Myrup Holst Camilla, Brøndum Andersen Nanna, Thinggaard Vibeke, Tilken Mine, Lautrup Sofie, Tesauro Cinzia, Stevnsner Tinna
Department of Molecular Biology & Genetics, Aarhus University, 8000 Aarhus, Denmark.
Department of Clinical Molecular Biology, University of Oslo and Akershus University Hospital, 1478 Lørenskog, Norway.
Antioxidants (Basel). 2023 Feb 2;12(2):355. doi: 10.3390/antiox12020355.
The DNA glycosylase NEIL2 plays a central role in maintaining genome integrity, in particular during oxidative stress, by recognizing oxidized base lesions and initiating repair of these via the base excision repair (BER) pathway. Post-translational modifications are important molecular switches that regulate and coordinate the BER pathway, and thereby enable a rapid and fine-tuned response to DNA damage. Here, we report for the first time that human NEIL2 is regulated by phosphorylation. We demonstrate that NEIL2 is phosphorylated by the two kinases cyclin-dependent kinase 5 (CDK5) and protein kinase C (PKC) in vitro and in human SH-SY5Y neuroblastoma cells. The phosphorylation of NEIL2 by PKC causes a substantial reduction in NEIL2 repair activity, while CDK5 does not directly alter the enzymatic activity of NEIL2 in vitro, suggesting distinct modes of regulating NEIL2 function by the two kinases. Interestingly, we show a rapid dephosphorylation of NEIL2 in response to oxidative stress in SH-SY5Y cells. This points to phosphorylation as an important modulator of NEIL2 function in this cellular model, not least during oxidative stress.
DNA糖基化酶NEIL2在维持基因组完整性方面发挥着核心作用，尤其是在氧化应激期间，它通过识别氧化碱基损伤并经由碱基切除修复（BER）途径启动对这些损伤的修复。翻译后修饰是调节和协调BER途径的重要分子开关，从而能够对DNA损伤做出快速且精细的反应。在此，我们首次报道人类NEIL2受磷酸化调控。我们证明，在体外以及在人SH-SY5Y神经母细胞瘤细胞中，NEIL2被细胞周期蛋白依赖性激酶5（CDK5）和蛋白激酶C（PKC）这两种激酶磷酸化。PKC对NEIL2的磷酸化导致NEIL2修复活性大幅降低，而CDK5在体外不会直接改变NEIL2的酶活性，这表明这两种激酶调节NEIL2功能的模式不同。有趣的是，我们发现SH-SY5Y细胞在受到氧化应激时NEIL2会快速去磷酸化。这表明在该细胞模型中，磷酸化是NEIL2功能的重要调节因子，尤其是在氧化应激期间。
