P2X receptors are a family of cation channels expressed in neurons and nonneuronal cells.They play a variety of roles including synaptic transmission, muscle contraction, neuronal secretion and inflammation response.Among P2X receptors, the P2X3 subtype is selectively expressed in dorsal root ganglion neurons.Lipid raft is a specialized membrane microdomain and participate many signal transduction events.Previous report showed that P2X3 receptor is localized in the lipid rafts of DRG neurons.We have found P2X3 receptor engaged in retrograde transport in the form of signaling endosome.Here we investigated the role of lipid rafts in α, β-MeATP-dependent endocytosis and signal transduction, and retrograde transport of P2X3 receptor.Disruption of lipid raft with MβCD or nystatin abolished ATP-dependent endocytosis of P2X3 receptor and ATP-induced ERK activation in P2X3 receptor-expressing HEK293 cells.In vivo sucrose gradient fractionation with vesicular pellets prepared from sciatic nerve axoplasm showed that abundant P2X3 receptor was localized in lipid raft fractions.Retrograde transported P2X3 receptors were colocalized with the lipid raft marker caveolinl a in sciatic nerve.Nerve terminal treatment with MβCD attenuated retrograde transport of P2X3 receptor in axon of dorsal root ganglion neuron.Together, lipid raft mediates ATP-induced endocytosis, signal transduction and retrograde transport of P2X3 receptor.