title: Panoramix enforces piRNA-dependent cotranscriptional silencing.
abstract: The Piwi-interacting RNA (piRNA) pathway is a small RNA-based innate immune system that defends germ cell genomes against transposons. In Drosophila ovaries, the nuclear Piwi protein is required for transcriptional silencing of transposons, though the precise mechanisms by which this occurs are unknown. Here we show that the CG9754 protein is a component of Piwi complexes that functions downstream of Piwi and its binding partner, Asterix, in transcriptional silencing. Enforced tethering of CG9754 to nascent messenger RNA transcripts causes cotranscriptional silencing of the source locus and the deposition of repressive chromatin marks. We have named CG9754 "Panoramix," and we propose that this protein could act as an adaptor, scaffolding interactions between the piRNA pathway and the general silencing machinery that it recruits to enforce transcriptional repression.
authors.affiliation: Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA. Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
authors.forename: Yang
authors.initials: Y
authors.lastname: Yu
authors.affiliation: Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA. Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA. State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai, China.
authors.forename: Jiaqi
authors.initials: J
authors.lastname: Gu
authors.affiliation: Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA.
authors.forename: Ying
authors.initials: Y
authors.lastname: Jin
authors.affiliation: Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA. Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
authors.forename: Yicheng
authors.initials: Y
authors.lastname: Luo
authors.affiliation: Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA. Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA.
authors.forename: Jonathan B
authors.initials: JB
authors.lastname: Preall
authors.affiliation: State Key Laboratory of Genetic Engineering, Collaborative Innovation Center of Genetics and Development, Department of Biochemistry, School of Life Sciences, Fudan University, Shanghai, China.
authors.forename: Jinbiao
authors.initials: J
authors.lastname: Ma
authors.affiliation: Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA. Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA. Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK.
authors.forename: Benjamin
authors.initials: B
authors.lastname: Czech
authors.affiliation: Watson School of Biological Sciences, Cold Spring Harbor Laboratory, Cold Spring Harbor, NY 11724, USA. Howard Hughes Medical Institute, Chevy Chase, MD 20815, USA. Cancer Research UK Cambridge Institute, Li Ka Shing Centre, University of Cambridge, Cambridge, UK. The New York Genome Center, 101 Avenue of the Americas, New York, NY 10013, USA. greg.hannon@cruk.cam.ac.uk.
authors.forename: Gregory J
authors.initials: GJ
authors.lastname: Hannon
mesh_terms: D000818:Animals; D060565:Argonaute Proteins / Q000378:metabolism; D004251:DNA Transposable Elements / Q000235:genetics; D029721:Drosophila Proteins / Q000235:genetics / Q000378:metabolism*; D004331:Drosophila melanogaster / Q000235:genetics*; D055785:Gene Knockdown Techniques; D020868:Gene Silencing; D009687:Nuclear Proteins / Q000235:genetics / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism*; D034741:RNA, Small Interfering / Q000378:metabolism*; D016601:RNA-Binding Proteins; D014158:Transcription, Genetic
chemical_list: D060565:Argonaute Proteins; D004251:DNA Transposable Elements; D029721:Drosophila Proteins; D009687:Nuclear Proteins; D012333:RNA, Messenger; D034741:RNA, Small Interfering; D016601:RNA-Binding Proteins; C584031:arx protein, Drosophila; C583036:panx protein, Drosophila; C116498:piwi protein, Drosophila