Wendte Jered M, Pikaard Craig S
Department of Biology, Indiana University, Bloomington, Indiana 47405, USA.
Department of Molecular and Cellular Biochemistry, Indiana University, Bloomington, Indiana 47405, USA.
Genes Dev. 2016 Dec 15;30(24):2649-2650. doi: 10.1101/gad.294900.116.
In many eukaryotes, siRNAs bound to Argonaute proteins guide chromatin-modifying enzymes to complementary loci, resulting in transcriptional gene silencing. Multiple lines of evidence indicate that siRNAs base-pair with longer RNAs produced at target loci, but the possibility that siRNAs base-pair directly with DNA remains an attractive hypothesis. In a recent study, Shimada et al. (pp. 2571-2580) conducted experiments that address these alternative hypotheses, yielding additional evidence that fission yeast siRNA-Argonaute silencing complexes are recruited to target loci exclusively via interactions with nascent transcripts.
在许多真核生物中，与AGO蛋白结合的小干扰RNA（siRNA）引导染色质修饰酶作用于互补位点，导致转录基因沉默。多条证据表明，siRNA与靶位点产生的较长RNA进行碱基配对，但siRNA直接与DNA进行碱基配对的可能性仍然是一个引人关注的假说。在最近的一项研究中，岛田等人（第2571 - 2580页）进行了实验来验证这些替代假说，得出了更多证据，即裂殖酵母siRNA-AGO沉默复合体仅通过与新生转录本的相互作用被招募到靶位点。
