Suggested Involvement of PP1/PP2A Activity and De Novo Gene Expression in Anhydrobiotic Survival in a Tardigrade, Hypsibius dujardini, by Chemical Genetic Approach.
Suggested Involvement of PP1/PP2A Activity and De Novo Gene Expression in Anhydrobiotic Survival in a Tardigrade, Hypsibius dujardini, by Chemical Genetic Approach.
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DOI：
10.1371/journal.pone.0144803
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发表时间：
2015
期刊：
影响因子：
3.7
通讯作者：
Kunieda T
中科院分区：
文献类型：
--
作者：
Kondo K;Kubo T;Kunieda T
在干燥时，一些缓步动物进入一种称为脱水的无代谢脱水状态，并且可以在这种状态下在干燥的环境中生存。为了成功地过渡到脱水生活，一些脱水生物缓步动物需要在高湿度条件下进行预孵育，这一过程称为预处理，然后暴露于严重的干燥环境中。虽然水熊虫被认为是准备过渡到脱水预处理过程中，这种过程的分子机制仍然未知。在这项研究中，我们使用化学遗传学的方法来阐明脱水的调节机制，脱水缓步动物，Hypsibius dujardini。我们首先证明，转录或翻译的抑制大大削弱了脱水生存，这表明从头基因表达是成功过渡到脱水在这缓步动物所必需的。然后，我们筛选了81种化学物质，并确定了5种化学物质，严重干燥后显着损害脱水生物的生存，相比之下，只有在高湿度暴露后的生存很少或没有影响。特别是，藜芦酸，蛋白磷酸酶（PP）1和PP 2A的选择性抑制剂，表现出最深刻的抑制作用。另一种PP 1/PP 2A抑制剂冈田酸也显著且特异性地损害脱水生物存活，表明PP 1/PP 2A活性在该物种的脱水生物中起重要作用。据我们所知，这是第一次报告所需的活动的信号分子的干燥耐受性的缓步动物。所鉴定的抑制性化学物质可能为阐明缓步动物脱水共生的调控机制提供新的线索。
Upon desiccation, some tardigrades enter an ametabolic dehydrated state called anhydrobiosis and can survive a desiccated environment in this state. For successful transition to anhydrobiosis, some anhydrobiotic tardigrades require pre-incubation under high humidity conditions, a process called preconditioning, prior to exposure to severe desiccation. Although tardigrades are thought to prepare for transition to anhydrobiosis during preconditioning, the molecular mechanisms governing such processes remain unknown. In this study, we used chemical genetic approaches to elucidate the regulatory mechanisms of anhydrobiosis in the anhydrobiotic tardigrade, Hypsibius dujardini. We first demonstrated that inhibition of transcription or translation drastically impaired anhydrobiotic survival, suggesting that de novo gene expression is required for successful transition to anhydrobiosis in this tardigrade. We then screened 81 chemicals and identified 5 chemicals that significantly impaired anhydrobiotic survival after severe desiccation, in contrast to little or no effect on survival after high humidity exposure only. In particular, cantharidic acid, a selective inhibitor of protein phosphatase (PP) 1 and PP2A, exhibited the most profound inhibitory effects. Another PP1/PP2A inhibitor, okadaic acid, also significantly and specifically impaired anhydrobiotic survival, suggesting that PP1/PP2A activity plays an important role for anhydrobiosis in this species. This is, to our knowledge, the first report of the required activities of signaling molecules for desiccation tolerance in tardigrades. The identified inhibitory chemicals could provide novel clues to elucidate the regulatory mechanisms underlying anhydrobiosis in tardigrades.