The Novel GTPase Rit Differentially Regulates Axonal and Dendritic Growth

• DOI: 10.1523/jneurosci.5633-06.2007
• Publication Date: 2007-04-25T16:38:41Z
• Authors: Pamela J. Lein; Xin Guo; Geng-Xian Shi; Melissa Moholt-Si...; Donald Bruun; Douglas A. Andres
• Keywords: Neurite; Small GTPase; Dendrite (mathematics)

The Rit GTPase is widely expressed in developing and adult nervous systems, our previous data with pheochromocytoma cells implicate signaling NGF-induced neurite outgrowth. In this study, we investigated a role for neuronal morphogenesis. Expression of dominant-negative (dn) mutant hippocampal neurons inhibited axonal growth but potentiated dendritic growth. Conversely, constitutively active (ca) promoted Dendritogenesis regulated differently sympathetic versus that require NGF bone morphogenetic proteins (BMPs) to trigger Despite these differences, dnRit caRit blocked BMP7-induced neurons. Biochemical studies indicated BMP7 treatments caused also decreased GTP loading. Additional demonstrate increased extracellular signal-regulated kinase 1/2 (ERK1/2) phosphorylation pharmacological inhibition MEK1 (mitogen-activated protein kinase/ERK 1) the axon-promoting dendrite-inhibiting effects caRit. These observations suggest convergence point multiple pathways it functions promote inhibit via activation ERK1/2. Modulation activational status may therefore represent generalized mechanism across divergent cell types regulating modes.