BRN3A: Proteins and Enzymes

Brn-3a is a transcription factor belonging to the class IV of POU domain transcription factors. It is expressed throughout the peripheral nervous system but especially in postmitotic sensory neurons of dorsal root ganglia. Brn-3a is known to regulate different genes involved in neuronal differentiation and survival (1). Characterization of Brn-3a suggests potential roles of Brn-3a in the development of retinal ganglion cells and sensory neurons, as well as potential roles in the pituitary gland and the immune system. Brn-3a is expressed in the pituitary gland and in a corticotroph cell line (2). The differentiation of the ND7 neuronal cell line to a nondividing phenotype bearing numerous neurite processes is accompanied by a dramatic increase in the levels of the activating POU family transcription factor Brn-3a and a corresponding fall in the levels of the closely related inhibitory factor Brn-3b. Over expression of Brn-3a in these cells can induce neurite outgrowth and the activation of genes encoding synaptic vesicle proteins in the absence of a differentiation-inducing stimulus (3).