Regulation of Wnt and FGF Signaling within the Endoplasmic Reticulum for Head Formation

Head formation requires the simultaneous inhibition of multiple caudalizing signals during early vertebrate embryogenesis. Elucidation of molecular mechanisms that establish the anterior-posterior axis of body patterning as well as the nervous system is a major topic in development. Recently, we have identified a novel antagonist against Wnt and FGF signaling for head formation, Shisa, which functions cellautonomously in the endoplasmic reticulum (ER). Shisa suppresses the processes of protein maturation and cellular transportation of Wnt and FGF receptors in ER, thereby inhibiting both signaling pathways. Thus, the study of Shisa provide new molecular concepts for signaling regulation in which cells control the establishment of particular signaling components in ER.