A Novel Role of UAP56 in piRNA Mediated Transposon Silencing: A Dissertation
Authors
Zhang, FanFaculty Advisor
William Theurkauf, PhDAcademic Program
Interdisciplinary Graduate ProgramUMass Chan Affiliations
Program in Molecular MedicineDocument Type
Doctoral DissertationPublication Date
2013-08-02Keywords
Dissertations, UMMSDEAD-box RNA Helicases
DNA Transposable Elements
Drosophila Proteins
Drosophila melanogaster
Germ Cells
Nuclear Envelope
RNA, Small Interfering
DEAD-box RNA Helicases
DNA Transposable Elements
Drosophila Proteins
Drosophila melanogaster
Germ Cells
Nuclear Envelope
Small Interfering RNA
Biochemistry
Genetics
Genomics
Molecular Biology
Molecular Genetics
Metadata
Show full item recordAbstract
Transposon silencing is required to maintain genome stability. The non-coding piRNAs effectively suppress of transposon activity during germline development. In the Drosophila female germline, long precursors of piRNAs are transcribed from discrete heterochromatic clusters and then processed into primary piRNAs in the perinuclear nuage. However, the detailed mechanism of piRNA biogenesis, specifically how the nuclear and cytoplasmic processes are connected, is not well understood. The nuclear DEAD box protein UAP56 has been previously implicated in protein-coding gene transcript splicing and export. I have identified a novel function of UAP56 in piRNA biogenesis. In Drosophila egg chambers, UAP56 co-localizes with the cluster-associated HP1 variant Rhino. Nuage is a germline-specific perinuclear structure rich in piRNA biogenesis proteins, including Vasa, a DEAD box with an established role in piRNA production. Vasa-containing nuage granules localize directly across the nuclear envelope from cluster foci containing UAP56 and Rhino, and cluster transcripts immunoprecipitate with both Vasa and UAP56. Significantly, a charge-substitution mutation that alters a conserved surface residue in UAP56 disrupts co-localization with Rhino, germline piRNA production, transposon silencing, and perinuclear localization of Vasa. I therefore propose that UAP56 and Vasa function in a piRNA-processing compartment that spans the nuclear envelope.DOI
10.13028/M2GS3JPermanent Link to this Item
http://hdl.handle.net/20.500.14038/32040Rights
Copyright is held by the author, with all rights reserved.ae974a485f413a2113503eed53cd6c53
10.13028/M2GS3J