Drosophila MAGI interacts with RASSF8 to regulate E-Cadherin-based adherens junctions in the developing eye.
Morphogenesis is crucial during development to generate organs and tissues of the correct size and shape. During Drosophila late eye development, interommatidial cells (IOCs) rearrange to generate the highly organized pupal lattice, in which hexagonal ommatidial units pack tightly. This process involves the fine regulation of adherens junctions (AJs) and of adhesive E-Cadherin (E-Cad) complexes. Localized accumulation of Bazooka (Baz), the Drosophila PAR3 homolog, has emerged as a critical step to specify where new E-Cad complexes should be deposited during junction remodeling. However, the mechanisms controlling the correct localization of Baz are still only partly understood. We show here that Drosophila Magi, the sole fly homolog of the mammalian MAGI scaffolds, is an upstream regulator of E-Cad-based AJs during cell rearrangements, and that Magi mutant IOCs fail to reach their correct position. We uncover a direct physical interaction between Magi and the Ras association domain protein RASSF8 through a WW domain-PPxY motif binding, and show that apical Magi recruits the RASSF8-ASPP complex during AJ remodeling in IOCs. We further show that this Magi complex is required for the cortical recruitment of Baz and of the E-Cad-associated proteins α- and β-catenin. We propose that, by controlling the proper localization of Baz to remodeling junctions, Magi and the RASSF8-ASPP complex promote the recruitment or stabilization of E-Cad complexes at junction sites.
IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier F-34298, France INSERM, U1194, Montpellier F-34298, France Université de Montpellier, Montpellier F-34090, France Institut régional du Cancer de Montpellier, Montpellier F-34298, France.
Sophie
S
Zaessinger
Apoptosis and Proliferation Control Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK.
Yanxiang
Y
Zhou
Department of Physiology Development and Neuroscience, University of Cambridge, Downing Street, Cambridge CB2 3DY, UK.
Sarah J
SJ
Bray
Apoptosis and Proliferation Control Laboratory, Cancer Research UK, London Research Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK.
Nicolas
N
Tapon
IRCM, Institut de Recherche en Cancérologie de Montpellier, Montpellier F-34298, France INSERM, U1194, Montpellier F-34298, France Université de Montpellier, Montpellier F-34090, France Institut régional du Cancer de Montpellier, Montpellier F-34298, France alexandre.djiane@inserm.fr.
Alexandre
A
Djiane
D022005:Adherens Junctions / Q000378:metabolism / Q000502:physiology*; D000818:Animals; D015153:Blotting, Western; D015820:Cadherins / Q000378:metabolism*; D002352:Carrier Proteins / Q000378:metabolism*; D004330:Drosophila; D029721:Drosophila Proteins / Q000378:metabolism*; D005123:Eye / Q000196:embryology*; D007150:Immunohistochemistry; D047468:Immunoprecipitation; D047908:Intracellular Signaling Peptides and Proteins / Q000378:metabolism; D009024:Morphogenesis / Q000502:physiology*; D046912:Multiprotein Complexes / Q000378:metabolism; D009703:Nucleoside-Phosphate Kinase / Q000378:metabolism*; D010957:Plasmids / Q000235:genetics; D020798:Two-Hybrid System Techniques
C548148:ASPP protein, Drosophila; D015820:Cadherins; D002352:Carrier Proteins; D029721:Drosophila Proteins; D047908:Intracellular Signaling Peptides and Proteins; D046912:Multiprotein Complexes; C548149:RASSF8 protein, Drosophila; C400774:baz protein, Drosophila; D009703:Nucleoside-Phosphate Kinase; C472856:MAGI protein, Drosophila
Adherens junctions; MAGI scaffolds; Morphogenesis