A glycomic approach to the identification and characterization of glycoprotein function in cells transfected with glycosyltransferase genes

Abstract

The transfection of glycoprotein glycosyltransferase genes into cells leads to modification of both the structure and function of the glycoproteins and as a result, changes in glycome patterns. N-glycan branching enzymes hold some promise as a model system for the identification of glycome patterns. Both N-acetylglucosaminyltransferase III and alpha 1-6 fucosyltransferase are typical glycosyltransferases, which are involved in the branching of N-glycans. The resulting enzymatic products, bisecting N-GlcNAc and alpha 1-6 fucose residues, are no longer modified by other glycosyltransferases and it is a relatively simple task to identify their modification by means of lectins. In this review, the glycome patterns of glycosyltransferase gene transfectants and the non-transfectants were compared by two-dimensional gel electrophoresis and lectin staining, and the biological significance of the two genes are described. Analyses of glycome patterns by transfecting glycosyltransferase genes will lead to new fields of study in the area of postgenome research.

The Asn418-Linked N-Glycan of ErbB3 Plays a Crucial Role in Preventing Spontaneous Heterodimerization and Tumor Promotion

“…It has been reported that glycosylation regulates the function of glycoproteins by inducing conformational changes or by affecting intramolecular interactions (6)(7)(8)(9)(10). Many membrane-bound proteins, such as receptors, are glycosylated, and it has been reported that glycosylation status is crucial for their function (11)(12)(13)(14)(15).…”

Branched N-glycans and their implications for cell adhesion, signaling and clinical applications for cancer biomarkers and in therapeutics

“…Even though capillary electrophoresis, Massspectrometry and NMR techniques have been extensively developed for the analysis of glycans, problems remain in terms of sensitivity and the quantitative analysis of glycans. For the last 20 year or so, our group has been interested in the functions of N-linked glycans, especially glycosyltransferases that are involved in the N-linked glycan branching (2)(3)(4)(5)(6)(7)(8). Over time, we purified a series of glycosyltransferases to homogeneity using classical but, in fact, unique and sophisticated methodology such as affinity chromatography using donor or acceptor substrates.…”

The role of ErbB3 N-glycan in dimer formation: Implications for transforming activity

“…It has been reported that glycosylation regulates the function of glycoproteins by aŠecting protein stability and conformation, or by in‰uencing cellular localization and intramolecular interactions (6)(7)(8)(9)(10). Members of the ErbB family undergo several posttranslational modiˆcations, including glycosylation.…”