THE DNA-BINDING ACTIVITY OF THE PAIRED BOX TRANSCRIPTION FACTOR PAX-3IS RAPIDLY DOWN-REGULATED DURING NEURONAL CELL-DIFFERENTIATION

Mutations in tile murine Pax-3 gene lead to a range of developmental a bnormalities including deficiencies in sensory and sympathetic neurone s. We have investigated Pax-3 expression during neuronal differentiati on and show levels of Pax-3 DNA binding decrease upon cell cycle arres t and morphological differentiation. The fall in Pax-3 DNA binding occ urs 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 activ ity precedes any changes in cell proliferation or morphology, suggesti ng that the downregulation of this transcription factor may be an impo rtant prerequisite for the differentiation of neuronal progenitor cell s. (C) 1998 Federation of European Biochemical Societies.