Human-specific protein that promotes neural progenitor proliferation and evolutionary expansion of the brain neocortex by regulating the Notch signaling pathway ( ). Able to promote neural progenitor self-renewal, possibly by down-regulating neuronal differentiation genes, thereby delaying the differentiation of neuronal progenitors and leading to an overall final increase in neuronal production . Acts by enhancing the Notch signaling pathway via two different mechanisms that probably work in parallel to reach the same effect . Enhances Notch signaling pathway in a non-cell-autonomous manner via direct interaction with NOTCH2 . Also promotes Notch signaling pathway in a cell-autonomous manner through inhibition of cis DLL1-NOTCH2 interactions, which promotes neuronal differentiation (By similarity).
Subcellular locations: Secreted
Expressed in radial glia neural stem cells during cortical development.