The DNA binding activity of the paired box transcription factor Pax-3 is rapidly downregulated during neuronal cell differentiation

Mutations in the murine Pax-3 gene lead to a range of developmental abnormalities including deficiencies in sensory and sympathetic neurones. We have investigated Pax-3 expression during neuronal differentiation and show levels of Pax-3 DNA binding decrease upon cell cycle arrest and morphological differentiation. The fall in Pax-3 DNA binding occurs within 1 h of the induction of differentiation and is mediated in part by a decrease in Pax-3 mRNA. This decrease in Pax-3 binding activity precedes any changes in cell proliferation or morphology, suggesting that the downregulation of this transcription factor may be an important prerequisite for the differentiation of neuronal progenitor cells. (C) 1998 Federation of European Biochemical Societies.