title: Abl regulates planar polarized junctional dynamics through β-catenin tyrosine phosphorylation.
abstract: Interactions between epithelial cells are mediated by adherens junctions that are dynamically regulated during development. Here we show that the turnover of β-catenin is increased at cell interfaces that are targeted for disassembly during Drosophila axis elongation. The Abl tyrosine kinase is concentrated at specific planar junctions and is necessary for polarized β-catenin localization and dynamics. abl mutant embryos have decreased β-catenin turnover at shrinking edges, and these defects are accompanied by a reduction in multicellular rosette formation and axis elongation. Abl promotes β-catenin phosphorylation on the conserved tyrosine 667 and expression of an unphosphorylatable β-catenin mutant recapitulates the defects of abl mutants. Notably, a phosphomimetic β-catenin(Y667E) mutation is sufficient to increase β-catenin turnover and rescue axis elongation in abl deficient embryos. These results demonstrate that the asymmetrically localized Abl tyrosine kinase directs planar polarized junctional remodeling during Drosophila axis elongation through the tyrosine phosphorylation of β-catenin.
authors.affiliation: Howard Hughes Medical Institute and Developmental Biology Program, Sloan-Kettering Institute, 1275 York Avenue, New York, NY 10065, USA.
authors.forename: Masako
authors.initials: M
authors.lastname: Tamada
authors.forename: Dene L
authors.initials: DL
authors.lastname: Farrell
authors.forename: Jennifer A
authors.initials: JA
authors.lastname: Zallen
mesh_terms: D000205:Actomyosin / Q000378:metabolism; D022005:Adherens Junctions / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D015153:Blotting, Western; D016764:Cell Polarity; D029721:Drosophila Proteins / Q000502:physiology*; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics* / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000378:metabolism / Q000473:pathology*; D005260:Female; D007124:Immunoenzyme Techniques; D047468:Immunoprecipitation; D008297:Male; D009024:Morphogenesis; D009119:Muscle Contraction; D009154:Mutation / Q000235:genetics; D010766:Phosphorylation; D011485:Protein Binding; D011505:Protein-Tyrosine Kinases / Q000502:physiology*; D034741:RNA, Small Interfering / Q000235:genetics; D014443:Tyrosine / Q000378:metabolism*; D051176:beta Catenin / Q000037:antagonists & inhibitors / Q000235:genetics / Q000378:metabolism*
chemical_list: D029721:Drosophila Proteins; D034741:RNA, Small Interfering; D051176:beta Catenin; D014443:Tyrosine; D000205:Actomyosin; D011505:Protein-Tyrosine Kinases; C506548:Abl protein, Drosophila