title: The Drosophila cell cycle gene fizzy is required for normal degradation of cyclins A and B during mitosis and has homology to the CDC20 gene of Saccharomyces cerevisiae.
abstract: The Drosophila cell cycle gene fizzy (fzy) is required for normal execution of the metaphase-anaphase transition. We have cloned fzy, and confirmed this by P-element mediated germline transformation rescue. Sequence analysis predicts that fzy encodes a protein of 526 amino acids, the carboxy half of which has significant homology to the Saccharomyces cerevisiae cell cycle gene CDC20. A monoclonal antibody against fzy detects a single protein of the expected size, 59 kD, in embryonic extracts. In early embryos fzy is expressed in all proliferating tissues; in late embryos fzy expression declines in a tissue-specific manner correlated with cessation of cell division. During interphase fzy protein is present in the cytoplasm; while in mitosis fzy becomes ubiquitously distributed throughout the cell except for the area occupied by the chromosomes. The metaphase arrest phenotype caused by fzy mutations is associated with failure to degrade both mitotic cyclins A and B, and an enrichment of spindle microtubules at the expense of astral microtubules. Our data suggest that fzy function is required for normal cell cycle-regulated proteolysis that is necessary for successful progress through mitosis.
authors.affiliation: Department of Cell Biology, Boyer Center for Molecular Medicine, Yale University School of Medicine, New Haven, Connecticut 06536-0812, USA.
authors.forename: I A
authors.initials: IA
authors.lastname: Dawson
authors.forename: S
authors.initials: S
authors.lastname: Roth
authors.forename: S
authors.initials: S
authors.lastname: Artavanis-Tsakonas
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D001483:Base Sequence; D064199:Cdc20 Proteins; D002451:Cell Compartmentation; D002453:Cell Cycle / Q000235:genetics; D018797:Cell Cycle Proteins / Q000235:genetics / Q000276:immunology / Q000302:isolation & purification / Q000502:physiology*; D003001:Cloning, Molecular; D016213:Cyclins / Q000378:metabolism*; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology / Q000235:genetics*; D005656:Fungal Proteins / Q000235:genetics; D017344:Genes, Insect / Q000235:genetics*; D015151:Immunoblotting; D007150:Immunohistochemistry; D008870:Microtubules / Q000378:metabolism; D008938:Mitosis / Q000235:genetics / Q000502:physiology*; D008969:Molecular Sequence Data; D012441:Saccharomyces cerevisiae / Q000235:genetics; D029701:Saccharomyces cerevisiae Proteins; D017422:Sequence Analysis, DNA; D017386:Sequence Homology, Amino Acid; D008941:Spindle Apparatus / Q000502:physiology
chemical_list: C577495:CDC20 protein, S cerevisiae; D064199:Cdc20 Proteins; D018797:Cell Cycle Proteins; D016213:Cyclins; D029721:Drosophila Proteins; D005656:Fungal Proteins; D029701:Saccharomyces cerevisiae Proteins; C577502:fzy protein, Drosophila