Inhibition of CDK5 alters Dopamine Transporter endocytosis in N2A neuroblastoma cells

FERNÁNDEZ GUILLERMO; QUASSOLLO G,; FAVIO ARIEL KRAPACHER; FERRERAS SOLEDAD ; PISANO VICTORIA; PAGLINI GABRIELA

Congreso; IXX Congreso Anual de la Sociedad Argentina de Investigación en Neurociencia (SAN); 2014

Attention Deficit Hyperactivity Disorder (ADHD) is one of the most common childhood brain disorders. Previous studies from our lab have demonstrated that transgenic mice lacking p35 protein (p35KO), the specific activator of Cyclin dependent kinase 5 (Cdk5) exhibit behaviors resemble those described in animal models of ADHD. P35KO mice show spontaneous locomotor hyperactivity, elevated striatal Dopamine (DA) synthesis, but with a low DA turnover. These behavioral and biochemical phenotypes are reverted by Methylphenidate and d-Amphetamine (Amph), drugs used in ADHD treatment. Although we have shown that p35KO mice have an altered dopaminergic system, the dynamic and activity of Dopamine Transporter (DAT) still remain unknown. DAT mediates uptake of DA from the synaptic cleft and it is involved in some forms of ADHD in human. In this work we studied the role of Cdk5 activity in DAT constitutive and substrate-mediated trafficking using N2A neuroblastoma cells. We found that Amph exposure increased DAT localization in endosomes compartments. Besides, inhibition of CDK5 activity decreased DAT superficial levels, affecting both constitutive and substrate induced DAT endocytosis. These results suggest that Cdk5 activity modulates DAT trafficking to the plasma membrane, and may help us to elucidate DAT contribution in p35KO animal model of ADHD and its treatment.