Fig. 9.

Model depicting regulation of Ncad trafficking in NC cells by Ovo1. Canonical Wnt/β-catenin signaling through Tcf transcription factors regulates ovo1 transcript levels in NC cells. Ovo1 normally represses the transcription of rab3c, rab12, rab11fip2 and sec6, which maintain the balance of intracellular and membrane-localized Ncad. Abnormally high levels of Rab3c, Rab12, Rab11fip2 and Sec6 in Ovo1-deficient NC promote hyperactive intracellular trafficking of Ncad; Ncad secretion from the trans-Golgi network (TGN) and recycling through the early and recycling endosomes (EE and RE) increases. Consequently, Ncad becomes depleted at the membrane. EC, extracellular space; IC, intracellular space.