Acute ethanol stress induces sumoylation of conserved chromatin structural proteins in Saccharomyces cerevisiae.
Acute ethanol stress induces sumoylation of conserved chromatin structural proteins in Saccharomyces cerevisiae.
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DOI：
10.1091/mbc.e20-11-0715
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发表时间：
2021-05-15
影响因子：
3.3
通讯作者：
Gardner RG
中科院分区：
文献类型：
--
作者：
Bradley AI;Marsh NM;Borror HR;Mostoller KE;Gama AI;Gardner RG
压力是生命中无处不在的，并且可以不可挽回地损害细胞中的基本生物分子和细胞器。为了生存，生物体必须感知和适应压力条件。一种高度保守的适应性应激反应是通过小泛素样修饰物（SUMO）对蛋白质的翻译后修饰。在这里，我们研究了急性乙醇胁迫对芽殖酵母酿酒酵母中蛋白质类小泛素化的影响。我们发现细胞在急性暴露于≤ 7.5%vol/vol乙醇后表现出短暂的sumoylation反应。相比之下，在10%乙醇暴露时，类小泛素化反应变为慢性。质谱分析确定了18种蛋白质在急性乙醇暴露后被sumoylated，其中15种已知与染色质相关。进一步分析后，我们发现，染色质结构蛋白Smc 5和Smc 6进行乙醇诱导的sumo化，这取决于E3 SUMO连接酶Mms 21的活性。利用细胞周期阻滞试验，我们观察到Smc 5和Smc 6乙醇诱导的类小泛素化发生在G1和G2/M期，而不是S期。急性乙醇暴露也导致Rad 52病灶的形成，其水平与暴露于DNA烷基化剂甲磺酸甲酯（MMS）后的Rad 52病灶形成相当。已知MMS暴露通过Rad 53磷酸化诱导S期内DNA损伤检查点，但乙醇暴露不诱导Rad 53磷酸化。当同时加入时，乙醇消除MMS对Rad 53磷酸化的影响。从这些研究中，我们提出，急性乙醇暴露诱导染色质的变化，导致特定的染色质结构蛋白类小泛素化。
Stress is ubiquitous to life and can irreparably damage essential biomolecules and organelles in cells. To survive, organisms must sense and adapt to stressful conditions. One highly conserved adaptive stress response is through the posttranslational modification of proteins by the small ubiquitin-like modifier (SUMO). Here, we examine the effects of acute ethanol stress on protein sumoylation in the budding yeast Saccharomyces cerevisiae. We found that cells exhibit a transient sumoylation response after acute exposure to ≤7.5% vol/vol ethanol. By contrast, the sumoylation response becomes chronic at 10% ethanol exposure. Mass spectrometry analyses identified 18 proteins that are sumoylated after acute ethanol exposure, with 15 known to associate with chromatin. Upon further analysis, we found that the chromatin structural proteins Smc5 and Smc6 undergo ethanol-induced sumoylation that depends on the activity of the E3 SUMO ligase Mms21. Using cell-cycle arrest assays, we observed that Smc5 and Smc6 ethanol-induced sumoylation occurs during G1 and G2/M phases but not S phase. Acute ethanol exposure also resulted in the formation of Rad52 foci at levels comparable to Rad52 foci formation after exposure to the DNA alkylating agent methyl methanesulfonate (MMS). MMS exposure is known to induce the intra-S-phase DNA damage checkpoint via Rad53 phosphorylation, but ethanol exposure did not induce Rad53 phosphorylation. Ethanol abrogated the effect of MMS on Rad53 phosphorylation when added simultaneously. From these studies, we propose that acute ethanol exposure induces a change in chromatin leading to sumoylation of specific chromatin structural proteins.