Ubiquitin carboxyl-terminal hydrolases are required for period maintenance of the circadian clock at high temperature in Arabidopsis
Ubiquitin carboxyl-terminal hydrolases are required for period maintenance of the circadian clock at high temperature in Arabidopsis
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DOI：
10.1038/s41598-019-53229-8
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发表时间：
2019-11-19
影响因子：
4.6
通讯作者：
Coupland, George
中科院分区：
文献类型：
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作者：
Hayama, Ryosuke;Yang, Peizhen;Coupland, George
蛋白质泛素化参与了许多重要的细胞过程，包括信号转导和转录，通常通过26 S蛋白酶体启动特定底物的降解。在泛素-蛋白酶体系统中，去泛素化酶（DUBs）不仅帮助产生和维持游离泛素单体的供应，还通过调节泛素化物质库来直接控制特定靶蛋白的功能和活性。泛素羧基末端水解酶（UCH）属于DUB的一个酶亚类，在拟南芥中由三个成员UCH 1、UCH 2和UCH 3代表。UCH 1和UCH 2通过其去泛素化活性影响拟南芥中生长素依赖的发育途径，而UCH 3的生物学和酶功能尚不清楚。在这里，我们表明，拟南芥UCH 3的行为，以维持在高温下的昼夜节律钟的周期与UCH 1和UCH 2冗余。而单一的uch 1，uch 2和uch 3突变体有弱的昼夜节律表型，三重的UCH突变体显示在高温下，这是更极端的比uch 1，uch 2双突变体的周期急剧延长。UCH 3还具有针对通过肽和异肽键连接泛素的一系列底物的广泛的去泛素化活性。虽然UCH 1 -3的蛋白质靶点尚不清楚，但我们提出这些DUB通过去除其结合的泛素部分作用于一个或多个控制生物钟周期长度的因素，从而确保即使在升高的温度下，生物钟也以适当的周期振荡。
Protein ubiquitylation participates in a number of essential cellular processes including signal transduction and transcription, often by initiating the degradation of specific substrates through the 26S proteasome. Within the ubiquitin-proteasome system, deubiquitylating enzymes (DUBs) not only help generate and maintain the supply of free ubiquitin monomers, they also directly control functions and activities of specific target proteins by modulating the pool of ubiquitylated species. Ubiquitin carboxyl-terminal hydrolases (UCHs) belong to an enzymatic subclass of DUBs, and are represented by three members in Arabidopsis, UCH1, UCH2 and UCH3. UCH1 and UCH2 influence auxin-dependent developmental pathways in Arabidopsis through their deubiquitylation activities, whereas biological and enzymatic functions of UCH3 remain unclear. Here, we demonstrate that Arabidopsis UCH3 acts to maintain the period of the circadian clock at high temperatures redundantly with UCH1 and UCH2. Whereas single uch1, uch2 and uch3 mutants have weak circadian phenotypes, the triple uch mutant displays a drastic lengthening of period at high temperatures that is more extreme than the uch1 uch2 double mutant. UCH3 also possesses a broad deubiquitylation activity against a range of substrates that link ubiquitin via peptide and isopeptide linkages. While the protein target(s) of UCH1-3 are not yet known, we propose that these DUBs act on one or more factors that control period length of the circadian clock through removal of their bound ubiquitin moieties, thus ensuring that the clock oscillates with a proper period even at elevated temperatures.