Identification and characterization of mitotic mutations in Drosophila.

Department of Biochemistry and Cell Biology, State University of New York at Stony Brook 11794-5215, USA.
Methods in cell biology (Impact Factor: 1.44). 02/1999; 61:317-46.
Source: PubMed
  • Article: Invadolysin
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    ABSTRACT: The cell cycle is widely known to be regulated by networks of phosphorylation and ubiquitin-directed proteolysis. Here, we describe IX-14/invadolysin, a novel metalloprotease present only in metazoa, whose activity appears to be essential for mitotic progression. Mitotic neuroblasts of Drosophila melanogaster IX-14 mutant larvae exhibit increased levels of nuclear envelope proteins, monopolar and asymmetric spindles, and chromosomes that appear hypercondensed in length with a surrounding halo of loosely condensed chromatin. Zymography reveals that a protease activity, present in wild-type larval brains, is missing from homozygous tissue, and we show that IX-14/invadolysin cleaves lamin in vitro. The IX-14/invadolysin protein is predominantly found in cytoplasmic structures resembling invadopodia in fly and human cells, but is dramatically relocalized to the leading edge of migrating cells. Strikingly, we find that the directed migration of germ cells is affected in Drosophila IX-14 mutant embryos. Thus, invadolysin identifies a new family of conserved metalloproteases whose activity appears to be essential for the coordination of mitotic progression, but which also plays an unexpected role in cell migration.
    The Journal of Cell Biology 11/2004; 167(4):673-686. · 9.69 Impact Factor
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    ABSTRACT: Here we briefly review techniques used to flatten cells that otherwise round in culture, so that their division can be more clearly analyzed in vitro by high resolution light microscopy. We then describe an agar overlay procedure for use with isolated Drosophila neuroblasts, which promotes their long-term viability while also allowing for correlative studies of the same cell in the living and fixed state. This same procedure can also be used to obtain high temporal and spatial resolution images of mitosis and cytokinesis in cultured Drosophila Schneider S2 cells, which are a popular model for RNAi studies.
    Cell Motility and the Cytoskeleton 11/2003; 56(3):141-6. DOI:10.1002/cm.10143 · 4.19 Impact Factor
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    ABSTRACT: During early embryogenesis of Drosophila melanogaster, mutations in the DNA-replication checkpoint lead to chromosome-segregation failures. Here we show that these segregation failures are associated with the assembly of an anastral microtubule spindle, a mitosis-specific loss of centrosome function, and dissociation of several components of the gamma-tubulin ring complex from a core centrosomal structure. The DNA-replication inhibitor aphidicolin and DNA-damaging agents trigger identical mitotic defects in wild-type embryos, indicating that centrosome inactivation is a checkpoint-independent and mitosis-specific response to damaged or incompletely replicated DNA. We propose that centrosome inactivation is part of a damage-control system that blocks chromosome segregation when replication/damage checkpoint control fails.
    Nature Cell Biology 03/2000; 2(2):90-5. DOI:10.1038/35000041 · 20.06 Impact Factor