POU Domain Class 4 Transcription Factor 1 (POU4F1)

BRN3A (POU4F1) is a class IV POU domain-containing transcription factor highly expressed in the developing sensory nervous system and in cells of the B- and T-lymphocytic lineages.Antibodies to Brn3a identified a large fraction of retinal ganglion cells. The 3 factors identified overlapping subsets of retinal ganglion cells and of neurons in the dorsal root and trigeminal ganglia, suggesting that primary somatosensory neurons and retinal ganglion cells share genetic regulatory hierarchies.Overexpression of BRN3B reduces process outgrowth and prevents the normal differentiation response. This inhibitory effect is abolished by mutating a single amino acid in the POU homeodomain of BRN3B to its equivalent in BRN3A. The converse mutation in BRN3A allows it to inhibit process outgrowth in response to induction of differentiation.