Jagged 2 Protein (JAG2)

JAG2 is one of several ligands that activate Notch and related receptors. The predicted 1,238-amino acid JAG2 protein has several recognizable motifs, including a signal peptide, 16 EGF-like repeats, a transmembrane domain, and a short cytoplasmic domain. The amino acid sequence of human JAG2 is 89% identical to that of rat Jag2. Northern blot analysis and in situ hybridization showed expression of Jag2 in various murine tissues. Immunohistochemistry revealed coexpression of Jag2 and Notch1 within murine fetal thymus and other murine fetal tissues. Coculture of fibroblasts expressing human JAG2 with murine C2C12 myoblasts inhibited myogenic differentiation. This effect was simulated by expression of constitutively active Notch1, suggesting that JAG2 engages the Notch1 pathway of signal transduction.