title: Xenopus Wntless and the retromer complex cooperate to regulate XWnt4 secretion.
abstract: Wnt signaling is implicated in a variety of developmental and pathological processes. The molecular mechanisms governing the secretion of Wnt ligands remain to be elucidated. Wntless, an evolutionarily conserved multipass transmembrane protein, is a dedicated secretion factor of Wnt proteins that participates in Drosophila melanogaster embryogenesis. In this study, we show that Xenopus laevis Wntless (XWntless) regulates the secretion of a specific Wnt ligand, XWnt4, and that this regulation is specifically required for eye development in Xenopus. Moreover, the Retromer complex is required for XWntless recycling to regulate the XWnt4-mediated eye development. Inhibition of Retromer function by Vps35 morpholino (MO) resulted in various Wnt deficiency phenotypes, affecting mesoderm induction, gastrulation cell movements, neural induction, neural tube closure, and eye development. Overexpression of XWntless led to the rescue of Vps35 MO-mediated eye defects but not other deficiencies. These results collectively suggest that XWntless and the Retromer complex are required for the efficient secretion of XWnt4, facilitating its role in Xenopus eye development.
authors.affiliation: Division of Molecular and Life Sciences, Pohang University of Science and Technology, Pohang, Kyungbuk 790-784, Republic of Korea.
authors.forename: Hyunjoon
authors.initials: H
authors.lastname: Kim
authors.forename: Seong-Moon
authors.initials: SM
authors.lastname: Cheong
authors.forename: Jihae
authors.initials: J
authors.lastname: Ryu
authors.forename: Hwa-Jin
authors.initials: HJ
authors.lastname: Jung
authors.forename: Eek-hoon
authors.initials: EH
authors.lastname: Jho
authors.forename: Jin-Kwan
authors.initials: JK
authors.lastname: Han
mesh_terms: D000818:Animals; D004627:Embryonic Induction; D005123:Eye / Q000196:embryology / Q000254:growth & development; D047908:Intracellular Signaling Peptides and Proteins / Q000502:physiology*; D008648:Mesoderm / Q000196:embryology; D046912:Multiprotein Complexes / Q000502:physiology; D054259:Neural Tube / Q000196:embryology; D033921:Vesicular Transport Proteins / Q000502:physiology*; D051153:Wnt Proteins / Q000378:metabolism*; D060528:Wnt4 Protein; D029867:Xenopus Proteins / Q000502:physiology*; D014982:Xenopus laevis
chemical_list: D047908:Intracellular Signaling Peptides and Proteins; D046912:Multiprotein Complexes; D033921:Vesicular Transport Proteins; C539904:WLS protein, Xenopus; D051153:Wnt Proteins; D060528:Wnt4 Protein; C555584:Wnt4 protein, Xenopus; D029867:Xenopus Proteins