| Assessment of Diadenylate Cyclase and c-di-AMP-phosphodiesterase Activities Using Thin-layer and Ion Exchange Chromatography
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Author:
Date:
2021-01-05
[Abstract] All living cells use cyclic nucleotides as second messengers for signal sensing and transduction. Cyclic di-3′,5′-adenosine monophosphate (c-di-AMP) is primarily involved in the control of bacterial and euryarcheal osmoadaptation and is produced by diadenylate cyclases from two molecules of ATP. Specific phosphodiesterases hydrolyze c-di-AMP to the linear phosphoadenylate adenosine 5′-pApA or to AMP. Different methods including high-performance liquid chromatography (HPLC), thin-layer chromatography (TLC) and ion exchange chromatography (IEX) can be used to determine activities of c-di-AMP-synthesizing and degrading enzymes. Here, we describe in detail the TLC and IEX methods adapted for characterization of the diadenylate cyclase DisA and the phosphodiesterase AtaC from ...
[摘要] [摘要]所有活细胞均使用环状核苷酸作为第二信使，以进行信号传感和转导。环状二-3 ' ，5 ' -腺苷一磷酸（C-二-AMP）主要涉及细菌和控制euryarcheal osmoadaptation并且由产生diadenylate环化酶从ATP的两个分子。特定的磷酸二酯酶将c-di-AMP水解为线性磷酸腺苷腺苷5'-pApA或AMP。可以使用包括高效液相色谱（HPLC），薄层色谱（TLC）和离子交换色谱（IEX）在内的各种方法来确定c-di-AMP合成和降解酶的活性。在这里，我们详细描述了TLC和IEX方法适合于表征diadenylate环化酶DISA和磷酸二酯酶ATAC从链霉菌venezuelae 。TLC可以快速，轻松地分离放射性标记的底物和产品，而IEX避免了潜在危险的放射性底物的利用，如果没有HPLC系统，则可以用作良好的替代品。与TLC分析不同，无法使用IEX分析并行分析样品，因此更加耗时。
[背景]环核苷酸第二信使是原核和真核信号通路中的关键分子。环状二-3 ' ，5 ' -腺苷一磷酸（三二- AMP）是一种细菌第二信使与许多重要的功能，如渗压剂动态平衡调节，细胞壁代谢，生物膜的形成，DNA完整，孢子形成，毒力和生长（Fahmi et ...
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| RNA Cap Methyltransferase Activity Assay
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Author:
Date:
2018-03-20
[Abstract] Methyltransferases that methylate the guanine-N7 position of the mRNA 5’ cap structure are ubiquitous among eukaryotes and commonly encoded by viruses. Here we provide a detailed protocol for the biochemical analysis of RNA cap methyltransferase activity of biological samples. This assay involves incubation of cap-methyltransferase-containing samples with a [32P]G-capped RNA substrate and S-adenosylmethionine (SAM) to produce RNAs with N7-methylated caps. The extent of cap methylation is then determined by P1 nuclease digestion, thin-layer chromatography (TLC), and phosphorimaging. The protocol described here includes additional steps for generating the [32P]G-capped RNA substrate and for preparing nuclear and cytoplasmic extracts from mammalian cells. This assay is ...
[摘要] 甲基化mRNA 5'帽结构的鸟嘌呤-N7位置的甲基转移酶在真核生物中普遍存在并且通常由病毒编码。这里我们提供生物样品的RNA帽甲基转移酶活性的生化分析的详细方案。该测定包括将含有帽 - 甲基转移酶的样品与[32 P] G-加帽的RNA底物和S-腺苷甲硫氨酸（SAM）温育以产生具有N7-甲基化帽的RNA。然后通过P1核酸酶消化，薄层色谱（TLC）和磷成像确定帽甲基化的程度。此处描述的方案包括用于产生[32 P] G-加帽的RNA底物和用于从哺乳动物细胞制备核和细胞质提取物的附加步骤。该分析也适用于分析其他生物样品（包括重组蛋白制剂和来自分析分离和免疫沉淀/下拉实验的级分）的帽甲基转移酶活性。
【背景】mRNA的5'端的N7-甲基鸟苷帽是适当的真核mRNA加工，定位和翻译所必需的修饰。 ...
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