title: Lypd6 enhances Wnt/β-catenin signaling by promoting Lrp6 phosphorylation in raft plasma membrane domains.
abstract: Wnt/β-catenin signaling plays critical roles during embryogenesis, tissue homeostasis, and regeneration. How Wnt-receptor complex activity is regulated is not yet fully understood. Here, we identify the Ly6 family protein LY6/PLAUR domain-containing 6 (Lypd6) as a positive feedback regulator of Wnt/β-catenin signaling. lypd6 enhances Wnt signaling in zebrafish and Xenopus embryos and in mammalian cells, and it is required for wnt8-mediated patterning of the mesoderm and neuroectoderm during zebrafish gastrulation. Lypd6 is GPI anchored to the plasma membrane and physically interacts with the Wnt receptor Frizzled8 and the coreceptor Lrp6. Biophysical and biochemical evidence indicates that Lypd6 preferentially localizes to raft membrane domains, where Lrp6 is phosphorylated upon Wnt stimulation. lypd6 knockdown or mislocalization of the Lypd6 protein to nonraft membrane domains shifts Lrp6 phosphorylation to these domains and inhibits Wnt signaling. Thus, Lypd6 appears to control Lrp6 activation specifically in membrane rafts, which is essential for downstream signaling.
authors.affiliation: Biotechnology Center, Technische Universität Dresden, Tatzberg 47, 01307 Dresden, Germany.
authors.forename: Günes
authors.initials: G
authors.lastname: Özhan
authors.forename: Erdinc
authors.initials: E
authors.lastname: Sezgin
authors.forename: Daniel
authors.initials: D
authors.lastname: Wehner
authors.forename: Astrid S
authors.initials: AS
authors.lastname: Pfister
authors.forename: Susanne J
authors.initials: SJ
authors.lastname: Kühl
authors.forename: Birgit
authors.initials: B
authors.lastname: Kagermeier-Schenk
authors.forename: Michael
authors.initials: M
authors.lastname: Kühl
authors.forename: Petra
authors.initials: P
authors.lastname: Schwille
authors.forename: Gilbert
authors.initials: G
authors.lastname: Weidinger
mesh_terms: D000818:Animals; D000950:Antigens, Ly / Q000378:metabolism*; D019521:Body Patterning / Q000235:genetics; D004625:Embryo, Nonmammalian / Q000378:metabolism; D018507:Gene Expression Regulation, Developmental; D017261:Glycosylphosphatidylinositols / Q000378:metabolism; D057809:HEK293 Cells; D006801:Humans; D060488:Low Density Lipoprotein Receptor-Related Protein-6 / Q000378:metabolism*; D021962:Membrane Microdomains / Q000378:metabolism*; D008648:Mesoderm / Q000196:embryology / Q000378:metabolism; D051379:Mice; D008954:Models, Biological; D008969:Molecular Sequence Data; D054258:Neural Plate / Q000196:embryology / Q000378:metabolism; D010766:Phosphorylation; D011485:Protein Binding; D021381:Protein Transport; D060490:Receptors, Wnt / Q000378:metabolism; D014158:Transcription, Genetic; D060449:Wnt Signaling Pathway / Q000235:genetics; D014981:Xenopus / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D015027:Zebrafish / Q000196:embryology / Q000235:genetics / Q000378:metabolism*; D029961:Zebrafish Proteins / Q000235:genetics / Q000378:metabolism
chemical_list: D000950:Antigens, Ly; D017261:Glycosylphosphatidylinositols; D060488:Low Density Lipoprotein Receptor-Related Protein-6; D060490:Receptors, Wnt; D029961:Zebrafish Proteins