Transcriptional repressor. Binds DNA on N-box motifs: 5'-CACNAG-3'. Promotes floor plate development and prechordal plate development. Required for lens development as early as the stage of lens field formation, partly through regulation of gene expression of the cell cycle inhibitor cdknx/p27(xic1). Required for formation of the neural crest downstream of multiple signaling pathways, and acts at the neural plate border via both DNA-binding dependent and independent mechanisms; acts in a DNA-binding dependent manner to repress pro-apoptotic and neural crest differentiation genes, including id3, delta1, and cdknx/p27(xic1), and thus promote the cell survival of neural plate border cells and maintain them in an undifferentiated state. Represses transcription of id3, at least in part through the repression of bmp4. On the other hand, acts in a DNA-independent manner separate from the transcriptional repressor function, to stimulate cell proliferation and promote neural crest formation. Via this DNA-independent route, acts in neurulae upstream of stat3 to transiently up-regulate the notch ligand dll1/delta1, which in turn up-regulates id3 expression. Then interacts directly with id3, which blocks the transcriptional repressor function of hes4-B/hairy2b to allow the progression of neural crest progenitors through specification and differentiation. Also acts via repressor-dependent and repressor-independent mechanisms in early gastrulae to establish the prospective anterior prechordal mesoderm identity in the Spemann organizer; induces specific genes independently from direct transcriptional regulation, and represses the genes specific for neighboring tissues through direct transcriptional repression. Modulates lateral inhibition during notch signaling and regulates the cell context dependent effects of notch (which can have inhibitory, permissive or enhancing roles in muscle or neural differentiation). Inhibits myogenesis. Transcription repression requires formation of a complex with a corepressor protein of the Groucho/TLE family. Interacts with the bHLH protein hes6; this interaction may inhibit the transcriptional repressor activity (By similarity). Binds DNA in the form of a heterodimer with the bHLH protein hey1/hrt1. Interacts (via Orange domain) with id3 (via HLH domain). Dynamically expressed in the borders of several tissue territories. Expressed in the pre-placodal ectoderm (PPE) from gastrula stage. During gastrulation, expressed in the deep layer of the dorsal lip, the Spemann organizer and three distinct regions in the prospective neuroectoderm: neural plate border, presumptive floor plate/notoplate and anterior neural plate. At later stages, expression is localized to the anterior of the prechordal plate, the presomitic mesoderm, neural tube, neural crest derivatives and several tissues of the central nervous system, with expression in the developing floor plate continues to at least the tadpole stage. From the early tailbud stage, expressed in the dorsoanterior region of the developing pronephros. During early tailbud stages, broadly expressed within the pronephric mesoderm. and in the sensorial layer of the ectoderm covering the pronephros anlagen. During late tailbud to early tadpole stages, expressed in the ventral region of the pronephros. Expression remains in the proximal and distal tubules at late tadpole stages (stage 35). Expressed zygotically. Shows higher zygotic expression than hes4-A/hairy2a. By Notch-signaling. Acts in a complex regulatory loop with other transcription factors and neural crest inducing signals at the neural plate border. Has a particular type of basic domain (presence of a helix-interrupting proline) that binds to the N-box (CACNAG), rather than the canonical E-box (CANNTG). The C-terminal WRPW motif is a transcriptional repression domain necessary for the interaction with Groucho/TLE family members, transcriptional corepressors recruited to specific target DNA by Hairy-related proteins (By similarity). The WPRW motif is also required for the inductive function, independent of a transcription regulation activity. PubMed:17724611 reports that the probe used in PubMed:12774230 cross-hybridizes with hes4-A/hairy2a, so the maternal expression reported in PubMed:12774230 is in fact due to hes4-A/hairy2a and not hes4-B/hairy2b.