In the nucleus, NICD4 forms a complex with RBPJ (CBF1, CSL) and MAML (mastermind) proteins MAML1, MAML2 or MAML3 (possibly also MAMLD1). NICD4:RBPJ:MAML complex activates transcription from RBPJ-binding promoter elements (Lin et al. 2002).

Besides NICD4, RBPJ and MAML, NOTCH4 coactivator complex likely includes other proteins, shown as components of the NOTCH1 coactivator complex. Since disruption of the RBPJ:NCOR corepressor and MAML-mediated recruitment of transcriptional activators has not been studied in the context of NICD4, it is not shown here. More details are available in the pathway Signaling by NOTCH1.

NOTCH4 does not alter DNA binding specificity of RBPJ (Del Bianco et al. 2010).