EGF-mediated migration signaling activated by N-acetylglucosaminyltransferase-V via receptor protein tyrosine phosphatase kappa

N-acetylglucosaminyltransferase-V (GnT-V) has been reported to be closely associated with tumor migration, but the mechanism has been not currently clear. In this study we found that GnT-V activated EGFR signaling and promoted cell migration through receptor protein tyrosine phosphatase kappa (RPTPκ). The overexpression of GnT-V gene in human hepatoma SMMC-7721 cell line not only induced the addition of β1,6 GlcNAc branch to N-glycan of RPTPκ but also decreased the protein level of RPTPκ, which both contributed to the decreased phosphatase activity of RPTPκ activating subsequently EGFR signaling. Moreover, we found that the knockdown of RPTPκ and its addition of β1,6 GlcNAc branch both promoted cell migration, which could be ascribed to the activation of EGFR signaling regulated by RPTPκ. Therefore, our findings could provide an insight into the molecular mechanism of how GnT-V promoted cell migration, suggesting that RPTPκ could be one of factors regulating the EGF-mediated migration signals.