VESICLE TRAFFICKING AND MONOMERIC GTPASES

SAVYV, DALLA VIAV, NARDUZZI C, ZANETTI ME, BLANCOFA

Mendoza

Congreso; Reunion Anual de SAIB (Sociedad Argentina de Investigaciones en Bioquímica y Biología Molecular); 2012

SociedadArgentina de Investigaciones en Bioquímica y Biología Molecular

Legume plants have the capacity to establish a symbiotic association with soil bacteria that fix atmospheric nitrogen. This infection process involves the mobilization of macromolecules through vesicles in the plant cell. In a previous work we have shown that a Rab GTPase of is required for root hair elongation and the infection process initiated by rhizobia. We identified the best homolog of the Rab in and analyzed co-regulated genes using public microarray data. Strikingly, 40% of the genes with a high correlation index encodes for proteins involved in the different stages of budding, transport, tethering and fusion of vesicles. The gene with the highest correlation index was a monomeric GTPase of the Arf family, which belongs to a highly conserved subfamily of six proteins almost identical. Expression analysis by qRT-PCR showed that the six Arf genes have a similar expression pattern during nodulation. Pharmacological evidence indicates that activation of Arf proteins is required for nodule formation, root hair curling and noduline induction. To further understand the function of vesicle trafficking during nodulation we generated constitutively active and negative dominant forms of Arf by directed mutagenesis. We are currently using deep sequencing technology to study the superfamily of Ras GTPases during the symbiotic interaction.