Transcription factor that binds to the octamer motif (5'- ATTTGCAT-3') (By similarity). Acts as a transcriptional activator when binding cooperatively with SOX4, SOX11, or SOX12 to gene promoters (By similarity). Acts as a transcriptional repressor of myelin-specific genes (By similarity). {ECO:0000250|UniProtKB:P20267, ECO:0000250|UniProtKB:P21952}. This is the function of POU3F1 (POU class 3 homeobox 1, ENSG00000185668).