A NOVEL GLYCOSIGNALING SYSTEM - GQ1B-DEPENDENT NEURITOGENESIS OF HUMAN NEUROBLASTOMA CELL-LINE, GOTO, IS CLOSELY ASSOCIATED WITH GQ1B-DEPENDENT ECTO-TYPE PROTEIN-PHOSPHORYLATION

Previously, we reported that ganglioside GQ1b specifically promoted neuritogenesis of human neuroblastoma cells (GOTO), and also that it specifically stimulated the phosphorylation of several cell surface proteins on the same cells. To disclose the relationship between the two events, we examined them using a novel protein kinase inhibitor, K-252b, which is a derivative of K-252a and cannot pass through cell membrane. K-252b inhibited the GQ1b-dependent neuritogenesis as well as the GQ1b-stimulated phosphorylation. This suggests the direct coupling between the two cell events and the occurrence of a new biosignal transduction system.