Altered glycosylation is an undisputed corollary of cancer development. Understanding these alterations is paramount but hampered by limitations underlying cellular model systems. For instance, the intricate interactions between tumour and host cannot be adequately recapitulated in monoculture of tumour-derived cell lines. More complex co-culture models usually rely on sorting procedures for proteome analyses and rarely capture the details of protein glycosylation. Here, we report a strategy termed Bio-Orthogonal Cell line-specific Tagging of Glycoproteins (BOCTAG). Cells are equipped by transfection with an artificial biosynthetic pathway that transforms bioorthogonally tagged sugars into the corresponding nucleotide-sugars. Only transfected cells incorporate bioorthogonal tags into glycoproteins in the presence of non-transfected cells. We employ BOCTAG as an imaging technique and to annotate cell-specific glycosylation sites in mass spectrometry-glycoproteomics. We demonstrate application in co-culture and mouse models, allowing for profiling of the glycoproteome as an important modulator of cellular function.

中文翻译：

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糖蛋白的细胞特异性生物正交标记

改变的糖基化是癌症发展的无可争议的必然结果。了解这些变化是最重要的，但受到细胞模型系统基础限制的阻碍。例如，肿瘤和宿主之间错综复杂的相互作用无法在肿瘤衍生细胞系的单一培养中得到充分概括。更复杂的共培养模型通常依赖于蛋白质组分析的分类程序，很少捕获蛋白质糖基化的细节。在这里，我们报告了一种称为生物正交细胞系特异性糖蛋白标记 (BOCTAG) 的策略。细胞通过转染配备人工生物合成途径，该途径将生物正交标记的糖转化为相应的核苷酸糖。在未转染的细胞存在的情况下，只有转染的细胞会将生物正交标签整合到糖蛋白中。我们采用 BOCTAG 作为成像技术，并在质谱-糖蛋白组学中注释细胞特异性糖基化位点。我们展示了在共培养和小鼠模型中的应用，允许分析糖蛋白质组作为细胞功能的重要调节剂。