Jagged 1 (JAG1)

Jagged-1 is a ligand of the Notch receptor, and their binding triggers a cascade of proteolytic cleavage that eventually leads to the release of the intracellular part of the receptor from the membrane, allowing it to translocate to the nucleus and activate transcription factors that play key roles in cell differentiation and morphogenesis
The jagged 1 protein encoded by JAG1 is the human homolog of the Drosophilia jagged protein. Human jagged 1 is the ligand for the receptor notch 1, the latter a human homolog of the Drosophilia jagged receptor notch. Mutations that alter the jagged 1 protein cause Alagille syndrome. Jagged 1 signalling through notch 1 has also been shown to play a role in hematopoiesis.