Induction by NeuroD of the components required for regulated exocytosis

NeuroD is a transcriptional factor critical in differentiation of neuronal cells, enteroendocrine cells, and pancreatic endocrine cells. However, little is known of its roles in cellular functions. We show here that introduction of NeuroD into human fetal epithelial cell line Intestine 407 cells induces neuron-like morphology. In addition, multiple genes associated with vesicular trafficking and exocytotic machinery, including Sec24D, carboxypeptidase E, myosin Va, SNAP25, syntaxin 1A, Rab, Rims, Munc18-1, and adenylyl cyclase, were up-regulated by NeuroD gene transfer. Moreover, low osmotic pressure-induced exocytosis monitored by FM1-43 was enhanced by overexpression of NeuroD. These results suggest that NeuroD plays an important role in regulated exocytosis by inducing expressions of various components required in the process.