Ph.D. National Tsing Hua University
Postdoc Assoc. Yale University
The RNA helicase DDX3 is essential for efficient expression of Rac1, which regulates actin dynamics in a range of cellular processes including neuronal morphogenesis. Here we demonstrate that DDX3 is important for dendritic spine formation. DDX3 knockdown decreased the population of mature mushroom-shaped dendritic spines, but increased the population of immature filopodia-shaped as well as irregular dendritic spines. Rac1 overexpression rescued dendritic spine density but not spine maturation in DDX3 knockdown neurons. The latter particularly required activation of PKA, a potential activator of Rac1 in neurons, suggesting that DDX3-activated PKA and Rac1 expression sequentially modulates dendritic spine formation.