Distinct domains of Brn-3a regulate apoptosis and neurite outgrowth in vivo.

The Brn-3a transcription factor is critical for the normal development of the nervous system, promoting both neuronal survival and neurite outgrowth. By manipulating the Brn-3a gene in intact mice, we show that these two functions are separately controlled with an N-terminal domain being essential for neuronal survival, whereas the POU domain is essential for neurite outgrowth. Hence the two naturally occurring forms of Brn-3a, which either contain or lack the N-terminal domain, are likely to play distinct roles in the nervous system.