Loss of expression of N‐acetylglucosaminyltransferase Va results in altered gene expression of glycosyltransferases and galectins

Abstract

We isolated mouse embryo fibroblasts (MEFs) from N-acetylglucosaminyltransferase Va (GnT-Va) knockout mice and studied the effects of loss of expression of GnT-Va on asparagine-linked glycans (N-glycan) synthesis and the gene expression of groups of glycosyltransferases and galectins. Loss of GnT-Va expression caused aberrant expression of several N-glycan structures, including N-linked b(1,6) branching, poly-N-lactosamine, bisecting N-acetylglucosamine (GlcNAc) and sialic acid. Using quantitative reverse transcriptase-PCR (qRT-PCR), altered gene expression of several groups of glycosyltransferases and galectins was observed in GnT-Va null MEFs, supporting the observed changes in N-glycan structures. These results suggest that genetic disruption of GnT-Va ultimately resulted in altered MEFs gene expression and decreased tumor progression associated with loss of GnT-Va observed may result in part from a combination of effects from these altered gene expressions.

Detection of Differentially Expressed Wound-Healing–Related Glycogenes in Galectin-3–Deficient Mice

“…Many published studies have reported statistically and biologically significant microarray data using a low cutoff rate similar to that used in the present study 21-26. Moreover, many differential gene expression studies have shown low changes in glycogenes, specifically glycosyltransferases, to be biologically relevant 27-30. For example, Comelli et al29 showed that a 1.3- to 1.5-fold decrease in ST3GalI expression between fresh and activated T cells (and B cells) is sufficient to cause hyposialylation of O-glycans.…”

Involvement of murine β-1,4-galactosyltransferase V in lactosylceramide biosynthesis

“…1-β-1,4-GalT V). As ablation of the N -acetylglucosaminyltransferase Va gene in mice affected the expression of several other glycosyltransferase genes [37], the expression levels of the β-1,4-GalT I, II, III, IV and VI genes were examined by RT-PCR. The results showed that no significant changes in their expression levels are observed among three samples (Fig.…”

N- and O-glycome analysis of serum and urine from bladder cancer patients using a high-throughput glycoblotting method

“…It has been already known that β1,6GlcNAc branching of N-glycans is often increased [26] and the chain length of mucintype O-glycans is generally shorten in cancer patients, notably "aberrant O-glycans" [27]. Branching N-glycan structures, such as bisecting GlcNAc and third branching1,6GlcNAc are produced by enzymes GlcNAc-transferase-III (GnT-III) and GlcNAc-transferase-IV or -V (GnT-IV or -V), respectively.…”