Cyclin-Dependent kinase 5 regulates Dopamine Transporter surface expression and internalization, clues to understand the dopaminergic system of p35 Knock-out mice

FERNÁNDEZ, GUILLERMO; MARI MACARENA; KRAPACHER FAVIO; PAGLINI GABRIELA

San Diego

Congreso; Neuroscience 2018 - SFN; 2018

Society of Neuroscience (SFN)

Dopamine transporter (DAT) catalyzed the Dopamine (DA) reuptake from the synaptic cleft. This process is the major regulator of dopamine signaling strength, limiting pre and postsynaptic DA receptors activation. Desregulation in DA signaling is common in a broad of psychiatric Disorders such as Parkinson disease, Schizophrenia, Attention Deficit hyperactivity Disorder (ADHD), etc. Therefore, DAT has been one of the most studied proteins in order to understand the neurobiology mechanism underlying these 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. p35 KO mice display hyperactivity which is reverted by Methylphenidate and d-Amphetamine, drugs targeting DAT. Although we have shown that p35KO mice have an altered Dopaminergic system, the trafficking and activity of Dopamine Transporter (DAT) still remain unknown. In this work we studied the implications of Cdk5 inhibition in DAT expression and trafficking in P35KO mice and N2a cell line. Through Biotinylation assay, we observed that p35KO mice have a normal DAT expression levels in Striatum synaptosomes but the superficial expression of the transporter is diminished in these mice. On the other hand, using the antibody feeding method, we demonstrated that, in N2a cell line, the genetically and pharmacologically inhibition of Cdk5 augment the constitutive endocytosis rate of DAT. These results suggest that Cdk5 activity modulates DAT trafficking from the plasma membrane, and its superficial levels. These findings may help us to elucidate DAT function in the hyperdopaminergic system of p35KO animal, model of ADHD.