title: Maelstrom, a Drosophila spindle-class gene, encodes a protein that colocalizes with Vasa and RDE1/AGO1 homolog, Aubergine, in nuage.
abstract: A hallmark of germline cells across the animal kingdom is the presence of perinuclear, electron-dense granules called nuage. In many species examined, Vasa, a DEAD-box RNA helicase, is found in these morphologically distinct particles. Despite its evolutionary conservation, the function of nuage remains obscure. We have characterized a null allele of maelstrom (mael) and shown that Maelstrom protein is localized to nuage in a Vasa-dependent manner. By phenotypic characterization, we have defined maelstrom as a spindle-class gene that affects Vasa modification. In a nuclear transport assay, we have determined that Maelstrom shuttles between the nucleus and cytoplasm, which may indicate a nuclear origin for nuage components. Interestingly, Maelstrom, but not Vasa, depends on two genes involved in RNAi phenomena, aubergine and spindle-E (spn-E), for its nuage localization. Furthermore, maelstrom mutant ovaries show mislocalization of two proteins involved in the microRNA and/or RNAi pathways, Dicer and Argonaute2, suggesting a potential connection between nuage and the microRNA-pathway.
authors.affiliation: Department of Biochemistry, Box 357350, University of Washington, Seattle, WA 98195-7350, USA.
authors.forename: Seth D
authors.initials: SD
authors.lastname: Findley
authors.forename: Mio
authors.initials: M
authors.lastname: Tamanaha
authors.forename: Nigel J
authors.initials: NJ
authors.lastname: Clegg
authors.forename: Hannele
authors.initials: H
authors.lastname: Ruohola-Baker
mesh_terms: D021581:Active Transport, Cell Nucleus / Q000502:physiology; D000251:Adenosine Triphosphatases; D000483:Alleles; D000818:Animals; D003594:Cytoplasmic Granules / Q000737:chemistry / Q000378:metabolism*; D053487:DEAD-box RNA Helicases; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics* / Q000502:physiology; D005231:Fatty Acids, Unsaturated / Q000378:metabolism; D005260:Female; D005854:Germ Cells / Q000166:cytology / Q000502:physiology; D006801:Humans; D007150:Immunohistochemistry; D017403:In Situ Hybridization; D019476:Insect Proteins / Q000235:genetics / Q000378:metabolism*; D009866:Oogenesis / Q000502:physiology; D010053:Ovary / Q000166:cytology / Q000378:metabolism; D010448:Peptide Initiation Factors / Q000378:metabolism*; D020365:RNA Helicases / Q000235:genetics / Q000378:metabolism*; D034622:RNA Interference
chemical_list: D029721:Drosophila Proteins; D005231:Fatty Acids, Unsaturated; D019476:Insect Proteins; D010448:Peptide Initiation Factors; C436124:aub protein, Drosophila; C109767:mael protein, Drosophila; D000251:Adenosine Triphosphatases; C498288:DDX4 protein, human; C096355:spn-E protein, Drosophila; C088269:vas protein, Drosophila; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases; C038753:leptomycin B