title: piRNAs mediate posttranscriptional retroelement silencing and localization to pi-bodies in the Drosophila germline.
abstract: Nuage, a well-conserved perinuclear organelle found in germline cells, is thought to mediate retroelement repression in Drosophila melanogaster by regulating the production of Piwi-interacting RNAs (piRNAs). In this study, we present evidence that the nuage-piRNA pathway components can be found in cytoplasmic foci that also contain retroelement transcripts, antisense piRNAs, and proteins involved in messenger RNA (mRNA) degradation. These mRNA degradation proteins, decapping protein 1/2 (DCP1/2), Me31B (maternal expression at 31B), and pacman (PCM), are normally thought of as components of processing bodies. In spindle-E (spn-E) and aubergine (aub) mutants that lack piRNA production, piRNA pathway proteins no longer overlap the mRNA degradation proteins. Concomitantly, spn-E and aub mutant ovaries show an accumulation of full-length retroelement transcripts and prolonged stabilization of HeT-A mRNA, supporting the role of piRNAs in mediating posttranscriptional retroelement silencing. HeT-A mRNA is derepressed in mRNA degradation mutants twin, dcp1, and ski3, indicating that these enzymes also aid in removing full-length transcripts and/or decay intermediates.
authors: Temasek Life Sciences Laboratory, The National University of Singapore, 117604 Singapore.
authors: Ai Khim
authors: AK
authors: Lim
authors: Liheng
authors: L
authors: Tao
authors: Toshie
authors: T
authors: Kai
mesh_terms: D000818:Animals; D020169:Caspases / Q000235:genetics / Q000378:metabolism; D053487:DEAD-box RNA Helicases / Q000235:genetics / Q000378:metabolism; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism; D004331:Drosophila melanogaster / Q000235:genetics* / Q000378:metabolism; D005095:Exoribonucleases / Q000235:genetics / Q000378:metabolism; D020868:Gene Silencing; D009154:Mutation; D012323:RNA Processing, Post-Transcriptional; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D034741:RNA, Small Interfering / Q000235:genetics / Q000378:metabolism*; D018626:Retroelements / Q000235:genetics*; D014157:Transcription Factors / Q000235:genetics / Q000378:metabolism
chemical_list: D029721:Drosophila Proteins; C470831:Lcp2 protein, Drosophila; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D018626:Retroelements; D014157:Transcription Factors; C532748:Me31B protein, Drosophila; D005095:Exoribonucleases; C487208:pcm protein, Drosophila; D020169:Caspases; C103568:Dcp-1 protein, Drosophila; D053487:DEAD-box RNA Helicases