Zhou Jincong, Liu Liangyu, Li Qin, Xu Wei, Li Kuan, Wang Zhi-Wei, Sun Qianwen
Tsinghua-Peking Joint Center for Life Sciences and Center for Plant Biology, School of Life Sciences, Tsinghua University, Beijing, China.
Key Laboratory of Plant Gene Resources and Biotechnology for Carbon Reduction and Environmental Improvement, Beijing Municipal Government, College of Life Sciences, Capital Normal University, Beijing, China.
Plant J. 2020 Mar;101(5):1185-1197. doi: 10.1111/tpj.14584. Epub 2019 Dec 8.
Intronic transposable elements (TEs) comprise a large proportion in eukaryotic genomes, but how they regulate the host genes remains to be explored. Our forward genetic screen disclosed the plant-specific RNA polymerases IV and V in suppressing intronic TE-mediated cryptic transcription initiation of a chimeric transcripts at FLC (FLC ). Initiation of FLC transcription is blocked by the locally formed intronic heterochromatin, which is directly associated with RNA Pol V to inhibit the entry of RNA Pol II and the occupancy of H3K4 methylation. Genome-wide Pol II Ser5p native elongation transcription sequencing revealed that a significant number of intronic heterochromatin-containing genes undergo this mechanism. This study sheds light on deeply understanding the function of intronic heterochromatin on host genes expression in eukaryotic genome.
内含子转座元件(TEs)在真核生物基因组中占很大比例,但它们如何调控宿主基因仍有待探索。我们的正向遗传学筛选揭示了植物特有的RNA聚合酶IV和V在抑制内含子TE介导的FLC(开花位点C)嵌合转录本的隐秘转录起始方面的作用。FLC转录的起始被局部形成的内含子异染色质所阻断,该异染色质直接与RNA聚合酶V相关联,以抑制RNA聚合酶II的进入和H3K4甲基化的占据。全基因组Pol II Ser5p天然延伸转录测序表明,大量含有内含子异染色质的基因经历了这种机制。这项研究为深入理解内含子异染色质在真核生物基因组中对宿主基因表达的功能提供了线索。