title: Isolation of Drosophila cyclin D, a protein expressed in the morphogenetic furrow before entry into S phase.
abstract: During Drosophila development, nuclear and cell divisions are coordinated in response to developmental signals. In yeast and mammalian cells, signals that control cell division regulate the activity of cyclin-dependent kinases (Cdks) through proteins such as cyclins that interact with the Cdks. Here we describe two Drosophila cyclins identified from a set of Cdk-interacting proteins. One, cyclin J, is of a distinctive sequence type; its exclusive maternal expression pattern suggests that it may regulate oogenesis or the early nuclear divisions of embryogenesis. The other belongs to the D class of cyclins, previously identified in mammalian cells. We show that Drosophila cyclin D is expressed in early embryos and in imaginal disc cells in a pattern that anticipates cell divisions. Expression in the developing eye disc at the anterior edge of the morphogenetic furrow suggests that cyclin D acts early, prior to cyclin E, in inducing G1-arrested cells to enter S phase. Our results also suggest that, although cyclin D may be necessary, its expression alone is not sufficient to initiate the events leading to S phase.
authors.affiliation: Department of Molecular Biology, Massachuttes General Hospital, Boston, 02114, USA.
authors.forename: R L
authors.initials: RL
authors.lastname: Finley
authors.forename: B J
authors.initials: BJ
authors.lastname: Thomas
authors.forename: S L
authors.initials: SL
authors.lastname: Zipursky
authors.forename: R
authors.initials: R
authors.lastname: Brent
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D002453:Cell Cycle; D017124:Conserved Sequence; D056741:Cyclin D; D016213:Cyclins / Q000096:biosynthesis* / Q000737:chemistry / Q000302:isolation & purification; D029721:Drosophila Proteins; D004331:Drosophila melanogaster / Q000196:embryology*; D004625:Embryo, Nonmammalian / Q000166:cytology / Q000502:physiology*; D015870:Gene Expression; D015723:Gene Library; D005816:Genetic Complementation Test; D007814:Larva; D008969:Molecular Sequence Data; D009024:Morphogenesis; D011994:Recombinant Proteins / Q000096:biosynthesis; D016196:S Phase; D012441:Saccharomyces cerevisiae; D017386:Sequence Homology, Amino Acid
chemical_list: C534694:CycD protein, Drosophila; D056741:Cyclin D; D016213:Cyclins; D029721:Drosophila Proteins; D011994:Recombinant Proteins