POU4F1

POU domain, class 4, transcription factor 1 (POU4F1) also known as brain-specific homeobox/POU domain protein 3A (BRN3A), homeobox/POU domain protein RDC-1 or Oct-T1 is a protein that in humans is encoded by the POU4F1 gene.

BRN3A (POU4F1) is a class IV POU domain-containing transcription factor highly expressed in the developing peripheral sensory nervous system (dorsal root ganglia, trigeminal ganglion, and hindbrain sensory ganglia), certain regions of the central nervous system, retinal neurons called ganglion cells, and in cells of the B- and T-lymphocytic lineages.

Discovery

Brn3a was initially discovered in mice based on homology to the prototypal POU transcription factors Pit1 (Pituitary-specific positive transcription factor 1, Pou1f1), Oct1 (Pou2f1), and the Caenorhabditis elegans factor Unc86, and named Brn3. When multiple members of the Brn3 gene class were discovered, it was renamed Brn3.0 and Brn3a by different groups of researchers. Subsequently, the gene was systematically renamed Pou4f1 in mice and POU4F1 in humans. The protein product is still frequently referred to as Brn3a.