Notch modulates Wnt signalling by associating with Armadillo/beta-catenin and regulating its transcriptional activity.
The establishment and stability of cell fates during development depend on the integration of multiple signals, which ultimately modulate specific patterns of gene expression. While there is ample evidence for this integration at the level of gene regulatory sequences, little is known about its operation at other levels of cellular activity. Wnt and Notch signalling are important elements of the circuitry that regulates gene expression in development and disease. Genetic analysis has suggested that in addition to convergence on the transcription of specific genes, there are modulatory cross-regulatory interactions between these signalling pathways. We report that the nodal point of these interactions is an activity of Notch that regulates the activity and the amount of the active/oncogenic form of Armadillo/beta-catenin. This activity of Notch is independent of that induced upon cleavage of its intracellular domain and which mediates transcription through Su(H)/CBF1. The modulatory function of Notch described here, contributes to the establishment of a robust threshold for Wnt signalling which is likely to play important roles in both normal and pathological situations.
Hayward
Penny
P
Department of Genetics, University of Cambridge, Cambridge CB2 3EH, UK.
Brennan
Keith
K
Sanders
Phil
P
Balayo
Tina
T
DasGupta
Ramanuj
R
Perrimon
Norbert
N
Martinez Arias
Alfonso
A
D000818:Animals; D051186:Armadillo Domain Proteins; D003598:Cytoskeletal Proteins / Q000378:metabolism*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster; D018507:Gene Expression Regulation, Developmental; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D036341:Intercellular Signaling Peptides and Proteins / Q000378:metabolism*; D008156:Luciferases; D008565:Membrane Proteins / Q000378:metabolism*; D034622:RNA Interference; D051880:Receptors, Notch; D015398:Signal Transduction / Q000502:physiology*; D015534:Trans-Activators / Q000378:metabolism*; D014157:Transcription Factors; D051153:Wnt Proteins; D051176:beta Catenin
C495305:ARM protein, Drosophila; D051186:Armadillo Domain Proteins; D003598:Cytoskeletal Proteins; D029721:Drosophila Proteins; D036341:Intercellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C497759:N protein, Drosophila; D051880:Receptors, Notch; D015534:Trans-Activators; D014157:Transcription Factors; D051153:Wnt Proteins; D051176:beta Catenin; D008156:Luciferases