Figure 9.

Sialylation led to reduced N-linked glycan branching. Cells were cultured with or without 100 μm Ac₄ManNAc or 40 mm ManNAc for 24 h. The effect of Ac₄ManNAc supplementation on sialylation and N-linked glycan branching was measured by flow cytometry detection of cell surface binding of the MAL-II lectin (A) and L-PHA lectin (B), respectively. The effect of ManNAc supplementation on sialylation and N-linked glycan branching was measured by flow cytometry detection of cell surface binding of the MAL-II lectin (C) and L-PHA lectin (D), respectively. Cell lines labeled in red did not express an active GNE epimerase domain and did not synthesize sialic acid. Data shown represent three biological replicates with error bars depicting the mean and S.E. Each data point represents the MFI of a single sample, typically of 10,000 cells. Flow cytometry experiments were performed at least twice. Statistical significance determined by unpaired Welch's test: **** indicates a p value < 0.0001, *** indicates a p value < 0.001, ** indicates a p value < 0.01, * indicates a p value < 0.05. ns indicates difference not statistically significant.