (NRGs) comprise a large family of EGF-like signaling molecules involved in cell-cell communication during development and disease. The neuregulin family of ligands has four members: NRG1, NRG2, NRG3, and NRG4. Relatively little is known about the biological functions of the NRG2, 3, and 4 proteins. In contrast, the NRG1 proteins have been demonstrated to play important roles during the development of the nervous system, heart, and mammary glands. For example, NRG1 has essential functions in the development of neural crest cells and some of their major derivatives, like Schwann cells and sympathetic neurons. NRG1 controls the trabeculation of the myocardial musculature and the ductal differentiation of the mammary epithelium. Moreover, there is emerging evidence for the involvement of NRG signals in the development and function of several other organ systems, and in human disease, including breast cancer and schizophrenia. Many different isoforms of the Neuregulin-1 gene are synthesized. Such isoforms differ in their tissue-specific expression patterns and their biological activities, thereby contributing to the great diversity of the in vivo functions of NRG1.