Innervation and Target Tissue Interactions Induce Rab-GDP Dissociation Inhibitor (GDI) Expression during Peripheral Synapse Formation in Developing Chick Ciliary Ganglion Neurons In Situ

摘要: Regulated exocytosis of neurotransmitter from synaptic vesicles involves the function a small GTP-binding protein, Rab3A. Rab-GDP dissociation inhibitor (GDI) is an important modulator Rab and subcellular distribution. We have characterized respective roles innervation target tissue interactions in regulating GDI expression during synapse formation chick ciliary ganglion (CG) neurons developing situ . Here we report first full-length cDNA sequence. It highly homologous to mammalian isoforms includes all sequence-conserved regions critical for Rab3A binding. This mRNA predominantly expressed as judged by Northern blot analysis distribution hybridization CG sections. Developmental increases levels occur two phases determined reverse transcription (RT)–PCR both normal-developing input- or tissue-deprived ganglia. The initial phase appears be independent cell–cell interactions. In contrast, second, larger increase induced presynaptic inputs postganglionic tissues but does not until innervation. Synaptic interaction with seems necessary regulatory response tissues. protein show similar changes. developmentally delayed ability targets influence differs regulation receptor neurons. These results suggest that distinct extrinsic signals synapse-related components at axon terminal versus postsynaptic membrane individual neuron.