title: Lava lamp, a novel peripheral golgi protein, is required for Drosophila melanogaster cellularization.
abstract: Drosophila cellularization and animal cell cytokinesis rely on the coordinated functions of the microfilament and microtubule cytoskeletal systems. To identify new proteins involved in cellularization and cytokinesis, we have conducted a biochemical screen for microfilament/microtubule-associated proteins (MMAPs). 17 MMAPs were identified; seven have been previously implicated in cellularization and/or cytokinesis, including KLP3A, Anillin, Septins, and Dynamin. We now show that a novel MMAP, Lava Lamp (Lva), is also required for cellularization. Lva is a coiled-coil protein and, unlike other proteins previously implicated in cellularization or cytokinesis, it is Golgi associated. Our functional analysis shows that cellularization is dramatically inhibited upon injecting anti-Lva antibodies (IgG and Fab) into embryos. In addition, we show that brefeldin A, a potent inhibitor of membrane trafficking, also inhibits cellularization. Biochemical analysis demonstrates that Lva physically interacts with the MMAPs Spectrin and CLIP190. We suggest that Lva and Spectrin may form a Golgi-based scaffold that mediates the interaction of Golgi bodies with microtubules and facilitates Golgi-derived membrane secretion required for the formation of furrows during cellularization. Our results are consistent with the idea that animal cell cytokinesis depends on both actomyosin-based contraction and Golgi-derived membrane secretion.
authors.affiliation: Department of Molecular, Cell and Developmental Biology, Sinsheimer Labs, University of California at Santa Cruz, Santa Cruz, California 95064, USA. sisson@darwin.ucsc.edu
authors.forename: J C
authors.initials: JC
authors.lastname: Sisson
authors.forename: C
authors.initials: C
authors.lastname: Field
authors.forename: R
authors.initials: R
authors.lastname: Ventura
authors.forename: A
authors.initials: A
authors.lastname: Royou
authors.forename: W
authors.initials: W
authors.lastname: Sullivan
mesh_terms: D000199:Actins / Q000378:metabolism; D000818:Animals; D030801:Animals, Genetically Modified; D029721:Drosophila Proteins / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000196:embryology*; D004625:Embryo, Nonmammalian / Q000166:cytology* / Q000502:physiology*; D006056:Golgi Apparatus / Q000502:physiology*; D007425:Intracellular Membranes / Q000378:metabolism / Q000648:ultrastructure; D008869:Microtubule-Associated Proteins / Q000378:metabolism*; D011485:Protein Binding; D013049:Spectrin / Q000378:metabolism
chemical_list: D000199:Actins; D029721:Drosophila Proteins; C502291:Lva protein, Drosophila; D008869:Microtubule-Associated Proteins; D013049:Spectrin