BioProject

The transposon silencing piRNAs are produced from precursors that are encoded by heterochromatic clusters and processed in the perinuclear nuage. More...

The transposon silencing piRNAs are produced from precursors that are encoded by heterochromatic clusters and processed in the perinuclear nuage. We show that the Drosophila nuclear DEAD box protein UAP56, previously implicated in mRNA splicing and nuclear export, co-localizes with the cluster-associated HP1 homologue Rhino. Prominent nuclear foci containing Rhi and UAP56 localize directly across the nuclear envelope from Vasa, a conserved DEAD box protein and core nuage component that is required for piRNA production, and piRNA precursors immunoprecipitate with both UAP56 and Vasa. A uap56 point mutation that prevents UAP56 protein co-localization with Rhino also disrupts nuage organization, transposon silencing, and expression of dual strand piRNA clusters. By contrast, this allele significantly increases ectopic piRNAs from protein coding genes. We therefore propose that UAP56 and Vasa organize a piRNA-processing compartment that spans the nuclear envelope, increasing the efficiency and specificity of piRNA biogenesis. Overall design: 3 replicates of each sample (uap56, vasa), total RNA samples hybridized to tiling array. Less...