A HUMAN POU DOMAIN GENE, MPOU, IS EXPRESSED IN DEVELOPING BRAIN AND SPECIFIC ADULT TISSUES

POU domain genes constitute a family of transcription factors that exh ibit distinct temporal and spatial patterns of expression. To investig ate the possible functions that POU proteins may have in muscle develo pment we have isolated four novel POU-domain-encoding sequences from h uman muscle tissue. One of these sequences, referred to as mPOU, encod es a new member of subclass VI of the POU family. In the embryo, mPOU is expressed exclusively in the developing brain, whereas in the adult its expression is restricted to brain, heart, skeletal muscle and lun g. In the brain, the highest expression levels were found in specific cell layers of the cortex, the olfactory bulb, the hippocampus and the cerebellum. mPOU is shown to bind to DNA sequences containing the oct amer motif and other POU factor target sites. The distinct expression pattern and divergent DNA-binding characteristics indicate that mPOU m ay regulate a distinct set of genes.