State Key Laboratory of Pharmaceutical Biotechnology, School of Life Sciences, Nanjing University, Nanjing 210023, China.
Department of Biological Sciences, National University of Singapore, Singapore 117543, Singapore.
Proc Natl Acad Sci U S A. 2023 Mar 7;120(10):e2216062120. doi: 10.1073/pnas.2216062120. Epub 2023 Mar 1.
SERRATE (SE) is a core protein for microRNA (miRNA) biogenesis as well as for mRNA alternative splicing. Investigating the regulatory mechanism of expression is hence critical to understanding its detailed function in diverse biological processes. However, little about the control of expression has been clarified, especially through long noncoding RNA (lncRNA). Here, we identified an antisense intragenic lncRNA transcribed from the 3' end of , named SEAIRa. SEAIRa repressed expression, which in turn led to serrated leaves. SEAIRa recruited plant U-box proteins PUB25/26 with unreported RNA binding ability and a ubiquitin-like protein related to ubiquitin 1 (RUB1) for H2A monoubiquitination (H2Aub) at exon 11 of . In addition, PUB25/26 helped cleave SEAIRa and release the 5' domain fragment, which recruited the PRC2 complex for H3 lysine 27 trimethylation (H3K27me3) deposition at the first exon of . The distinct modifications of H2Aub and H3K27me3 at different sites of the locus cooperatively suppressed expression. Collectively, our results uncover an epigenetic mechanism mediated by the lncRNA SEAIRa that modulates expression, which is indispensable for plant growth and development.
锯齿（SE）是 miRNA（miRNA）生物发生以及 mRNA 可变剪接的核心蛋白。因此，研究其表达的调控机制对于理解其在各种生物过程中的详细功能至关重要。然而，关于表达的调控知之甚少，特别是通过长非编码 RNA（lncRNA）。在这里，我们鉴定了一种反义基因内 lncRNA，它从 3' 端转录而来，命名为 SEAIRa。SEAIRa 抑制 表达，进而导致锯齿状叶片。SEAIRa 招募植物 U-box 蛋白 PUB25/26，具有未报道的 RNA 结合能力和与泛素 1（RUB1）相关的类泛素蛋白，用于 在 的外显子 11 上进行 H2A 单泛素化（H2Aub）。此外，PUB25/26 有助于切割 SEAIRa 并释放 5' 结构域片段，该片段招募 PRC2 复合物在 的第一个外显子上进行 H3 赖氨酸 27 三甲基化（H3K27me3）沉积。在 基因座不同位点的 H2Aub 和 H3K27me3 的不同修饰协同抑制 表达。总之，我们的研究结果揭示了一种由 lncRNA SEAIRa 介导的表观遗传机制，该机制调节 表达，这对于植物生长和发育是必不可少的。
