Repository logo
 

Specialization of the Drosophila nuclear export family protein Nxf3 for piRNA precursor export.

Accepted version
Peer-reviewed

Type

Article

Change log

Authors

Munafò, Marzia 
Eastwood, Evelyn L 
Deumer, Undine-Sophie 
Preall, Jonathan B 

Abstract

The PIWI-interacting RNA (piRNA) pathway is a conserved small RNA-based immune system that protects animal germ cell genomes from the harmful effects of transposon mobilization. In Drosophila ovaries, most piRNAs originate from dual-strand clusters, which generate piRNAs from both genomic strands. Dual-strand clusters use noncanonical transcription mechanisms. Although transcribed by RNA polymerase II, cluster transcripts lack splicing signatures and poly(A) tails. mRNA processing is important for general mRNA export mediated by nuclear export factor 1 (Nxf1). Although UAP56, a component of the transcription and export complex, has been implicated in piRNA precursor export, it remains unknown how dual-strand cluster transcripts are specifically targeted for piRNA biogenesis by export from the nucleus to cytoplasmic processing centers. Here we report that dual-strand cluster transcript export requires CG13741/Bootlegger and the Drosophila nuclear export factor family protein Nxf3. Bootlegger is specifically recruited to piRNA clusters and in turn brings Nxf3. We found that Nxf3 specifically binds to piRNA precursors and is essential for their export to piRNA biogenesis sites, a process that is critical for germline transposon silencing. Our data shed light on how dual-strand clusters compensate for a lack of canonical features of mature mRNAs to be specifically exported via Nxf3, ensuring proper piRNA production.

Description

Keywords

PIWI proteins, RNA export, nuclear export factor, piRNA clusters, transposon control, Active Transport, Cell Nucleus, Animals, DNA Transposable Elements, Drosophila, Drosophila Proteins, Intracellular Signaling Peptides and Proteins, Nucleocytoplasmic Transport Proteins, RNA Precursors, RNA, Small Interfering, RNA-Binding Proteins

Journal Title

Genes Dev

Conference Name

Journal ISSN

0890-9369
1549-5477

Volume Title

33

Publisher

Cold Spring Harbor Laboratory

Rights

All rights reserved
Sponsorship
Wellcome Trust (110161/Z/15/Z)
Cancer Research UK (C14303/A17197)
Cancer Research UK (C14303/A17197)
Relationships
Is derived from: