Direct regulation of the Nrarp gene promoter by the Notch signaling pathway.
Nrarp encodes for an evolutionarily conserved small ankyrin repeat-containing protein that functions as a negative regulator of Notch signaling. Interestingly, increased Nrarp transcription was observed following induction of Notch signaling, suggesting the existence of a negative feedback loop. We show here that both mouse and human promoter regions of Nrarp share two conserved regions located approximately 2 and approximately 3 kb upstream of the transcription start site each containing a perfect putative binding site for the Notch-dependent transcription factor Su(H). A 4.4 kb genomic fragment of the mouse Nrarp locus containing those conserved regions and fused to a luciferase reporter gene showed basal promoter activity in 293T cells and this activity was strongly increased by the intracellular domain of Notch, NICD. NICD-dependent stimulation was attenuated by a dominant negative mutant of Su(H), Su(H)DBM, and was not observed in Su(H)-deficient cells (OT-11). Promoter bashing and gel shift assays revealed that the most distal putative Su(H) binding site located within the -3 kb conserved element plays a crucial role in this induction. Collectively, these results provide definitive support for direct regulation of the Nrarp gene by the Notch pathway.
Pirot
Pierre
P
Laboratoire d'Embryologie Moléculaire, Université Libre de Bruxelles, Institut de Biologie et de Médecine Moléculaires, rue des Profs. Jeener et Brachet 12, B-6041 Gosselies, Belgium.
van Grunsven
Leo A
LA
Marine
Jean-Christophe
JC
Huylebroeck
Danny
D
Bellefroid
Eric J
EJ
D000818:Animals; D001483:Base Sequence; D005786:Gene Expression Regulation / Q000502:physiology*; D017930:Genes, Reporter; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000378:metabolism*; D051379:Mice; D008969:Molecular Sequence Data; D011401:Promoter Regions, Genetic; D011506:Proteins / Q000235:genetics* / Q000378:metabolism; D051880:Receptors, Notch; D015398:Signal Transduction / Q000502:physiology*; D024363:Transcription Initiation Site
D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C499040:Nrarp protein, mouse; D011506:Proteins; D051880:Receptors, Notch