Cooperative recruitment of RDR6 by SGS3 and SDE5 during small interfering RNA amplification in <i>Arabidopsis</i>
Manabu Yoshikawa, Yong-Woon Han, Hirofumi Fujii, Shu Aizawa, Tatsuya Nishino, Masayuki Ishikawa
Abstract
Significance In plants, RNA-induced silencing complexes that contain 22-nucleotide small interfering RNA (siRNA) and Argonaute 1 protein induce siRNA amplification from their targets. In this pathway, double-stranded RNAs (dsRNAs) are synthesized by RNA-dependent RNA polymerase proteins, and the dsRNAs are processed into siRNAs by Dicer-like proteins, leading to amplification of siRNAs to targets. Because dsRNA formation from nontarget RNAs causes nonspecific siRNA production, this pathway needs to be strictly regulated. By using an in vitro siRNA amplification system, we demonstrate that RNA-dependent RNA polymerase proteins are specifically recruited to targets in coordination with two plant-specific proteins. Based on the results, we discuss how specificity of siRNA amplification is secured.