Role of atypical GTPase RhoD during the development of neuronal polarity.

MARTÍN ,JOSEFINA; QUASSOLLO, GONZALO; BISBAL, MARIANO

Córdoba

Congreso; Sociedad Argentina de Investigación en Neurociencias (SAN) XXXIII Annual Meeting.; 2018

Sociedad Argentina de Investigación en Neurociencias

Neurons are highly polarized cells typically extending a long thin axon and mul�ple short brancheddendrites. These specialized compartments are developed through the coordina�on of cellular andmolecular mechanisms in order to ensure the proper func�oning of the nervous system, and arehighly regulated by several small Rho GTPases with their effectors controlling different aspects ofneuronal morphology. Among others, these events include ac�n and microtubules cytoskeletonassembly, and the addi�on of membrane in neuron specialized regions. Even though most ofstudies have been focused on classical Rho GTPases (RhoA, Rac1 and Cdc42), other less studiedmembers of this family such as RhoD suggest to have unique effects on cytoskeleton andmembrane dynamics. In this study we have analyzed the role of RhoD during the development ofaxonal polariza�on and neurite extension. Our results reveal that hippocampal cultures highlyexpress messenger ARN codifying for RhoD protein quan�fied by qPCR. Besides, the expression ofRhoD ac�ve mutant in hippocampal neurons induces the genera�on of mul�ple axons and increaseneuri�c outgrowth and complexity. These results suggest that RhoD plays an important role duringneuronal differen�a�on and neuri�c outgrowth. In addi�on, we have designed an unimolecularac�vity RhoD biosensor based on resonance energy transfer (FRET) to study the space-�medynamics of this Rho GTPase in cultured hippocampal neurons. Finally, we have evaluated howRhoD affects different dynamic parameters of microtubules cytoskeleton in fibroblast cells.