Promotes loss of intracellular domain (ICD) of Notch1 in embryos. By down-regulating ICD levels, could function as a negative feedback regulator of Notch signaling that attenuates ICD-mediated transcription (PubMed:11485984). Involved in angiogenesis. May be involved in somitogenesis (By similarity). Forms a ternary complex with the intracellular domain (ICD) of notch1 and rbpj/suh. Detected at late gastrulae stages within the prospective trigeminal placodes, followed soon in the posterior neural plate where the differentiation of primary neurons occurs. Expression is associated with neurogenesis throughout neural development. Expressed in a ring of tissue that will form the early somites in gastrulating embryos and in a region of paraxial mesoderm called the tailbud domain, which grows out to give rise to somites in the tail in later-stage embryos. By Notch signaling via a CBF1/Su(H)/Lag-1 (CSL)-dependent pathway. Belongs to the NRARP family.