The Notch signaling pathway is a highly conserved Cell signaling system present in most multicellular organisms. Mammals possess four different Notch receptors, referred to as NOTCH1, NOTCH2, NOTCH3, and NOTCH4. (https://en.wikipedia.org/wiki/Notch_signaling_pathway)
The notch receptor is a single-pass Cell surface receptor. It is a hetero-oligomer composed of a large extracellular portion, which associates in a calcium-dependent, non-covalent interaction with a smaller piece of the notch protein composed of a short extracellular region, a single transmembrane-pass, and a small intracellular region. Notch signaling promotes proliferative signaling during neurogenesis, and its activity is inhibited by NUMB to promote neural differentiation. It plays a major role in the regulation of Embryonic development.