RRC ID 75976
Author Huang X, Cheng P, Weng C, Xu Z, Zeng C, Xu Z, Chen X, Zhu C, Guang S, Feng X.
Title A chromodomain protein mediates heterochromatin-directed piRNA expression.
Journal Proc Natl Acad Sci U S A
Abstract PIWI-interacting RNAs (piRNAs) play significant roles in suppressing transposons, maintaining genome integrity, and defending against viral infections. How piRNA source loci are efficiently transcribed is poorly understood. Here, we show that in Caenorhabditis elegans, transcription of piRNA clusters depends on the chromatin microenvironment and a chromodomain-containing protein, UAD-2. piRNA clusters form distinct focus in germline nuclei. We conducted a forward genetic screening and identified UAD-2 that is required for piRNA focus formation. In the absence of histone 3 lysine 27 methylation or proper chromatin-remodeling status, UAD-2 is depleted from the piRNA focus. UAD-2 recruits the upstream sequence transcription complex (USTC), which binds the Ruby motif to piRNA promoters and promotes piRNA generation. Vice versa, the USTC complex is required for UAD-2 to associate with the piRNA focus. Thus, transcription of heterochromatic small RNA source loci relies on coordinated recruitment of both the readers of histone marks and the core transcriptional machinery to DNA.
Volume 118(27)
Published 2021-7-6
DOI 10.1073/pnas.2103723118
PII 2103723118
PMID 34187893
PMC PMC8271797
MeSH Animals Caenorhabditis elegans / genetics Caenorhabditis elegans / metabolism* Caenorhabditis elegans Proteins / metabolism* Chromatin Assembly and Disassembly Genetic Testing Germ Cells / cytology Germ Cells / metabolism Heterochromatin / metabolism* Histones / metabolism Lysine / metabolism Methylation Peptides / metabolism Polycomb Repressive Complex 2 / metabolism Protein Binding RNA, Small Interfering / metabolism* Temperature
Resource
C.elegans tm6157 tm1227