During mitosis, phosphorylation and dephosphorylation of lamins triggers the nuclear envelope disassembly/assembly. However, it hasn’t been known whether lamin proteins undergo any modification other than phosphorylation during the cell cycle. Glycosylation of lamin proteins is one of the less studied post-translational modification. Glycosylation and phosphorylation compete for the same positions and interplay between two modifications generate a post-translational code in the cell. Based on this, we hypothesized that glycosylation of lamin A/C protein may be important in the regulation of the structural organization of the nuclear lamina during interphase and mitosis. We analysed the glycan units of lamin A/C protein in lung carcinoma cells synchronized at G2/M and S phases via CapLC-ESI-MS/MS. Besides, the outermost glycan units were determined using lectin blotting and gold-conjugated antibody and lectin staining. TEM studies also allowed us to observe the localization of glycosylated lamin A/C protein. With this study, we determined that lamin A/C protein shows O-glycosylation at G2/M and S phases of the cell cycle. In addition to O-GlcNAcylation and O-GalNAcylation, lamin A/C is found to be contain Gal, Fuc, Man, and Sia sugars at G2/M and S phases for the first time. Having found the glycan units of the lamin A/C protein suggests that glycosylation might have a role in the nuclear organization during the cell cycle.

在有丝分裂过程中，核纤层蛋白的磷酸化和去磷酸化会触发核膜的分解/组装。然而，尚不清楚核纤层蛋白在细胞周期中是否经历除磷酸化之外的任何修饰。核纤层蛋白的糖基化是研究较少的翻译后修饰之一。糖基化和磷酸化竞争相同的位置，并且两种修饰之间的相互作用在细胞中产生翻译后密码。基于此，我们假设核纤层蛋白 A/C 蛋白的糖基化可能在间期和有丝分裂期间核纤层结构组织的调节中起重要作用。我们通过 CapLC-ESI-MS/MS 分析了在 G2/M 和 S 期同步的肺癌细胞中核纤层蛋白 A/C 蛋白的聚糖单位。除了，使用凝集素印迹和金结合抗体和凝集素染色确定最外层的聚糖单位。TEM 研究还使我们能够观察到糖基化核纤层蛋白 A/C 蛋白的定位。通过这项研究，我们确定核纤层蛋白 A/C 蛋白在细胞周期的 G2/M 和 S 期显示 O-糖基化。除O-GlcNAcylation和O-GalNAcylation外，首次发现lamin A/C在G2/M和S期含有Gal、Fuc、Man和Sia糖。发现核纤层蛋白 A/C 蛋白的聚糖单元表明糖基化可能在细胞周期的核组织中起作用。我们确定核纤层蛋白 A/C 蛋白在细胞周期的 G2/M 和 S 期显示 O-糖基化。除O-GlcNAcylation和O-GalNAcylation外，首次发现lamin A/C在G2/M和S期含有Gal、Fuc、Man和Sia糖。发现核纤层蛋白 A/C 蛋白的聚糖单元表明糖基化可能在细胞周期的核组织中起作用。我们确定核纤层蛋白 A/C 蛋白在细胞周期的 G2/M 和 S 期显示 O-糖基化。除O-GlcNAcylation和O-GalNAcylation外，首次发现lamin A/C在G2/M和S期含有Gal、Fuc、Man和Sia糖。发现核纤层蛋白 A/C 蛋白的聚糖单元表明糖基化可能在细胞周期的核组织中起作用。