Figure 3
Sialylation and migration effects of non-cleavable ST6Gal I (L37A/K40A). A. SW480 cells were transfected with WT ST6Gal I (WT) or ST6Gal I (L37A/K40A) and cell lysates were analyzed for the phosphorylated form of p130CAS (p-P130CASY410) and integrin β1 by immunoblotting. Expression of ST6Gal I was assessed using an anti-Flag antibody. Sialylation of integrin β1 was determined by SNA lectin affinity assay. B. SW480 cells were co-transfected with BACE1 and the WT or L37A/K40A form of ST6Gal I. Cell lysates were immunoblotted with antibodies against BACE1 and Flag. C. SW480 cells and CT26 cells were co-transfected with BACE1 and WT or L37A/K40A. Twenty-four hours after transfection, cell migration was determined using Transwell migration assays. Upper: images of migrated cells captured by phase-contrast microscopy; lower: migration measured by counting cells. Data are presented as means ± SDs of three replicates (*p < 0.05 vs. the corresponding control).