Abstract
Plasma membrane ingression during cytokinesis involves both actin remodeling and vesicle-mediated membrane addition. Vesicle-based membrane delivery from the recycling endosome (RE) has an essential but ill-defined involvement in cytokinesis. In the Drosophila melanogaster early embryo, Nuf (Nuclear fallout), a Rab11 effector which is essential for RE function, is required for F-actin and membrane integrity during furrow ingression. We find that in nuf mutant embryos, an initial loss of F-actin at the furrow is followed by loss of the associated furrow membrane. Wild-type embryos treated with Latrunculin A or Rho inhibitor display similar defects. Drug- or Rho-GTP-induced increase of actin polymerization or genetically mediated decrease of actin depolymerization suppresses the nuf mutant F-actin and membrane defects. We also find that RhoGEF2 does not properly localize at the furrow in nuf mutant embryos and that RhoGEF2-Rho1 pathway components show strong specific genetic interactions with Nuf. We propose a model in which RE-derived vesicles promote furrow integrity by regulating the rate of actin polymerization through the RhoGEF2-Rho1 pathway.
Publication types
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Research Support, N.I.H., Extramural
MeSH terms
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Actin Cytoskeleton / metabolism
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Actin Cytoskeleton / ultrastructure
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Actins / metabolism*
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Animals
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Cell Membrane Structures / genetics
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Cell Membrane Structures / metabolism
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Cell Membrane Structures / ultrastructure
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Cytokinesis / genetics
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Cytokinesis / physiology*
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Cytoplasmic Vesicles / metabolism
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Cytoplasmic Vesicles / ultrastructure
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Drosophila Proteins / genetics
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Drosophila Proteins / metabolism*
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Drosophila melanogaster / embryology*
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Drosophila melanogaster / metabolism
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Embryo, Nonmammalian / metabolism*
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Embryonic Development / physiology
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Guanine Nucleotide Exchange Factors / genetics
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Guanine Nucleotide Exchange Factors / metabolism
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Mutation / genetics
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Nuclear Proteins / genetics
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Nuclear Proteins / metabolism*
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Polymers / metabolism
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Protein Synthesis Inhibitors / pharmacology
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Rho Guanine Nucleotide Exchange Factors
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Signal Transduction / genetics
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rab GTP-Binding Proteins / genetics
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rab GTP-Binding Proteins / metabolism*
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rho GTP-Binding Proteins / genetics
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rho GTP-Binding Proteins / metabolism
Substances
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Actins
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Drosophila Proteins
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Guanine Nucleotide Exchange Factors
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Nuclear Proteins
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Polymers
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Protein Synthesis Inhibitors
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Rho Guanine Nucleotide Exchange Factors
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nuf protein, Drosophila
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rab11 protein
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Rho1 protein, Drosophila
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rab GTP-Binding Proteins
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rho GTP-Binding Proteins