Spliceosome disassembly factors ILP1 and NTR1 promote miRNA biogenesis in Arabidopsis thaliana
Spliceosome disassembly factors ILP1 and NTR1 promote miRNA biogenesis in Arabidopsis thaliana
复制标题
剪接体分解因子 ILP1 和 NTR1 促进拟南芥中 miRNA 的生物合成
DOI：
10.1093/nar/gkz526
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发表时间：
2019-09-05
影响因子：
14.9
通讯作者：
Ren, Guodong
中科院分区：
文献类型：
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作者：
Wang, Junli;Chen, Susu;Ren, Guodong
摘要 内含子-套索剪接体（ILS）复合物在真核生物中高度保守，其解体标志着典型剪接周期的结束。在这项研究中，我们发现拟南芥中 ILS 复合体的两个保守分解因子，多倍体 1-1D 水平升高 (ILP1) 和 NTC 相关蛋白 1 (NTR1)，通过促进拟南芥中 MIRNA (MIR) 基因的转录延伸，正向调节 microRNA (miRNA) 的生物发生。 ILP1 和 NTR1 形成了一个稳定的复合体，并共同调控拟南芥基因组中一百多个基因的选择性剪接，其中包括 miRNA 的一些初级转录本 (pri-miRNA)。有趣的是，当 ILP1 或 NTR1 功能受损时，pri-miRNA，无论是否有内含子，都会整体下调。 ILP1 和 NTR1 与核心 miRNA 加工蛋白 Dicer-like 1 和 Serrate 相互作用，是 RNA 聚合酶 II 正确占据 MIR 染色质延长区域所必需的，而不影响 MIR 启动子活性或 pri-miRNA 衰减。我们的结果进一步深入了解剪接体机制在 miRNA 生物发生中的调节作用。
Abstract The intron-lariat spliceosome (ILS) complex is highly conserved among eukaryotes, and its disassembly marks the end of a canonical splicing cycle. In this study, we show that two conserved disassembly factors of the ILS complex, Increased Level of Polyploidy1-1D (ILP1) and NTC-Related protein 1 (NTR1), positively regulate microRNA (miRNA) biogenesis by facilitating transcriptional elongation of MIRNA (MIR) genes in Arabidopsis thaliana. ILP1 and NTR1 formed a stable complex and co-regulated alternative splicing of more than a hundred genes across the Arabidopsis genome, including some primary transcripts of miRNAs (pri-miRNAs). Intriguingly, pri-miRNAs, regardless of having introns or not, were globally down-regulated when the ILP1 or NTR1 function was compromised. ILP1 and NTR1 interacted with core miRNA processing proteins Dicer-like 1 and Serrate, and were required for proper RNA polymerase II occupancy at elongated regions of MIR chromatin, without affecting either MIR promoter activity or pri-miRNA decay. Our results provide further insights into the regulatory role of spliceosomal machineries in the biogenesis of miRNAs.