Antoniali Giulia, Lirussi Lisa, D'Ambrosio Chiara, Dal Piaz Fabrizio, Vascotto Carlo, Casarano Elena, Marasco Daniela, Scaloni Andrea, Fogolari Federico, Tell Gianluca
Department of Biomedical Sciences and Technologies, University of Udine, 33100 Udine, Italy Proteomics and Mass Spectrometry Laboratory, ISPAAM, National Research Council, 80147 Naples, Italy Department of Biomedical and Pharmaceutical Sciences, University of Salerno, 84084 Fisciano (Salerno), Italy Department of Pharmacy, University of Naples "Federico II," 80134 Naples, Italy Institute of Biostructures and Bioimaging, National Research Council, 80134 Naples, Italy.
Mol Biol Cell. 2014 Feb;25(4):532-47. doi: 10.1091/mbc.E13-05-0286. Epub 2013 Dec 19.
Apurinic/apyrimidinic endonuclease 1 (APE1) is a multifunctional protein contributing to genome stability via repair of DNA lesions via the base excision repair pathway. It also plays a role in gene expression regulation and RNA metabolism. Another, poorly characterized function is its ability to bind to negative calcium responsive elements (nCaRE) of some gene promoters. The presence of many functional nCaRE sequences regulating gene transcription can be envisioned, given their conservation within ALU repeats. To look for functional nCaRE sequences within the human genome, we performed bioinformatic analyses and identified 57 genes potentially regulated by APE1. We focused on sirtuin-1 (SIRT1) deacetylase due to its involvement in cell stress, including senescence, apoptosis, and tumorigenesis, and its role in the deacetylation of APE1 after genotoxic stress. The human SIRT1 promoter presents two nCaRE elements stably bound by APE1 through its N-terminus. We demonstrate that APE1 is part of a multiprotein complex including hOGG1, Ku70, and RNA Pol II, which is recruited on SIRT1 promoter to regulate SIRT1 gene functions during early response to oxidative stress. These findings provide new insights into the role of nCaRE sequences in the transcriptional regulation of mammalian genes.
脱嘌呤/脱嘧啶内切酶1（APE1）是一种多功能蛋白质，通过碱基切除修复途径修复DNA损伤，从而有助于基因组稳定性。它还在基因表达调控和RNA代谢中发挥作用。另一个特征不明确的功能是其与某些基因启动子的负钙反应元件（nCaRE）结合的能力。鉴于它们在ALU重复序列中的保守性，可以设想存在许多调节基因转录的功能性nCaRE序列。为了在人类基因组中寻找功能性nCaRE序列，我们进行了生物信息学分析，并鉴定出57个可能受APE1调控的基因。由于沉默调节蛋白-1（SIRT1）脱乙酰酶参与细胞应激，包括衰老、凋亡和肿瘤发生，以及在基因毒性应激后对APE1进行脱乙酰化的作用，我们将重点放在了它上面。人类SIRT1启动子有两个nCaRE元件，APE1通过其N端与之稳定结合。我们证明，APE1是一个多蛋白复合物的一部分，该复合物包括hOGG1、Ku70和RNA聚合酶II，在氧化应激早期反应过程中，该复合物被招募到SIRT1启动子上以调节SIRT1基因功能。这些发现为nCaRE序列在哺乳动物基因转录调控中的作用提供了新的见解。
