Transcriptional regulator that plays a central role in lin-12/Notch and glp-1/Notch signaling pathways, involved in cell-cell communication that regulate a broad spectrum of cell-fate determinations (PubMed:8625826). Binds directly to the 5'-[A/G]TGGGAA-3' DNA consensus sequence, which is present in the regulatory region of several genes (PubMed:8625826, PubMed:18706403, PubMed:23615264, PubMed:15297877, PubMed:32196486, PubMed:21737278). Acts as a transcriptional repressor when it is not associated with Notch proteins (By similarity). When in a complex with a Notch intracellular domain (NICD) product of lin-12/Notch or glp-1/Notch, and transcription regulator lag-3, it may act as a transcriptional activator that activates transcription of target genes(PubMed:18381292, PubMed:10830967, PubMed:32196486, PubMed:9003776). Probably represses or activates transcription via the recruitment of chromatin remodeling complexes containing histone deacetylase or histone acetylase proteins, respectively (By similarity). Autonomously required in the germline for the stem cell fate, acting in the glp-1-dependent transcriptional activation of genes, including lst-1 and sygl-1 (PubMed:32196486). Involved in cell-fate specification during reproductive system development, by positively autoregulating its own expression, in response to lin-12/Notch signaling (PubMed:23615264, PubMed:32839181). Plays a role in Notch-dependent induction of left-right asymmetry in interneurons and motoneurons (PubMed:21737278). May repress expression of hlh-6, in a lin-12/Notch-independent manner (PubMed:18706403).