Changes in glycosylation on proteins or lipids are one of the hallmarks of tumorigenesis. In many cases, it is still not understood how glycan information is translated into biological function. In this review, we discuss at the example of specific cancer-related glycoproteins how their endocytic uptake into eukaryotic cells is tuned by carbohydrate modifications. For this, we not only focus on overall uptake rates, but also illustrate how different uptake processes—dependent or not on the conventional clathrin machinery—are used under given glycosylation conditions. Furthermore, we discuss the role of certain sugar-binding proteins, termed galectins, to tune glycoprotein uptake by inducing their crosslinking into lattices, or by co-clustering them with glycolipids into raft-type membrane nanodomains from which the so-called clathrin-independent carriers (CLICs) are formed for glycoprotein internalization into cells. The latter process has been termed glycolipid–lectin (GL-Lect) hypothesis, which operates in a complementary manner to the clathrin pathway and galectin lattices.

中文翻译：

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癌症中的糖基化和筏内吞作用

蛋白质或脂质糖基化的变化是肿瘤发生的标志之一。在许多情况下，仍然不了解聚糖信息如何转化为生物功能。在这篇综述中，我们以特定的癌症相关糖蛋白为例讨论了它们如何通过碳水化合物修饰来调节真核细胞的内吞吸收。为此，我们不仅关注整体摄取率，而且还说明了在给定糖基化条件下如何使用不同的摄取过程（依赖或不依赖于传统网格蛋白机制）。此外，我们讨论了某些糖结合蛋白（称为半乳糖凝集素）通过诱导它们交联成晶格来调节糖蛋白摄取的作用，或者通过将它们与糖脂共簇成筏型膜纳米域，从中形成所谓的网格蛋白非依赖性载体 (CLIC)，用于糖蛋白内化到细胞中。后一个过程被称为糖脂-凝集素（GL-Lect）假说，它以与网格蛋白途径和半乳糖凝集素晶格互补的方式运作。