Kuhlmann Nora, Chollet Constance, Baldus Linda, Neundorf Ines, Lammers Michael
Institute for Genetics and Cologne Excellence Cluster on Cellular Stress Responses in Aging-Associated Diseases, CECAD, University of Cologne, Joseph-Stelzmann-Str. 26, 50931, Cologne, Germany.
Institute for Biochemistry, University of Cologne, Zülpicher Straße 47, 50674, Cologne, Germany.
ChemMedChem. 2017 Oct 20;12(20):1703-1714. doi: 10.1002/cmdc.201700414. Epub 2017 Sep 25.
RhoGDIα is a key regulator of Rho proteins, coordinating their GTP/GDP and membrane/cytosol cycle. Recently, it was demonstrated by quantitative mass spectrometry that RhoGDIα is heavily targeted by post-translational lysine acetylation. For one site in its N-terminal domain, namely K52, we reported earlier that acetylation completely switches off RhoGDIα function. Herein we show that K52-acetylated RhoGDIα is specifically deacetylated by the sirtuin deacetylase Sirt2. We show that acetylation at K52 decelerates cervical cancer cell proliferation, suggesting RhoGDIα acetylation to be a promising therapeutic target. We demonstrate that treatment of cervical cancer cells with a RhoGDIα-derived K52-trifluoroacetylated, substrate-derived peptidic sirtuin inhibitor severely impairs cell proliferation. Finally, we conclude that the potency of substrate-derived sirtuin inhibitors depends on structural features, the substrate-derived amino acid sequence as a determinant for selectivity, as well as the presence of an acetyl-lysine analogue to increase its potency. These data reveal a prospective therapeutic potential for novel substrate-derived sirtuin inhibitors.
RhoGDIα是Rho蛋白的关键调节因子，协调其GTP/GDP以及膜/胞质溶胶循环。最近，定量质谱分析表明，RhoGDIα是翻译后赖氨酸乙酰化的主要作用靶点。对于其N端结构域中的一个位点，即K52，我们之前报道过乙酰化会完全关闭RhoGDIα的功能。在此我们表明，K52乙酰化的RhoGDIα会被沉默调节蛋白去乙酰化酶Sirt2特异性地去乙酰化。我们发现K52位点的乙酰化会减缓宫颈癌细胞的增殖，这表明RhoGDIα的乙酰化可能是一个有前景的治疗靶点。我们证明，用RhoGDIα衍生的K52 - 三氟乙酰化底物衍生肽类沉默调节蛋白抑制剂处理宫颈癌细胞会严重损害细胞增殖。最后，我们得出结论，底物衍生的沉默调节蛋白抑制剂的效力取决于结构特征、作为选择性决定因素的底物衍生氨基酸序列，以及增加其效力的乙酰赖氨酸类似物的存在。这些数据揭示了新型底物衍生的沉默调节蛋白抑制剂潜在的治疗前景。
