P5A-ATPase controls the ER translocation of Wnt in neuronal migration

Abstract

Wnt family are conserved secretory proteins required for developmental patterning and tissue homeostasis. The mechanisms underlying intracellular maturation and intercellular signal transduction of Wnt proteins have been extensively studied. However, how Wnt is targeted to the endoplasmic reticulum (ER) for processing and secretion remains elusive. Here we report that CATP-8/P5A-ATPase directs neuronal migration non-cell autonomously in C. elegans by regulating EGL-20/Wnt biogenesis. CATP-8 functions as a translocase to translocate EGL-20/Wnt nascent polypeptide into the ER by interacting with the hydrophobic core region of EGL-20 signal sequence. Such regulation of Wnt biogenesis by P5A-ATPase is conserved in human cells. These findings reveal physiological roles of P5A-ATPase in neural development and identify Wnt proteins as direct substrates of P5A-ATPase for ER translocation.