生物钟是协调遗传的生物计时系统,新陈代谢,和外部昼夜周期的生理行为。植物中的时钟依赖于转录-翻译反馈环(TTFL),由转录因子组成,包括PSUEDO响应调节剂(PRR)蛋白,植物谱系特异性转录抑制因子。这里,我们报道了一种新的合成小分子调节剂,5-(3,4-二氯苯基)-1-苯基-1,7-二氢-4H-吡唑并[3,4-d]嘧啶-4,6(5H)-二酮(TU-892),影响PRR7蛋白量。针对MaybridgeHitfinder10K化学文库中的10,000个小分子筛选拟南芥的时钟报告线。该筛选发现TU-892是延长周期的分子。基因表达分析显示TU-892处理上调瑞卡迪安时钟相关1(CCA1)mRNA表达。TU-892处理减少了PRR7蛋白的量,CCA1的转录抑制因子之一。通过TU-892处理,其他PRR蛋白(包括CAB表达的时序1(TOC1))改变较少。TU-892依赖性CCA1上调在突变体受损的PRR7中减弱。总的来说,TU-892是一种新型的时钟调制器,可降低PRR7蛋白的水平。
Circadian clocks are biological timekeeping systems that coordinate genetic, metabolic and physiological behaviors with the external day-night cycle. The clock in plants relies on the transcriptional-translational feedback loops transcription-translation feedback loop (TTFL), consisting of transcription factors including PSUEDO-RESPONSE REGULATOR (PRR) proteins, plant lineage-specific transcriptional repressors. Here, we report that a novel synthetic small-molecule modulator, 5-(3,4-dichlorophenyl)-1-phenyl-1,7-dihydro-4H-pyrazolo[3,4-d] pyrimidine-4,6(5H)-dione (TU-892), affects the
PRR7 protein amount. A clock reporter line of Arabidopsis was screened against the 10,000 small molecules in the Maybridge Hitfinder 10K chemical library. This screening identified TU-892 as a period-lengthening molecule. Gene expression analyses showed that TU-892 treatment upregulates CIRCADIAN CLOCK-ASSOCIATED 1 (CCA1) mRNA expression. TU-892 treatment reduced the amount of
PRR7 protein, a transcriptional repressor of CCA1. Other PRR proteins including TIMING OF CAB EXPRESSION 1 were altered less by TU-892 treatment. TU-892-dependent CCA1 upregulation was attenuated in mutants impaired in
PRR7. Collectively, TU-892 is a novel type of clock modulator that reduces the levels of
PRR7 protein.