KIF5C is essential for polarized insertion of IGF-1r in developing neurons

MARIANA OKSDATH; SANTIAGO QUIROGA

Huerta Grande, Córdoba

Congreso; : XXVIII Congreso Anual de la Sociedad Argentina de Investigación en Neurociencias; 2013

Sociedad Argentina de Investigación en Neurociencias.

KIF5C is essential for polarized insertion of IGF-1r in developing neurons. Mariana Oksdath y Santiago Quiroga. Departamento de Química Biológica y CIQUIBIC, Universidaad Nacional de Córdoba-CONICET.   In neuronal development occur early events of polarity in morphologically still-unpolarized neurons. As the segregation of active (phosphorylated) IGF-1 receptor in a single neurite. In the other hand, in axogenesis the cytoskeleton undergo to intense rearrangements such as increasing the stability of microtubule (MT) along the shaft of a single neurite. The preference of motor proteins by MT with increased stability or specific posttranslational modifications may mediate direct traffic in the axon. The experiments reported was designed to establish a correlation between these two early events in neuronal development. Application of low doses of the microtubule destabilizing nocodazole or stabilizing drugs taxol, the polarized distribution of active IGF-1r is modified. It was also observed that those neuritic processes in stage 2 of differentiation, with high accumulation of acetylated tubulin are coincident with process that has high levels of active receptor. This experiments suggested that the stable MTs would be an early marker for the polarized insertion of the receptor. We found that cells can?t polarize in low concentration of insulin, even in presence of microtubule-stabilizing drugs. So, the stabilization of MTs plays an active role during axonal specification but not sufficient to stimulate neuronal polarity. Finally the kinesin KIF5C would essential for the establishment of neuronal polarity and for the polarized insertion of IGF-1 receptor in stage 2 neurons.