Nuf, a Rab11 effector, maintains cytokinetic furrow integrity by promoting local actin polymerization.
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.
Cao
Jian
J
Sinsheimer Laboratories, Department of Molecular, Cellular, and Developmental Biology, University of California, Santa Cruz, Santa Cruz, CA 95064, USA.
Albertson
Roger
R
Riggs
Blake
B
Field
Christine M
CM
Sullivan
William
W
D008841:Actin Cytoskeleton / Q000378:metabolism / Q000648:ultrastructure; D000199:Actins / Q000378:metabolism*; D000818:Animals; D021961:Cell Membrane Structures / Q000235:genetics / Q000378:metabolism / Q000648:ultrastructure; D048749:Cytokinesis / Q000235:genetics / Q000502:physiology*; D022162:Cytoplasmic Vesicles / Q000378:metabolism / Q000648:ultrastructure; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology* / Q000378:metabolism; D004625:Embryo, Nonmammalian / Q000378:metabolism*; D047108:Embryonic Development / Q000502:physiology; D020662:Guanine Nucleotide Exchange Factors / Q000235:genetics / Q000378:metabolism; D009154:Mutation / Q000235:genetics; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D011108:Polymers / Q000378:metabolism; D011500:Protein Synthesis Inhibitors / Q000494:pharmacology; D064067:Rho Guanine Nucleotide Exchange Factors; D015398:Signal Transduction / Q000235:genetics; D020691:rab GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism*; D020741:rho GTP-Binding Proteins / Q000235:genetics / Q000378:metabolism; D000099193:rab11 GTP-Binding Proteins
D000199:Actins; D029721:Drosophila Proteins; D020662:Guanine Nucleotide Exchange Factors; D009687:Nuclear Proteins; D011108:Polymers; D011500:Protein Synthesis Inhibitors; D064067:Rho Guanine Nucleotide Exchange Factors; D020691:rab GTP-Binding Proteins; D020741:rho GTP-Binding Proteins; D000099193:rab11 GTP-Binding Proteins; C111662:nuf protein, Drosophila; C511153:Rho1 protein, Drosophila