Physical interaction between a novel domain of the receptor Notch and the transcription factor RBP-J kappa/Su(H)

Curr Biol. 1995 Dec 1;5(12):1416-23. doi: 10.1016/s0960-9822(95)00279-x.


Background: The mammalian transcription factor RBP-J kappa binds to the DNA sequence motif CGTGGGAA and is involved in the regulation of gene expression; for example, it plays a part in the transactivation of viral and cellular genes by Epstein-Barr virus nuclear antigen-2. The Drosophila homologue of RBP-J kappa is the product of the Suppressor of Hairless (Su(H)) gene. Su(H) is a neurogenic gene that acts downstream of Notch, which encodes a cell-surface receptor. Furthermore, in the mouse, the phenotypes of homozygous mutant Notch1 embryos are very similar to those of homozygous mutant RBP-J kappa embryos. Recent studies, using the yeast two-hybrid system, have led to the suggestion that the CDC10/ankyrin-like repeats of the Drosophila Notch protein interact with the Su(H) protein.

Results: We searched for proteins that interact with mouse RBP-J kappa using the yeast two-hybrid system, and in this way identified a short intracellular region (mRAM23) of the mouse Notch1 protein that lacks any known sequence motif. In vitro interaction studies, using proteins fused to glutathione-S-transferase, showed that RBP-J kappa and Su(H) bind directly to the RAM23 regions of mouse Notch1 and Drosophila Notch, respectively. Immunoprecipitation analysis showed that RBP-J kappa and the mRAM23 region of mouse Notch1 also interact in vivo. Further studies, including site-directed mutagenesis experiments, narrowed down the region of mouse Notch1 that interacts with RBP-J kappa. The results indicate that this region is less than 50 amino-acid residues in length, and lies immediately downstream of the transmembrane region.

Conclusions: We show that the transcription factor RBP-J kappa/Su(H) interacts directly with a novel intracellular domain of the cell-surface receptor Notch. RBP-J kappa/Su(H) does not appear to interact with Notch via the CDC10/ankyrin repeats implicated in previous studies.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Amino Acid Sequence
  • Animals
  • Base Sequence
  • Binding Sites
  • Cell Line
  • DNA / genetics
  • DNA-Binding Proteins / metabolism*
  • Drosophila Proteins*
  • Membrane Proteins / chemistry
  • Membrane Proteins / metabolism*
  • Models, Biological
  • Molecular Sequence Data
  • Nuclear Proteins*
  • Receptor, Notch1
  • Receptors, Cell Surface / chemistry
  • Receptors, Cell Surface / metabolism*
  • Receptors, Notch
  • Repressor Proteins / metabolism*
  • Signal Transduction
  • Transcription Factors / metabolism*
  • Yeasts


  • DNA-Binding Proteins
  • Drosophila Proteins
  • Membrane Proteins
  • Nuclear Proteins
  • Receptor, Notch1
  • Receptors, Cell Surface
  • Receptors, Notch
  • Repressor Proteins
  • Su(H) protein, Drosophila
  • Transcription Factors
  • DNA