Department of Laboratory Medicine, Medical School, University of Pécs, Pécs H7624, Hungary.
Department of Biophysics, Medical School, University of Pécs, Pécs H7624, Hungary.
Molecules. 2018 May 26;23(6):1275. doi: 10.3390/molecules23061275.
-linked -acetylglucosamine (-GlcNAc) is a dynamic post-translational modification of serine and threonine residues on nuclear and cytoplasmic proteins. -GlcNAc modification influences many cellular mechanisms, including carbohydrate metabolism, signal transduction and protein degradation. Multiple studies also showed that cell cycle might be modulated by -GlcNAc. Although the role of -GlcNAc in the regulation of some cell cycle processes such as mitotic spindle organization or histone phosphorylation is well established, the general behaviour of -GlcNAc regulation during cell cycle is still controversial. In this study, we analysed the dynamic changes of overall -GlcNAc levels in HeLa cells using double thymidine block. -GlcNAc levels in G₁, S, G₂ and M phase were measured. We observed that -GlcNAc levels are significantly increased during mitosis in comparison to the other cell cycle phases. However, this change could only be detected when mitotic cells were enriched by harvesting round shaped cells from the G₂/M fraction of the synchronized cells. Our data verify that -GlcNAc is elevated during mitosis, but also emphasize that -GlcNAc levels can significantly change in a short period of time. Thus, selection and collection of cells at specific cell-cycle checkpoints is a challenging, but necessary requirement for -GlcNAc studies.
-O-连接-N-乙酰氨基葡萄糖（-GlcNAc）是核质蛋白丝氨酸和苏氨酸残基上的一种动态翻译后修饰。-GlcNAc 修饰影响许多细胞机制，包括碳水化合物代谢、信号转导和蛋白质降解。多项研究还表明，细胞周期可能受到 -GlcNAc 的调节。尽管 -GlcNAc 在调节某些细胞周期过程（如有丝分裂纺锤体的组织或组蛋白磷酸化）中的作用已得到充分证实，但 -GlcNAc 调节在细胞周期中的一般行为仍存在争议。在这项研究中，我们使用双胸苷阻断法分析了 HeLa 细胞中总 -GlcNAc 水平的动态变化。测量了 G1、S、G2 和 M 期的 -GlcNAc 水平。我们观察到与其他细胞周期阶段相比，-GlcNAc 水平在有丝分裂期间显著增加。然而，只有当从同步化细胞的 G2/M 部分收获圆形细胞以富集有丝分裂细胞时，才能检测到这种变化。我们的数据证实 -GlcNAc 在有丝分裂期间升高，但也强调 -GlcNAc 水平可以在短时间内发生显著变化。因此，在特定的细胞周期检查点选择和收集细胞是 -GlcNAc 研究的一个具有挑战性但必要的要求。
