N-acetylglucosaminyltranferase VB expression enhances beta1 integrin- dependent PC12 neurite outgrowth on laminin and collagen.

N-acetylglucosaminyltransferase VB (GnT-VB, -IX) is a newly discovered glycosyltransferase expressed exclusively in high levels in neuronal tissue during early development. Its homolog, GnT-V, is expressed in many tissues and modulates cell–cell and cell–matrix adhesion. The ability of GnT-VB to regulate cell–matrix interactions was initially investigated using the rat pheochromocytoma PC12 neurite outgrowth model. PC12 cells stably transfected with GnT-VB consistently showed an enhanced rate of nerve growth factor (NGF)-induced neurite outgrowth on collagen and laminin substrates. Levels of TrkA receptor phosphorylation and downstream ERK activation induced by NGF were not influenced by GnT-VB expression. No significant difference was observed in the rate of neurite outgrowth when cells were cultured on non-coated culture dishes, indicating that integrin–ECM interaction is required for the stimulatory effects. Neurite outgrowth induced by manganese-dependent activation of β1 integrin on collagen and laminin substrates, however, showed a significant increase in neurite length for the PC12/GnT-VB cells, compared with control cells, suggesting that the enhancement is most likely mediated by alteration of β1 integrin–ECM interaction by GnT-VB. These results demonstrate that GnT-VB expression can modulate the rate of neurite outgrowth by affecting β1 integrin–ECM interaction.