title: Pak4 Is Required during Epithelial Polarity Remodeling through Regulating AJ Stability and Bazooka Retention at the ZA.
abstract: The ability of epithelial cells to assemble into sheets relies on their zonula adherens (ZA), a circumferential belt of adherens junction (AJ) material, which can be remodeled during development to shape organs. Here, we show that during ZA remodeling in a model neuroepithelial cell, the Cdc42 effector P21-activated kinase 4 (Pak4/Mbt) regulates AJ morphogenesis and stability through β-catenin (β-cat/Arm) phosphorylation. We find that β-catenin phosphorylation by Mbt, and associated AJ morphogenesis, is needed for the retention of the apical determinant Par3/Bazooka at the remodeling ZA. Importantly, this retention mechanism functions together with Par1-dependent lateral exclusion of Par3/Bazooka to regulate apical membrane differentiation. Our results reveal an important functional link between Pak4, AJ material morphogenesis, and polarity remodeling during organogenesis downstream of Par3.
authors.affiliation: MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, WC1E 6BT London, UK.
authors.forename: Rhian F
authors.initials: RF
authors.lastname: Walther
authors.affiliation: MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, WC1E 6BT London, UK.
authors.forename: Francisca
authors.initials: F
authors.lastname: Nunes de Almeida
authors.affiliation: MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, WC1E 6BT London, UK.
authors.forename: Evi
authors.initials: E
authors.lastname: Vlassaks
authors.affiliation: MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, WC1E 6BT London, UK.
authors.forename: Jemima J
authors.initials: JJ
authors.lastname: Burden
authors.affiliation: MRC Laboratory for Molecular Cell Biology, University College London, Gower Street, WC1E 6BT London, UK. Electronic address: f.pichaud@ucl.ac.uk.
authors.forename: Franck
authors.initials: F
authors.lastname: Pichaud
mesh_terms: D022005:Adherens Junctions / Q000378:metabolism* / Q000648:ultrastructure; D000818:Animals; D002454:Cell Differentiation; D016764:Cell Polarity; D054910:Compound Eye, Arthropod / Q000166:cytology / Q000196:embryology / Q000378:metabolism*; D004330:Drosophila / Q000166:cytology / Q000196:embryology / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004847:Epithelial Cells / Q000166:cytology / Q000378:metabolism*; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins / Q000378:metabolism; D011494:Protein Kinases / Q000235:genetics / Q000378:metabolism*; D051176:beta Catenin / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; D047908:Intracellular Signaling Peptides and Proteins; D008565:Membrane Proteins; C400774:baz protein, Drosophila; D051176:beta Catenin; D011494:Protein Kinases; C116684:mbt protein, Drosophila