Exp Neurobiol.  2011 Mar;20(1):29-34. 10.5607/en.2011.20.1.29.

Characterization of the Rho GTPase-Activating Protein RhoGAP68F

• Nahm M
• Lee S

• KMID: 2165343
• DOI: http://doi.org/10.5607/en.2011.20.1.29

Abstract

Rho small GTPases control multiple aspects of neuronal morphogenesis by regulating the assembly and organization of the actin cytoskeleton. Although they are negatively regulated by GTPase activating proteins (GAPs), the roles of RhoGAPs in the nervous system have not been fully investigated. Here we describe a characterization of Drosophila RhoGAP68F that is mainly expressed in the embryonic central nervous system. RNA in situ hybridization analysis showed that expression of RhoGAP68F is highly restricted to the embryonic brain and ventral nerve cord. Database search revealed that RhoGAP68F contains an N-terminal Sec14 domain and a C-terminal RhoGAP domain. Rho-GTP pull-down assay demonstrated that the RhoGAP domain of RhoGAP68F inactivates RhoA but not Rac1 or Cdc42 in HEK293 cells. In addition, expression of RhoGAP68F in NIH3T3 cells suppressed LPA-induced stress fiber formation, which is mediated by RhoA. Finally, neuronal overexpression of RhoGAP68F causes synaptic overgrowth at the larval neuromuscular junction (NMJ). Taken together, these results suggest that RhoGAP68F may play a role in synaptic growth regulation by inactivating RhoA.

Keyword

GAP; RhoGAP68F; RhoA; F-actin; nervous system; drosophila

MeSH Terms

Actin Cytoskeleton
Actins
Brain
Central Nervous System
Drosophila
GTPase-Activating Proteins
HEK293 Cells
In Situ Hybridization
Monomeric GTP-Binding Proteins
Morphogenesis
Nervous System
Neuromuscular Junction
Neurons
RNA
Stress Fibers
Actins
GTPase-Activating Proteins
Monomeric GTP-Binding Proteins
RNA