Phase separation of SGS3 drives siRNA body formation and promotes endogenous gene silencing

• DOI: 10.1016/j.celrep.2022.111985
• Publication Date: 2023-01-09T10:19:37Z
• Authors: Huijuan Tan; Wentao Luo; Wei Yan; Jie Liu; Yalikunjiang Aizezi; Ruixue Cui; Ruijun Tian; Jinbiao Ma; Hongwei Guo
• Keywords: Trans-acting siRNA; RNA Silencing; Dicer; RNA-induced silencing complex; Argonaute; RNA-induced transcriptional silencing

The generation of small interfering RNA (siRNA) involves many processing components, including SUPPRESSOR OF GENE SILENCING 3 (SGS3), RNA-DEPENDENT POLYMERASE 6 (RDR6), and DICER-LIKE proteins (DCLs). Nonetheless, how these components are coordinated to produce siRNAs is unclear. Here, we show that SGS3 forms condensates via phase separation in vivo vitro. interacts with RDR6 drives it form siRNA bodies cytoplasm, which promoted by SGS3-targeted RNAs. Disrupting abrogates body assembly biogenesis, whereas coexpression induces formation tobacco yeast cells. Dysfunction translation mRNA decay increases the number bodies, DCL2/4 mutations enhance their size. Purification identifies numerous RNA-binding components. Together, our findings reveal separation-mediated essential for production gene silencing.