The Essential Functions and Detection of Bisecting GlcNAc in Cell Biology

Abstract

The N-glycans of mammalian glycoproteins vary greatly in structure, and the biological importance of these variations is mostly unknown. It is widely acknowledged that the bisecting N-acetylglucosamine (GlcNAc) structure, a β1,4-linked GlcNAc attached to the core β-mannose residue, represents a special type of N-glycosylated modification, and it has been reported to be involved in various biological processes, such as cell adhesion, fertilization and fetal development, neuritogenesis, and tumor development. In particular, the occurrence of N-glycans with a bisecting GlcNAc modification on proteins has been proven, with many implications for immune biology. Due to the essential functions of bisecting GlcNAc structures, analytical approaches to this modification are highly required. The traditional approach that has been used for bisecting GlcNAc determinations is based on the lectin recognition of Phaseolus vulgaris erythroagglutinin (PHA-E); however, poor binding specificity hinders the application of this method. With the development of mass spectrometry (MS) with high resolution and improved sensitivity and accuracy, MS-based glycomic analysis has provided precise characterization and quantification for glycosylation modification. In this review, we first provide an overview of the bisecting GlcNAc structure and its biological importance in neurological systems, immune tolerance, immunoglobulin G (IgG), and tumor metastasis and development and then summarize approaches to its determination by MS for performing precise functional studies. This review is valuable for those readers who are interested in the importance of bisecting GlcNAc in cell biology.

On the Use of Surface Plasmon Resonance Biosensing to Understand IgG-FcγR Interactions

“…Other than fucose, the presence of a bisecting N-acetyl glucosamine (GlcNAc) and high-mannose glycans have also been associated, to a lesser degree, with enhanced ADCC activation via FcγRIIIa binding [ 48 , 49 ]. However, many studies have suggested that this enhanced ADCC activation might be only due to the fact that these glycan subtypes have a lesser core fucosylation level.…”

Bisecting GlcNAc modification diminishes the pro‐metastatic functions of small extracellular vesicles from breast cancer cells

“…However, high levels of bisecting GlcNAc cause a reduction of galectin binding in cell surface, and suppress cell adhesion and migration (Kariya et al., 2010). Beside its functions in tumour development and progression, bisecting GlcNAc was also reported to play essential roles in certain organ growth and development (Bhattacharyya, Bhaumik, Raju, & Stanley, 2002; Kizuka et al., 2015), and in immune tolerance (Chen, Tan, Guan, & Ren, 2020).…”

Identification, mapping and relative quantitation of SARS-CoV-2 Spike glycopeptides by Mass-Retention Time Fingerprinting

“…Expression in insect cell lines has also been reported, producing alternative glycosylation 14 . Interestingly, we have observed a number of G0F+GlcNAc glycopeptides that appear to have a bisecting GlcNAc 15 ; these have been implicated in immune-response tolerance 16 . Whatever the glycosylation, a biopharmaceutical vaccine derived from Spike protein requires rigorous characterization and quality control including the glycosylation.…”