GSE115277
The SUMO ligase Su(var)2-10 induces co-transcriptional repression of piRNA targets
In Drosophila, Piwi-induced transcriptional repression is associated with the establishment of repressive chromatin marks by the histone methyltrasferase SetDB1, however how the Piwi/piRNA complex recruits this effector to chromatin targets is poorly understood. We identified a new player in piRNA-guided transcriptional silencing encoded by the Su(var)2-10 gene. Su(var)2-10 is required for transcriptional silencing and deposition of repressive chromatin marks on transposons and it physically associates with the Piwi/piRNA target recognition complex. Recruitment of Su(var)2-10 to a target locus in a piRNA-independent fashion induces transcriptional repression and deposition of the H3K9 trimethyl mark by the histone methyltransferase dSetDB1/Eggless. Su(var)2-10 belongs to a conserved family of proteins that function as SUMO E3 ligases and we found that the SUMO pathway is essential for the repressive function of Su(var)2-10 and for transcriptional repression of transposons. Together, our data identifies Su(var)2-10 as an essential component of the piRNA-induced transcriptional silencing pathway that links the target recognition complex to the silencing effector and reveals a novel role of SUMO modification in the piRNA-induced repression. Overall design: Gene expression and genome occupancy profiling by high throughput sequencing