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

Abstract

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 (RPTPkappa). The overexpression of GnT-V gene in human hepatoma SMMC-7721 cell line not only induced the addition of beta1,6 GlcNAc branch to N-glycan of RPTPkappa but also decreased the protein level of RPTPkappa, which both contributed to the decreased phosphatase activity of RPTPkappa activating subsequently EGFR signaling. Moreover, we found that the knockdown of RPTPkappa and its addition of beta1,6 GlcNAc branch both promoted cell migration, which could be ascribed to the activation of EGFR signaling regulated by RPTPkappa. Therefore, our findings could provide an insight into the molecular mechanism of how GnT-V promoted cell migration, suggesting that RPTPkappa could be one of factors regulating the EGF-mediated migration signals.