Notch proteins participate in intercellular signalling events that mediate cell-fate specification. Three are four mammalian Notches: Notch1, Notch2, Notch3 and Notch4/Int-3. Notch is expressed in uncommitted proliferative cells during development and is believed to function in the adult to maintain the proliferative capacity of immature cells. Disruption or disregulation of Notch signalling has been associated with human neoplastic disease, cerebral autosomal dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), and Alagille syndrome.
Notch is involved in the cell fate determination of many cell lineages.
The intracellular region (RAMIC) of Notch1 transactivates genes by interaction with RBP-J/Su(H). RAMIC comprises two separate domains, IC for transactivation and RAM for RBP-J/Su(H) binding. Although the physical interaction of IC with RBP-J/Su(H) was much weaker than with RAM, transactivation activity of IC was shown to involve RBP-J/Su(H) by using an RBP-J/Su(H) null mutant cell line .