title: Belle is a Drosophila DEAD-box protein required for viability and in the germ line.
abstract: DEAD-box proteins are ATP-dependent RNA helicases that function in various stages of RNA processing and in RNP remodeling. Here, we report identification and characterization of the Drosophila protein Belle (Bel), which belongs to a highly conserved subfamily of DEAD-box proteins including yeast Ded1p, Xenopus An3, mouse PL10, human DDX3/DBX, and human DBY. Mutations in DBY are a frequent cause of male infertility in humans. Bel can substitute in vivo for Ded1p, an essential yeast translation factor, suggesting a requirement for Bel in translation initiation. Consistent with an essential cellular function, strong loss of function mutations in bel are recessive lethal with a larval growth defect phenotype. Hypomorphic bel mutants are male-sterile. Bel is also closely related to the Drosophila DEAD-box protein Vasa (Vas), a germ line-specific translational regulator. We find that Bel and Vas colocalize in nuage and at the oocyte posterior during oogenesis, and that bel function is required for female fertility. However, unlike Vas, Bel is not specifically enriched in embryonic pole cells. We conclude that the DEAD-box protein Bel has evolutionarily conserved roles in fertility and development.
authors.affiliation: Department of Biology, McGill University, Montréal, Québec, Canada H3A 1B1.
authors.forename: Oona
authors.initials: O
authors.lastname: Johnstone
authors.forename: Renate
authors.initials: R
authors.lastname: Deuring
authors.forename: Ronald
authors.initials: R
authors.lastname: Bock
authors.forename: Patrick
authors.initials: P
authors.lastname: Linder
authors.forename: Margaret T
authors.initials: MT
authors.lastname: Fuller
authors.forename: Paul
authors.initials: P
authors.lastname: Lasko
mesh_terms: D000595:Amino Acid Sequence; D000818:Animals; D018797:Cell Cycle Proteins / Q000502:physiology; D003001:Cloning, Molecular; D053487:DEAD-box RNA Helicases; D004330:Drosophila; D029721:Drosophila Proteins / Q000502:physiology*; D005260:Female; D005298:Fertility; D007814:Larva / Q000254:growth & development; D008297:Male; D008969:Molecular Sequence Data; D009866:Oogenesis; D012313:RNA / Q000378:metabolism; D020365:RNA Helicases / Q000502:physiology*; D029701:Saccharomyces cerevisiae Proteins / Q000502:physiology
chemical_list: D018797:Cell Cycle Proteins; D029721:Drosophila Proteins; D029701:Saccharomyces cerevisiae Proteins; D012313:RNA; C490120:Ddx1 protein, Drosophila; C492152:DED1 protein, S cerevisiae; D053487:DEAD-box RNA Helicases; D020365:RNA Helicases