TCGAP Is Required For Neuronal Morphogenesis During The Early Stages Of Neural Development

Neuronal morphogenesis plays an important role in neuronal development. Abnormal neuronal morphogenesis associates with many neuronal diseases. Many molecular including Rho GTPases and GAPs associate with this process. TC10β/CDC42 GTPase-activating protein (TCGAP) is known to be a brain-enriched multiple domain protein. It has been reported that TCGAP involved in NGF-induced neurite outgrowth in PC12 cells, but the role of TCGAP in neuronal development process is poorly understood. In the present study, we investigated the role of TCGAP in neuronal morphogenesis. We showed that TCGAP regulated the neuronal morphogenesis majorly by involving in dendritic morphogenesis. Knocking down TCGAP by RNA interference led to a decrease in the overall length of dendrite arbors and the number of dendrite branches both in vitro and in vivo, and this defect could be rescued by expressing a knock-down resistant form TCGAP. Overexpressing TCGAP increased dendritic outgrowth and branching. In contrast, neither downregulating nor overexpressing TCGAP had any effect on axonal morphogenesis in vitro and downregulating TCGAP didn't affect axonal projection in vivo. Besids, our work demonstrated that TCGAP didn't involve in BDNF-induced dendritic outgrowth. All of our works suggest that TCGAP regulates neuronal morphogenesis in early developmental stage.