Department of Genetics, University of North Carolina, Chapel Hill, North Carolina.
Department of Biostatistics, University of North Carolina, Chapel Hill, North Carolina.
J Biol Chem. 2020 May 29;295(22):7608-7619. doi: 10.1074/jbc.RA120.013513. Epub 2020 Apr 17.
The circadian clock in plants temporally coordinates biological processes throughout the day, synchronizing gene expression with diurnal environmental changes. Circadian oscillator proteins are known to regulate the expression of clock-controlled plant genes by controlling their transcription. Here, using a high-throughput RNA-Seq approach, we examined genome-wide circadian and diurnal control of the transcriptome, finding that the oscillation patterns of different transcripts of multitranscript genes can exhibit substantial differences and demonstrating that the circadian clock affects posttranscriptional regulation. In parallel, we found that two major posttranscriptional mechanisms, alternative splicing (AS; especially intron retention) and alternative polyadenylation (APA), display circadian rhythmicity resulting from oscillation in the genes involved in AS and APA. Moreover, AS-related genes exhibited rhythmic AS and APA regulation, adding another layer of complexity to circadian regulation of gene expression. We conclude that the circadian clock not only controls transcription of genes but also affects their posttranscriptional regulation by influencing alternative splicing and alternative polyadenylation.
植物中的生物钟在一天中定时协调生物过程，使基因表达与昼夜环境变化同步。已知生物钟振荡器蛋白通过控制转录来调节时钟控制的植物基因的表达。在这里，我们使用高通量 RNA-Seq 方法，检查了转录组的全基因组昼夜节律和昼夜控制，发现多转录基因的不同转录本的振荡模式可能存在显著差异，并证明生物钟会影响转录后调控。同时，我们发现两种主要的转录后机制，可变剪接（AS；特别是内含子保留）和可变多聚腺苷酸化（APA），由于参与 AS 和 APA 的基因的振荡而表现出昼夜节律性。此外，与 AS 相关的基因表现出有节奏的 AS 和 APA 调节，为基因表达的昼夜调节增加了另一层复杂性。我们的结论是，生物钟不仅控制基因的转录，还通过影响可变剪接和可变多聚腺苷酸化来影响它们的转录后调控。
