ADP-induced endocytosis in sensory DRG neurons
【摘要】：正Endoeytosis is a fundamental cellular event in membrane retrieval following exocytosis and in the regulation of receptor-mediated signal transduction. The kinetics of exocytosis and endocytosis is important for the rate of transmitter release and for the vesicle recycling. In contrast to the well-studied depolarization-induced membrane recycling, little is known about the kinetics of ligand-induced endocytosis of G-protein-coupled receptors (GPCRs) or receptor of tyrosine kinase (RTK.) in neurons. Here we investigated the temporal dynamics of ligand-receptor binding-induced endocytosis in rat sensory neurons by applying membrane capacitance assay and a modified confocal imaging technique (FM). ADP-induced endocytosis of P2Y-receptor has a time constant of 1.7 s. which is 100 times faster than that previously estimated for a GPCR signaling. We conclude that ligand-receptor binding leads to rapid internalization of the GPCR/P2Y in the cytoplasm of rat dorsal root ganglion (DRG) neurons.