Heterotypic piRNA Ping-Pong requires qin, a protein with both E3 ligase and Tudor domains
Koppetsch, Birgit S.
Theurkauf, William E.
Zamore, Phillip D.
UMass Chan AffiliationsProgram in Molecular Medicine
Program in Bioinformatics and Integrative Biology
Department of Biochemistry and Molecular Pharmacology
Document TypeJournal Article
DNA Transposable Elements
Membrane Transport Proteins
Peptide Initiation Factors
Protein Structure, Tertiary
RNA, Small Interfering
RNA-Induced Silencing Complex
Biochemistry, Biophysics, and Structural Biology
MetadataShow full item record
AbstractpiRNAs guide PIWI proteins to silence transposons in animal germ cells. Reciprocal cycles of piRNA-directed RNA cleavage--catalyzed by the PIWI proteins Aubergine (Aub) and Argonaute3 (Ago3) in Drosophila melanogaster--expand the population of antisense piRNAs in response to transposon expression, a process called the Ping-Pong cycle. Heterotypic Ping-Pong between Aub and Ago3 ensures that antisense piRNAs predominate. We show that qin, a piRNA pathway gene whose protein product contains both E3 ligase and Tudor domains, colocalizes with Aub and Ago3 in nuage, a perinuclear structure implicated in transposon silencing. In qin mutants, less Ago3 binds Aub, futile Aub:Aub homotypic Ping-Pong prevails, antisense piRNAs decrease, many families of mobile genetic elements are reactivated, and DNA damage accumulates in nurse cells and oocytes. We propose that Qin enforces heterotypic Ping-Pong between Aub and Ago3, ensuring that transposons are silenced and maintaining the integrity of the germline genome.
Mol Cell. 2011 Nov 18;44(4):572-84. doi: 10.1016/j.molcel.2011.10.011. Link to article on publisher's site
Permanent Link to this Itemhttp://hdl.handle.net/20.500.14038/26025
Author Zhao Zhang is a student in the Interdisciplinary Graduate Program in the Graduate School of Biomedical Sciences (GSBS) at UMass Medical School.
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