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 (RPTP kappa). The overexpression of GnT-V gene in human hepatoma SMMC-7721 cell line not only induced the addition of beta 1,6 GlcNAc branch to N-glycan of RPTP kappa but also decreased the protein level of RPTP kappa, which both contributed to the decreased phosphatase activity of RPTP kappa activating subsequently EGFR signaling. Moreover, we found that the knockdown of RPTP kappa and its addition of PI,6 GlcNAc branch both promoted cell migration, which could be ascribed to the activation of EGFR signaling regulated by RPTP kappa. Therefore, our findings could provide an insight into the molecular mechanism of how GnT-V promoted cell migration, suggesting that RPTP kappa could be one of factors regulating the EGF-mediated migration signals. (C) 2009 Elsevier Inc. All rights reserved.