Open AccessDimerisation of the PICTS complex via LC8/Cut-up drives co-transcriptional transposon silencing in Drosophila
Author(s) -
Evelyn L Eastwood,
Kayla A Jara,
Susanne Bornelöv,
Marzia Munafò,
Vasileios Frantzis,
Emma Kneuss,
Elisar Barbar,
Benjamin Czech,
Gregory J. Han
Publication year - 2021
Publication title -
elife
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 5.879
H-Index - 139
ISSN - 2050-084X
DOI - 10.7554/elife.65557
Subject(s) - piwi interacting rna , transposable element , biology , rasirna , genetics , gene silencing , chromatin , argonaute , heterochromatin , rna interference , rna , microbiology and biotechnology , gene , genome
In animal gonads, the PIWI-interacting RNA (piRNA) pathway guards genome integrity in part through the co-transcriptional gene silencing of transposon insertions. In Drosophila ovaries, piRNA-loaded Piwi detects nascent transposon transcripts and instructs heterochromatin formation through the P anoramix- i nduced c o- t ranscriptional s ilencing (PICTS) complex, containing Panoramix, Nxf2 and Nxt1. Here, we report that the highly conserved dynein light chain LC8/Cut-up (Ctp) is an essential component of the PICTS complex. Loss of Ctp results in transposon de-repression and a reduction in repressive chromatin marks specifically at transposon loci. In turn, Ctp can enforce transcriptional silencing when artificially recruited to RNA and DNA reporters. We show that Ctp drives dimerisation of the PICTS complex through its interaction with conserved motifs within Panoramix. Artificial dimerisation of Panoramix bypasses the necessity for its interaction with Ctp, demonstrating that conscription of a protein from a ubiquitous cellular machinery has fulfilled a fundamental requirement for a transposon silencing complex.