NUCLEAR ACCESS AND ACTION OF NOTCH IN-VIVO

The Drosophila Notch (N) gene encodes a conserved single-pass transmem brane receptor that transduces extracellular signals controlling cell fate. Here, we present evidence that the intracellular domain of Notch gains access to the nucleus in response to ligand, possibly through a mechanism involving proteolytic cleavage and release from the remaind er of the protein. In addition, our results suggest that signal transd uction by Notch depends on the ability of the intracellular domain, pa rticularly the portion containing the CDC10 repeats, to reach the nucl eus and to participate in the transcriptional activation of downstream target genes.